Communication method, related device, and communication system

Abstract

The present application relates to the field of communications, and specifically relates to a communication method, a related device, and a communication system. The method comprises: a target NF network element receiving first domain name information in a first DNS request message that is sent from an SMF network element, and the target NF network element generating a first processing rule for the first DNS request message on the basis of the first domain name information of the first DNS request message and EAS deployment information which is stored in the target NF network element; and generating a second processing rule for a second DNS message on the basis of the EAS deployment information stored in the target NF network element, and the target NF network element sending the first processing rule and the second processing rule to a first discovery function network element, wherein the first processing rule and the second processing rule are used for processing the first DNS request message and / or the second DNS message. The present application is conducive to reducing the load of an SMF network element.

Description

Communication method, related equipment and communication system

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on February 4, 2024, with application number 202410160725.0 and invention name “Communication Method, Related Equipment and Communication System”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communications, and in particular to a communication method, related equipment, and a communication system. Background Art

[0003] In edge computing (EC) deployment scenarios, some services may be provided by multiple edge application servers (EAS) deployed at the edge of the network. These EASs can provide the same services and content, but have different addresses. When a user equipment (UE) needs to access the service, the UE will be required to access the available EAS closest to the UE. Therefore, the UE needs to obtain the address of the nearest available EAS.

[0004] The 3rd Generation Partnership Project (3GPP) standard TS23.548 defines a new network element to assist in EAS discovery - the edge application server discovery function (EASDF) network element. The EASDF network element interacts with the session management function (SMF) network element to discover EAS for the UE. During this process, the SMF network element needs to generate processing rules to guide the EASDF network element to process the UE's DNS messages (including request messages and response messages) and send them to the EASDF network element. Since the service scope of the SMF network element is very large (such as provincial and municipal levels), the SMF network element needs to participate every time the EAS discovery process is executed for UEs within the service scope of the SMF network element, resulting in a heavy load on the SMF network element. Summary of the Invention

[0005] The embodiments of the present application provide a communication method, related equipment and a communication system. Adopting the embodiments of the present application is beneficial to reducing the load of the SMF network element when performing EAS discovery.

[0006] In a first aspect, embodiments of the present application provide a communication method. The method can be applied to a target network function (NF) element, which is used to perform local EAS discovery. The target NF element can be a local SMF element or a newly introduced element specifically used to perform local EAS discovery, and the present application does not limit this.

[0007] The target NF network element receives the first domain name information in the first DNS request message sent from the SMF network element, and the domain name information can be a fully qualified domain name (FQDN). The first DNS request message is a message transmitted between the UE and the first discovery function network element. The target NF network element generates a first processing rule for the first DNS request message based on the first domain name information of the first DNS request message and the EAS deployment information stored in the target NF network element; generates a second processing rule for the second DNS message based on the EAS deployment information stored in the target NF network element, and the second DNS message is a message transmitted between the UE and the first discovery function network element later than the first DNS request message; the target NF network element sends the first processing rule and the second processing rule to the first discovery function network element, and the first processing rule and the second processing rule are used to generate the processing rule of the first discovery function network element, and the processing rule of the first discovery function network element is used to process the first DNS request message and / or the second DNS message.

[0008] The target NF network element is different from the SMF network element. In one example, the coverage area of ​​the SMF network element includes a first area, a second area, and a third area. The network to which the SMF network element belongs includes NF network element A, NF network element B, and NF network element C; wherein, the EAS deployment information stored in NF network element A is the EAS deployment information of the first area, the EAS deployment information stored in NF network element B is the EAS deployment information of the second area, and the EAS deployment information stored in NF network element C is the EAS deployment information of the third area. The EAS deployment information stored in the SMF network element includes part of the EAS deployment information of the first area, and / or part of the EAS deployment information of the second area, and / or part of the EAS deployment information of the third area.

[0009] It should be noted that the EAS deployment information stored in the target NF network element may be configured on the target NF network element, or stored or updated by the target NF network element after obtaining the EAS deployment information.

[0010] In one possible implementation, the first discovery function network element is the EASDF network element corresponding to the SMF network element, that is, the first discovery function network element can implement the EAS discovery process of UE within the service range of the SMF network element with the SMF network element and the target NF network element.

[0011] The second DNS message includes a first DNS response message, a second DNS request message, and a second DNS response message. The first DNS response message is a response to the first DNS request message, the second DNS request message is a message transmitted between the UE and the first discovery function network element later than the first DNS request message, and the second DNS response message is a response to the second DNS request message.

[0012] It can be seen that the processing rules used by the first discovery function network element to process the above-mentioned DNS messages are generated by the target NF network element based on the EAS deployment information stored by it, rather than by the SMF network element. Therefore, the SMF network element does not need to store all of the EAS deployment information stored by the target NF network element, thereby reducing the EAS deployment information stored by the SMF network element. That is, the participation of the SMF network element is reduced when executing the EAS discovery process, which is beneficial to reducing the load on the SMF network element.

[0013] In conjunction with the first aspect, in one possible implementation, the method of this embodiment further includes:

[0014] The target NF network element receives the address of the first EAS from the first discovery function network element; the first EAS provides the UE with the first service corresponding to the first domain name information in the first DNS request; the target NF network element determines the first anchor point and the first diversion point based on the first EAS address, and the first anchor point and the first diversion point are used to transmit data of the service corresponding to the first domain name information between the first EAS and the UE. The target NF network element notifies the first discovery function network element to send a first DNS response message to the UE. The first DNS response message is a response to the first DNS request message, and the first DNS response message includes the address of the first EAS.

[0015] Among them, the address in this application can be an IPv4 address, IPv6 address, MAC address or other types of addresses, which are not limited here.

[0016] Optionally, the first anchor point and the first diversion point are two different functional network elements, such as two different user plane function (UPF) network elements, or different functional modules in the same functional network element, such as two different functional modules in the same UPF network element. In other words, the first anchor point and the first diversion point are combined in the same functional network element.

[0017] It can be seen that determining the first diversion point and the first anchor point and notifying the first discovery function network element to send the first DNS response message to the UE is performed by the target NF network element, rather than the SMF network element, which is conducive to further reducing the workload of the SMF network element.

[0018] In conjunction with the first aspect, in one possible implementation, the method of this embodiment further includes:

[0019] The target NF network element receives the address of the second EAS sent from the first discovery function network element, and the second EAS provides the UE with the second service corresponding to the second domain name information in the second DNS request message. If the target NF network element determines based on the address of the second EAS that the first anchor point and the first diversion point can be used to transmit data of the second service corresponding to the second domain name information between the UE and the second EAS, the first discovery function network element is notified to send a second DNS response message to the UE. The second DNS response message is a response to the second DNS request message, and the second DNS response message includes the address of the second EAS; or, if the target NF network element determines based on the address of the second EAS that the first anchor point and the first diversion point cannot be used to transmit data of the second service between the UE and the second EAS, the target NF network element determines the second anchor point and the second diversion point based on the address of the second EAS, and the second anchor point and the second diversion point are used to transmit data of the second service between the second EAS and the UE; the target NF network element notifies the first discovery function network element to send a second DNS response message to the UE.

[0020] Optionally, the second anchor point and the second branch point are two different functional network elements, or different functional modules in the same functional network element. In other words, the second anchor point and the second branch point are both provided in the same functional network element.

[0021] It can be seen that determining whether the first anchor point and the first diversion point can be used to transmit data of the second service between the UE and the second EAS, determining the second diversion point and the second anchor point, and notifying the first discovery function network element to send a second DNS response message to the UE are performed by the target NF network element, rather than the SMF network element, which is conducive to reducing the workload of the SMF network element and thus reducing the load of the SMF network element.

[0022] In conjunction with the first aspect, in one possible implementation, the second DNS response message matches the second processing rule, the second processing rule includes first endpoint information, the first endpoint information is used to indicate the target NF network element, and the address of the second EAS is sent by the first discovery function network element to the target NF network element based on the first endpoint information. It should be understood that when the first DNS response message matches the second processing rule, the address of the first EAS in the first DNS response message is sent by the first discovery function network element to the target NF network element based on the first endpoint information. When the second DNS request message matches the second processing rule, the domain name information in the second DNS request message is sent by the first discovery function network element to the target NF network element based on the first endpoint information.

[0023] Optionally, the first endpoint information is a notification endpoint.

[0024] It can be seen that by introducing the first endpoint information in the second processing rule, the first discovery function network element knows based on the first endpoint information that the relevant message in the DNS message that matches the second processing rule should be reported to the target NF network element instead of reporting to the SMF network element, so that the target NF network element can perform the corresponding operation without the need for the SMF network element to execute it, which is conducive to further reducing the workload of the SMF network element.

[0025] In combination with the first aspect, in one possible implementation, the target NF network element sends the first processing rule and the second processing rule to the first discovery function network element based on the address of the first discovery function network element or through the SMF network element.

[0026] By sending the first processing rule and the second processing rule to the first discovery function network element, when the first discovery function network element processes the first DNS request message and the second DNS message based on the first processing rule and the second processing rule, it interacts with the target NF network element instead of the SMF network element, thereby reducing the workload of the SMF network element. In addition, the target NF network element directly sends the first processing rule and the second processing rule to the first discovery function network element through the address of the first discovery function network element, without the need for forwarding through the SMF network element, which is conducive to further reducing the workload of the SMF network element.

[0027] In conjunction with the first aspect, in one possible implementation, the method of this embodiment further includes:

[0028] The target NF network element sends the identifier of the first EASDF context to the first discovery function network element based on the address of the first discovery function network element or through the SMF network element, so as to trigger the first discovery function network element to update the processing rules in the first EASDF context based on the identifier of the first EASDF context, and the processing rules of the first discovery function network element include the processing rules of the updated first EASDF context;

[0029] The first EASDF context before the update includes the fifth processing rule and the sixth processing rule. The fifth processing rule is a processing rule generated by the SMF network element for the third DNS message. The third DNS message is a message whose domain name information belongs to the domain name information in the first deployment information. The sixth processing rule is a processing rule generated by the SMF network element for the fourth DNS message. The fourth DNS message is a message whose domain name information belongs to the domain name information in the second deployment information.

[0030] The updated first EASDF context includes the first processing rule, the second processing rule, and the fifth processing rule, or the updated first EASDF context includes the first processing rule, the second processing rule, the fifth processing rule, and the sixth processing rule.

[0031] Among them, the third DNS message in this application includes a DNS request message and a DNS response message, and the fourth DNS message includes a DNS request message and a DNS response message.

[0032] It should be pointed out here that the SMF network element stores the first deployment information and the second deployment information. Among them, the first deployment information includes EAS deployment information such as the domain name information of the services supported by the EAS in the first DN, the DNAI corresponding to the first DN, and the address of the EAS in the first DN. Among them, the first DN is a DN that includes the EAS deployment information connected to the UPF network element controlled by the SMF network element. In one example, the second deployment information includes EAS deployment information such as the domain name information of the services supported by the EAS in the second DN, the DNAI corresponding to the second DN, but does not include the address of the EAS in the second DN. In another example, the second deployment information includes the domain name information of the services supported by the EAS in the second DN. The second DN is the DN connected to the UPF network element controlled by each NF network element. The above-mentioned NF network elements are NF network elements in the network to which the SMF network element belongs, and each NF network element includes the above-mentioned target NF network element.

[0033] By sending the identifier of the first EASDF context to the first discovery function network element, the first discovery function network element updates the processing rules in the first EASDF context based on the first processing rules and the second processing rules, instead of updating the processing rules in other EASDF contexts, thereby avoiding the failure to match the corresponding processing rules when subsequently processing DNS messages.

[0034] In combination with the first aspect, in one possible implementation, the first discovery function network element includes a second discovery function network element and a third discovery function network element. The second discovery function network element is an EASDF network element corresponding to the SMF network element. The second discovery function network element interacts with the SMF network element to implement the EAS discovery process. The third discovery function network element is a network element corresponding to the target NF network element. The third discovery function network element and the target NF network element are responsible for local EAS discovery. The third discovery function network element can be a newly introduced local network element or a local EASDF network element, and this application does not limit it.

[0035] The second processing rule includes a third processing rule and a fourth processing rule. The target NF network element sends the first processing rule and the third processing rule to the second discovery function network element. The third processing rule is a processing rule generated by the target NF network element for the first DNS response message based on the first domain name information and the EAS deployment information stored by the target NF network element. The first processing rule and the third processing rule are used to generate the processing rule of the second discovery function network element. The processing rule of the second discovery function network element is used by the second discovery function network element to process the first DNS request message and the first DNS response message; the fourth processing rule is sent to the third discovery function network element. The fourth processing rule is a processing rule generated by the target NF network element for the second DNS request message and the second DNS response message based on the EAS deployment information stored by the target NF network element.

[0036] It can be seen that the DNS messages originally processed by one discovery function network element are processed by two discovery function network elements respectively, which is equivalent to introducing additional discovery function network elements on the basis of the original discovery function network element to share the work of the original discovery function network element, thereby reducing the workload of the original discovery function network element.

[0037] In conjunction with the first aspect, in one possible implementation, the method of this embodiment further includes:

[0038] The target NF network element receives the address of the first EAS from the second discovery function network element; the first EAS is used to provide the UE with a first service corresponding to the first domain name information; the target NF network element determines a first anchor point and a first diversion point based on the address of the first EAS; the first anchor point and the first diversion point are used to transmit data of the first service between the first EAS and the UE; the target NF network element notifies the second discovery function network element to send a first DNS response message to the UE, and the first DNS response message includes the address of the first EAS.

[0039] It can be seen that the determination of the first anchor point and the first diversion point and the notification of the second discovery function network element to send the first DNS response message to the UE are performed by the target NF network element, rather than the SMF network element, which is conducive to reducing the workload of the SMF network element and thus reducing the load of the SMF network element.

[0040] In conjunction with the first aspect, in one possible implementation, the method of this embodiment further includes:

[0041] The target NF network element receives the address of the second EAS from the third discovery function network element; the second EAS is used to provide the UE with the second service corresponding to the second domain name information in the second DNS request message; the target NF network element determines the second anchor point and the second diversion point based on the address of the second EAS; the second anchor point and the second diversion point are used to transmit data of the second service between the second EAS and the UE; the target NF network element notifies the third discovery function network element to send a second DNS response message to the UE, and the second DNS response message includes the address of the second EAS.

[0042] It can be seen that the determination of the second anchor point and the second diversion point and the notification of the third discovery function network element to send the second DNS response message to the UE are performed by the target NF network element, rather than the SMF network element, which is conducive to reducing the workload of the SMF network element and thus reducing the load of the SMF network element.

[0043] In conjunction with the first aspect, in one possible implementation, the first DNS response message matches a third processing rule, the third processing rule includes second endpoint information, the second endpoint information is used to indicate a target NF network element, and the address of the first EAS is sent by the second discovery function network element to the target NF network element based on the second endpoint information. Optionally, the second endpoint information is a notification endpoint.

[0044] It can be seen that by introducing the second endpoint information in the third processing rule, the second discovery function network element knows based on the second endpoint information that the address of the first EAS should be reported to the target NF network element instead of to the SMF network element, so that the target NF network element can perform the corresponding operation without the need for the SMF network element to execute it, which is conducive to further reducing the workload of the SMF network element.

[0045] In conjunction with the first aspect, in one possible implementation, the second DNS response message matches the fourth processing rule, the fourth processing rule includes third endpoint information, and the third endpoint information is used to indicate the target NF network element. The address of the second EAS is sent by the third discovery function network element to the target NF network element based on the third endpoint information. It should be understood that when the second DNS request message matches the fourth processing rule, the domain name information in the second DNS request message is sent by the third discovery function network element to the target NF network element based on the third endpoint information. Optionally, the third endpoint information is a notification endpoint.

[0046] It can be seen that by introducing the third endpoint information in the fourth processing rule, the third discovery function network element knows based on the third endpoint information that the relevant message in the DNS message that matches the fourth processing rule should be reported to the target NF network element instead of reporting to the SMF network element, so that the target NF network element can perform the corresponding operation without the need for the SMF network element to execute it, which is conducive to further reducing the workload of the SMF network element.

[0047] In combination with the first aspect, in a possible implementation, the target NF network element sends the first processing rule and the third processing rule to the second discovery function network element, including: the target NF network element sends the first processing rule and the third processing rule to the second discovery function network element through the SMF network element or based on the address of the second discovery function network element;

[0048] The target NF network element sends the fourth processing rule to the third discovery function network element, including: the target NF network element sends the fourth processing rule to the third discovery function network element based on the address of the third discovery function network element.

[0049] It can be seen that by sending processing rules to the second discovery function network element and the third discovery function network element, the second discovery function network element and the third discovery function network element process the corresponding DNS messages based on the processing rules, interacting with the target NF network element instead of interacting with the SMF network element, thereby reducing the workload of the SMF network element. The target NF network element directly sends the processing rules to the second discovery function network element and the third discovery function network element respectively through the addresses of the second discovery function network element and the third discovery function network element, without the need for forwarding through the SMF network element, which is conducive to further reducing the workload of the SMF network element.

[0050] In conjunction with the first aspect, in one possible implementation, the method of this embodiment further includes:

[0051] The target NF network element sends the identifier of the first EASDF context to the second discovery function network element based on the address of the second discovery function network element or through the SMF network element, so as to trigger the second discovery function network element to update the processing rules in the first EASDF context, and the processing rules of the second discovery function network element include the processing rules in the updated first EASDF context.

[0052] The first EASDF context before the update includes the fifth processing rule and the sixth processing rule. The fifth processing rule is a processing rule generated by the SMF network element for the third DNS message. The third DNS message is a message whose domain name information belongs to the domain name information in the first deployment information. The sixth processing rule is a processing rule generated by the SMF network element for the fourth DNS message. The fourth DNS message is a message whose domain name information belongs to the domain name information in the first deployment information.

[0053] The updated processing rules in the first EASDF context include the first processing rule, the third processing rule and the fifth processing rule, or the updated processing rules in the first EASDF context include the first processing rule, the third processing rule, the fifth processing rule and the sixth processing rule.

[0054] By sending the identifier of the first EASDF context to the second discovery function network element, the second discovery function network element updates the processing rules in the first EASDF context based on the first processing rules and the third processing rules, instead of updating the processing rules in other EASDF contexts, thereby avoiding the failure to match the corresponding processing rules when processing DNS messages subsequently.

[0055] In combination with the first aspect, in one possible implementation, the target NF network element is determined by the access and mobility management function (AMF) network element based on the UE's location information; when the first domain name information does not belong to the domain name information in the EAS deployment information stored in the target NF network element, the forwarding action in the first processing rule includes the first information, and the first information is used by the first discovery function network element to set the ECS option of the first DNS request message sent to the DNS server to empty.

[0056] It should be understood that the first domain name information of the first DNS request message does not belong to the domain name information in the EAS deployment information stored in the target NF network element, which means that the target NF network element does not store the EAS related information corresponding to the first domain name information. The forwarding action in the first processing rule for the first DNS request message generated by the target NF network element includes the first information. The first discovery function network element sets the ECS option of the first DNS request message to empty based on the first information, so that the DNS server processes the first DNS request message with an empty ECS option as a remote service.

[0057] In a second aspect, an embodiment of the present application provides a communication method, which is applied to a first discovery function network element. The first discovery function network element is an EASDF network element corresponding to an SMF network element, and the first discovery function network element, the SMF network element, and the target NF network element implement an EAS discovery process for UEs within the service range of the SMF network element.

[0058] The first discovery function network element receives a first DNS request message from the UE, and the first discovery function network element receives a second DNS message after the first DNS request message; the first discovery function network element receives a first processing rule and a second processing rule from a target NF network element, and the target NF network element is used to perform local EAS discovery, which can be a local SMF network element or a newly introduced network element specifically used to perform local EAS discovery, etc.; the first processing rule is a processing rule for the first DNS request message, and the second processing rule is a processing rule for the second DNS message; the first discovery function network element generates a processing rule of the first discovery function network element based on the first processing rule and the second processing rule; and processes the first DNS request message or the second DNS message based on the processing rule of the first discovery function network element.

[0059] The second DNS message includes a first DNS response message, a second DNS request message, and a second DNS response message. The second DNS response message is a response to the first DNS request message, the second DNS request message is a message transmitted between the UE and the first discovery function network element later than the first DNS request message, and the second DNS response message is a response to the second DNS request message.

[0060] It can be seen that since the first processing rule and the second processing rule are generated by the target NF network element based on the EAS deployment information stored by it, rather than by the SMF network element, the SMF network element does not need to store all of the EAS deployment information stored by the target NF network element, thereby reducing the EAS deployment information stored by the SMF network element. That is, the participation of the SMF network element is reduced when executing the EAS discovery process, which is beneficial to reducing the load of the SMF network element.

[0061] In conjunction with the second aspect, in one possible implementation, the first discovery function network element generates a processing rule for the first discovery function network element based on the first processing rule and the second processing rule, including:

[0062] The first discovery function network element updates the processing rules in the first EASDF context based on the first processing rule and the second processing rule; the processing rules of the first discovery function network element include the updated processing rules in the first EASDF context;

[0063] Among them, the first EASDF context before the update includes the fifth processing rule and the sixth processing rule. The fifth processing rule is a processing rule generated by the SMF network element for the third DNS message. The third DNS message is a message whose domain name information belongs to the domain name information in the first deployment information. The sixth processing rule is a processing rule generated by the SMF network element for the fourth DNS message. The fourth DNS message is a message whose domain name information belongs to the domain name information in the second deployment information.

[0064] The updated processing rules in the first EASDF context include the first processing rule, the second processing rule and the fifth processing rule, or the updated processing rules in the first EASDF context include the first processing rule, the second processing rule, the fifth processing rule and the sixth processing rule.

[0065] It should be pointed out here that the SMF network element stores the first deployment information and the second deployment information. Among them, the first deployment information includes the domain name information of the services supported by the EAS in the first DN, the DNAI corresponding to the first DN, and the EAS deployment information such as the address of the EAS in the first DN. The first DN is the DN connected to the UPF network element controlled by the SMF network element. In one example, the second deployment information includes the domain name information of the services supported by the EAS in the second DN, the DNAI corresponding to the second DN, and other EAS deployment information, but does not include the address of the EAS in the second DN. In another example, the second deployment information includes the domain name information of the services supported by the EAS in the second DN. The second DN is the DN connected to the UPF network element controlled by each NF network element. The above-mentioned NF network elements are NF network elements in the network to which the SMF network element belongs, and each NF network element includes the above-mentioned target NF network element.

[0066] By updating the processing rules of the first discovery function network element based on the first processing rules and the second processing rules generated by the target NF network element, the first discovery function network element will report the relevant information in the DNS message (including the DNS request message and the DNS response message) to the target NF network element when performing subsequent processing based on the first processing rules and the second processing rules, so that the target NF network element performs relevant operations, instead of reporting it to the SMF network element and asking the SMF network element to perform relevant operations, thereby reducing the workload of the SMF network element.

[0067] In conjunction with the second aspect, in one possible implementation, the method of this embodiment further includes:

[0068] The first discovery function network element obtains an identifier of the first EASDF context, and updates a processing rule in the first EASDF context corresponding to the identifier of the first EASDF context based on the first processing rule and the second processing rule.

[0069] By sending the identifier of the first EASDF context to the first discovery function network element, the first discovery function network element updates the processing rules in the first EASDF context based on the first processing rules and the second processing rules, instead of updating the processing rules in other EASDF contexts, thereby avoiding the failure to match the corresponding processing rules when subsequently processing DNS messages.

[0070] In conjunction with the second aspect, in one possible implementation, the method of this embodiment further includes:

[0071] The first discovery function network element obtains a first identifier and a second identifier, the first identifier is used to indicate that the first processing rule and the second processing rule are processing rules generated by the target NF network element for the fifth DNS message, the fifth DNS message is a message whose domain name information belongs to the domain name information in the EAS deployment information stored by the target NF network element, and the second identifier is used to indicate that the sixth processing rule is a processing rule generated by the SMF network element for the fourth DNS message; the first discovery function network element updates the sixth processing rule in the first EASDF context to the first processing rule and the second processing rule based on the first identifier and the second identifier, and the updated processing rules of the first EASDF context include the first processing rule, the second processing rule and the fifth processing rule.

[0072] By introducing the first identifier and the second identifier, the first discovery function network element can accurately update the sixth processing rule in the first EASDF context to the first processing rule and the second processing rule, instead of updating the fifth processing rule to the first processing rule and the second processing rule, thereby ensuring the accuracy of the processing rules in the first EASDF context.

[0073] In combination with the second aspect, in a possible implementation, the processing rules of the first discovery function network element include the processing rules in the first EASDF context and the processing rules in the second EASDF context; wherein, the processing rules in the first EASDF context include the fifth processing rule and the sixth processing rule, the fifth processing rule is the processing rule generated by the SMF network element for the third DNS message, the third DNS message is a message whose domain name information belongs to the domain name information in the first deployment information, the sixth processing rule is the processing rule generated by the SMF network element for the fourth DNS message; the fourth DNS message is a message whose domain name information belongs to the domain name information in the second deployment information; the processing rules in the second EASDF context include the first processing rule and the second processing rule.

[0074] By generating a new EASDF context based on the first processing rule and the second processing rule, the new EASDF context serves as part of the processing rule of the first discovery function network element. When subsequently processing the DNS message, the first discovery function network element interacts with the target NF network element based on the processing rule of the new EASDF context instead of interacting with the SMF network element, which helps to reduce the workload of the SMF network element. Moreover, the EASDF context itself includes endpoint information, so this method does not require adding endpoint information to the processing rule.

[0075] In conjunction with the second aspect, in one possible implementation, the method of this embodiment further includes:

[0076] The first discovery function network element receives the fifth processing rule and the sixth processing rule from the SMF network element, wherein the matching priority of the sixth processing rule is higher than the priority of the fifth processing rule, and the first discovery function network element matches the DNS request message from the UE with the sixth processing rule based on the matching priority of the sixth processing rule; if the DNS request message from the UE does not match the sixth processing rule, the first discovery function network element matches the DNS request message from the UE with the fifth processing rule based on the matching priority of the fifth processing rule; wherein the first DNS request message is the message in the DNS request message from the UE that matches the fifth processing rule or the sixth processing rule.

[0077] Since the DNS request message from the UE may match both the fifth processing rule and the sixth processing rule, when the DNS request message from the UE matches the fifth processing rule first, it means that the SMF network element can provide the UE with the service corresponding to the domain name information in the DNS request message, and there is no need to introduce the target NF network element. Therefore, the DNS request message from the UE is preferentially matched with the sixth processing rule. If it matches, it means that the target NF network element is preferentially introduced to process the DNS request message, thereby reducing the workload of the SMF network element.

[0078] In conjunction with the second aspect, in one possible implementation, the first discovery function network element processes the first DNS request message based on a processing rule of the first discovery function network element, including:

[0079] The first discovery function network element matches the first DNS request message based on the first processing rule; if the first processing rule matches the first DNS request message, the first discovery function network element sends the first DNS request message to the DNS server, and the first discovery function network element receives the first DNS response message from the DNS server, and the first DNS response message is a response to the first DNS request message; the first DNS response message includes the address of the first EAS, and the first EAS provides the UE with the first service corresponding to the first domain name information; the second DNS message includes the first DNS response message; the first discovery function network element matches the first DNS response message with the second processing rule; if the first DNS response message matches the second processing rule, the first discovery function network element sends the first EAS address to the target NF network element, and the first EAS address is used by the NF network element to determine the first anchor point and the first diversion point; the first anchor point and the first diversion point are used to transmit data of the first service between the first EAS and the UE; when it is detected that the NF network element executes the operation of notifying the first discovery function network element to send the first DNS response message to the UE, the first DNS response message is sent to the UE.

[0080] It can be seen that the first discovery function network element interacts with the target NF network element instead of the SMF network element, which is conducive to further reducing the workload of the SMF network element.

[0081] In conjunction with the second aspect, in one possible implementation, the second processing rule includes first endpoint information, which is used to indicate the NF network element. The address of the first EAS is sent by the first discovery function network element to the target NF network element based on the first endpoint information. It should be understood that when the second DNS request message matches the second processing rule, the domain name information in the second DNS request message is sent by the first discovery function network element to the target NF network element based on the first endpoint information. When the second DNS response message matches the second processing rule, the address of the second EAS in the second DNS response message is sent by the first discovery function network element to the target NF network element based on the first endpoint information.

[0082] It can be seen that by introducing the first endpoint information in the second processing rule, the first discovery function network element knows based on the first endpoint information that the relevant message in the DNS message that matches the second processing rule should be reported to the target NF network element instead of reporting to the SMF network element, so that the target NF network element can perform the corresponding operation without the need for SMF execution, which is conducive to further reducing the workload of SMF.

[0083] In combination with the second aspect, in one possible implementation, the target NF network element is determined by the AMF network element based on the location information of the UE. When the first domain name information does not belong to the domain name information in the EAS deployment information stored in the target NF network element, the forwarding action in the first processing rule includes the first information. The method of this embodiment also includes: the first discovery function network element sets the ECS option of the first DNS request message to empty based on the first information.

[0084] It should be understood that the first domain name information of the first DNS request message does not belong to the domain name information in the EAS deployment information stored in the target NF network element, which means that the target NF network element does not store the EAS-related information corresponding to the first domain name information. The forwarding action in the first processing rule for the first DNS request message generated by the target NF network element includes the first information. The first discovery function network element sets the ECS option of the first DNS request message to empty based on the first information, so that the DNS server processes the first DNS request message with an empty ECS option as a remote service.

[0085] In a third aspect, an embodiment of the present application provides a communication method, which is applied to a second discovery function network element. The second discovery function network element is an EASDF network element corresponding to the SMF network element, and the second discovery function network element interacts with the SMF network element to implement an EAS discovery process.

[0086] The second discovery function network element receives the first DNS request message from the UE; the second discovery function network element receives the first processing rule and the third processing rule from the target NF network element, the target NF network element is used to perform local EAS discovery, and can be a local SMF network element or a newly introduced network element specifically used to perform local EAS discovery, etc.; the first processing rule is a processing rule for the first DNS request message, and the third processing rule is a processing rule for the first DNS response message; the first DNS response message is a response to the first DNS request message; the second discovery function network element generates a processing rule for the second discovery function network element based on the first processing rule and the third processing rule; the second discovery function network element processes the first DNS request message and the first DNS response message based on the processing rule of the second discovery function network element.

[0087] It can be seen that since the first processing rule and the second processing rule are generated by the target NF network element based on the EAS deployment information stored by it, rather than by the SMF network element, the SMF network element does not need to store all of the EAS deployment information stored by the target NF network element, thereby reducing the EAS deployment information stored by the SMF network element. That is, the participation of the SMF network element is reduced when executing the EAS discovery process, which is beneficial to reducing the load of the SMF network element.

[0088] In conjunction with the third aspect, in one possible implementation, the second discovery function network element generates a processing rule for the second discovery function network element based on the first processing rule and the third processing rule, including:

[0089] The second discovery function network element updates the processing rules in the first EASDF context based on the first processing rule and the third processing rule; the processing rules of the second discovery function network element include the updated processing rules in the first EASDF context;

[0090] Among them, the first EASDF context before the update includes the fifth processing rule and the sixth processing rule. The fifth processing rule is a processing rule generated by the SMF network element for the third DNS message. The third DNS message is a message whose domain name information belongs to the domain name information in the first deployment information. The sixth processing rule is a processing rule generated by the SMF network element for the fourth DNS message. The fourth DNS message is a message whose domain name information belongs to the domain name information in the second deployment information. The domain name information in the first deployment information includes the domain name information of the service supported by the EAS in the first DN. The first DN is the DN connected to the UPF network element controlled by the SMF network element. The domain name information in the second deployment information includes the domain name information of the service supported by the EAS in the second DN. The second DN is the DN connected to the UPF network element controlled by each NF network element. Each NF network element is an NF network element in the network to which the SMF network element belongs.

[0091] The updated processing rules in the first EASDF context include the first processing rule, the third processing rule and the fifth processing rule, or the updated processing rules in the first EASDF context include the first processing rule, the third processing rule, the fifth processing rule and the sixth processing rule.

[0092] It should be pointed out here that the SMF network element stores the first deployment information and the second deployment information. Among them, the first deployment information includes the domain name information of the services supported by the EAS in the first DN, the DNAI corresponding to the first DN, and the EAS deployment information such as the address of the EAS in the first DN. The first DN is the DN connected to the UPF network element controlled by the SMF network element. In one example, the second deployment information includes the domain name information of the services supported by the EAS in the second DN, the DNAI corresponding to the second DN, and other EAS deployment information, but does not include the address of the EAS in the second DN. In another example, the second deployment information includes the domain name information of the services supported by the EAS in the second DN. The second DN is the DN connected to the UPF network element controlled by each NF network element. The above-mentioned NF network elements are NF network elements in the network to which the SMF network element belongs, and each NF network element includes the above-mentioned target NF network element.

[0093] By updating the processing rules of the second discovery function network element based on the first processing rules and the third processing rules generated by the target NF network element, the second discovery function network element will report the relevant information in the DNS message (including the DNS request message and the DNS response message) to the target NF network element when performing subsequent processing based on the first processing rules and the third processing rules, so that the target NF network element performs relevant operations, instead of reporting it to the SMF network element and asking the SMF network element to perform relevant operations, thereby reducing the workload of the SMF network element.

[0094] In conjunction with the third aspect, in one possible implementation, the method of this embodiment further includes:

[0095] The second discovery function network element obtains the identifier of the first EASDF context, and updates the processing rule in the first EASDF context corresponding to the identifier of the first EASDF context based on the first processing rule and the third processing rule.

[0096] By sending the identifier of the first EASDF context to the second discovery function network element, the second discovery function network element updates the processing rules in the first EASDF context based on the first processing rules and the third processing rules, instead of updating the processing rules in other EASDF contexts, thereby avoiding the failure to match the corresponding processing rules when processing DNS messages subsequently.

[0097] In conjunction with the third aspect, in one possible implementation, the method of this embodiment further includes:

[0098] The second discovery function network element obtains a third identifier and a second identifier, the third identifier is used to indicate that the first processing rule and the third processing rule are processing rules generated by the target NF network element for the first DNS request message and the first DNS response message respectively, and the second identifier is used to indicate that the sixth processing rule is a processing rule generated by the SMF network element for the fourth DNS message; the second discovery function network element updates the sixth processing rule in the first EASDF context to the first processing rule and the third processing rule based on the third identifier and the second identifier.

[0099] By introducing the third identifier and the second identifier, the second discovery function network element can accurately update the sixth processing rule in the first EASDF context to the first processing rule and the third processing rule, instead of updating the fifth processing rule to the first processing rule and the third processing rule, thereby ensuring the accuracy of the processing rules in the first EASDF context.

[0100] With reference to the third aspect, in one possible implementation, the processing rule of the second discovery function network element includes a processing rule in the first EASDF context and a processing rule in the second EASDF context;

[0101] Among them, the processing rules in the first EASDF context include the fifth processing rule and the sixth processing rule. The fifth processing rule is the processing rule generated by the SMF network element for the third DNS message. The third DNS message is a message whose domain name information belongs to the domain name information in the first deployment information. The sixth processing rule is the processing rule generated by the SMF network element for the fourth DNS message. The fourth DNS message is a message whose domain name information belongs to the domain name information in the second deployment information. The processing rules in the second EASDF context include the first processing rule and the third processing rule.

[0102] By generating a new EASDF context based on the first processing rule and the third processing rule, the new EASDF context serves as part of the processing rule of the first discovery function network element. When subsequently processing the DNS message, the second discovery function network element interacts with the target NF network element based on the processing rule of the new EASDF context instead of interacting with the SMF network element, which helps to reduce the workload of the SMF network element. In addition, the EASDF context itself includes endpoint information, so this method does not require adding endpoint information to the processing rules.

[0103] In conjunction with the third aspect, in one possible implementation, the method of this embodiment further includes:

[0104] The second discovery function network element receives the fifth processing rule and the sixth processing rule from the SMF network element, wherein the matching priority of the sixth processing rule is higher than the priority of the fifth processing rule, and the second discovery function network element matches the DNS request message from the UE with the sixth processing rule based on the matching priority of the sixth processing rule; if the DNS request message from the UE does not match the sixth processing rule, the second discovery function network element matches the DNS request message from the UE with the fifth processing rule based on the matching priority of the fifth processing rule; wherein the first DNS request message is a message in the DNS request message from the UE that matches the fifth processing rule or the sixth processing rule.

[0105] Since the DNS request message from the UE may match both the fifth processing rule and the sixth processing rule, when the DNS request message from the UE matches the fifth processing rule first, it means that the SMF network element can provide the UE with the service corresponding to the domain name information in the DNS request message, and there is no need to introduce the target NF network element. Therefore, the DNS request message from the UE is preferentially matched with the sixth processing rule. If it matches, it means that the target NF network element is preferentially introduced to process the DNS request message, thereby reducing the workload of the SMF network element.

[0106] In conjunction with the third aspect, in one possible implementation, the second discovery function network element processes the first DNS request message and the first DNS response message based on a processing rule of the second discovery function network element, including:

[0107] The second discovery function network element matches the first DNS request message based on the first processing rule; if the first processing rule matches the first DNS request message, the second discovery function network element sends the first DNS request message to the DNS server, and receives the first DNS response message from the DNS server, the first DNS response message including the address of the first EAS; the first EAS provides the UE with the first service corresponding to the first domain name information; the second discovery function network element matches the first DNS response message with the third processing rule; if the first DNS response message matches the third processing rule, the first EAS address is sent to the target NF network element, and the first EAS address is used by the target NF network element to determine the first anchor point and the first diversion point; the first anchor point and the first diversion point are used to transmit data of the first service between the first EAS and the UE; when it is detected that the target NF network element executes the operation of notifying the second discovery function network element to send the first DNS response message to the UE, the first DNS response message is sent to the UE.

[0108] It can be seen that the second discovery function network element interacts with the target NF network element instead of the SMF network element, which is conducive to further reducing the workload of the SMF network element.

[0109] In combination with the third aspect, in one possible implementation, the target NF network element is determined by the AMF network element based on the UE's location information; when the first domain name information does not belong to the domain name information in the EAS deployment information stored in the target NF network element, the forwarding action in the first processing rule includes the first information, and the method of this embodiment also includes: the second discovery function network element sets the ECS option of the first DNS request message to empty based on the first information.

[0110] It should be understood that the first domain name information of the first DNS request message does not belong to the domain name information in the EAS deployment information stored in the target NF network element, which means that the target NF network element does not store the EAS-related information corresponding to the first domain name information. The forwarding action in the first processing rule for the first DNS request message generated by the target NF network element includes the first information. The second discovery function network element sets the ECS option of the first DNS request message to empty based on the first information, so that the DNS server processes the first DNS request message with an empty ECS option as a remote service.

[0111] In combination with the third aspect, in one possible implementation, the third processing rule includes second endpoint information, the second endpoint information is used to indicate the target NF network element, and the address of the first EAS is sent by the second discovery function network element to the target NF network element based on the first endpoint information.

[0112] It can be seen that by introducing the second endpoint information in the third processing rule, the second discovery function network element knows based on the endpoint information that the first EAS address in the first DNS response message will be reported to the target NF network element instead of being reported to the SMF network element for processing, which is conducive to further reducing the workload of the SMF.

[0113] In conjunction with the third aspect, in one possible implementation, the method of this embodiment further includes:

[0114] The second discovery function network element sends a second DNS request message to the third discovery function network element, wherein the second DNS request message is a message from the UE that matches the fifth processing rule or the sixth processing rule except the first DNS request message.

[0115] By sending the cached DNS request message to the third discovery function network element and letting the third discovery function network element process it, the workload of the second discovery function network element is reduced.

[0116] Fourthly, embodiments of the present application provide a communication method, which is applied to a third discovery function network element. The third discovery function network element is a network element corresponding to a target NF network element, and the third discovery function network element and the target NF network element implement EAS discovery of UEs within the service range of the target NF network element. The third discovery function network element can be a newly introduced local network element or a local EASDF network element, and this application does not limit this.

[0117] The third discovery function network element receives the fourth processing rule from the target NF network element, and the fourth processing rule is the processing rule of the target NF network element for the second DNS request message; the target NF network element is used to perform local EAS discovery, and can be a local SMF network element or a newly introduced network element specifically used to perform local EAS discovery, etc.; the third discovery function network element receives the second DNS request message from the second discovery function network element or from the UE; the third discovery function network element processes the second DNS request message based on the fourth processing rule.

[0118] It can be seen that since the fourth processing rule is generated by the target NF network element based on the EAS deployment information stored by it, rather than by the SMF network element, the SMF network element does not need to store all the information stored by the target NF network element, which is beneficial to reducing the EAS deployment information stored by the SMF network element, that is, reducing the participation of the SMF network element when executing the EAS discovery process, which is beneficial to reducing the load of the SMF network element.

[0119] In conjunction with the fourth aspect, in one possible implementation, the second DNS request message includes the second domain name information, and the third discovery function network element processes the second DNS request message based on the fourth processing rule, including:

[0120] If the fourth processing rule matches the second DNS request message, the third discovery function network element sends the second DNS request message to the DNS server, and the third discovery function network element receives the second DNS response message from the DNS server, where the second DNS response message is a response to the second DNS request message; the second DNS response message includes the address of the second EAS; the second EAS provides the UE with the second service corresponding to the second domain name information; if the second DNS response message matches the fourth processing rule, the third discovery function network element sends the second EAS address to the target NF network element, where the second EAS address is used to determine the second anchor point and the second diversion point; the second anchor point and the second diversion point are used to transmit data of the second service between the second EAS and the UE; when it is detected that the target NF network element executes the operation of notifying the third discovery function network element to send the second DNS response message to the UE, the second DNS response message is sent to the UE.

[0121] It can be seen that the third discovery function network element interacts with the target NF network element to implement the EAS discovery process, rather than interacting with the SMF network element, which is conducive to further reducing the workload of the SMF network element.

[0122] In conjunction with the fourth aspect, in one possible implementation, the fourth processing rule includes third endpoint information, where the third endpoint information is used to indicate a target NF network element. The address of the second EAS is sent by the third discovery function network element to the target NF network element based on the third endpoint information. It should be understood that the domain name information in the second DNS request message is sent by the third discovery function network element to the target NF network element based on the third endpoint information.

[0123] By introducing the third endpoint information in the fourth processing rule, the third discovery function network element knows based on the third endpoint information to report the domain name information in the second DNS request message and the second EAS address in the second DNS response message to the target NF network element instead of reporting to the SMF network element, which is conducive to further reducing the workload of the SMF.

[0124] In a fifth aspect, an embodiment of the present application provides a communication method, which is applied to an SMF network element.

[0125] The SMF network element receives the first domain name information in the first DNS request message from the first discovery function network element or the second discovery function network element; the first DNS request message is a message transmitted between the UE and the first discovery function network element or the second discovery function network element; the SMF network element determines the target DNAI based on the first domain name information, the correspondence between the domain name information and the DNAI and the location information of the UE, and the distance between the DN identified by the target DNAI and the UE is less than the distance between the DN identified by other DNAIs corresponding to the first domain name information and the UE; if the target DNAI belongs only to the DNAI in the EAS deployment information stored by each NF network element, or the target DNAI If it belongs to the DNAI in the EAS deployment information stored in each NF network element and the DNAI in the EAS deployment information stored in the SMF network element, the SMF network element sends the target DNAI to the AMF network element, and the target DNAI is used by the AMF network element to determine the target NF network element; each NF network element is an NF network element in the network to which the SMF network element belongs; the SMF network element receives the address of the target NF network element from the AMF network element; the SMF network element sends the first domain name information to the target NF network element based on the address of the target NF network element, and the first domain name information is used by the target NF network element to generate a processing rule for the first DNS request message based on the EAS deployment information stored in the target NF network element.

[0126] It should be noted that the EAS deployment information stored by the SMF network element may be configured on the SMF network element, or the SMF network element may store or update the EAS deployment information after obtaining the EAS deployment information. The EAS deployment information stored by each NF network element may be configured on each NF network element, or the NF network element may store or update the EAS deployment information after obtaining the EAS deployment information.

[0127] Among them, the first discovery function network element is the EASDF network element corresponding to the SMF network element, that is, the first discovery function network element can implement the EAS discovery process of UE within the service range of the SMF network element with the SMF network element and the target NF network element. The second discovery function network element is the network element corresponding to the SMF network element, that is, the second discovery function network element interacts with the SMF network element to implement the EAS discovery process.

[0128] It should be pointed out that the distance between the DN identified by the target DNAI and the UE is smaller than the distance between the DN identified by other DNAIs corresponding to the first domain name information and the UE, including different situations. For example, the distance between the DN identified by the target DNAI and the UE is smaller than the distance between all DNs in the DN identified by other DNAIs corresponding to the first domain name information and the UE. For another example, the distance between the DN identified by the target DNAI and the UE is smaller than the distance between some DNs in the DN identified by other DNAIs corresponding to the first domain name information and the UE.

[0129] It can be seen that through the above method, it is possible to determine a suitable target NF network element to share the work of the SMF network element. For example, based on the EAS deployment information stored by the target NF network element, a processing rule for the first DNS request message is generated. The SMF network element does not need to store all of the EAS deployment information stored by the target NF network element, which is beneficial to reducing the load on the SMF network element. Taking DNAI into consideration when determining the target NF network element can ensure that the determined target NF network element can process the UE's DNS message.

[0130] In conjunction with the fifth aspect, in one possible implementation, the method of this embodiment further includes:

[0131] The SMF network element obtains the first deployment information and the second deployment information from the application function (AF) network element; wherein the first deployment information includes the domain name information of the service supported by the EAS in the first DN, the DNAI corresponding to the first DN and the address of the EAS in the first DN, and the first DN is the DN connected to the UPF network element controlled by the SMF network element; the second deployment information includes the domain name information of the service supported by the EAS in the second DN and the DNAI corresponding to the second DN, and the second DN is the DN connected to the UPF network element controlled by each NF network element; the SMF network element generates the fifth processing rule and the sixth processing rule based on the first deployment information and the second deployment information respectively; the fifth processing rule is for the third DNS The fifth processing rule and the sixth processing rule are used by the first discovery function network element or the second discovery function network element to determine the first DNS request message from the DNS request message from the UE. The first DNS request message is a message in the DNS request message from the UE that matches the fifth processing rule or the sixth processing rule.

[0132] It can be seen that the purpose of generating the fifth processing rule and the sixth processing rule and sending them to the discovery function network element is to enable the discovery function network element to determine the first DNS request from the DNS request from the UE based on the fifth processing rule and the sixth processing rule, and then trigger the execution of subsequent processes (including the NF network element generating processing rules based on the domain name information in the first DNS request, etc.).

[0133] In a sixth aspect, an embodiment of the present application provides a communication method, which is applied to an SMF network element.

[0134] The SMF network element receives the first domain name information in the first DNS request message from the first discovery function network element or the second discovery function network element; the first DNS request message is a message transmitted between the UE and the first discovery function network element or the second discovery function network element; if the first domain name information belongs to the domain name information of the service supported by EAS in the second DN, the SMF network element obtains the address of the target NF network element determined by the AMF based on the location information of the UE from the AMF network element, and the second DN is the DN connected to the UPF network element controlled by each network function NF network element, and each NF network element is an NF network element in the network to which the SMF network element belongs; each NF network element includes the target NF network element; the SMF network element sends the first domain name information to the target NF network element based on the address of the target NF network element, and the first domain name information is used by the target NF network element to generate a processing rule for the first DNS request message based on the EAS deployment information stored in the target NF network element.

[0135] Optionally, if the first domain name information belongs to the domain name information of the service supported by EAS in the second DN, and does not belong to the domain name information of the service supported by EAS in the first DN, the address of the target NF network element is obtained from the AMF network element, and the AMF determines the location information of the target NF network element based on the UE, and the first DN is the DN connected to the UPF network element controlled by the SMF network element.

[0136] Among them, the first discovery function network element is the EASDF network element corresponding to the SMF network element, that is, the first discovery function network element can implement the EAS discovery process of UE within the service range of the SMF network element with the SMF network element and the target NF network element. The second discovery function network element is the network element corresponding to the SMF network element, that is, the second discovery function network element interacts with the SMF network element to implement the EAS discovery process.

[0137] It can be seen that through the above method, it is possible to determine a suitable target NF network element to share the work of the SMF network element. For example, based on the EAS deployment information stored in the target NF network element, a processing rule for the first DNS request message is generated. The SMF network element does not need to store all of the EAS deployment information stored in the target NF network element, which is beneficial to reducing the load of the SMF network element.

[0138] In conjunction with the sixth aspect, in one possible implementation, if the first domain name information belongs to the domain name information of the service supported by the EAS in the second DN, and belongs to the domain name information of the service supported by the EAS in the first DN, the operation of obtaining the address of the target NF network element from the AMF network element is not performed. That is to say, the target NF network element is not introduced, and the first DNS request message is processed by the SMF network element and the first discovery function network element or the second discovery function network element.

[0139] In conjunction with the sixth aspect, in one possible implementation, the method of this embodiment further includes:

[0140] The SMF network element receives the first deployment information and the second deployment information from the AF network element; wherein the first deployment information includes the domain name information of the services supported by the EAS in the first DN, the DNAI corresponding to the first DN, and the address of the EAS in the first DN and other information; the second deployment information includes the domain name information of the services supported by the EAS in the second DN; the SMF network element generates the fifth processing rule and the sixth processing rule based on the first deployment information and the second deployment information respectively; the fifth processing rule is the processing rule for the third DNS message, and the third DNS message is a message whose domain name information belongs to the domain name information in the first deployment information, and the sixth processing rule is the processing rule for the fourth DNS message; the fourth DNS message is a message whose domain name information belongs to the domain name information in the second deployment information; the SMF network element sends the fifth processing rule and the sixth processing rule to the first discovery function network element or the second discovery function network element, and the fifth processing rule and the sixth processing rule are used for the first discovery function network element or the second discovery function network element to determine the first DNS request message from the DNS request message from the UE, and the first DNS request message matches the fifth processing rule or the sixth processing rule.

[0141] It can be seen that the purpose of generating the fifth processing rule and the sixth processing rule and sending them to the discovery function network element is to enable the discovery function network element to determine the first DNS request from the DNS request from the UE based on the fifth processing rule and the sixth processing rule, and then trigger the execution of subsequent processes (including the NF network element generating processing rules based on the domain name information in the first DNS request, etc.). And because the second deployment information only includes the domain name information of the services supported by the EAS in the second DN, and does not include the DNAI corresponding to the second DN and the address of the EAS in the second DN, that is, the SMF network element only needs to store the domain name information, and does not need to store other information such as DNAI, which is also conducive to reducing the load of the SMF network element.

[0142] In a seventh aspect, an embodiment of the present application provides a communication method, including:

[0143] The SMF network element sends domain name information of a first DNS request message to the target NF network element. The first DNS request message is a message transmitted between the UE and the first discovery function network element;

[0144] The target NF network element generates a first processing rule for the first DNS request message based on the first domain name information and the EAS deployment information stored in the target NF network element; generates a second processing rule for the second DNS message based on the EAS deployment information stored in the target NF network element; the second DNS message is a message transmitted between the UE and the first discovery function network element later than the first DNS request message; the target NF network element sends the first processing rule and the second processing rule to the first discovery function network element;

[0145] The first discovery function network element generates a processing rule of the first discovery function network element based on the first processing rule and the second processing rule; the first discovery function network element processes the first DNS request message / or the second DNS message based on the processing rule of the first discovery function network element.

[0146] Among them, the first discovery function network element is the EASDF network element corresponding to the SMF network element. The first discovery function network element can implement the EAS discovery process of UE within the service range of the SMF network element with the SMF network element and the target NF network element.

[0147] It can be seen that the processing rules used by the first discovery function network element to process the above-mentioned DNS messages are generated by the target NF network element based on the EAS deployment information stored by it, rather than by the SMF network element. Therefore, the SMF network element does not need to store all of the EAS deployment information stored by the target NF network element, thereby reducing the EAS deployment information stored by the SMF network element. That is, the participation of the SMF network element is reduced when executing the EAS discovery process, which is beneficial to reducing the load on the SMF network element.

[0148] In an eighth aspect, an embodiment of the present application provides a communication method, the method comprising:

[0149] The SMF network element sends domain name information of a first DNS request message to the target NF network element. The first DNS request message is a message transmitted between the UE and the first discovery function network element;

[0150] The target NF network element generates a first processing rule for the first DNS request message and a third processing rule for the first DNS response message based on the first domain name information and the EAS deployment information stored in the target NF network element, and the first DNS response message is a response to the first DNS request message; the target NF network element generates a fourth processing rule for the second DNS request message and the second DNS response message based on the EAS deployment information stored in the target NF network element; the second DNS request message is a message transmitted between the UE and the second discovery function network element later than the first DNS request message, and the second DNS response message is a response to the second DNS request message; the target NF network element sends the first processing rule and the third processing rule to the second discovery function network element; the target NF network element sends the fourth processing rule to the third discovery function network element;

[0151] The second discovery function network element generates a processing rule for the second discovery function network element based on the first processing rule and the third processing rule; processes the first DNS request message and the first DNS response message based on the processing rule of the second discovery function network element; and the third discovery function network element processes the second DNS request message and the second DNS response message based on the fourth processing rule.

[0152] Among them, the second discovery function network element is the network element corresponding to the SMF network element, and the second discovery function network element can implement the EAS discovery process of UEs in the service range of the SMF network element except for UEs in the service range of the target NF network element with the SMF network element. The third discovery function network element is the EASDF network element corresponding to the target NF network element, that is, the third discovery function network element can implement the EAS discovery process of UEs in the service range of the target NF network element with the target NF network element.

[0153] It can be seen that the processing rules used by the second discovery function network element and the third discovery function network element to process the above-mentioned DNS messages are generated by the target NF network element based on the EAS deployment information stored by it, rather than by the SMF network element. Therefore, the SMF network element does not need to store all of the EAS deployment information stored by the target NF network element, thereby reducing the EAS deployment information stored by the SMF network element. That is, the participation of the SMF network element is reduced when executing the EAS discovery process, which is beneficial to reducing the load of the SMF network element.

[0154] In a ninth aspect, an embodiment of the present application provides a target NF network element, comprising a unit or module for implementing the method provided in the first aspect or any possible implementation method of the first aspect.

[0155] In the tenth aspect, an embodiment of the present application provides a first discovery function network element, comprising a unit or module for implementing the method provided in the second aspect or any possible implementation method of the second aspect.

[0156] In the eleventh aspect, an embodiment of the present application provides a second discovery function network element, including a unit or module for implementing the method provided by the third aspect or any possible implementation method of the third aspect.

[0157] In the twelfth aspect, an embodiment of the present application provides a third discovery function network element, including a unit or module for implementing the method provided in the fourth aspect or any possible implementation method of the fourth aspect.

[0158] In the thirteenth aspect, an embodiment of the present application provides an SMF network element, comprising a unit or module for implementing the method provided in the fifth aspect or any possible implementation method of the fifth aspect.

[0159] In the fourteenth aspect, an embodiment of the present application provides an SMF network element, comprising a unit or module for implementing the method provided in the fifth aspect or any possible implementation method of the fifth aspect.

[0160] In a fifteenth aspect, an embodiment of the present application provides a network element (NF) comprising a processor and a memory. The memory is configured to store program code. The processor is configured to invoke the program code stored in the memory to execute the method provided in the first aspect or any possible implementation of the first aspect.

[0161] In a sixteenth aspect, an embodiment of the present application provides a first discovery function network element, comprising a processor and a memory. The memory is configured to store program code. The processor is configured to invoke the program code stored in the memory to execute the method provided in the second aspect or any possible implementation of the second aspect.

[0162] In a seventeenth aspect, an embodiment of the present application provides a second discovery function network element, comprising a processor and a memory. The memory is configured to store program code. The processor is configured to invoke the program code stored in the memory to execute the method provided in the third aspect or any possible implementation of the third aspect.

[0163] In an eighteenth aspect, an embodiment of the present application provides a third discovery function network element, comprising a processor and a memory. The memory is configured to store program code. The processor is configured to invoke the program code stored in the memory to execute the method provided in the fourth aspect or any possible implementation manner of the fourth aspect.

[0164] In a nineteenth aspect, an embodiment of the present application provides an SMF network element, comprising a processor and a memory. The memory is configured to store program code. The processor is configured to invoke the program code stored in the memory to execute the method provided in the fifth aspect or any possible implementation manner of the fifth aspect, or the method provided in the sixth aspect or any possible implementation manner of the sixth aspect.

[0165] In a twentieth aspect, an embodiment of the present application provides a communication system, the communication system including the target NF network element according to the ninth aspect, the first discovery function network element according to the tenth aspect or the sixteenth aspect, and the SMF network element according to the thirteenth aspect or the fourteenth aspect or the nineteenth aspect.

[0166] Alternatively, the communication system includes the target NF network element as described in the ninth aspect, the second discovery function network element as described in the eleventh aspect or the seventeenth aspect, the third discovery function network element as described in the twelfth aspect or the eighteenth aspect, and the SMF network element as described in the thirteenth aspect or the fourteenth aspect or the nineteenth aspect.

[0167] In aspect 21, an embodiment of the present application provides a computer storage medium comprising computer instructions, which, when executed on an electronic device, enables the electronic device to execute a method as provided in any one of aspects 1 to 8.

[0168] In aspect 22, an embodiment of the present application provides a computer program product, which, when executed on a computer, enables the computer to execute the method provided in any one of aspects 1 to 8.

[0169] It can be understood that the beneficial effects of the embodiments described in aspects 9 to 22 can refer to the beneficial effects of the methods described in aspects 1 to 8, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0170] FIG1a is a schematic diagram of a network architecture provided by an embodiment of the present application;

[0171] FIG1b is a schematic diagram of another network architecture provided in an embodiment of the present application;

[0172] FIG2 is a flow chart of a communication method provided in an embodiment of the present application;

[0173] FIG3a is a schematic diagram of a flow chart of another communication method provided in an embodiment of the present application;

[0174] FIG3 b is a flow chart of another communication method provided in an embodiment of the present application;

[0175] FIG3c is a flow chart of another communication method provided in an embodiment of the present application;

[0176] FIG4a is a schematic diagram of a flow chart of another communication method provided in an embodiment of the present application;

[0177] FIG4 b is a schematic diagram of a flow chart of another communication method provided in an embodiment of the present application;

[0178] FIG5 is a schematic diagram of an interactive flow chart of another communication method provided in an embodiment of the present application;

[0179] FIG6 is a schematic diagram of an interactive flow chart of another communication method provided in an embodiment of the present application;

[0180] FIG7 is a schematic diagram of the structure of a target NF network element provided in an embodiment of the present application;

[0181] FIG8 is a schematic structural diagram of a first discovery function network element provided in an embodiment of the present application;

[0182] FIG9 is a schematic structural diagram of another second discovery function network element provided in an embodiment of the present application;

[0183] FIG10 is a schematic structural diagram of another third discovery function network element provided in an embodiment of the present application;

[0184] FIG11 is a schematic structural diagram of an SMF network element provided in an embodiment of the present application;

[0185] FIG12 is a schematic structural diagram of another SMF network element provided in an embodiment of the present application;

[0186] FIG13 is a schematic diagram of the structure of another target NF network element provided in an embodiment of the present application;

[0187] FIG14 is a schematic diagram of the structure of a discovery function network element provided in an embodiment of the present application;

[0188] Figure 15 is a structural diagram of another SMF network element provided in an embodiment of the present application. DETAILED DESCRIPTION

[0189] The terms "first", "second", "third" and "fourth" in the specification, claims and drawings of this application are used to distinguish different objects rather than to describe a specific order.

[0190] "Multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating the existence of three relationships. For example, "A and / or B" means: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally indicates that the related objects are in an "or" relationship.

[0191] The embodiments of the present application are described below with reference to the accompanying drawings.

[0192] Various communication systems involve data transmission. For example, a common operator network, also known as a public land mobile network (PLMN), is a network established and operated by the government or an operator approved by it, such as a mobile network operator (MNO), for the purpose of providing land mobile communication services to the public, which involves data transmission. The embodiments of the present application may be based on PLMN or a network that meets the requirements of the third generation partnership project (3GPP) standards, referred to as a 3GPP network. Among them, the 3GPP network includes but is not limited to the fifth generation (5th-generation, 5G) mobile communication network, the fourth generation (4G) mobile communication network (also known as the long term evolution (LTE) network), and other future communication systems, such as the sixth generation (6th-generation, 6G) mobile communication network.

[0193] FIG1a uses a 5G network based on a service-based architecture (SBA) in a 3GPP non-roaming scenario as an example to provide a schematic diagram of a network architecture 100 applicable to an embodiment of the present application. As shown in FIG1a , the network architecture 100 may include a UE 110, a first DN 140, a second DN 150, a third DN 160, and an operator network portion. The operator network may include, but is not limited to, a (radio) access network (R)AN 120 and a core network (CN). The following briefly describes the devices or network elements of each portion.

[0194] Among them, (R)AN 120 may include one or more access network elements or access network devices, and the following description will be made using the access network device as an example. The interface between the access network device and the UE may be a Uu interface (or air interface). Of course, in future communications, the interface name may remain unchanged or may be replaced by other names, and this application is not limited to this. The access network device is a device that provides wireless communication functions for the UE, and can connect the UE to a node or device in the network, that is, a network device. (R)AN can be regarded as a subnetwork of the operator network, and is an implementation system between the service node and the UE in the operator network. For example, the UE can connect to the service node of the operator network through the (R)AN, thereby obtaining the services provided by the service node. The access network equipment in (R)AN includes but is not limited to: the next generation node base station (gNB) in the 5G system, the evolved node B (eNB) in the long term evolution (LTE), the radio network controller (RNC), the node B (NB), the base station controller (BSC), the base transceiver station (BTS), the home base station (for example, home evolved nodeB, or home nodeB, HNB), the base band unit (BBU), the transmitting and receiving point (TRP), the transmitting point (TP), the small base station equipment, the mobile switching center, or the network equipment in the future network. The access network equipment can also be a module or unit that performs the functions of a base station, such as a centralized unit (CU) and a distributed unit (DU); in a possible network structure, the CU can be used to support communications under protocols such as radio resource control (RRC), packet data convergence protocol (PDCP), and service data adaptation protocol (SDAP); the DU can be used to support communications under the radio link control (RLC) layer protocol, the medium access control (MAC) layer protocol, and the physical layer protocol.The embodiments of this application do not limit the specific technology and specific device form used by the access network device. In systems using different wireless access technologies, the name of the device with access network device functions may vary. For ease of description, in all embodiments of this application, the device that provides wireless communication functions for the UE is collectively referred to as the access network device, and in the embodiments of this application, the access network device can be replaced by the access network element. It should be understood that the embodiments of this application do not limit the specific type of access network device.

[0195] First DN 140, also known as a packet data network (PDN), is typically located outside the operator's network, such as a third-party network. First DN 140 may include one or more EASs 141, which provide local services to the UE by transmitting data with the UE. First DN 140 may also be referred to as a local DN.

[0196] The second DN 150, also known as a PDN, is typically located outside the operator's network, such as a third-party network. The second DN 150 may include one or more EASs 151, which provide local services to the UE by performing data transmission with the UE. The second DN 150 may also be referred to as a local DN.

[0197] The third DN 160, also known as a PDN, is typically located outside the operator's network, such as a third-party network. The third DN 160 may include one or more application servers (ASs) 161, which provide remote services to the UE by transmitting data with the UE. The third DN 160 may also be referred to as a remote DN.

[0198] The core network may include, but is not limited to, the following network elements: a user plane function (UPF) network element, an access and mobility management function (AMF) network element 132, a session management function (SMF) network element 133, a policy control function (PCF) network element 134, a network exposure function (NEF) network element 135, a network function repository function (NRF) network element 136, a unified data management function (UDM) network element 137, a unified data repository (UDR) network element 138, and a first discovery function network element 139. The following is a brief description of some network elements in the core network.

[0199] 1. The UPF network element 131-1 is used to support the UE's session, which is used for data transmission between the UE and the third DN 160. That is, the UPF network element is used to forward service data between the UE and the third DN 160. The session can be a protocol data unit (PDU) session. The UPF network element can be used to implement user-plane related functions such as data packet routing and transmission, data packet detection, service usage reporting, quality of service (QoS) processing, legal monitoring, uplink data packet detection, downlink data packet storage, etc. For example, during the session establishment process, the SMF network element selects a UPF network element for the session. The UPF network element can be called the anchor point of the session, such as a PDU session anchor (PSA).

[0200] Optionally, the network architecture 100 may further include a UPF network element 131-2 for diverting data transmitted in a session, that is, the UPF network element 131-2 may send data transmitted in a session to different anchor points. For example, the UPF network element 131-2 may identify data sent by the UE to the first DN 140 or the third DN 160, and send the data to the UPF network element 131-1 or the UPF network element 131-3. The UPF network element 131-2 is an uplink classifier (UL CL), which diverts data according to the destination address of the data packet; or, the UPF network element 131-2 is a brunching point (BP), which diverts data according to the source address of the data packet. The UPF network element 131-2 may be recorded as UL CL / BP.

[0201] Optionally, the network architecture 100 may further include a UPF network element 131-3 for supporting data transmission between the UE and the first DN 140 (such as EAS141), or in other words, for supporting the UE to access the first DN 140 and for supporting local access of the UE. The UPF network element 131-3 may be referred to as a local anchor point for the session, such as an L-PSA. Compared to the UPF network element 131-1, the UPF network element 131-3 is usually closer to the UE, which helps to reduce the end-to-end delay of data transmission between the UE and the first DN 140.

[0202] Optionally, the network architecture 100 may further include a UPF network element 131-4 for offloading data transmitted in a session, that is, the UPF network element 131-4 may send data transmitted in a session to different anchor points. For example, the UPF network element 131-4 may identify data sent by the UE to the second DN 150 and send the data to the UPF network element 131-5. The UPF network element 131-4 is a UL CL and offloads data based on the destination address of the data packet; alternatively, the UPF network element 131-4 is a BP and offloads data based on the source address of the data packet. The UPF network element 131-4 may be denoted as a UL CL / BP.

[0203] Optionally, the network architecture 100 may further include a UPF network element 131-5 for supporting data transmission between the UE and the second DN 150 (such as EAS151), or in other words, for supporting the UE to access the second DN 150 and for supporting local access of the UE. The UPF network element 131-5 may be referred to as a local anchor point for the session, such as an L-PSA. Compared to the UPF network element 131-1, the UPF network element 131-5 is generally closer to the UE, which helps to reduce the end-to-end delay of data transmission between the UE and the second DN 150 as shown in the figure.

[0204] 2. The AMF network element 132 is responsible for access control and mobility management of UEs accessing the operator's network, such as mobile state management, allocation of temporary user identities, authentication and authorization of UEs, etc.

[0205] 3. The SMF network element 133 is used to manage UE sessions, such as session establishment, modification, and release. It is also used for the selection and reselection of UPF network elements, UE Internet Protocol (IP) address allocation, and Quality of Service (QoS) control. The SMF network element is also used to implement edge application server (EAS) discovery, including the selection of discovery function network elements and the configuration of domain name system (DNS) processing rules for discovery function network elements.

[0206] 4. The target NF network element 133-1 is used to manage local UE sessions, such as session establishment, modification, and release, as well as the selection and reselection of UPF network elements, local UE IP address allocation, QoS control, etc. The target NF network element is also used to implement EAS discovery, including configuring DNS processing rules for the discovery function network element.

[0207] 5. The PCF network element 134 is used to support a unified policy framework to govern network behavior, provide policy rules to other control functions, and provide contract information related to policy decisions.

[0208] 6. NEF network element 135 is used to enable third parties to use the services provided by the operator's network, support the network to open its capabilities, event and data analysis, provide PLMN security configuration information from external applications, and convert interactive information within and outside the PLMN.

[0209] 7. The NRF network element 136 is a control plane function provided by the operator and can be used to store real-time information about network functions and services in the network. For example, it supports network service discovery, stores the NF configuration data (NF profile) of NF instances and the services they support, supports SCP service discovery, stores the SCP configuration data (SCP profile) of SCP instances, sends notifications about newly registered, deregistered, and updated NFs and SCPs, and stores the health status of NFs and SCPs.

[0210] 8. The UDM network element 137 is a control plane function provided by the operator and is responsible for storing information such as the subscriber permanent identifier (SUPI), the generic public subscription identifier (GPSI), and credentials of subscribers in the operator's network.

[0211] 9. The UDR network element 138 is a control plane function provided by the operator. It provides the UDM with the functions of storing and retrieving subscription data, the PCF with the functions of storing and retrieving policy data, and the user's NF group ID information.

[0212] 10. The first discovery function network element 139 is configured to assist in edge application server (EAS) discovery. For example, the first discovery function network element may receive a DNS request message from a UE, obtain the EAS address based on the DNS request message, and send the EAS address to the UE. The first discovery function network element may also process the DNS request message and DNS response message based on processing rules configured by the SMF network element 133 and the target NF network element 133-1, such as DNS processing rules.

[0213] In a feasible example, the first discovery function network element 139 is located in the third DN 160 .

[0214] Figure 1b illustrates another network architecture. As shown in Figure 1b, the core network includes not only the UPF network element, the AMF network element, the SMF network element, the target NF network element, the PCF network element, the UDR network element, the UDM network element, the NEF network element, and the NRF network element, but also a second discovery function network element 139-1 and a third discovery function network element 139-2.

[0215] The second discovery function network element 139-1 is used to assist in EAS discovery. For example, the second discovery function network element may receive a DNS request message from the UE, obtain the EAS address based on the DNS request message, and send the EAS address to the UE. The second discovery function network element may also process the DNS request message and the DNS response message based on the processing rules configured by the SMF network element 133, such as the DNS processing rules.

[0216] The third discovery function network element 139-2 is used to assist in EAS discovery. For example, the third discovery function network element 139-2 can receive a DNS request message from the UE, obtain the EAS address based on the DNS request message, and send the EAS address to the UE. The third discovery function network element can also process the DNS request message and DNS response message according to the processing rules configured by the target NF network element 133-1, such as the DNS processing rules.

[0217] In a feasible example, the second discovery function network element 139 - 1 is located in the first DN 140 , and the third discovery function network element 139 - 2 is located in the second DN 150 .

[0218] See Figure 2, which is a flow chart of a communication method provided in an embodiment of the present application. The method is applied to a target NF network element, which is the target NF network element in the network architecture shown in Figure 1a or Figure 1b. As shown in Figure 2, the method includes:

[0219] S201. The target NF network element receives the first domain name information in the first DNS request message from the SMF network element.

[0220] The first DNS request message is a message transmitted between the UE and the first discovery function network element. Further, the first DNS request message is sent by the UE to the first discovery function network element. The first DNS request message includes first domain name information. In one example, the domain name information is an FQDN.

[0221] S202. The target NF network element generates a first processing rule for the first DNS request message based on the first domain name information in the first DNS request message and the EAS deployment information stored in the target NF network element; and generates a second processing rule for the second DNS message based on the EAS deployment information stored in the target NF network element.

[0222] The second DNS message includes a first DNS response message, a second DNS request message, and a second DNS response message. The second DNS response message is a response to the second DNS request message, the second DNS request message is a message transmitted between the UE and the first discovery function network element later than the first DNS request message, and the second DNS response message is a response to the second DNS request message.

[0223] It should be noted that the EAS deployment information stored in the target NF network element may be configured on the target NF network element, or stored or updated by the target NF network element after obtaining the EAS deployment information.

[0224] The EAS deployment information stored by the target NF network element includes the domain name information corresponding to the EAS-supported service in the second DN, the DNAI corresponding to the second DN, the EAS address in the second DN, and the DNS server identifier within the coverage area of ​​the target NF network element. Other information may also be included, which is not limited here. The second DN is the DN connected to the UPF network element controlled by the target NF network element.

[0225] In a specific example, the first processing rule includes a first detection rule and a forwarding action, and the first detection rule includes the address of the UE and the first domain name information in the first DNS request message. If the first domain name information of the first DNS request message belongs to the domain name information in the EAS deployment information stored by the target NF network element, the forwarding action of the first processing rule includes the second information, and the first discovery function network element generates an ECS option of the first DNS request message based on the second information, and the ECS option is used to characterize the location information of the UE. When receiving the first DNS request message, the DNS server determines the address of the first EAS based on the ECS option of the first DNS request message, and the first EAS provides the UE with the service corresponding to the first domain name information.

[0226] If the first domain name information of the first DNS request message does not belong to the domain name information in the EAS deployment information stored in the target NF network element, it means that the target NF network element does not store the EAS related information corresponding to the first domain name information, then the forwarding action of the first processing rule includes the first information, and the first discovery function network element sets the ECS option of the first DNS request message to empty based on the first information. When the DNS server receives the first DNS request message with the ECS option set to empty, it processes the first DNS request message as a remote service.

[0227] In addition to the second detection rule, the second processing rule also includes at least one of a reporting action, a caching action, and a forwarding action. The second detection rule includes a DNS request message detection rule and a DNS response message detection rule. The DNS request message detection rule includes a set of UE address and domain name information. The DNS response message detection rule includes a set of domain name information. Optionally, the DNS response message detection rule also includes a set of EAS addresses.

[0228] It should be noted that the domain name information set here includes the domain name information of the services supported by the EAS in the second DN. The EAS address set here includes the address of the EAS in the second DN.

[0229] It should be noted that the address in this application can be an IPv4 address, IPv6 address, MAC address or other types of addresses, which are not limited here.

[0230] Specifically, the EAS deployment information stored in the target NF network element includes the domain name information of the services supported by the EAS in the second DN and the DNAI corresponding to the second DN. Optionally, the EAS deployment information stored in the target NF network element also includes the address of the EAS in the second DN. Of course, other information may also be included, which is not limited here.

[0231] Optionally, the target NF network element further receives the identifier of the first DNS request message from the SMF network element. The target NF network element binds the first processing rule with the identifier of the first DNS request message, so that the first discovery function network element knows that the first processing rule is specifically used to process the first DNS request message.

[0232] S203: The target NF network element sends the first processing rule and the second processing rule to the first discovery function network element.

[0233] The first processing rule and the second processing rule are used to generate a processing rule of the first discovery function network element, and the processing rule of the first discovery function network element is used to process the first DNS request message and / or the second DNS message.

[0234] In a feasible implementation, the target NF network element sends the first processing rule and the second processing rule to the first discovery function network element through the SMF network element, or the target NF network element obtains the address of the first discovery function network element from the SMF network element, and the target NF network element sends the first processing rule and the second processing rule to the first discovery function network element based on the address of the first discovery function network element.

[0235] By sending the first processing rule and the second processing rule to the first discovery function network element, when the first discovery function network element processes the first DNS request message and the second DNS message based on the first processing rule and the second processing rule, it interacts with the target NF network element instead of the SMF network element, thereby reducing the workload of the SMF network element. In addition, the target NF network element can directly send the first processing rule and the second processing rule to the first discovery function network element through the address of the first discovery function network element, without the need for forwarding through the SMF network element, which is conducive to further reducing the workload of the SMF network element.

[0236] In a feasible implementation manner, the target NF network element sends the identifier of the first EASDF context to the first discovery function network element based on the address of the first discovery function network element or through the SMF network element, so as to trigger the first discovery function network element to update the processing rules in the first EASDF context based on the identifier of the first EASDF context, and the processing rules of the first discovery function network element include the processing rules of the updated first EASDF context;

[0237] The first EASDF context before the update includes the fifth processing rule and the sixth processing rule. The fifth processing rule is a processing rule generated by the SMF network element for the third DNS message. The third DNS message is a message connected to the UPF network element controlled by the target NF network element. The sixth processing rule is a processing rule generated by the SMF network element for the fourth DNS message. The fourth DNS message is a message whose domain name information belongs to the domain name information in the first deployment information.

[0238] The updated first EASDF context includes the first processing rule, the second processing rule, and the fifth processing rule, or the updated first EASDF context includes the first processing rule, the second processing rule, the fifth processing rule, and the sixth processing rule.

[0239] That is to say, the first discovery function network element replaces the sixth processing rule in the first EASDF context with the first processing rule and the second processing rule based on the identifier of the first EASDF context, or the first discovery function network element adds the first processing rule and the second processing rule to the first EASDF context based on the identifier of the first EASDF context.

[0240] It should be pointed out here that the SMF network element stores the first deployment information and the second deployment information. Among them, the first deployment information includes EAS deployment information such as the domain name information of the services supported by the EAS in the first DN, the DNAI corresponding to the first DN, and the address of the EAS in the first DN. The first DN here is the DN connected to the UPF network element controlled by the SMF network element. In one example, the second deployment information includes EAS deployment information such as the domain name information of the services supported by the EAS in the second DN, the DNAI corresponding to the second DN, but does not include the address of the EAS in the second DN. In another example, the second deployment information includes the domain name information of the services supported by the EAS in the second DN. The second DN here is the DN connected to the UPF network element controlled by each NF network element. The above-mentioned NF network elements are NF network elements in the network to which the SMF network element belongs, and each NF network element includes the above-mentioned target NF network element.

[0241] It can be seen that by sending the identifier of the first EASDF context to the first discovery function network element, the first discovery function network element updates the processing rules in the first EASDF context based on the first processing rules and the second processing rules, instead of updating the processing rules in other EASDF contexts, thereby avoiding the inability to match the corresponding processing rules when processing DNS messages subsequently.

[0242] In a feasible implementation, when the first discovery function network element processes the first DNS request message based on the first processing rule, it interacts with the target NF network element. During this process, the target NF network element performs the following operations:

[0243] The target NF network element receives the address of the first EAS in the first DNS response message from the first discovery function network element; the first EAS provides the UE with the first service corresponding to the first domain name information in the first DNS request message, and the first DNS response message is a response to the first DNS request message; the target NF network element determines the first anchor point and the first diversion point based on the first EAS address. In one example, the first anchor point and the first diversion point are two different functional network elements, or different functional modules in the same functional network element. In other words, the first anchor point and the first diversion point can be combined in the same functional network element. The first anchor point and the first diversion point are used to transmit data of the first service corresponding to the first domain name information between the first EAS and the UE; the target NF network element notifies the first discovery function network element to send the first DNS response message to the UE.

[0244] It can be seen that determining the first diversion point and the first anchor point and sending the first DNS response message to the UE are performed by the target NF network element, rather than the SMF network element, which is conducive to further reducing the workload of the SMF network element.

[0245] Specifically, the target NF network element also receives the identifier of the first DNS response message and the domain name information in the first DNS response message from the SMF network element, wherein the domain name information in the first DNS response message is the same as the domain name information in the first DNS request message, both of which are first domain name information; the target NF network element notifies the first discovery function network element to send the first DNS response message to the UE, specifically in the following manner: the target NF network element generates a new processing rule based on the first domain name information and the EAS deployment information stored by the target NF network element, the processing rule including the detection rule and the action of sending the cached first DNS response message to the UE, the target NF network element sends the newly generated processing rule and the identifier of the first DNS response message to the first discovery function network element; the first discovery function network element matches the first DNS response message indicated by the identifier of the first DNS response message based on the newly generated processing rule, if the first DNS response message matches the detection rule of the newly generated processing rule, the first discovery function network element performs the action of sending the cached first DNS response message to the UE, that is, sends the first DNS response message to the UE. It should be understood that before the first discovery function network element sends the identifier of the first DNS response message and the domain name information in the first DNS response message to the target NF network element, the first discovery function network element has cached the first DNS response message.

[0246] In a feasible implementation, when the first discovery function network element processes the second DNS request message based on the first processing rule, it interacts with the target NF network element. During this process, the target NF network element performs the following operations:

[0247] The target NF network element receives the address of the second EAS in the second DNS response message from the first discovery function network element. The second EAS provides the UE with the second service corresponding to the second domain name information in the second DNS request message. Since the first anchor point and the first diversion point have been introduced before, the target NF network element determines whether the first anchor point and the first diversion point can be used to transmit the data of the second service corresponding to the second domain name information between the UE and the second EAS based on the address of the second EAS; if it is determined that the first anchor point and the first diversion point can be used to transmit the data of the second service corresponding to the second domain name information between the UE and the second EAS, the target NF network element directly notifies the first discovery function network element to send the second DNS response message to the UE. If it is determined that the first anchor point and the first diversion point cannot be used to transmit the data of the second service corresponding to the second domain name information between the UE and the second EAS, the target NF network element determines the second anchor point and the second diversion point based on the second EAS address, and the second anchor point and the second diversion point are used to transmit the data of the second service corresponding to the second domain name information between the second EAS and the UE. In one example, the second anchor point and the second branch point are two different functional network elements, or different functional modules in the same functional network element. In other words, the second anchor point and the second branch point can be co-located in the same functional network element. The target NF network element notifies the first discovery function network element to send a second DNS response message to the UE; the second DNS response message is a response to the second DNS request message.

[0248] It should be pointed out that the specific implementation method of the target NF network element notifying the first discovery function network element to send the second DNS response message to the UE can be found in the implementation process of the target NF network element notifying the first discovery function network element to send the first DNS response message to the UE, which will not be described here.

[0249] It can be seen that determining whether the first anchor point and the first diversion point can be used to transmit data of the second service between the UE and the second EAS, determining the second diversion point and the second anchor point, and notifying the first discovery function network element to send a second DNS response message to the UE are performed by the target NF network element, rather than the SMF network element, which is conducive to reducing the workload of the SMF network element and thus reducing the load of the SMF network element.

[0250] In one possible implementation, the first discovery function network element includes a second discovery function network element and a third discovery function network element, wherein the second discovery function network element and the third discovery function network element are the second discovery function network element and the third discovery function network element in the communication system shown in FIG1B . The third processing rule is a processing rule generated by the target NF network element for the first DNS response message based on the first domain name information and the EAS deployment information stored by the target NF network element; and the fourth processing rule is a processing rule generated by the target NF network element for the second DNS request message and the second DNS response message based on the EAS deployment information stored by the target NF network element.

[0251] The target NF network element sends the first processing rule and the third processing rule to the second discovery function network element. The first processing rule and the third processing rule are used to generate the processing rule of the second discovery function network element. The processing rule of the second discovery function network element is used to process the first DNS request message and the first DNS response message; the target NF network element sends the fourth processing rule to the third discovery function network element. The fourth processing rule is used to process the second DNS request message and the second DNS response message.

[0252] It can be seen that the DNS messages originally processed by one discovery function network element are processed by two discovery function network elements respectively, which is equivalent to introducing additional discovery function network elements on the basis of the original discovery function network element to share the work of the original discovery function network element, thereby reducing the workload of the original discovery function network element.

[0253] In a feasible implementation, the target NF network element sends the first processing rule and the third processing rule to the second discovery function network element through the SMF network element or based on the address of the second discovery function network element, and the target NF network element sends the fourth processing rule to the third discovery function network element based on the address of the third discovery function network element. It should be noted that the third discovery function network element is selected by the target NF network element, so the target NF network element knows the address of the third discovery function network element, so when the target NF network element sends the fourth processing rule to the third discovery function network element, it does not need to be forwarded by the SMF network element.

[0254] It can be seen that by sending processing rules to the second and third discovery function network elements, the second and third discovery function network elements process the corresponding DNS messages based on the processing rules, interacting with the target NF network element instead of the SMF network element, thereby reducing the workload of the SMF network element. In addition, the target NF network element sends the processing rules to the second and third discovery function network elements respectively through the addresses of the second and third discovery function network elements, without the need for forwarding through the SMF network element, which is conducive to further reducing the workload of the SMF network element.

[0255] In one possible implementation, the target NF network element sends the identifier of the first EASDF context to the second discovery function network element based on the address of the second discovery function network element or through the SMF network element, so as to trigger the second discovery function network element to update the processing rules in the first EASDF context, and the processing rules of the second discovery function network element include the processing rules in the updated first EASDF context.

[0256] The first EASDF context before the update includes the fifth processing rule and the sixth processing rule. The fifth processing rule is a processing rule generated by the SMF network element for the third DNS message. The third DNS message is a domain name information belonging to the domain name information in the first deployment information. The sixth processing rule is a processing rule generated by the SMF network element for the fourth DNS message. The fourth DNS message is a domain name information belonging to the domain name information in the second deployment information.

[0257] The updated processing rules in the first EASDF context include the first processing rule, the third processing rule, and the fifth processing rule, or the updated processing rules in the first EASDF context include the first processing rule, the third processing rule, the fifth processing rule, and the sixth processing rule. That is, the second discovery function network element replaces the sixth processing rule in the first EASDF context with the first processing rule and the third processing rule based on the identifier of the first EASDF context, or the second discovery function network element adds the first processing rule and the third processing rule to the first EASDF context based on the identifier of the first EASDF context.

[0258] It should be noted that the specific description of the first deployment information and the second deployment information can be found in the above related description and will not be described again here.

[0259] By sending the identifier of the first EASDF context to the second discovery function network element, the second discovery function network element updates the processing rules in the first EASDF context based on the first processing rules and the third processing rules, instead of updating the processing rules in other EASDF contexts, thereby avoiding the failure to match the corresponding processing rules when processing DNS messages subsequently.

[0260] In a feasible implementation, when the second discovery function network element processes the first DNS response message based on the third processing rule, it interacts with the target NF network element. In this process, the target NF network element performs the following operations:

[0261] The target NF network element receives the address of the first EAS in the first DNS response message from the second discovery function network element; the first EAS provides the UE with the first service corresponding to the first domain name information in the first DNS request, and the first DNS response message is a response to the first DNS request message; the target NF network element determines the first anchor point and the first diversion point based on the first EAS address, and the first anchor point and the first diversion point are used to transmit data of the first service corresponding to the first domain name information between the first EAS and the UE; the target NF network element notifies the second discovery function network element to send the first DNS response message to the UE.

[0262] Among them, the first DNS response message matches the third processing rule, the third processing rule includes the second endpoint information, the second endpoint information is used to indicate the target NF network element, and the address of the first EAS is sent by the second discovery function network element to the target NF network element based on the second endpoint information.

[0263] It should be pointed out that the specific implementation method of the target NF network element notifying the second discovery function network element to send the first DNS response message to the UE can be found in the implementation process of the target NF network element notifying the first discovery function network element to send the first DNS response message to the UE, which will not be described here.

[0264] In one example, all endpoint information in this application may be notification endpoints.

[0265] In a feasible implementation, when the third discovery function network element processes the second DNS response message based on the fourth processing rule, it interacts with the target NF network element. During this process, the target NF network element performs the following operations:

[0266] The target NF network element receives the address of the second EAS in the second DNS response message from the third discovery function network element; the second EAS is used to provide the UE with the second service corresponding to the second domain name information in the second DNS request message; the second DNS response message is a response to the second DNS request message; the target NF network element determines whether the first anchor point and the first diversion point can be used to transmit the data of the second service corresponding to the second domain name information between the UE and the second EAS based on the address of the second EAS; if it is determined that the first anchor point and the first diversion point can be used to transmit the data of the second service corresponding to the second domain name information between the UE and the second EAS, the target NF network element directly notifies the first discovery function network element to send the second DNS response message to the UE; if it is determined that the first anchor point and the first diversion point cannot be used to transmit the data of the second service corresponding to the second domain name information between the UE and the second EAS, the target NF network element determines the second anchor point and the second diversion point based on the address of the second EAS; the second anchor point and the second diversion point are used to transmit the data of the second service between the second EAS and the UE; the target NF network element notifies the third discovery function network element to send the second DNS response message to the UE.

[0267] Among them, the second DNS response message matches the fourth processing rule, the fourth processing rule includes the third endpoint information, the third endpoint information is used to indicate the target NF network element, and the address of the second EAS is sent by the third discovery function network element to the target NF network element based on the third endpoint information.

[0268] It should be pointed out that the specific implementation method of the target NF network element notifying the third discovery function network element to send the second DNS response message to the UE can be referred to the implementation process of the target NF network element notifying the first discovery function network element to send the first DNS response message to the UE, which will not be described here.

[0269] In one possible implementation, the target NF network element is determined by the AMF network element based on the location information of the UE; since the target NF network element determined based on the location information of the UE may store the relevant information of the EAS corresponding to the first domain name information, or may not store the relevant information of the EAS corresponding to the first domain name information. When the first domain name information does not belong to the domain name information in the EAS deployment information stored by the target NF network element, that is, the target NF network element does not store the relevant information of the EAS corresponding to the first domain name information, the forwarding action in the first processing rule for the first DNS request message generated by the target NF network element includes the first information, and the first discovery function network element sets the ECS option of the first DNS request message to empty based on the first information, so that the DNS server processes the first DNS request message with the empty ECS option as a remote service.

[0270] It can be seen that in the solution of the present application, the load of the SMF network element is shared by introducing the target NF network element. For example, the target NF network element generates the first processing rule and the second processing rule based on the EAS deployment information stored therein. Since the target NF network element has stored the EAS deployment information, the SMF network element is not required to store the EAS deployment information stored by the target NF network element, thereby reducing the load of the SMF network element. The first discovery function network element completes the EAS discovery process based on the processing rules by interacting with the target NF network element, which is conducive to reducing the workload of the SMF network element and thus reducing the load of the SMF network element. The endpoint information for indicating the target NF network element is introduced in the above-mentioned processing rules, so that when the discovery function network element reports the relevant information in the DNS message, it knows based on the endpoint information that it is reporting to the target NF network element instead of reporting to the SMF network element, which is also conducive to reducing the load of the SMF network element.

[0271] See Figure 3a, which is a flow chart of a communication method provided in an embodiment of the present application. The method is applied to a first discovery function network element, which is the first discovery function network element in the network architecture shown in Figure 1a. As shown in Figure 3a, the method includes:

[0272] S301a. The first discovery function network element receives a first DNS request message from the UE, and receives a second DNS message after the first DNS request message.

[0273] The first DNS request message is a DNS message in the DNS request message from the UE that matches the fifth processing rule or the sixth processing rule.

[0274] Specifically, the first discovery function network element receives the fifth processing rule and the sixth processing rule sent by the SMF network element; wherein, the fifth processing rule is the processing rule generated by the SMF network element for the third DNS message, and the third DNS message is a message whose domain name information belongs to the domain name information in the first deployment information; the sixth processing rule is the processing rule generated by the SMF network element for the fourth DNS message, and the fourth DNS message is a message whose domain name information belongs to the domain name information in the second deployment information.

[0275] Among them, the first deployment information includes EAS deployment information such as the domain name information of the services supported by the EAS in the first DN, the DNAI corresponding to the first DN, and the address of the EAS in the first DN. The first DN is the DN connected to the UPF network element controlled by the SMF network element. In one example, the second deployment information includes EAS deployment information such as the domain name information of the services supported by the EAS in the second DN, the DNAI corresponding to the second DN, but does not include the address of the EAS in the second DN. In another example, the second deployment information includes the domain name information of the services supported by the EAS in the second DN. The first deployment information and the second deployment information are EAS deployment information stored in the SMF network element. The second DN here is the DN connected to the UPF network element controlled by each NF network element.

[0276] It should be pointed out that the EAS deployment information stored in the SMF network element may be configured on the SMF network element, or stored or updated by the SMF network element after obtaining the EAS deployment information.

[0277] Among them, the fifth processing rule includes, in addition to the detection rule, at least one of a reporting action, a forwarding action and a control action. The control action includes a caching action and an action of sending a cached DNS message to the UE. The detection rules here include detection rules for DNS request messages and detection rules for DNS response messages. Specifically, the detection rules for the DNS request message here include the address of the UE within the service range of the SMF network element and the domain name information in the first deployment information; the detection rules for the DNS response message here include the domain name information in the first deployment information. Optionally, the detection rules for the DNS response message here also include the address of the EAS in the DN connected to the UPF network element controlled by the SMF network element.

[0278] Similarly, the sixth processing rule includes, in addition to the detection rule, at least one of a reporting action, a forwarding action, and a control action. The control action includes a caching action and an action of sending a cached DNS message to the UE. The detection rules here include detection rules for DNS request messages and detection rules for DNS response messages. Specifically, the detection rules for the DNS request message here include the address of the UE within the service range of each NF network element and the domain name information in the second deployment information; the detection rules for the DNS response message here include the domain name information in the second deployment information. Optionally, the detection rules for the DNS response message here also include the address of the EAS in the second DN. The second DN here is the DN connected to the UPF network element controlled by each NF network element.

[0279] Optionally, the priority of the sixth processing rule is higher than the priority of the fifth processing rule.

[0280] After receiving the DNS request message from the UE, the first discovery function network element matches the received DNS request message with the sixth processing rule based on the priority of the sixth processing rule. Specifically, it determines whether the UE address and domain name information in the DNS request message from the UE respectively belong to the UE address and domain name information of the DNS request message in the sixth processing rule. If the UE address and domain name information in the DNS request message from the UE respectively belong to the UE address and domain name information of the DNS request message in the sixth processing rule, the first discovery function network element determines that the received DNS request message matches the sixth processing rule; if the UE address in the DNS request message from the UE does not belong to the UE address in the detection rule of the DNS request message in the sixth processing rule, or the domain name information in the DNS request message from the UE does not belong to the domain name information in the detection rule of the DNS request message in the sixth processing rule, the first discovery function network element determines that the DNS request message from the UE does not match the sixth processing rule.

[0281] When the DNS request message from the UE matches the DNS request message detection rule in the sixth processing rule, the first discovery function network element executes the action in the sixth processing rule.

[0282] If the action in the sixth processing rule includes a reporting action and a caching action, the first discovery function network element reports the domain name information in the DNS request message from the UE to the SMF network element and caches the DNS request message. In an example, the sixth processing rule includes endpoint information, and the endpoint information is used to indicate the SMF network element. The first discovery function network element reports the domain name information in the DNS request message from the UE to the SMF network element based on the endpoint information in the sixth processing rule. The SMF network element generates a new processing rule for the DNS request message based on the domain name information in the DNS request message from the UE and the EAS deployment information stored in the SMF network element, wherein the detection rule in the processing rule includes the UE address and the domain name information of the DNS request message, and the action in the processing rule includes a forwarding action; the forwarding action includes information used to generate the ECS option of the DNS request message; the SMF network element sends the newly generated processing rule to the first discovery function network element; the first discovery function network element matches the DNS request message with the newly generated processing rule; if there is a match, the ECS option of the DNS request message is generated based on the information in the forwarding action in the newly generated processing rule, and sends the DNS request message to the DNS server; the first discovery function network element receives a DNS response message for the DNS request message from the DNS server, the DNS response message includes the address of the fourth EAS and the domain name information of the DNS response message, and the domain name information in the DNS response message is the same as the domain name information in the DNS request message; the first discovery function network element matches the DNS response message with the DNS response message detection rule in the sixth processing rule; the DNS response message detection rule includes a domain name information set. The domain name information set includes the domain name information of the services supported by the EAS in the DN corresponding to the UPF network element controlled by each NF network element. Optionally, the DNS response message detection rule also includes an EAS address set. The EAS address set includes the address of the EAS in the second DN, where the second DN is the DN corresponding to the UPF network element controlled by each NF network element. In one example, if the domain name information in the DNS response message belongs to the domain name information set in the DNS response message detection rule, the first discovery function network element determines that the DNS response message matches the DNS response message detection rule in the sixth processing rule. In another example, if the domain name information in the DNS response message belongs to the domain name information set in the DNS response message detection rule, and the address of the fourth EAS belongs to the address set of the EAS in the DNS response message detection rule, the first discovery function network element determines that the DNS response message matches the DNS response message detection rule in the sixth processing rule.If there is a match, the first discovery function network element performs a caching action to cache the DNS response message; generates an identifier for the DNS response message, and performs a reporting action, and the first discovery function network element sends the identifier of the DNS response message and the address of the fourth EAS to the SMF network element. In one example, the first discovery function network element reports the identifier and the fourth EAS address in the DNS response message to the SMF network element based on the endpoint information in the sixth processing rule. The SMF network element determines the fourth diversion point and the fourth anchor point based on the address of the fourth EAS, and configures a diversion rule for the fourth diversion point; the fourth diversion point and the fourth anchor point are used to transmit data of the service corresponding to the domain name information in the DNS response message between the UE and the fourth EAS. The SMF network element generates a new processing rule for the DNS response message, the detection rule in the processing rule includes the domain name information in the DNS response message, and the action in the processing rule includes the action of sending the cached DNS response message to the UE. The SMF network element sends the identifier of the DNS response message and the newly generated processing rules to the first discovery function network element. The first discovery function network element matches the DNS response message with the detection rules in the newly generated processing rules based on the identifier of the DNS response message. If they match, the first discovery function network element executes the action of sending the cached DNS response message to the UE, that is, sending the cached DNS response message to the UE.

[0283] When the request message from the UE does not match the sixth processing rule, the first discovery function network element matches the request message from the UE with the fifth processing rule based on the priority of the fifth processing rule. The specific matching process and subsequent processing process can be found in the relevant description of the matching of the above-mentioned DNS request message with the sixth processing rule, which will not be described here.

[0284] The first DNS request message is one of the DNS request messages cached by the first discovery function network element. In one example, the first DNS request message is the first DNS request message cached by the first discovery function network element.

[0285] The second DNS message includes a first DNS response message, a second DNS request message, and a second DNS response message. The second DNS request message is a message transmitted between the UE and the first discovery function network element later than the first DNS request message, and the second DNS response message is a response to the first DNS request message. The second DNS request message includes DNS request messages other than the first DNS request message among the DNS request messages cached by the first discovery function network element and a DNS request message received from the UE after the first discovery function network element generates a processing rule for the first discovery function network element.

[0286] S302a: The first discovery function network element receives the first processing rule and the second processing rule from the target NF network element.

[0287] It should be noted that for the detailed description of the first processing rule and the second processing rule, please refer to the relevant description of S202 and will not be described again here.

[0288] S303a: The first discovery function network element generates a processing rule of the first discovery function network element based on the first processing rule and the second processing rule.

[0289] In a specific implementation, the first discovery function network element generates a first EASDF context based on the fifth processing rule and the sixth processing rule. The first discovery function network element adds the first processing rule and the second processing rule to the first EASDF context, or replaces the sixth processing rule in the first EASDF context with the first processing rule and the second processing rule, to complete the update of the first EASDF context; the processing rules of the first discovery function network element include the processing rules in the updated first EASDF context.

[0290] In another specific embodiment, there may be multiple EASDF contexts in the first discovery function network element. The first discovery function network element obtains the identifier of the first EASDF context. The first discovery function network element adds the first processing rule and the second processing rule to the first EASDF context based on the identifier of the first EASDF context, or replaces the sixth processing rule in the first EASDF context with the first processing rule and the second processing rule based on the identifier of the first EASDF context to complete the update of the first EASDF context. It should be pointed out that the identifier of the first EASDF context is sent to the first discovery function network element by the target NF network element when the first processing rule and the second processing rule are sent to the first discovery function network element. In other words, the identifier of the first EASDF context, the first processing rule and the second processing rule are sent by the target NF network element to the second discovery function network element through the same message. The identifier of the first EASDF context from the target NF network element is sent to the target NF network element by the SMF network element after obtaining the identifier of the first EASDF context from the first discovery function network element;

[0291] The first EASDF context before the update includes a fifth processing rule and a sixth processing rule. The fifth processing rule is a processing rule generated by the SMF network element for the third DNS message. The third DNS message is a message whose domain name information belongs to the domain name information in the EAS deployment information stored by the SMF network element. The sixth processing rule is a processing rule generated by the SMF network element for the fourth DNS message. The fourth DNS message is a message whose domain name information belongs to the domain name information in the EAS deployment information stored by each NF network element. Each NF network element includes a target NF network element.

[0292] The updated processing rules in the first EASDF context include the first processing rule, the second processing rule and the fifth processing rule, or the updated processing rules in the first EASDF context include the first processing rule, the second processing rule, the fifth processing rule and the sixth processing rule.

[0293] It should be noted that the EAS deployment information stored by the SMF network element may be configured on the SMF network element, or the SMF network element may store or update the EAS deployment information after obtaining the EAS deployment information. The EAS deployment information stored by each NF network element may be configured on each NF network element, or the NF network element may store or update the EAS deployment information after obtaining the EAS deployment information.

[0294] By updating the processing rules of the first discovery function network element based on the first processing rules and the second processing rules generated by the NF, when the first discovery function network element subsequently processes the DNS message based on the first processing rules and the second processing rules, it reports the relevant information in the DNS message (such as the address of the first EAS in the first DNS response message, the domain name information in the second DNS request message and the second domain name information in the second DNS response message) to the target NF network element, so that the target NF network element performs related operations, instead of reporting it to the SMF network element and asking the SMF network element to perform related operations, thereby reducing the workload of the SMF network element.

[0295] Furthermore, the first discovery function network element obtains a first identifier and a second identifier, wherein the first identifier is used to indicate that the first processing rule and the second processing rule are processing rules generated by the target NF network element for the fifth DNS message, and the fifth DNS message is a message containing domain name information in the EAS deployment information stored by the target NF network element. The second identifier is used to indicate that the sixth processing rule is a processing rule generated by the SMF network element for the fourth DNS message; based on the first identifier and the second identifier, the first discovery function network element updates the sixth processing rule in the first EASDF context to the first processing rule and the second processing rule.

[0296] By introducing the first identifier and the second identifier, the first discovery function network element can accurately update the sixth processing rule in the first EASDF context to the first processing rule and the second processing rule, instead of updating the fifth processing rule to the first processing rule and the second processing rule, thereby ensuring the accuracy of the processing rule update in the first EASDF context.

[0297] In another specific implementation, after receiving the first processing rule and the second processing rule, the first discovery function network element generates a second EASDF context and an identifier of the second EASDF context based on the first processing rule and the second processing rule. In this case, the processing rules of the first discovery function network element include the processing rules in the first EASDF context and the processing rules in the second EASDF context.

[0298] By generating a new EASDF context based on the first and second processing rules, and using the new EASDF context as part of the processing rules of the first discovery function network element, when subsequently processing the DNS message, the first discovery function network element interacts with the NF network element based on the processing rules of the new EASDF context, rather than interacting with the SMF network element, which helps reduce the workload of the SMF network element. Furthermore, the EASDF context itself includes endpoint information, and this endpoint information is used to indicate the target NF network element. When the DNS message matches the processing rules of the second EASDF context, the first discovery function network element reports the relevant information in the DNS message to the target NF network element based on the endpoint information. This approach eliminates the need to set endpoint information in the processing rules.

[0299] S304a: The first discovery function network element processes the first DNS request message or the second DNS message based on the processing rule of the first discovery function network element.

[0300] In a specific implementation, the first discovery function network element matches the first DNS request message based on the first processing rule; if the first domain name information and the UE address in the first DNS request message belong to the domain name information and the UE address in the first processing rule respectively, it is determined that the first processing rule matches the first DNS request message; if the first domain name information in the first DNS request message does not belong to the domain name information in the first processing rule, or the UE address in the first DNS request message does not belong to the UE address in the first processing rule, it is determined that the first processing rule does not match the first DNS request message. If the first processing rule matches the first DNS request message, when the forwarding action in the first processing rule includes the first information, the first discovery function network element clears the ECS option of the first DNS request message based on the first information; when the forwarding action in the first processing rule includes the second information, the first discovery function network element adds the second information as the ECS option of the first DNS request message to the first DNS request message. The first discovery function network element executes the forwarding action in the first processing rule and sends a first DNS request message to the DNS server; the first discovery function network element receives a first DNS response message from the DNS server, and the first DNS response message is a response to the first DNS request message; the first DNS response message includes the address of the first EAS, and the address of the first EAS is determined by the DNS server based on the ECS option in the first DNS request message, and the first EAS provides the UE with a first service corresponding to the first domain name information; the first discovery function network element matches the first DNS response message with the second processing rule; in an example, if the domain name information in the first DNS response message belongs to the domain name information in the second processing rule, it is determined that the second processing rule matches the first DNS response message; if the domain name information in the first DNS response message does not belong to the domain name information in the second processing rule, it is determined that the first processing rule does not match the first DNS request message. In another example, the second processing rule also includes the address of the EAS, which is the address of the EAS in the second DN, where the second DN is the address of the EAS in the DN connected to the UPF network element controlled by the target NF network element; if the domain name information in the first DNS response message belongs to the domain name information in the second processing rule, and the address of the first EAS belongs to the address of the EAS in the second processing rule, then it is determined that the second processing rule matches the first DNS response message; if the domain name information in the first DNS response message does not belong to the domain name information in the second processing rule, or the address of the first EAS does not belong to the address of the EAS in the second processing rule, then it is determined that the first processing rule does not match the first DNS request message.If the first processing rule matches the first DNS request message, the first discovery function network element sends the first EAS address to the target NF network element, and the first EAS address is used by the target NF network element to determine the first anchor point and the first diversion point; the first anchor point and the first diversion point are used to transmit data of the first service between the first EAS and the UE; when the first discovery function network element detects that the target NF network element executes the operation of notifying the first discovery function network element to send the first DNS response message to the UE, it sends the first DNS response message to the UE.

[0301] It should be noted that the specific implementation method of the target NF network element notifying the discovery function to send the first DNS response message to the UE can be found in the relevant description of S203 and will not be described here.

[0302] It should be pointed out that the target NF network element is determined by the AMF network element based on the UE's location information, or is determined based on the UE's location information and DNAI; when the target NF network element is the SMF network element and the AMF network element is determined based on the UE's location information and DNAI, the first domain name information belongs to the domain name information in the EAS deployment information stored by the target NF network element; when the target NF network element is determined by the AMF network element based on the UE's location information, the first domain name information may belong to the domain name information in the EAS deployment information stored by the target NF network element, or may not belong to the domain name information in the EAS deployment information stored by the target NF network element.

[0303] When the target NF network element generates the first processing rule, if the first domain name information of the first DNS request message belongs to the domain name information in the EAS deployment information stored by the target NF network element, the forwarding action in the first processing rule includes the second information, and the second information is used as the ECS option in the first DNS request message, and the ECS option is used to represent the location information of the UE; if the first domain name information of the first DNS request message does not belong to the domain name information in the EAS deployment information stored by the target NF network element, the forwarding action in the first processing rule includes the first information, and the first information is used for the first discovery function network element to set the ECS option of the first DNS request message sent to the DNS server to empty, so that the DNS server processes the first DNS request message with the ECS option empty as a remote service.

[0304] In another possible implementation, the first discovery function network element processes the second DNS request message as follows:

[0305] The first discovery function network element matches the second processing rule with the second DNS request message. If the domain name information and the UE address in the second DNS request message match the domain name information and the UE address in the second processing rule, respectively, the second processing rule is determined to match the second DNS request message. If the domain name information in the second DNS request message does not match the domain name information in the second processing rule, or the UE address in the second DNS message does not match the UE address in the second processing rule, the second processing rule is determined to not match the second DNS request message. If the second processing rule matches the second DNS request message, the first discovery function network element performs the reporting action in the second processing rule and sends the second domain name information in the second DNS request message to the target NF network element. Optionally, the second processing rule also includes first endpoint information, which indicates the target NF network element. The first discovery function network element reports the second domain name information to the target NF network element based on the first endpoint information. The target NF network element generates a new processing rule based on the second domain name information and the EAS deployment information stored by the target NF network element. The forwarding action of the processing rule includes third information, which is used to generate an ECS option in the first DNS request message. The ECS option is used to represent the UE location information. The target NF network element sends the above-mentioned new processing rules to the first discovery function network element; the first discovery function network element matches the second DNS request message with the new rules. If the second DNS request message matches the new rules, the first discovery function network element executes the forwarding action in the new processing rules and sends the second DNS request message to the DNS server. Before sending, the first discovery function network element adds the third information as the ECS option of the second DNS request message to the second DNS request message; the first discovery function network element receives the second DNS response message from the DNS server; the second DNS response message includes the address of the second EAS; the second EAS provides the UE with the second service corresponding to the second domain name information; the first discovery function network element matches the second DNS response message with the second processing rules. The specific matching process can be found in the matching process between the above-mentioned first DNS response message and the second processing rule, which will not be described here. If the second DNS response message matches the second processing rule, the first discovery function network element sends the second EAS address to the target NF network element based on the first endpoint information, and the second EAS address is used by the target NF network element to determine the second anchor point and the second diversion point; the second anchor point and the second diversion point are used to transmit data of the second service between the second EAS and the UE; when it is detected that the target NF network element executes the operation of notifying the first discovery function network element to send the second DNS response message to the UE, the second DNS response message is sent to the UE.

[0306] It should be noted that the specific implementation method of the target NF network element notifying the first discovery function network element to send the second DNS response message to the UE can be found in the relevant description of S203 and will not be described here.

[0307] It should be pointed out here that among the processing rules of the first discovery function network element, there are multiple processing rules for the second DNS request message and the second DNS response message, so the first discovery function network element will set matching priorities for the multiple processing rules; for example, the matching priority of the second processing rule is higher than the matching priority of the sixth processing rule, and the matching priority of the sixth processing rule is higher than the matching priority of the fifth processing rule. The first discovery function network element will prioritize matching the second DNS request message or the second DNS response message with the second processing rule based on the matching priority of the second processing rule; if the second DNS request message or the second DNS response message does not match the second processing rule, the first discovery function network element will match the second DNS request message or the second DNS response message with the sixth processing rule based on the matching priority of the sixth processing rule; if the second DNS request message or the second DNS response message does not match the sixth processing rule, the first discovery function network element will match the second DNS request message or the second DNS response message with the fifth processing rule.

[0308] Optionally, the fifth processing rule also includes fourth endpoint information, and the fourth endpoint information is used to indicate the SMF network element. The first discovery function network element reports the relevant information in the DNS message that matches the fifth processing rule to the SMF network element based on the fourth endpoint information. The sixth processing rule also includes fifth endpoint information, and the fifth endpoint information is used to indicate the target NF network element. The first discovery function network element reports the relevant information in the DNS message that matches the sixth processing rule to the SMF network element based on the fifth endpoint information.

[0309] It can be seen that in the solution of this embodiment, since the first processing rule and the second processing rule are generated by the target NF network element based on the EAS deployment information stored by it, rather than by the SMF network element, the SMF network element does not need to store all the information stored by the target NF network element, which is conducive to reducing the EAS deployment information stored by the SMF network element, and then helps to reduce the load of the SMF network element. In addition, the first processing rule and the second processing rule are generated by the target NF network element, rather than by the SMF network element, which can also reduce the workload of the SMF network element. Introducing the first endpoint information for indicating the target NF network element in the second processing rule allows the first discovery function network element to know that the relevant information in the DNS message that matches the second processing rule is reported to the target NF network element based on the first endpoint information, rather than to the SMF network element, which is also conducive to reducing the load of the SMF network element. The first discovery function network element generates a new EASDF context based on the first and second processing rules. Since the EASDF context itself contains endpoint information, and this endpoint information is used to indicate the target NF network element, when the DNS message matches the processing rules of the second EASDF context, the first discovery function network element reports the relevant information in the DNS message to the target NF network element based on the endpoint information. This method does not require setting endpoint information in the processing rules of the second EASDF context.

[0310] See Figure 3b, which is a flow chart of a communication method provided in an embodiment of the present application. The method is applied to a second discovery function network element, which is the second discovery function network element in the network architecture shown in Figure 1b. As shown in Figure 3b, the method includes:

[0311] S301b. The second discovery function network element receives a first DNS request message from the UE.

[0312] It should be noted that for the detailed description of the first DNS request message, the fifth processing rule and the sixth processing rule, reference may be made to the relevant description of S301a and will not be repeated here.

[0313] S302b: The second discovery function network element receives the first processing rule and the third processing rule from the target NF network element.

[0314] Among them, the first processing rule is a processing rule for the first DNS request message, and the third processing rule is a processing rule for the first DNS response message; the first DNS response message is a response to the first DNS request message.

[0315] It should be noted that for the detailed description of the first processing rule and the third processing rule, please refer to the relevant description of S202 and will not be described again here.

[0316] S303b: The second discovery function network element generates a processing rule of the second discovery function network element based on the first processing rule and the third processing rule.

[0317] In one possible implementation, the second discovery function network element adds the first processing rule and the third processing rule to the first EASDF context, or replaces the sixth processing rule in the first EASDF context with the first processing rule and the third processing rule to complete the update of the first EASDF context; the processing rules of the second discovery function network element include the processing rules in the updated first EASDF context.

[0318] In one possible implementation, the second discovery function network element obtains the identifier of the first EASDF context, and the second discovery function network element adds the first processing rule and the third processing rule to the first EASDF context based on the identifier of the first EASDF context, or replaces the sixth processing rule in the first EASDF context with the first processing rule and the third processing rule based on the identifier of the first EASDF context to complete the update of the first EASDF context. It should be pointed out that the identifier of the first EASDF context is sent to the second discovery function network element by the target NF network element when sending the first processing rule and the third processing rule to the second discovery function network element. In other words, the identifier of the first EASDF context, the first processing rule and the third processing rule are sent by the target NF network element to the second discovery function network element through the same message.

[0319] Among them, the first EASDF context before the update includes the fifth processing rule and the sixth processing rule, and the processing rules in the first EASDF context after the update include the first processing rule, the third processing rule and the fifth processing rule, or the processing rules in the first EASDF context after the update include the first processing rule, the third processing rule, the fifth processing rule and the sixth processing rule.

[0320] By updating the processing rules of the second discovery function network element based on the first processing rules and the third processing rules generated by the target NF network element, when the second discovery function network element subsequently processes the first DNS request message and the first DNS response message based on the first processing rules and the third processing rules, it interacts with the target NF network element instead of the SMF network element, thereby reducing the workload of the SMF network element.

[0321] In one possible implementation, the second discovery function network element obtains a third identifier and a second identifier, the third identifier is used to indicate that the first processing rule and the third processing rule are processing rules generated by the target NF network element for the DNS message whose domain name information belongs to the domain name information in the EAS deployment information stored by the target NF network element, and the second identifier is used to indicate that the sixth processing rule is a processing rule generated by the SMF network element for the DNS message whose domain name information belongs to the domain name information in the first deployment information; the second discovery function network element updates the sixth processing rule in the first EASDF context to the first processing rule and the third processing rule based on the third identifier and the second identifier.

[0322] By introducing the third identifier and the second identifier, the second discovery function network element can accurately update the sixth processing rule in the first EASDF context to the first processing rule and the third processing rule, instead of updating the fifth processing rule to the first processing rule and the second processing rule, thereby ensuring the accuracy of the processing rules in the first EASDF context.

[0323] In one possible implementation, after receiving the first and third processing rules, the second discovery function network element generates a second EASDF context and an identifier of the second EASDF context based on the first and third processing rules. In this case, the processing rules of the second discovery function network element include the processing rules in the first EASDF context and the processing rules in the second EASDF context.

[0324] By generating a new EASDF context based on the first processing rule and the second processing rule, the new EASDF context serves as part of the processing rule of the first discovery function network element. When subsequently processing the DNS message, the first discovery function network element interacts with the NF network element based on the processing rule of the new EASDF context, rather than interacting with the SMF network element, which helps reduce the workload of the SMF network element. The EASDF context itself includes endpoint information, and the endpoint information is used to indicate the target NF network element. When the DNS message matches the processing rule of the second EASDF context, the second discovery function network element reports the relevant information in the DNS message to the target NF network element based on the endpoint information. This method does not require setting endpoint information in the processing rules.

[0325] S304b: The second discovery function network element processes the first DNS request message and the first DNS response message based on the processing rule of the second discovery function network element.

[0326] It should be noted here that the specific process of the second discovery function network element processing the first DNS request message and the first DNS response message based on the processing rules of the second discovery function network element can be found in the relevant description of S304a and will not be described here. The difference from S304a is that the second discovery function network element matches the first DNS request message with the first processing rule, and the second discovery function network element matches the first DNS response message with the third processing rule.

[0327] In one possible implementation, the third processing rule includes second endpoint information, where the second endpoint information is used to indicate a target NF network element. The address of the first EAS is sent by the second discovery function network element to the target NF network element based on the first endpoint information.

[0328] By introducing the third endpoint information into the third processing rule, the first discovery function network element knows based on the third endpoint information that the first EAS address in the first DNS response message that matches the third processing rule will be reported to the target NF network element for processing instead of reporting it to the SMF network element for processing, which is conducive to further reducing the workload of the SMF.

[0329] In one possible implementation, the second discovery function network element sends a second DNS request message to the third discovery function network element, wherein the second DNS request message is a message other than the first DNS request message in the DNS request message from the UE that matches the fifth processing rule or the sixth processing rule. In other words, the second DNS request message is a DNS message other than the first DNS request message in the DNS request message cached by the second discovery function network element. By sending the cached DNS request message to the third discovery function network element and having the third discovery function network element process it, the workload of the second discovery function network element is reduced.

[0330] It can be seen that in the solution of this embodiment, since the first processing rule and the third processing rule are generated by the target NF network element based on the EAS deployment information stored by it, rather than by the SMF network element, the SMF network element does not need to store all the information stored by the target NF network element, which is conducive to reducing the EAS deployment information stored by the SMF network element, and thus helps to reduce the load of the SMF network element. In addition, the first processing rule and the third processing rule are generated by the target NF network element, rather than by the SMF network element, which can also reduce the workload of the SMF network element. The second endpoint information for indicating the target NF network element is introduced into the third processing rule, so that when the second discovery function network element reports the address of the first EAS in the first DNS response message that matches the third processing rule, it knows based on the second endpoint information that it is reporting to the target NF network element, rather than to the SMF network element, which is also conducive to reducing the load of the SMF network element. The second discovery function network element generates a new EASDF context based on the first processing rule and the second processing rule. Since there is endpoint information in the EASDF context itself, and the endpoint information is used to indicate the target NF network element, when the DNS message matches the processing rule of the second EASDF context, the second discovery function network element reports the relevant information in the DNS message to the target NF network element based on the endpoint information. In this way, there is no need to set the endpoint information in the processing rule in the second EASDF context.

[0331] See Figure 3c, which is a flow chart of a communication method provided in an embodiment of the present application. The method is applied to a third discovery function network element, which is the third discovery function network element in the network architecture shown in Figure 1b. As shown in Figure 3c, the method includes:

[0332] S301c. The third discovery function network element receives the fourth processing rule from the target NF network element.

[0333] Among them, the fourth processing rule is the processing rule of the target NF network element for the second DNS request message, and the second DNS response message is a response to the second DNS request message.

[0334] In one example, in addition to the fifth detection rule, the fourth processing rule also includes a reporting action and a caching action. Among them, the fifth detection rule includes a DNS request message detection rule and a DNS response message detection rule. The DNS request message detection rule here includes the address and domain name information set of the UE. The DNS response message detection rule here includes a domain name information set. Optionally, the DNS response message detection rule here also includes an EAS address set. It should be pointed out that the domain name information set here includes the domain name information of the services supported by the EAS in the second DN. The EAS address set here includes the address of the EAS in the second DN. The second DN here is the DN connected to the UPF network element controlled by the target NF network element.

[0335] S302c: The third discovery function network element receives a second DNS request message from the second discovery function network element or from the UE.

[0336] The second DNS request message from the second discovery function network element is described in detail in S304b and is not described again here. The second DNS request message from the UE is a DNS request message sent by the UE to the third discovery function network element via the access network device, the first branch point, and the first anchor point after being inserted into the first anchor point and the first branch point.

[0337] S303c. The third discovery function network element processes the second DNS request message based on the fourth processing rule.

[0338] The second DNS request message includes a second DNS request message from a second discovery function network element or from a UE.

[0339] Specifically, the third discovery function network element matches the fourth processing rule with the second DNS request message. If the fourth processing rule matches the second DNS request message, the third discovery function network element executes the reporting action in the fourth processing rule and sends the second domain name information in the second DNS request message to the target NF network element. Optionally, the fourth processing rule also includes third endpoint information, and the third endpoint information is used to indicate the target NF network element; the third discovery function network element reports the second domain name information to the target NF network element based on the third endpoint information. The target NF network element generates a new processing rule based on the second domain name information and the EAS deployment information stored by the target NF network element. The forwarding action of the processing rule includes the third information; the target NF network element sends the above-mentioned new processing rule to the third discovery function network element; the third discovery function network element matches the second DNS request message with the new rule. If the second DNS request message matches the new rule, the third discovery function network element executes the forwarding action in the new processing rule and sends the second DNS request message to the DNS server. Before sending, the third discovery function network element adds the third information as the ECS option of the second DNS request message to the second DNS request message; the ECS option in the second DNS request message is used to characterize the UE's location; the third discovery function network element receives a second DNS response message from the DNS server; the second DNS response message includes the address of the second EAS; the second EAS provides the UE with a second service corresponding to the second domain name information; if the second DNS response message matches the fourth processing rule, the third discovery function network element sends the second EAS address to the target NF network element based on the third endpoint information, and the second EAS address is used by the target NF network element to determine the second anchor point and the second diversion point; the second anchor point and the second diversion point are used to transmit data of the second service between the second EAS and the UE; when it is detected that the target NF network element executes the operation of notifying the third discovery function network element to send the second DNS response message to the UE, the second DNS response message is sent to the UE.

[0340] It should be noted that the specific implementation method of the target NF network element notifying the third discovery function network element to send the first DNS response message to the UE can be found in the relevant description of S203 and will not be described here.

[0341] In the solution of this embodiment, since the fourth processing rule is generated by the target NF network element based on the EAS deployment information stored by it, rather than by the SMF network element, the SMF network element does not need to store all the information stored by the target NF network element, which is conducive to reducing the EAS deployment information stored by the SMF network element, and thus helps to reduce the load of the SMF network element. In addition, the fourth processing rule is generated by the target NF network element, rather than by the SMF network element, which can also reduce the workload of the SMF network element. Introducing the third endpoint information for indicating the target NF network element in the fourth processing rule allows the third discovery function network element to know that the relevant information in the DNS message that matches the third processing rule is reported to the target NF network element based on the third endpoint information, rather than to the SMF network element, which is also conducive to reducing the load of the SMF network element.

[0342] Referring to FIG4a, FIG4a is a flow chart of a communication method provided in an embodiment of the present application. The method is applied to the SMF network element in the communication system shown in FIG1a or FIG1b. As shown in FIG4a, the method includes:

[0343] S401a. The SMF network element receives the first domain name information in the first DNS request message from the first discovery function network element or the second discovery function network element.

[0344] The first DNS request message is a message transmitted between the UE and the first discovery function network element or the second discovery function network element. It should be noted that the specific description of the first DNS request message can refer to the relevant description of S301a and will not be described here.

[0345] In one possible implementation, the SMF network element receives first deployment information and second deployment information from the AF network element, wherein the first deployment information includes EAS deployment information such as the domain name information of the services supported by the EAS in the first DN, the DNAI corresponding to the first DN, and the address of the EAS in the first DN. The first DN here is the DN connected to the UPF network element controlled by the SMF network element. The second deployment information includes EAS deployment information such as the domain name information of the services supported by the EAS in the second DN, the DNAI corresponding to the second DN, but does not include the address of the EAS in the second DN. The second DN here is the DN connected to the UPF network element controlled by each NF network element.

[0346] The SMF network element generates the fifth processing rule and the sixth processing rule based on the first deployment information and the second deployment information respectively. It should be noted that the specific description of the fifth processing rule and the sixth processing rule can be found in the relevant description of S301a, which will not be described here. The SMF network element sends the fifth processing rule and the sixth processing rule to the first discovery function network element. The fifth processing rule and the sixth processing rule are used by the first discovery function network element to determine the first DNS request message from the DNS request message from the UE. The first DNS request message is a message in the DNS request message from the UE that matches the fifth processing rule or the sixth processing rule. It should be noted that the matching process of the DNS request message from the UE with the fifth processing rule and the sixth processing rule can be found in the relevant description of S301a, which will not be described here.

[0347] It can be seen that the purpose of generating the fifth processing rule and the sixth processing rule and sending them to the discovery function network element is to enable the discovery function network element to determine the first DNS request from the DNS request from the UE based on the fifth processing rule and the sixth processing rule, and then trigger the execution of subsequent processes (including the NF network element generating processing rules based on the domain name information in the first DNS request, etc.).

[0348] S402a, the SMF network element determines the target DNAI based on the first domain name information, the correspondence between the domain name information and the DNAI, and the UE's location information.

[0349] Specifically, the SMF network element obtains the location information of the UE from the AMF network element by subscription. The SMF network element determines the DNAI corresponding to the first domain name information based on the first domain name information and the correspondence between the domain name information and the DNAI, and then determines the target DNAI from the DNAI corresponding to the first domain name information based on the UE's location information. The distance between the DN identified by the target DNAI and the UE is less than the distance between the DN identified by other DNAIs corresponding to the first domain name information and the UE.

[0350] It should be pointed out that the distance between the DN identified by the target DNAI and the UE is smaller than the distance between the DN identified by other DNAIs corresponding to the first domain name information and the UE, including different situations. For example, the distance between the DN identified by the target DNAI and the UE is smaller than the distance between all DNs in the DN identified by other DNAIs corresponding to the first domain name information and the UE. For another example, the distance between the DN identified by the target DNAI and the UE is smaller than the distance between some DNs in the DN identified by other DNAIs corresponding to the first domain name information and the UE.

[0351] S403a. If the target DNAI belongs only to the DNAI in the EAS deployment information stored by each NF network element, or the target DNAI belongs to both the DNAI in the EAS deployment information stored by each NF network element and the DNAI in the EAS deployment information stored by the SMF network element, the SMF network element sends the target DNAI to the AMF network element.

[0352] Specifically, the SMF network element determines the relationship between the target DNAI and the DNAI in the EAS deployment information stored by each NF network element, as well as the relationship between the target DNAI and the DNAI in the EAS deployment information stored by the SMF network element; if the target DNAI only belongs to the DNAI in the EAS deployment information stored by each NF network element, the SMF network element sends the target DNAI to the AMF network element; if the target DNAI belongs to both the DNAI in the EAS deployment information stored by each NF network element and the DNAI in the EAS deployment information stored by the SMF network element, the SMF network element sends the target DNAI to the AMF network element. The AMF network element determines the address of the target NF network element based on the target DNAI.

[0353] It should be pointed out that each NF network element is an NF network element in the network where the SMF network element is located, and there may be multiple of them. The target DNAI belongs to the DNAI in the EAS deployment information stored in each NF network element, including two situations: 1. The target DNAI belongs to the DNAI in the EAS deployment information stored by only one NF network element in each NF network element; 2. The target DNAI belongs to the DNAI in the EAS deployment information stored by multiple NF network elements in each NF network element; 3. The target DNAI belongs to the DNAI in the EAS deployment information stored by each NF network element. It can also mean that the target DNAI belongs to the DNAI in the EAS deployment information stored by each NF network element in each NF network element.

[0354] It should be noted that the EAS deployment information stored by the SMF network element may be configured on the SMF network element, or the SMF network element may store or update the EAS deployment information after obtaining the EAS deployment information. The EAS deployment information stored by each NF network element may be configured on each NF network element, or the NF network element may store or update the EAS deployment information after obtaining the EAS deployment information.

[0355] S404a, the SMF network element receives the address of the target NF network element from the AMF network element; the SMF network element sends the first domain name information to the target NF network element based on the address of the target NF network element.

[0356] The first domain name information is used by the target NF network element to generate a first processing rule for the first DNS request message based on the EAS deployment information stored in the target NF network element.

[0357] It should be noted that the EAS deployment information stored in the target NF network element may be configured on the target NF network element, or stored or updated by the target NF network element after obtaining the EAS deployment information.

[0358] It can be seen that through the above method, it is possible to determine a suitable target NF network element to share the work of the SMF network element. For example, based on the EAS deployment information stored by the target NF network element, a processing rule for the first DNS request message is generated. The SMF network element does not need to store all of the EAS deployment information stored by the target NF network element, which is conducive to reducing the load on the SMF network element. In addition, when determining the target NF network element, the DNAI, the domain name information in the first DNS request message, and the UE's location information are taken into consideration, ensuring that the target NF network element can support the UE's EAS discovery process.

[0359] Referring to FIG4b, FIG4b is a flow chart of a communication method provided in an embodiment of the present application. The method is applied to the SMF network element in the communication system shown in FIG1a or FIG1b. As shown in FIG4b, the method includes:

[0360] S401b. The SMF network element receives the first domain name information in the first DNS request message from the first discovery function network element or the second discovery function network element.

[0361] The first DNS request message is a message transmitted between the UE and the first discovery function network element or the second discovery function network element. It should be noted that the specific description of the first DNS request message can refer to the relevant description of S301a and will not be described here.

[0362] In one possible implementation, the SMF network element receives first deployment information and second deployment information from the AF network element, wherein the first deployment information includes EAS deployment information such as domain name information of services supported by the EAS in the first DN, DNAI corresponding to the first DN, and the address of the EAS in the first DN. The first DN here is the DN connected to the UPF network element controlled by the SMF network element. The second deployment information includes domain name information of services supported by the EAS in the second DN. The second DN here is the DN connected to the UPF network element controlled by each NF network element. The SMF network element generates the fifth processing rule and the sixth processing rule based on the first deployment information and the second deployment information respectively. It should be pointed out here that the specific description of the fifth processing rule and the sixth processing rule can be found in the relevant description of S301a and will not be described here. The SMF network element sends the fifth processing rule and the sixth processing rule to the first discovery function network element or the second discovery function network element. The fifth processing rule and the sixth processing rule are used to determine the first DNS request message from the DNS request message from the UE. The first DNS request message is a message in the DNS request message from the UE that matches the fifth processing rule or the sixth processing rule. It should be noted that the matching process of the DNS request message from the UE with the fifth processing rule and the sixth processing rule can be found in the relevant description of S301a and will not be described again here.

[0363] It can be seen that the purpose of generating the fifth processing rule and the sixth processing rule and sending them to the discovery function network element is to enable the discovery function network element to determine the first DNS request from the DNS request from the UE based on the fifth processing rule and the sixth processing rule, and then trigger the execution of subsequent processes (including the NF network element generating processing rules based on the domain name information in the first DNS request, etc.).

[0364] S402b. If the first domain name information belongs to the domain name information in the EAS deployment information stored in each NF network element, the SMF network element obtains the address of the target NF network element from the AMF network element, and the AMF network element determines the address of the target NF network element based on the UE's location information.

[0365] In one example, when the first domain name information belongs to the domain name information in the EAS deployment information stored by each NF network element, that is, at least one NF network element among the NF network elements stores the relevant information of the EAS corresponding to the first domain name information, the SMF network element and the AMF network element interact to determine the target NF network element from each NF network element, and introduce the target NF network element to store the relevant information of the EAS corresponding to the first domain name information. At this time, regardless of whether the SMF network element can store the relevant information of the EAS corresponding to the first domain name information for the UE. Introducing the target NF network element in this way is conducive to reducing the workload of the SMF network element.

[0366] In another example, when the first domain name information belongs to the domain name information in the EAS deployment information stored by each NF network element and does not belong to the domain name information in the EAS deployment information stored by the SMF network element, that is, at least one NF network element in each NF network element stores the relevant information of the EAS corresponding to the first domain name information, but the SMF network element does not store the relevant information of the EAS corresponding to the first domain name information, the SMF network element interacts with the AMF to determine the target NF, and introduces the target NF to store the relevant information of the EAS corresponding to the first domain name information for the UE. Introducing the target NF network element in this way is conducive to reducing the workload of the SMF network element.

[0367] S403b. The SMF network element sends the first domain name information to the target NF network element based on the address of the target NF network element.

[0368] The first domain name information is used by the target NF network element to generate a first processing rule for the first DNS request message based on the EAS deployment information stored in the target NF network element.

[0369] In another example, when the first domain name information belongs to the domain name information in the EAS deployment information stored by the SMF network element, it means that the SMF network element has stored the relevant information of the EAS corresponding to the first domain name information, so the SMF network element does not perform the operation of obtaining the address of the target NF network element. In other words, the target NF network element is not introduced, and the first DNS request message is processed by the SMF network element and the first discovery function network element or the second discovery function network element.

[0370] It can be seen that through the above method, it is possible to determine a suitable target NF network element to share the work of the SMF network element. For example, based on the EAS deployment information stored by the target NF network element, a processing rule for the first DNS request message is generated. The SMF network element does not need to store all of the EAS deployment information stored by the target NF network element, which is conducive to reducing the load on the SMF network element. In addition, the second deployment information stored by the SMF network element only includes the domain name information of the EAS-supported services in the second DN connected to the UPF network element controlled by each NF network element, and does not include information such as DNAI. In other words, the SMF only needs to store domain name information and does not need to store other information such as DNAI, further reducing the load on the SMF network element.

[0371] Referring to FIG5 , FIG5 is a schematic diagram of an interactive flow of a communication method provided in an embodiment of the present application. The method is applied to the communication system shown in FIG1a . As shown in FIG5 , the method includes:

[0372] S501. The AF network element sends the first deployment information and the second deployment information to the SMF network element, and sends the EAS deployment information of each NF network element to each NF network element.

[0373] It should be understood that each NF network element refers to the NF network element in the network to which the SMF network element belongs, and there can be one or more NF network elements in the network to which the SMF network element belongs.

[0374] Among them, the first deployment information includes EAS deployment information such as the domain name information of the services supported by the EAS in the first DN, the DNAI corresponding to the first DN, and the address of the EAS in the first DN. The first DN here is the DN connected to the UPF network element controlled by the SMF network element. In one example, the second deployment information includes the domain name information of the services supported by the EAS in the second DN and the DNAI corresponding to the second DN. The second deployment information does not include the address of the EAS in the second DN. The second DN here is the DN connected to the UPF network element controlled by each NF network element.

[0375] In another example, the second deployment information includes the domain name information of the services supported by the EAS in the second DN, but does not include the DNAI corresponding to the second DN and the address of the EAS in the second DN. The second DN here is the DN connected to the UPF network element controlled by each NF network element. In this case, the SMF network element only needs to store the domain name information, not the DNAI and EAS address, which helps reduce the load on the SMF network element.

[0376] The EAS deployment information stored in each NF network element includes the domain name information of the services supported by the EAS in the second DN connected to the UPF network element controlled by the NF network element, the DNAI corresponding to the second DN, and the address of the EAS in the second DN, etc.

[0377] S502. The UE establishes a target PDU session with the SMF network element.

[0378] Specifically, the UE sends a PDU session creation request to the SMF network element, and the SMF network element sends a response message to the UE for the PDU session creation request. In this way, the UE and the SMF network element create a target PDU session between the UE and the SMF network element. Optionally, the PDU session creation request includes a UE identifier, and the SMF network element determines whether the UE supports edge services based on the UE identifier. The response message to the PDU session creation request includes the result of whether the UE supports edge services. When the SMF network element determines that the UE supports edge services, it executes S503 and subsequent processes.

[0379] S503. The SMF network element determines the first discovery function network element.

[0380] S504. The SMF network element generates a fifth processing rule and a sixth processing rule based on the first deployment information and the second deployment information respectively.

[0381] The fifth processing rule is a processing rule generated by the SMF network element for the third DNS message, where the domain name information of the third DNS message belongs to the domain name information in the first deployment information. The sixth processing rule is a processing rule generated by the SMF network element for the fourth DNS message, where the domain name information of the fourth DNS message belongs to the domain name information in the second deployment information. It should be understood that the DNS messages herein include DNS request messages and DNS response messages.

[0382] Among them, the fifth processing rule includes, in addition to the detection rule, at least one of a reporting action, a forwarding action and a control action. The control action includes a caching action and an action of sending a cached DNS message to the UE. The detection rules here include detection rules for DNS request messages and detection rules for DNS response messages. Specifically, the detection rules for the DNS request message here include the address of the UE within the service range of the SMF network element and the domain name information in the first deployment information; the detection rules for the DNS response message here include the domain name information in the first deployment information. Optionally, the detection rules for the DNS response message here also include the address of the EAS in the first DN.

[0383] Similarly, the sixth processing rule includes not only detection rules, but also reporting actions and caching actions. The control action includes a caching action and an action of sending the cached DNS message to the UE. The detection rules here include detection rules for DNS request messages and detection rules for DNS response messages. Specifically, the detection rules for the DNS request message here include the address of the UE within the service range of each NF network element and the domain name information in the second deployment information; the detection rules for the DNS response message here include the domain name information in the second deployment information. Optionally, the detection rules for the DNS response message here also include the address of the EAS in the second DN.

[0384] Optionally, the priority of the sixth processing rule is higher than the priority of the fifth processing rule.

[0385] Optionally, the sixth processing rule includes a second identifier, which is used to indicate that the sixth processing rule is a processing rule of the SMF network element for the fourth DNS message. Optionally, the fifth processing rule includes a fourth identifier, which is used to indicate that the fifth processing rule is a processing rule for a DNS message whose domain name information belongs to the domain name information in the first deployment information.

[0386] The sixth processing rule also includes a first indication information, which is used to indicate that before the first discovery function network element generates the processing rule of the first discovery function network element, if there are multiple DNS request messages that match the sixth processing rule or the fifth processing rule, the first discovery function network element only reports one DNS request message from the multiple DNS request messages to the SMF network element.

[0387] S505. The SMF network element sends the fifth processing rule and the sixth processing rule to the first discovery function network element.

[0388] In one example, the first discovery function network element generates a first EASDF context and an identifier of the first EASDF context based on the fifth processing rule and the sixth processing rule. The processing rules in the first EASDF context are used to generate processing rules of the first discovery function network element, and the processing rules in the first EASDF context correspond to the target PDU session pair.

[0389] Optionally, the SMF network element sends the address of the UE to the first discovery function network element. In another example, the first discovery function network element generates a first EASDF context and an identifier of the first EASDF context based on the address of the UE, the fifth processing rule, and the sixth processing rule. The processing rules in the first EASDF context correspond to the UE, that is, to the target PDU session.

[0390] S506. The first discovery function network element receives a DNS request message from the UE.

[0391] The DNS request message includes the address and domain name information of the UE. The DNS request message is used to request the address of the EAS that provides the UE with the service corresponding to the domain name information in the DNS request message.

[0392] Optionally, the address referred to in this application is an IPv4 address, IPv6 address, MAC address or other types of addresses, which are not limited here.

[0393] It should be noted that the DNS request message is sent by the UE to the first discovery function network element through the target PDU session. Before the first discovery function network element generates its processing rule, the first discovery function network element may receive one or more DNS request messages from the UE.

[0394] S507: The first discovery function network element matches the received DNS request message based on the fifth processing rule and the sixth processing rule.

[0395] After receiving the DNS request message from the UE, the first discovery function network element matches the received DNS request message with the sixth processing rule based on the priority of the sixth processing rule. Specifically, it determines whether the UE address and domain name information in the DNS request message from the UE respectively belong to the UE address and domain name information of the DNS request message in the sixth processing rule. If the UE address and domain name information in the DNS request message from the UE respectively belong to the UE address and domain name information of the DNS request message in the sixth processing rule, the first discovery function network element determines that the received DNS request message matches the sixth processing rule; if the UE address in the DNS request message from the UE does not belong to the UE address in the detection rule of the DNS request message in the sixth processing rule, or the domain name information in the DNS request message from the UE does not belong to the domain name information in the detection rule of the DNS request message in the sixth processing rule, the first discovery function network element determines that the DNS request message from the UE does not match the sixth processing rule.

[0396] When the DNS request message from the UE matches the DNS request message detection rule in the sixth processing rule, the first discovery function network element executes the action in the sixth processing rule.

[0397] If the action in the sixth processing rule includes a reporting action and a caching action, then if the action in the sixth processing rule includes a reporting action and a caching action, the first discovery function network element reports the domain name information in the DNS request message from the UE to the SMF network element and caches the DNS request message. In one example, the sixth processing rule includes endpoint information, and the endpoint information is used to indicate the SMF network element. The first discovery function network element reports the domain name information in the DNS request message from the UE to the SMF network element based on the endpoint information in the sixth processing rule. The SMF network element generates a new processing rule for the DNS request message based on the domain name information in the DNS request message from the UE and the EAS deployment information stored in the SMF network element, wherein the detection rule in the processing rule includes the UE address and the domain name information of the DNS request message, and the action in the processing rule includes a forwarding action; the forwarding action includes information used to generate the ECS option of the DNS request message; the SMF network element sends the newly generated processing rule to the first discovery function network element; the first discovery function network element matches the DNS request message with the newly generated processing rule; if there is a match, the ECS option of the DNS request message is generated based on the information in the forwarding action in the newly generated processing rule, and sends the DNS request message to the DNS server; the first discovery function network element receives a DNS response message for the DNS request message from the DNS server, the DNS response message includes the address of the fourth EAS and the domain name information of the DNS response message, and the domain name information in the DNS response message is the same as the domain name information in the DNS request message; the first discovery function network element matches the DNS response message with the DNS response message detection rule in the sixth processing rule; the DNS response message detection rule includes a domain name information set. The domain name information set includes the domain name information of the services supported by the EAS in the DN corresponding to the UPF network element controlled by each NF network element of YU. Optionally, the DNS response message detection rule also includes an EAS address set. The EAS address set includes the address of the EAS in the DN corresponding to the UPF network element controlled by each NF network element. In one example, if the domain name information in the DNS response message belongs to the domain name information set in the DNS response message detection rule, the first discovery function network element determines that the DNS response message matches the DNS response message detection rule in the sixth processing rule. Further, if the domain name information in the DNS response message belongs to the domain name information set in the DNS response message detection rule, and the address of the fourth EAS belongs to the address set of the EAS in the DNS response message detection rule, the first discovery function network element determines that the DNS response message matches the DNS response message detection rule in the sixth processing rule.If there is a match, the first discovery function network element performs a caching action to cache the DNS response message; generates an identifier for the DNS response message, and performs a reporting action, and the first discovery function network element sends the identifier of the DNS response message and the address of the fourth EAS to the SMF network element. In one example, the first discovery function network element reports the identifier and the fourth EAS address in the DNS response message to the SMF network element based on the endpoint information in the sixth processing rule. The SMF network element determines the fourth diversion point and the fourth anchor point based on the address of the fourth EAS, and configures a diversion rule for the fourth diversion point; the fourth diversion point and the fourth anchor point are used to transmit data of the service corresponding to the domain name information in the DNS response message between the UE and the fourth EAS. The SMF network element generates a new processing rule for the DNS response message, the detection rule in the processing rule includes the domain name information in the DNS response message, and the action in the processing rule includes the action of sending the cached DNS response message to the UE. The SMF network element sends the identifier of the DNS response message and the newly generated processing rules to the first discovery function network element. The first discovery function network element matches the DNS response message with the detection rules in the newly generated processing rules based on the identifier of the DNS response message. If they match, the first discovery function network element executes the action of sending the cached DNS response message to the UE, that is, sending the cached DNS response message to the UE.

[0398] When the request message from the UE does not match the sixth processing rule, the first discovery function network element matches the request message from the UE with the fifth processing rule based on the priority of the fifth processing rule. The specific matching process and subsequent processing process can be found in the relevant description of the matching of the above-mentioned DNS request message with the sixth processing rule, which will not be described here.

[0399] The first DNS request message is one of the DNS request messages cached by the first discovery function network element. In one example, the first DNS request message is the first DNS request message cached by the first discovery function network element.

[0400] S508. The first discovery function network element sends the first domain name information in the first DNS request message and the identifier in the first DNS request message to the SMF network element.

[0401] In one example, the first domain name information in the first DNS request message and the identifier in the first DNS request message are reported by the first discovery function network element to the SMF network element based on the first indication information in the sixth processing rule.

[0402] Optionally, the first discovery function network element sends the address of the UE to the SMF network element. Optionally, the first discovery function network element sends the identifier of the first EASDF context to the SMF network element.

[0403] In one feasible implementation, if the second deployment information does not include the DNAI corresponding to the second DN, if the first domain name information belongs to the domain name information in the second deployment information, that is, at least one of the NF network elements stores the relevant information about the EAS corresponding to the first domain name information, then the SMF network element obtains from the AMF network element the address of the target NF network element determined by the AMF network element based on the UE's location information. Furthermore, if the first domain name information belongs to the domain name information in the second deployment information and does not belong to the domain name information in the first deployment information, that is, at least one of the NF network elements stores the relevant information about the EAS corresponding to the first domain name information, but the SMF network element does not store the relevant information about the EAS corresponding to the first domain name information, then the SMF network element obtains from the AMF network element the target NF network element determined by the AMF network element based on the UE's location information. The distance between the target NF network element and the UE is less than the distance between the other NF network elements and the UE. In this case, S509-S512 are not executed, and S513 is executed when the address of the target NF network element is determined. If the first domain name information belongs to the domain name information in the first deployment information, it means that the SMF network element stores the relevant information of the EAS corresponding to the first domain name information, and processes the first DNS request message in the manner described in S522, wherein the target NF network element is replaced by the SMF network element.

[0404] The distance between the target NF network element and the UE is smaller than the distance between other NF network elements and the UE, including different situations. For example, the distance between the target NF network element and the UE is smaller than the distance between all other NF network elements and the UE, that is, the target NF network element is the NF network element with the smallest distance between it and the UE among all NF network elements; for another example, the distance between the target NF network element and the UE is smaller than the distance between some of the other NF network elements and the UE.

[0405] S509. The SMF network element determines the target DNAI based on the first domain name information.

[0406] Specifically, the SMF network element determines the DNAI corresponding to the first domain name information based on the correspondence between the domain name information and the DNAI; the SMF network element obtains the UE location information from the AMF network element through subscription; the SMF network element determines the target DNAI from the DNAI corresponding to the first domain name information based on the UE location information, and the distance between the DN identified by the target DNAI and the UE is less than the distance between the DN identified by other DNAIs corresponding to the first domain name information and the UE.

[0407] It should be pointed out that the distance between the DN identified by the target DNAI and the UE is smaller than the distance between the DN identified by other DNAIs corresponding to the first domain name information and the UE, including different situations. For example, the distance between the DN identified by the target DNAI and the UE is smaller than the distance between all DNs in the DN identified by other DNAIs corresponding to the first domain name information and the UE. For another example, the distance between the DN identified by the target DNAI and the UE is smaller than the distance between some DNs in the DN identified by other DNAIs corresponding to the first domain name information and the UE.

[0408] Optionally, after receiving the address of the UE, the SMF network element stores the relationship between the address of the UE and the identifier of the first EASDF context.

[0409] S510. The SMF network element performs subsequent operations based on the target DNAI.

[0410] Specifically, when the target DNAI only belongs to the DNAI in the EAS deployment information stored in the SMF network element, the first discovery function network element and the SMF network element process the first DNS request message in the manner described in S522. It should be pointed out that in the process of processing the first DNS request message according to the steps of S522, the target NF network element is replaced with the SMF network element; when the target DNAI only belongs to the DNAI in the EAS deployment information stored in each NF network element, S511 is executed; when the target DNAI belongs to both the DNAI in the EAS deployment information stored in the SMF network element and the DNAI in the EAS deployment information stored in each NF network element, S511 is executed.

[0411] S511. The SMF network element sends the target DNAI to the AMF network element.

[0412] S512. The AMF network element sends the address of the target NF network element to the SMF network element.

[0413] Specifically, the AMF network element determines the address of the target NF network element based on the target DNAI.

[0414] S513. The SMF network element sends the first domain name information to the target NF network element based on the address of the target NF network element.

[0415] Optionally, the SMF network element further sends an identifier of the first DNS request message to the target NF network element. Optionally, the SMF network element further sends an identifier of the first EASDF context to the target NF network element. Optionally, the SMF network element further sends an address of the UE to the target NF network element. Optionally, the SMF network element further sends an address of the first discovery function network element to the target NF network element.

[0416] S514: The target NF generates a first processing rule and a second processing rule.

[0417] The first processing rule is a processing rule for the first DNS request message, and the second processing rule is a processing rule for the first DNS response message, the second DNS request message, and the second DNS response message. The second DNS request message includes DNS request messages other than the first DNS request message in the DNS request messages cached in the first discovery function network element and DNS request messages received from the UE after the first discovery function network element generates its processing rule.

[0418] In one example, the target NF network element generates a first processing rule for the first DNS request message based on the first domain name information and EAS deployment information stored by the target NF network element. In another example, the target NF network element generates a first processing rule for the first DNS request message based on the UE address, the first domain name information, and the EAS deployment information stored by the target NF network element. The first processing rule corresponds to the identifier of the first DNS request message. The actions in the first processing rule include forwarding actions, reporting actions, and caching actions, and the detection rules of the first processing rule include the UE address and the first domain name information.

[0419] When the first domain name information does not belong to the domain name information in the EAS deployment information stored by the target NF network element, the forwarding action in the first processing rule includes first information, and the first information is used by the first discovery function network element to clear the ECS option in the first DNS request message. When the first domain name information belongs to the domain name information in the EAS deployment information stored by the target NF network element, the forwarding action in the first processing rule includes second information, and the second information is used by the first discovery function network element to generate an ECS option in the first DNS request message, and the ECS option is used to represent the location of the UE.

[0420] In one example, the target NF network element generates a second processing rule for the second DNS message based on the EAS deployment information stored by the target NF network element. In another example, the target NF network element generates a second processing rule for the second DNS message based on the address of the UE and the EAS deployment information stored by the target NF network element. The actions in the second processing rule include a reporting action and a caching action, and the request message detection rule in the second processing rule includes the address of the UE and the domain name information supported by EAS in the second DN, where the second DN is the DN connected to the UPF network element controlled by the target NF network element. The response message detection rule of the second processing rule includes the domain name information supported by EAS in the DN connected to the UPF network element controlled by the target NF network element. Optionally, the response message detection rule in the second processing rule includes the address of the EAS in the DN connected to the UPF network element controlled by the target NF network element. Optionally, the second processing rule also includes first endpoint information, and the first endpoint information is used to indicate the target NF network element.

[0421] Optionally, the target NF network element sets a matching priority of the second processing rule, wherein the matching priority of the second processing rule is higher than the matching priority of the sixth processing rule.

[0422] S515a: The target NF network element sends the first processing rule and the second processing rule to the SMF network element.

[0423] Optionally, the target NF network element sends the identifier of the first EASDF context to the SMF network element. Optionally, the target NF network element sends the address of the UE to the SMF network element.

[0424] S516. The SMF network element sends the first processing rule and the second processing rule to the first discovery function network element.

[0425] Optionally, the SMF network element sends an identifier of the first EASDF context to the first discovery function network element. Optionally, the SMF network element sends an address of the UE to the first discovery function network element.

[0426] It should be pointed out that when the SMF network element only receives the UE address, the SMF network element sends the first EASDF context identifier to the first discovery function network element based on the UE address and the UE address stored in the SMF network element and the identifier of the first EASDF context.

[0427] Optionally, the SMF network element generates a first identifier for the first processing rule and the second processing rule to identify that the first processing rule and the second processing rule are processing rules for a fifth DNS message, where the fifth DNS message is a message for the domain name information supported by EAS in the second DN, where the second DN is a DN that the domain name information belongs to and is connected to the UPF network element controlled by the target NF network element. The SMF network element sends the first identifier of the first processing rule and the second processing rule to the first discovery function network element.

[0428] S515b: The target NF network element sends the first processing rule and the second processing rule to the first discovery function network element.

[0429] It should be pointed out here that if the target NF network element has obtained the address of the first discovery function network element from the SMF network element, the target NF network element will send the first processing rule, the second processing rule and the identifier of the first EASDF context to the EASDF network element based on the address of the first discovery function network element, without the need for forwarding through the SMF network element.

[0430] It should be noted that S515a and S516 are executed alternatively to S515b. That is, if S515a and S516 are executed, S515b will not be executed; if S515b is executed, S515a and S516 will not be executed.

[0431] S517: The first discovery function network element generates a processing rule for the first discovery function network element.

[0432] In one possible implementation, the first discovery function network element adds the first processing rule and the second processing rule to the first EASDF context based on the identifier of the first EASDF context to obtain an updated first EASDF context. The processing rules of the first discovery function network element include the processing rules in the updated first EASDF context, and the processing rules in the updated first EASDF context include the first processing rule, the second processing rule, the fifth processing rule, and the sixth processing rule.

[0433] In another possible implementation, the first discovery function network element obtains the first identifiers of the first processing rule and the second processing rule, and the first discovery function network element replaces the sixth processing rule in the first EASDF context with the first processing rule and the second processing rule based on the identifier of the first EASDF context, the first identifier, and the second identifier of the sixth processing rule to obtain an updated first EASDF context. The processing rules of the first discovery function network element include the processing rules in the updated first EASDF context, and the processing rules in the updated first EASDF context include the first processing rule, the second processing rule, and the fifth processing rule.

[0434] It should be pointed out that when the first discovery function network element receives the address of the UE but does not receive the identifier of the first EASDF context, since the first EASDF context is generated based on the UE address, the fifth processing rule and the sixth processing rule, the first discovery function network element knows the relationship between the UE address and the first EASDF context. Therefore, the first discovery function network element can update the processing rules in the first EASDF context based on the UE address, that is, the first discovery function network element adds the first processing rule and the second processing rule to the first EASDF context based on the UE address, or replaces the sixth processing rule in the first EASDF context with the first processing rule and the second processing rule based on the UE address.

[0435] In another possible implementation, the first discovery function network element receives the UE address from the SMF network element. The first discovery function network element generates a second EASDF context and an identifier for the second EASDF context based on the UE address, the first processing rule, and the second processing rule. It should be noted that by generating the second EASDF context based on the UE address, the first processing rule, and the second processing rule, the first discovery function network element knows that the processing rules in the second EASDF context are associated with the UE, that is, associated with the target PDU session. The processing rules of the first discovery function network element include the processing rules in the first EASDF context and the processing rules in the second EASDF context. In this case, the processing rules of the first discovery function network element include the first processing rule, the second processing rule, the fifth processing rule, and the sixth processing rule. The second EASDF context includes sixth endpoint information, which indicates the target NF network element. During subsequent processing, if the DNS message matches the processing rules in the second EASDF context, the first discovery function network element reports the relevant information in the DNS message to the target NF network element based on the sixth endpoint information. It should be noted that in this case, the second processing rule does not need to include the first endpoint information.

[0436] S518. The first discovery function network element processes the first DNS request message.

[0437] Specifically, the first discovery function network element matches the first DNS request message with the first processing rule based on the identifier of the first DNS request message. The specific method is: the first discovery function network element matches the UE address and domain name information included in the first DNS request message with the UE address and domain name information in the first processing rule respectively. If the UE address included in the first DNS request message is the UE address in the first processing rule, and the domain name information included in the first DNS request message belongs to the domain name information in the first processing rule, then the first discovery function network element determines that the first DNS request message matches the first processing rule. The first discovery function network element executes the forwarding action in the first processing rule, that is, based on the first information of the forwarding action, the ECS option of the first DNS request message is cleared, and then the first DNS request message is forwarded to the DNS server, or the ECS option of the first DNS request message is generated based on the second information in the forwarding action, the ECS option is added to the first DNS request message, and the first DNS request message is sent to the DNS server.

[0438] If the UE address included in the first DNS request message is different from the UE address in the first processing rule, or the domain name information included in the first DNS request message does not belong to the domain name information in the first processing rule, the first discovery function network element determines that the first DNS request message does not match the first processing rule, and the first discovery function network element discards the first DNS request message or does not process the first DNS request message.

[0439] S519. The DNS server sends a first DNS response message to the first discovery function network element.

[0440] The first DNS response message is a response to the first DNS request message. The first DNS response message includes the address of the first EAS and the first domain name information. The first EAS provides the UE with a service corresponding to the first domain name information.

[0441] S520. The first discovery function network element processes the first DNS response message.

[0442] In a specific embodiment, the DNS response message detection rule of the second processing rule includes domain name information and the address of the EAS. The first discovery function network element matches the first DNS response message with the second processing rule to determine whether the domain name information of the first DNS response message and the address of the first EAS in the first DNS response message belong to the domain name information and the address of the EAS in the DNS response message detection rule in the second processing rule respectively; if the domain name information of the first DNS response message and the address of the first EAS in the first DNS response message belong to the domain name information and the address of the EAS in the DNS response message detection rule in the second processing rule respectively, then it is determined that the first DNS response message matches the second processing rule; if the domain name information of the first DNS response message does not belong to the domain name information in the DNS response message detection rule in the second processing rule, or the address of the first EAS in the first DNS response message does not belong to the address of the EAS in the DNS response message detection rule in the second processing rule, then it is determined that the first DNS response message does not match the second processing rule.

[0443] In another specific embodiment, the DNS response message detection rule of the second processing rule includes domain name information, and the first discovery function network element matches the first DNS response message with the second processing rule to determine whether the domain name information of the first DNS response message belongs to the domain name information in the DNS response message detection rule in the second processing rule; if the domain name information of the first DNS response message belongs to the domain name information in the DNS response message detection rule in the second processing rule, it is determined that the first DNS response message matches the second processing rule; if the domain name information of the first DNS response message does not belong to the domain name information in the DNS response message detection rule in the second processing rule, it is determined that the first DNS response message does not match the second processing rule.

[0444] If the first DNS response message matches the second processing rule, the first discovery function network element performs the reporting operation and caching operation in the second processing rule on the first DNS response message. Specifically, the first discovery function network element caches the first DNS response message and reports the address of the first EAS and the identifier of the first DNS response message to the target NF network element. In one example, the first discovery function network element reports the address of the first EAS and the identifier of the first DNS response message to the target NF network element based on the first endpoint information in the second processing rule. Optionally, the first discovery function network element also sends the domain name information in the first DNS response message and the ECS option in the first DNS request message to the target NF network element.

[0445] It should be understood that the processing rules of the first discovery function network element also include other processing rules in addition to the second processing rule, such as the fifth processing rule and the sixth processing rule. Since the matching priority of the second processing rule is higher than the matching priority of other processing rules, the first discovery function network element prioritizes matching the first DNS response message with the second processing rule. When the first DNS response message does not match the second processing rule, the first discovery function network element matches the first DNS response message with a processing rule with a higher matching priority among the other processing rules. If the first DNS response message matches a processing rule with a higher matching priority among the other processing rules, the first discovery function network element executes the action in the processing rule on the first DNS response message.

[0446] S521. The target NF network element determines a first diversion point and a first anchor point based on the address of the first EAS.

[0447] Specifically, the target NF network element determines a first diversion point and a first anchor point based on the address of the first EAS and EAS deployment information stored by the target NF network element, and configures a first diversion rule for the first diversion point. The first diversion point and the first anchor point are used to transmit data of the service corresponding to the first domain name information between the first EAS and the UE. The target NF network element notifies the first discovery function network element to send a first DNS response message to the UE.

[0448] The target NF network element notifies the first discovery function network element to send a first DNS response message to the UE. The specific method is: the target NF network element generates a new processing rule based on the first domain name information and the EAS deployment information stored by the target NF network element. The processing rule includes a detection rule and an action of sending a cached first DNS response message to the UE. The target NF network element sends the newly generated processing rule and the identifier of the first DNS response message to the first discovery function network element; the first discovery function network element matches the first DNS response message indicated by the identifier of the first DNS response message based on the newly generated processing rule. If the first DNS response message matches the detection rule of the newly generated processing rule, the first discovery function network element performs the action of sending the cached first DNS response message to the UE, that is, sends the first DNS response message to the UE.

[0449] S522: The first discovery function network element and the target NF network element process the second DNS request message cached by the first discovery function network element.

[0450] The second DNS request message cached by the first discovery function network element is a DNS request message other than the first DNS request message among the DNS request messages cached in the first discovery function network element.

[0451] Specifically, the first discovery function network element matches the second DNS request message with the second processing rule based on the matching priority of the second processing rule. For the matching process, please refer to the relevant description of the matching process of the first DNS request message and the first processing rule, which will not be described here. If a match occurs, the first discovery function network element performs the reporting operation and caching operation in the second processing rule on the second DNS request message. Specifically, the first discovery function network element caches the second DNS request message and reports the domain name information in the second DNS request message to the target NF network element. In one example, the first discovery function network element reports the domain name information of the second DNS request message to the target NF network element based on the first endpoint information in the second processing rule. The target NF network element generates a processing rule for the second DNS request message based on the domain name information of the second DNS request message, the EAS deployment information UE stored in the target NF network element, and the location information of the UE, the processing rule including a detection rule and a forwarding action, the detection rule including the domain name information of the second DNS request message, and the forwarding action including the third information; the target NF network element sends the processing rule for the second DNS request message to the first discovery function network element; the first discovery function network element matches the second DNS request message with the processing rule for the second DNS request message, and if there is a match, the first discovery function network element executes the forwarding action in the processing rule of the second DNS request message on the second DNS request message, that is, generates an ECS option for the second DNS request message based on the third information in the forwarding action, and the ECS option is used to characterize the location of the UE; the ECS option is added to the second DNS request message, and the second DNS request message is sent to the DNS server.

[0452] The DNS server sends a second DNS response message to the first discovery function network element. The second DNS response message is a response to the second DNS request message. The second DNS response message includes the address of the second EAS and the domain name information in the second DNS response message. The domain name information in the second DNS response message is the same as the domain name information in the second DNS request message. The second EAS provides the UE with the service corresponding to the domain name information in the second DNS response message. The first discovery function network element matches the second DNS response message with the second processing rule. For the matching process, please refer to the relevant description of the matching process between the first DNS response message and the second processing rule above and will not be described here. If the second DNS response message matches the second processing rule, the first discovery function network element performs the reporting operation and caching operation in the second processing rule on the second DNS response message. Specifically, the first discovery function network element caches the second DNS response message and reports the address of the second EAS and the identifier of the second DNS response message to the target NF network element. In one example, the first discovery function network element reports the address of the second EAS and the domain name information of the second DNS response message to the target NF network element based on the first endpoint information in the second processing rule. Optionally, the first discovery function network element further sends the domain name information in the second DNS response message and the ECS option in the second DNS request message to the target NF network element.

[0453] The target NF network element determines, based on the address of the second EAS, whether the first anchor point and the first diversion point can be used to transmit data of the service corresponding to the domain name information in the second DNS request message between the second EAS and the UE; if the first anchor point and the first diversion point can be used to transmit data of the service corresponding to the domain name information in the second DNS request message between the second EAS and the UE, the target NF network element notifies the first discovery function network element to send a second DNS response message to the UE. The specific process can be found in the above-mentioned description of the target NF network element notifying the first discovery function network element to send the first DNS response message to the UE, which will not be described again here. The first discovery function network element sends a second DNS response message to the UE.

[0454] If the first anchor point and the first diversion point cannot be used to transmit data of the service corresponding to the domain name information of the second DNS request message between the second EAS and the UE, the target NF network element determines a second diversion point and a second anchor point based on the address of the second EAS and the EAS deployment information stored by the target NF network element, and configures a second diversion rule for the second diversion point. The second diversion point and the second anchor point are used to transmit data of the service corresponding to the domain name information of the second DNS request message between the second EAS and the UE. The target NF network element notifies the first discovery function network element to send a second DNS response message to the UE.

[0455] The target NF network element will inform the access network device through the AMF network element to send the DNS request message from the UE directly to the second diversion point. The second diversion point will forward the received DNS request message to the second anchor point based on the second diversion rule. At the same time, the target NF network element will inform the second anchor point to forward the DNS request message from the second diversion point to the first discovery function network element. The target NF network element notifies the first discovery function network element to send a second DNS response message to the UE. The specific process can be found in the above description of the target NF network element notifying the first discovery function network element to send the first DNS response message to the UE, which will not be described here.

[0456] It should be understood that the processing rules of the first discovery function network element also include other processing rules in addition to the second processing rule, such as the fifth processing rule and the sixth processing rule. Since the matching priority of the second processing rule is higher than the matching priority of other processing rules, the first discovery function network element gives priority to matching the second DNS request message or the second DNS response message with the second processing rule. When the second DNS request message or the second DNS response message does not match the second processing rule, the first discovery function network element will then match the second DNS request message or the second DNS response message with the processing rule with a higher matching priority among the other processing rules.

[0457] S523. The first discovery function network element and the target NF network element process the second DNS request message from the UE.

[0458] It should be noted here that the second DNS request message from the UE is the DNS request message received from the UE after the first discovery function network element generates the processing rule of the first discovery function network element.

[0459] Specifically, the first discovery function network element matches the second DNS request message with the second processing rule; if the second DNS request message matches the second processing rule, the first discovery function network element and the target NF network element process the second DNS request message from the UE according to the specific description of S522, which will not be described here. If the second DNS request message does not match the second processing rule, the first discovery function network element processes the second DNS request message from the UE based on other processing rules in the processing rules of the first discovery function network element.

[0460] It can be seen that in the solution of this embodiment, since the first processing rule and the second processing rule are generated by the target NF network element based on its stored EAS deployment information, rather than by the SMF network element, the SMF network element does not need to store all of the EAS deployment information stored by the target NF network element, thereby reducing the EAS deployment information stored by the SMF network element, which is conducive to reducing the load on the SMF network element. In addition, when the first discovery function network element subsequently processes the first DNS response message, the second DNS request message, and the second DNS response message, it interacts with the target NF network element, rather than the SMF network element, which reduces the workload of the SMF network element and further reduces the load on the SMF network element.

[0461] Referring to FIG6 , FIG6 is a schematic diagram of an interactive flow of a communication method provided in an embodiment of the present application. The method is applied to the communication system shown in FIG1b . As shown in FIG6 , the method includes:

[0462] S601. The AF network element sends the first deployment information and the second deployment information to the SMF network element, and sends the EAS deployment information of each NF network element to each NF network element.

[0463] S602. The UE establishes a target PDU session with the SMF network element.

[0464] S603. The SMF network element determines the second discovery function network element.

[0465] S604. The SMF network element generates a fifth processing rule and a sixth processing rule based on the first deployment information and the second deployment information respectively.

[0466] S605. The SMF network element sends the fifth processing rule and the sixth processing rule to the second discovery function network element.

[0467] S606. The second discovery function network element receives a DNS request message from the UE.

[0468] S607: The second discovery function network element matches the received DNS request message based on the fifth processing rule and the sixth processing rule.

[0469] S608. The second discovery function network element sends the first domain name information in the first DNS request message and the identifier in the first DNS request message to the SMF network element.

[0470] S609. The SMF network element determines the target DNAI based on the first domain name information.

[0471] S610. The SMF network element performs subsequent operations based on the target DNAI.

[0472] S611. The SMF network element sends the target DNAI to the AMF network element.

[0473] S612. The AMF network element sends the address of the target NF network element to the SMF network element.

[0474] S613. The SMF network element sends the first domain name information to the target NF network element based on the address of the target NF network element.

[0475] It should be noted that for the specific description of S601-S613, reference can be made to the relevant description of S501-S513, which will not be described again here.

[0476] S614: The target NF generates a first processing rule, a third processing rule, and a fourth processing rule.

[0477] The first processing rule is a processing rule for the first DNS request message, the third processing rule is a processing rule for the first DNS response message, and the fourth processing rule is a processing rule for the second DNS request message and the second DNS response message. The second DNS request message includes the DNS request message other than the first DNS request message in the DNS request message cached in the second discovery function network element and the DNS request message received by the third discovery function network element from the UE.

[0478] It should be noted here that the description of the first processing rule can refer to the relevant description of the first processing rule in S514, and the description of the fourth processing rule can refer to the relevant description of the second processing rule in S514, which will not be described again here.

[0479] In one example, the target NF network element generates a third processing rule based on the first domain name information and the EAS deployment information stored by the target NF network element. In another example, the target NF network element generates a second processing rule for the second DNS message based on the UE address and the EAS deployment information stored by the target NF network element. The actions in the third processing rule include reporting actions and caching actions, and the detection rules of the third processing rule include the first domain name information. Optionally, the detection rules of the third processing rule also include the address of the EAS in the second DN, where the second DN is the DN connected to the UPF network element controlled by the target NF network element. Optionally, the third processing rule also includes second endpoint information, and the second endpoint information is used to indicate the target NF network element.

[0480] S615. The target NF network element determines the address of the third discovery function network element.

[0481] It should be pointed out here that the execution order of S614 and S615 can be S614 executed first and then S615, or S615 executed first and then S613, or S614 and S615 executed at the same time, which is not limited here.

[0482] S616. The target NF network element sends the fourth processing rule to the third discovery function network element.

[0483] Specifically, the target NF network element sends the fourth processing rule to the third discovery function network element based on the address of the third discovery function network element.

[0484] S617: The target NF network element sends the first processing rule and the third processing rule to the second discovery function network element.

[0485] In one implementation, the target NF network element sends the first processing rule and the third processing rule to the second discovery function network element through the SMF network element. In another implementation, when executing S613, the SMF network element sends the address of the second discovery function network element to the target NF network element, and the target NF network element sends the first processing rule and the third processing rule to the second discovery function network element based on the address of the second discovery function network element.

[0486] Optionally, the target NF network element further sends an identifier of the first EASDF context to the second discovery function network element. Optionally, the SMF network element sends an address of the UE to the second discovery function network element.

[0487] It should be pointed out that when the SMF network element only receives the UE address, the SMF network element sends the first EASDF context identifier to the first discovery function network element based on the UE address and the UE address stored in the SMF network element and the identifier of the first EASDF context.

[0488] Optionally, the SMF network element generates a third identifier for the first processing rule and the third processing rule to identify that the first processing rule and the third processing rule are processing rules for the first DNS request message and the first DNS response message. The SMF network element sends the third identifier of the first processing rule and the third processing rule to the second discovery function network element.

[0489] S618. The second discovery function network element generates a processing rule of the second discovery function network element based on the first processing rule and the third processing rule.

[0490] In one possible implementation, the second discovery function network element adds the first processing rule and the second processing rule to the first EASDF context based on the identifier of the first EASDF context to obtain an updated first EASDF context. The processing rules of the second discovery function network element include the processing rules in the updated first EASDF context, and the processing rules in the updated first EASDF context include the first processing rule, the third processing rule, the fifth processing rule, and the sixth processing rule.

[0491] In another possible implementation, the second discovery function network element replaces the sixth processing rule in the first EASDF context with the first processing rule and the third processing rule based on the first identifiers of the first processing rule and the third processing rule to obtain an updated first EASDF context. The processing rules of the second discovery function network element include the processing rules in the updated first EASDF context, and the processing rules in the updated first EASDF context include the first processing rule, the third processing rule, and the fifth processing rule.

[0492] It should be pointed out that when the first discovery function network element receives the address of the UE but does not receive the identifier of the first EASDF context, since the first EASDF context is generated based on the UE address, the fifth processing rule and the sixth processing rule, the first discovery function network element knows the relationship between the UE address and the first EASDF context. Therefore, the first discovery function network element can update the processing rules in the first EASDF context based on the UE address, that is, the first discovery function network element adds the first processing rule and the third processing rule to the first EASDF context based on the UE address, or replaces the sixth processing rule in the first EASDF context with the first processing rule and the third processing rule based on the UE address.

[0493] In another possible implementation, the second discovery function network element receives the UE address from the SMF network element. The second discovery function network element generates a second EASDF context and an identifier for the second EASDF context based on the UE address, the first processing rule, and the third processing rule. It should be noted that, by generating the second EASDF context based on the UE address, the first processing rule, and the third processing rule, the second discovery function network element knows that the processing rules in the second EASDF context are associated with the UE, that is, associated with the target PDU session. The processing rules of the second discovery function network element include the processing rules in the first EASDF context and the processing rules in the second EASDF context. In this case, the processing rules of the second discovery function network element include the first processing rule, the third processing rule, the fifth processing rule, and the sixth processing rule. The second EASDF context includes sixth endpoint information, which is used to indicate the target NF network element. During subsequent processing, if the DNS message matches the processing rules in the second EASDF context, the second discovery function network element reports the relevant information in the DNS message to the target NF network element based on the sixth endpoint information. It should be noted that, at this time, the third processing rule does not need to include the first endpoint information.

[0494] It should be noted that S616-S617 are executed after S614 and S615. The execution order of S616 and S617-S618 can be S616 first and then S617-S618, S617-S618 first and then S616, or S616 and S617-S618 can be executed simultaneously, without limitation.

[0495] S619: The second discovery function network element and the target NF network element process the first DNS request message and the first DNS response message.

[0496] The second discovery function network element matches the first DNS request message with the first processing rule, specifically in the following manner: the second discovery function network element matches the UE address and domain name information included in the first DNS request message with the UE address and domain name information in the first processing rule. If the UE address in the first DNS request message is the UE address in the first processing rule, and the domain name information in the first DNS request message belongs to the domain name information in the first processing rule, then the second discovery function network element determines that the first DNS request message matches the first processing rule. The second discovery function network element executes the forwarding action in the first processing rule, that is, it clears the ECS option of the first DNS request message based on the first information of the forwarding action, and then forwards the first DNS request message to the DNS server, or generates the ECS option of the first DNS request message based on the second information in the forwarding action, adds the ECS option to the first DNS request message, and sends the added first DNS request message to the DNS server.

[0497] The DNS server sends a first DNS response message to the second discovery function network element. The first DNS response message includes the address of the first EAS and the first domain name information. The first EAS provides the UE with the service corresponding to the first domain name information. The second discovery function network element matches the first DNS response message with the third processing rule. For the matching process, please refer to the relevant description of the matching process of the first DNS response message and the second processing rule above, which will not be described here. If the first DNS response message matches the second processing rule, the second discovery function network element performs the reporting operation and caching operation in the third processing rule on the first DNS response message. Specifically, the second discovery function network element caches the first DNS response message and reports the address of the first EAS and the identifier of the first DNS response message to the target NF network element. In one example, the second discovery function network element reports the address of the first EAS and the identifier of the first DNS response message to the target NF network element based on the second endpoint information in the third processing rule. Optionally, the second discovery function network element also sends the domain name information of the first DNS response message and the ECS option of the first DNS request message to the target NF network element.

[0498] The target NF determines a first diversion point and a first anchor point based on the address of the first EAS and EAS deployment information stored in the target NF, and configures a first diversion rule for the first diversion point. The first diversion point and the first anchor point are used to transmit data of the service corresponding to the first domain name information between the first EAS and the UE. The target NF notifies the second discovery function element to send a first DNS response message to the UE.

[0499] The target NF network element will inform the access network device through the AMF network element to send the DNS request message from the UE directly to the first diversion point. The first diversion point forwards the DNS request message from the UE to the first anchor point based on the first diversion rule, wherein the first diversion point replaces the destination address in the DNS request message from the UE with the address of the third discovery function network element, so that the DNS request message from the UE can be forwarded to the third discovery function network element. At the same time, the target NF network element informs the first anchor point to forward the DNS request message from the first diversion point to the third discovery function network element. The target NF network element notifies the second discovery function network element to send a first DNS response message to the UE. For the specific process, please refer to the relevant description of S520 and will not be described here.

[0500] It should be pointed out that the above-mentioned first diversion point replaces the destination address in the DNS request message from the UE with the address of the third discovery function network element, so that the DNS request message from the UE can be forwarded to the third discovery function network element. This is a feasible way. In another feasible way, the target NF network element determines a diversion point different from the first diversion point based on the address of the first EAS and the EAS deployment information stored in the target NF network element, and configures a diversion rule on the diversion point. After receiving the DNS request message from the UE, the diversion point replaces the destination address in the DNS request message from the UE with the address of the third discovery function network element based on the configured diversion rule, so that the DNS request message from the UE can be forwarded to the third discovery function network element.

[0501] If the UE address included in the first DNS request message is different from the UE address in the first processing rule, or the domain name information included in the first DNS request message does not belong to the domain name information in the first processing rule, the first discovery function network element determines that the first DNS request message does not match the first processing rule, and the first discovery function network element discards the first DNS request message or does not process the first DNS request message.

[0502] S620. The second discovery function network element sends a second DNS request message to the third discovery function network element.

[0503] The second DNS request message from the second discovery function network element is a DNS request message other than the first DNS request message in the DNS request messages cached in the second discovery function network element.

[0504] Specifically, the second discovery function network element may send the second DNS request message to the third discovery function network element in the following manner:

[0505] Method 1: The second discovery function network element determines whether the second DNS request message is transmitted by the UE through the target PDU session based on the ECS option of the second DNS request message. If it is determined that the second DNS request message is transmitted by the UE through the target PDU session, the second discovery function network element sends the second DNS request message to the third discovery function network element, and the ECS option of the second DNS request message includes the address of the UE.

[0506] Method 2: The second discovery function network element and the third discovery function network element establish a forwarding tunnel between the second discovery function network element and the third discovery function network element, and the forwarding tunnel corresponds to the target PDU session; for the second DNS request message sent by the UE through the target PDU session, the second discovery function network element sends the second DNS request message to the third discovery function network element through the forwarding tunnel.

[0507] Method three: The second discovery function network element determines whether the second DNS request message is transmitted by the UE through the target PDU session based on the source address of the second DNS request message. If it is determined that the second DNS request message is transmitted by the UE through the target PDU session, the second discovery function network element modifies the destination address of the second DNS request message to the address of the third discovery function network element, and forwards the second DNS request message to the third discovery function network element.

[0508] S621. The third discovery function network element and the target NF network element process the second DNS request message from the second discovery function network element.

[0509] After receiving the second DNS request message, the third discovery function network element also processes it in three corresponding ways to the three ways in S620:

[0510] Method 1: The third discovery function network element determines whether the second DNS request message belongs to the target PDU session based on the ECS option of the second DNS request message. If it is determined that the second DNS request message belongs to the target PDU session, the third discovery function network element processes the second DNS request message from the second discovery function network element according to the processing rules corresponding to the target PDU session.

[0511] Method 2: The third discovery function network element determines the target PDU session based on the tunnel that transmits the second DNS request message. If it is determined that the second DNS request message belongs to the target PDU session, the third discovery function network element processes the second DNS request message from the second discovery function network element according to the processing rules corresponding to the target PDU session.

[0512] Method three: The third discovery function network element determines whether the second DNS request message belongs to the target PDU session based on the source address of the second DNS request message. If it is determined that the second DNS request message belongs to the target PDU session, the third discovery function network element processes the second DNS request message from the second discovery function network element according to the processing rules corresponding to the target PDU session.

[0513] It should be noted that the third discovery function network element processes the second DNS request message. Specifically, the third discovery function network element processes the second DNS request message from the second discovery function network element based on the fourth processing rule and the target NF network element. The specific process can be found in the relevant description of S522 and will not be described here. It should be noted that in the process of processing the second DNS request message from the second discovery function network element according to the steps of S522, the second processing rule is replaced by the fourth processing rule, and the first discovery function network element is replaced by the third discovery function network element.

[0514] S622. The third discovery function network element and the target NF network element process the second DNS request message from the UE.

[0515] It should be pointed out here that the second DNS request message from the UE is a DNS request message sent by the UE and forwarded to the third discovery function network element via the first diversion point and the first anchor point. The third discovery function network element processes the second DNS request message from the UE based on the fourth processing rule and the target NF network element. The specific process can be found in the relevant description of S522 and will not be described here. It should be pointed out that in the process of processing the second DNS request message from the UE according to the steps of S522, the second processing rule is replaced by the fourth processing rule, and the first discovery function network element is replaced by the third discovery function network element. Optionally, the DNS server is replaced by a local DNS server. Compared with the DNS server, the local DNS server is closer to the third discovery function network element.

[0516] It can be seen that in the solution of this embodiment, since the first processing rule, the third processing rule, and the fourth processing rule are generated by the target NF network element based on its stored EAS deployment information, rather than by the SMF network element, the SMF network element does not need to store all of the EAS deployment information stored by the target NF network element, thereby reducing the EAS deployment information stored by the SMF network element and facilitating the reduction of the load on the SMF network element. Furthermore, when the second discovery function network element subsequently processes the first DNS response message and the third discovery function network element processes the second DNS request message and the second DNS response message, they interact with the target NF network element rather than the SMF network element, thereby reducing the workload of the SMF network element and further reducing the load on the SMF network element. Introducing two discovery function network elements to process different DNS messages is equivalent to introducing an additional discovery function network element on the basis of the original discovery function network element to share the work of the original discovery function network element, thereby reducing the workload of the original discovery function network element.

[0517] 7, which is a schematic diagram of the structure of a target NF network element provided in an embodiment of the present application. As shown in FIG7, the target NF network element 700 includes:

[0518] The transceiver unit 701 is configured to receive first domain name information in a first DNS request message sent from an SMF network element, where the first DNS request message is a message transmitted between a UE and a first discovery function network element.

[0519] A generating unit 702 is configured to generate a first processing rule for the first DNS request message based on the first domain name information of the first DNS request message and the EAS deployment information stored in the target NF network element; and generate a second processing rule for the second DNS message based on the EAS deployment information stored in the target NF network element, where the second DNS message is a message transmitted between the UE and the first discovery function network element later than the first DNS request message.

[0520] The transceiver unit 701 is also used to send the first processing rule and the second processing rule to the first discovery function network element. The first processing rule and the second processing rule are used to generate the processing rule of the first discovery function network element. The processing rule of the first discovery function network element is used to process the first DNS request message and / or the second DNS message.

[0521] Among them, the second DNS message includes a first DNS response message, a second DNS request message and a second DNS response message. The first DNS response message is a response to the first DNS request message; the second DNS request message is a message transmitted between the UE and the first discovery function network element later than the first DNS request message, and the second DNS response message is a response to the second DNS request message.

[0522] In a possible implementation, the transceiver unit 701 is further configured to receive an address of a first EAS from a first discovery function network element; the first EAS provides the UE with a first service corresponding to the first domain name information in the first DNS request;

[0523] The target NF network element 700 also includes:

[0524] A determining unit 703 is configured to determine a first anchor point and a first branch point based on the first EAS address, where the first anchor point and the first branch point are used to transmit data of a service corresponding to the first domain name information between the first EAS and the UE;

[0525] The notification unit 704 is configured to notify the first discovery function network element to send a first DNS response message to the UE, where the first DNS response message includes the address of the first EAS.

[0526] In one possible implementation, the transceiver unit 701 is further configured to receive an address of a second EAS sent from the first discovery function network element, where the second EAS provides the UE with a second service corresponding to the second domain name information in the second DNS request message, where the second DNS request message is a message transmitted between the UE and the first discovery function network element later than the first DNS request message.

[0527] The notification unit 704 is also used to notify the first discovery function network element to send a second DNS response message to the UE if it is determined based on the address of the second EAS that the first anchor point and the first diversion point can be used to transmit data of the second service corresponding to the second domain name information between the UE and the second EAS, and the second DNS response message includes the address of the second EAS.

[0528] In one possible implementation, the determining unit 703 is further configured to: if it is determined based on the address of the second EAS that the first anchor point and the first branch point cannot be used to transmit data of the second service between the UE and the second EAS, determine a second anchor point and a second branch point based on the address of the second EAS, and the second anchor point and the second branch point are used to transmit data of the second service between the second EAS and the UE;

[0529] The notification unit 704 is further configured to notify the first discovery function network element to send a second DNS response message to the UE.

[0530] In one possible implementation, the second DNS response message matches the second processing rule, the second processing rule includes first endpoint information, the first endpoint information is used to indicate the target NF network element, and the address of the second EAS is sent by the first discovery function network element to the target NF network element based on the first endpoint information.

[0531] In one possible implementation, in terms of sending the first processing rule and the second processing rule to the first discovery function network element, the transceiver unit 701 is specifically configured to:

[0532] The first processing rule and the second processing rule are sent to the first discovery function network element based on the address of the first discovery function network element or through the SMF network element.

[0533] In one possible implementation, the transceiver unit 701 is further configured to send an identifier of the first EASDF context to the first discovery function network element based on the address of the first discovery function network element or through the SMF network element, so as to trigger the first discovery function network element to update the processing rules in the first EASDF context based on the identifier of the first EASDF context, and the processing rules of the first discovery function network element include the processing rules of the updated first EASDF context;

[0534] The first EASDF context before the update includes the fifth processing rule and the sixth processing rule. The fifth processing rule is the processing rule generated by the SMF network element for the third DNS message. The third DNS message is a message whose domain name information belongs to the domain name information in the first deployment information. The sixth processing rule is the processing rule generated by the SMF network element for the fourth DNS message. The fourth DNS message is a message whose domain name information belongs to the domain name information in the second deployment information. The domain name information in the first deployment information includes the domain name information of the services supported by the EAS in the first DN. The first DN is the DN connected to the UPF network element controlled by the SMF network element. The domain name information in the second deployment information includes the domain name information of the services supported by the EAS in the second DN. The second DN is the DN connected to the UPF network element controlled by each NF network element. Each NF network element includes the target NF network element. Each NF network element is an NF network element in the network to which the SMF network element belongs. The updated first EASDF context includes the first processing rule, the second processing rule and the fifth processing rule, or the updated first EASDF context includes the first processing rule, the second processing rule, the fifth processing rule and the sixth processing rule.

[0535] In one possible implementation, the first discovery function network element is an EASDF network element corresponding to the SMF network element.

[0536] In one possible implementation, the first discovery function network element includes a second discovery function network element and a third discovery function network element, the second discovery function network element is an EASDF network element corresponding to the SMF network element, and the thi...

Claims

1. A communication method, characterized in that: The method is applied to a target network function NF network element, and the method includes: Receiving first domain name information in a first domain name system DNS request message from a session management function SMF network element, where the first DNS request message is a message transmitted between a user equipment UE and a first discovery function network element; generating a first processing rule for the first DNS request message based on the first domain name information and the edge application server EAS deployment information stored in the target NF network element; Generating a second processing rule for a second DNS message based on the EAS deployment information stored in the target NF network element; the second DNS message is a message transmitted between the UE and the first discovery function network element later than the first DNS request message; The first processing rule and the second processing rule are sent to the first discovery function network element, where the first processing rule and the second processing rule are used to generate the processing rule of the first discovery function network element, and the processing rule of the first discovery function network element is used by the first discovery function network element to process the first DNS request message and / or the second DNS message.

2. The method according to claim 1, characterized in that The second DNS message includes a first DNS response message, a second DNS request message, and a second DNS response message, wherein the first DNS response message is a response to the first DNS request message; The second DNS request message is a message transmitted between the UE and the first discovery function network element later than the first DNS request message, and the second DNS response message is a response to the second DNS request message.

3. The method according to claim 1 or 2, characterized in that The method further comprises: receiving an address of a first EAS from the first discovery function network element; the first EAS is used to provide the UE with a first service corresponding to the first domain name information; Determining a first anchor point and a first branch point based on the address of the first EAS; the first anchor point and the first branch point are used to transmit data of the first service between the first EAS and the UE; Notify the first discovery function network element to send a first DNS response message to the UE, where the first DNS response message is a response to the first DNS request message; the first DNS response message includes the address of the first EAS.

4. The method according to claim 3, characterized in that The method further comprises: receiving an address of a second EAS sent from the first discovery function network element; the second EAS providing the UE with a second service corresponding to the second domain name information in the second DNS request message; the second DNS request message being a message transmitted between the UE and the first discovery function network element later than the first DNS request message; If it is determined based on the second EAS address that the first anchor point and the first diversion point can be used to transmit data of the second service between the second EAS and the UE, notifying the first discovery function network element to send a second DNS response message to the UE, where the second DNS response message is a response to the second DNS request message; the second DNS response message includes the address of the second EAS; or, If it is determined based on the address of the second EAS that the first anchor point and the first diversion point cannot be used to transmit data of the second service between the second EAS and the UE, a second anchor point and a second diversion point are determined based on the address of the second EAS; the second anchor point and the second diversion point are used to transmit data of the second service between the second EAS and the UE; and the first discovery function network element is notified to send the second DNS response message to the UE.

5. The method according to claim 4, characterized in that The second DNS response message matches the second processing rule, the second processing rule includes first endpoint information, the first endpoint information is used to indicate the target NF network element, and the address of the second EAS is sent by the first discovery function network element to the target NF network element based on the first endpoint information.

6. The method according to any one of claims 1 to 5, characterized in that The sending the first processing rule and the second processing rule to the first discovery function network element includes: Sending the first processing rule and the second processing rule to the first discovery function network element through the SMF network element, or, The first processing rule and the second processing rule are sent to the first discovery function network element based on the address of the first discovery function network element.

7. The method according to claim 6, characterized in that The method further comprises: sending an identifier of a first EASDF context to the first discovery function network element based on the address of the first discovery function network element or through the SMF network element, for triggering the first discovery function network element to update a processing rule in the first EASDF context, where the processing rule of the first discovery function network element includes the processing rule in the updated first EASDF context, The first EASDF context before updating includes a fifth processing rule and a sixth processing rule, the fifth processing rule being a processing rule generated by the SMF network element for a third DNS message, the third DNS message being a message whose domain name information belongs to the domain name information in the first deployment information, the sixth processing rule being a processing rule generated by the SMF network element for a fourth DNS message, the fourth DNS message being a message whose domain name information belongs to the domain name information in the second deployment information, the domain name information in the first deployment information including the domain name information of the service supported by the EAS in the first data network DN; the first DN being the DN connected to the user plane function UPF network element controlled by the SMF network element; the domain name information in the second deployment information including the domain name information of the service supported by the EAS in the second DN, the second DN being the DN connected to the UPF network element controlled by each NF network element; the each NF network element including the target NF network element; the each NF network element being an NF network element in the network to which the SMF network element belongs; The processing rules in the updated first EASDF context include the first processing rule, the second processing rule and the fifth processing rule, or the processing rules in the updated first EASDF context include the first processing rule, the second processing rule, the fifth processing rule and the sixth processing rule.

8. The method according to any one of claims 1 to 7, characterized in that The first discovery function network element is an edge application server discovery function EASDF network element corresponding to the SMF network element.

9. The method according to claim 2, characterized in that The first discovery function network element includes a second discovery function network element and a third discovery function network element, the second discovery function network element is an EASDF network element corresponding to the SMF network element, the third discovery function network element is an EASDF network element corresponding to the target NF network element, the second processing rule includes a third processing rule and a fourth processing rule, and sending the first processing rule and the second processing rule to the first discovery function network element includes: Sending the first processing rule and the third processing rule to the second discovery function network element, where the third processing rule is a processing rule generated by the target NF network element for the first DNS response message based on the first domain name information and the EAS deployment information stored by the target NF network element, and the first processing rule and the third processing rule are used to generate a processing rule of the second discovery function network element, and the processing rule of the second discovery function network element is used to process the first DNS request message and the first DNS response message; The fourth processing rule is sent to the third discovery function network element, where the fourth processing rule is a processing rule generated by the target NF network element for the second DNS request message and the second DNS response message based on the EAS deployment information stored by the target NF network element.

10. The method according to claim 9, characterized in that The method further comprises: Receiving an address of a first edge application server EAS from the second discovery function network element; the first EAS is used to provide the UE with a first service corresponding to the first domain name information; Determining a first anchor point and a first branch point based on the address of the first EAS; the first anchor point and the first branch point are used to transmit data of the first service between the first EAS and the UE; Notify the second discovery function network element to send a first DNS response message to the UE, where the first DNS response message includes the address of the first EAS.

11. The method according to claim 10, characterized in that The method further comprises: receiving an address of a second EAS from the third discovery function network element; the second EAS is used to provide the UE with a second service corresponding to the second domain name information in the second DNS request message; Determining a second anchor point and a second branch point based on the address of the first EAS; the second anchor point and the second branch point are used to transmit data of the second service between the second EAS and the UE; Notify the third discovery function network element to send a second DNS response message to the UE, where the second DNS response message includes the address of the second EAS.

12. The method according to claim 10, characterized in that The first DNS response message matches the third processing rule, the third processing rule includes second endpoint information, the second endpoint information is used to indicate the target NF network element, and the address of the first EAS is sent by the second discovery function network element to the target NF network element based on the second endpoint information.

13. The method according to claim 11, characterized in that The second DNS response message matches the fourth processing rule, the fourth processing rule includes third endpoint information, the third endpoint information is used to indicate the target NF network element, and the address of the second EAS is sent by the third discovery function network element to the target NF network element based on the third endpoint information.

14. The method according to claim 9, characterized in that The sending the first processing rule and the third processing rule to the second discovery function network element includes: Sending the first processing rule and the third processing rule to the second discovery function network element through the SMF network element, or sending the first processing rule and the third processing rule to the second discovery function network element based on the address of the second discovery function network element, The sending the fourth processing rule to the third discovery function network element includes: The fourth processing rule is sent to the third discovery function network element based on the address of the third discovery function network element.

15. The method according to claim 14, characterized in that The method further comprises: Based on the address of the second discovery function network element or through the SMF network element, the identifier of the first EASDF context is sent to the second discovery function network element, which is used to trigger the second discovery function network element to update the processing rules in the first EASDF context, where the processing rules of the second discovery function network element include the processing rules in the updated first EASDF context, The first EASDF context before updating includes a fifth processing rule and a sixth processing rule, the fifth processing rule being a processing rule generated by the SMF network element for a third DNS message, the third DNS message being a message whose domain name information belongs to the domain name information in the first deployment information, the sixth processing rule being a processing rule generated by the SMF network element for a fourth DNS message, the fourth DNS message being a message whose domain name information belongs to the domain name information in the second deployment information; the domain name information in the first deployment information includes the domain name information of the services supported by the EAS in the first DN; the first DN is the DN connected to the UPF network element controlled by the SMF network element; the domain name information in the second deployment information includes the domain name information of the services supported by the EAS in the second DN; the second DN is the DN connected to the UPF network element controlled by each NF network element, the each NF network element including the target NF network element; the each NF network element is an NF network element in the network to which the SMF network element belongs; The updated processing rules in the first EASDF context include the first processing rule, the third processing rule and the fifth processing rule, or the updated processing rules in the first EASDF context include the first processing rule, the third processing rule, the fifth processing rule and the sixth processing rule.

16. The method according to any one of claims 1 to 15, characterized in that The target NF network element is determined by the access and mobility management function AMF network element based on the location information of the UE; when the first domain name information does not belong to the domain name information in the EAS deployment information stored by the target NF network element, the forwarding action in the first processing rule includes first information, and the first information is used by the first discovery function network element to set the ECS option of the first DNS request message sent to the DNS server to empty.

17. A communication method, characterized in that: The method is applied to a first discovery function network element, and the method includes: Receiving a first domain name system DNS request message from a user equipment UE; After the first DNS request message, receiving a second DNS message; receiving a first processing rule and a second processing rule from a target network function NF network element, wherein the first processing rule is a processing rule for the first DNS request message, and the second processing rule is a processing rule for the second DNS message; generating a processing rule for the first discovery function network element based on the first processing rule and the second processing rule; The first DNS request message or the second DNS message is processed based on the processing rules of the first discovery function network element.

18. The method according to claim 17, characterized in that The generating the processing rule of the first discovery function network element based on the first processing rule and the second processing rule includes: updating the processing rules in the first edge application server discovery function EASDF context based on the first processing rule and the second processing rule; the processing rules of the first discovery function network element include the updated processing rules in the first EASDF context; Among them, the first EASDF context before the update includes the fifth processing rule and the sixth processing rule, the fifth processing rule is the processing rule generated by the SMF network element for the third DNS message, the third DNS message is a message for which the domain name information belongs to the domain name information in the first deployment information, the sixth processing rule is the processing rule generated by the SMF network element for the fourth DNS message, the fourth DNS message is a message for which the domain name information belongs to the domain name information in the second deployment information, the domain name information in the first deployment information includes the domain name information of the service supported by the EAS in the first data network DN; the first DN is the DN connected to the user plane function UPF network element controlled by the SMF network element; the domain name information in the second deployment information includes the domain name information of the service supported by the EAS in the second DN, and the second DN is the DN connected to the UPF network element controlled by each NF network element; the each NF network element includes the target NF network element; the each NF network element is the NF network element in the network to which the SMF network element belongs; The updated processing rules in the first EASDF context include the first processing rule, the second processing rule and the fifth processing rule, or the updated processing rules in the first EASDF context include the first processing rule, the second processing rule, the fifth processing rule and the sixth processing rule.

19. The method according to claim 17, wherein The method further comprises: Get the identifier of the first EASDF context, Updating the processing rules in the first EASDF context based on the first processing rules and the second processing rules includes: The processing rule in the first EASDF context corresponding to the identifier of the first EASDF context is updated based on the first processing rule and the second processing rule.

20. The method according to claim 17 or 18, characterized in that The method further comprises: Obtain a first identifier and a second identifier, where the first identifier is used to indicate that the first processing rule and the second processing rule are processing rules generated by the target NF network element for the fifth DNS message, and the fifth DNS message is a message whose domain name information belongs to the domain name information in the EAS deployment information stored by the target NF network element. The second identifier is used to indicate that the sixth processing rule is a processing rule generated by the SMF network element for the fourth DNS message; Updating the processing rules in the first EASDF context based on the first processing rules and the second processing rules includes: The sixth processing rule in the first EASDF context is updated to the first processing rule and the second processing rule based on the first identifier and the second identifier.

21. The method according to claim 17, wherein The processing rules of the first discovery function network element include processing rules in the first EASDF context and processing rules in the second EASDF context, Among them, the processing rules in the first EASDF context include the fifth processing rule and the sixth processing rule, and the processing rules in the second EASDF context include the first processing rule and the second processing rule; the fifth processing rule is the processing rule generated by the SMF network element for the third DNS message, and the third DNS message is a message whose domain name information belongs to the domain name information in the first deployment information; the sixth processing rule is the processing rule generated by the SMF network element for the fourth DNS message, and the fourth DNS message is a message whose domain name information belongs to the domain name information in the second deployment information; the domain name information in the first deployment information includes the domain name information of the EAS supported services in the first DN, and the first DN is the DN connected to the UPF network element controlled by the SMF network element; the domain name information in the second deployment information includes the domain name information of the EAS supported services in the second DN; the second DN is the DN connected to the UPF network element controlled by each NF network element; the each NF network element includes the target NF network element; and the each NF network element is the NF network element in the network to which the SMF network element belongs.

22. The method according to any one of claims 18 to 21, characterized in that The method further comprises: receiving the fifth processing rule and the sixth processing rule from the SMF network element, wherein the matching priority of the sixth processing rule is higher than the priority of the fifth processing rule, matching the DNS request message from the UE with the sixth processing rule based on the matching priority of the sixth processing rule; If the DNS request message from the UE does not match the sixth processing rule, matching the DNS request message from the UE with the fifth processing rule based on the matching priority of the fifth processing rule; The first DNS request message is the message in the DNS request message from the UE that matches the fifth processing rule or the sixth processing rule.

23. The method according to any one of claims 17 to 22, characterized in that: The processing of the first DNS request message based on the processing rule of the first discovery function network element includes: Matching the first DNS request message based on the first processing rule; if a match is found, sending the first DNS request message to a DNS server, and receiving a first DNS response message from the DNS server, the first DNS response message being a response to the first DNS request message; the first DNS response message including an address of a first EAS; and the first EAS providing the UE with a first service corresponding to the first domain name information; Matching the first DNS response message with the second processing rule; if a match is found, sending the first EAS address to the target NF network element, where the first EAS address is used by the target NF network element to determine a first anchor point and a first diversion point; the first anchor point and the first diversion point are used to transmit data of the first service between the first EAS and the UE; When it is detected that the target NF network element executes the operation of notifying the first discovery function network element to send the first DNS response message to the UE, the first DNS response message is sent to the UE.

24. The method according to claim 23, wherein The target NF network element is determined by the SMF network element and the access and mobility management function AMF network element based on the location information of the UE; when the first domain name information does not belong to the domain name information in the EAS deployment information stored by the target NF network element, the forwarding action in the first processing rule includes the first information, and the method further includes: The ECS option of the first DNS request message is set to empty based on the first information.

25. The method according to claim 23, characterized in that The second processing rule includes first endpoint information, where the first endpoint information is used to indicate the target NF network element. The address of the first EAS is sent by the first discovery function network element to the target NF network element based on the first endpoint information.

26. A communication method, characterized in that: The method is applied to a second discovery function network element, and the method includes: Receiving a first domain name system DNS request message from a user equipment UE; receiving a first processing rule and a third processing rule from the target NF network element, wherein the first processing rule is a processing rule for the first DNS request message, and the third processing rule is a processing rule for the first DNS response message; the first DNS response message is a response to the first DNS request message; generating a processing rule for the second discovery function network element based on the first processing rule and the third processing rule; The first DNS request message and the first DNS response message are processed based on the processing rules of the second discovery function network element.

27. The method according to claim 26, characterized in that The generating the processing rule of the second discovery function network element based on the first processing rule and the third processing rule includes: Updating the processing rules in the first EASDF context based on the first processing rule and the third processing rule; the processing rules of the second discovery function network element include the updated processing rules in the first EASDF context; Among them, the first EASDF context before the update includes the fifth processing rule and the sixth processing rule, the fifth processing rule is the processing rule generated by the SMF network element for the third DNS message, the third DNS message is a message for which the domain name information belongs to the domain name information in the first deployment information, the sixth processing rule is the processing rule generated by the SMF network element for the fourth DNS message, the fourth DNS message is a message for which the domain name information belongs to the domain name information in the second deployment information, the domain name information in the first deployment information includes the domain name information of the service supported by the EAS in the first data network DN; the first DN is the DN connected to the user plane function UPF network element controlled by the SMF network element; the domain name information in the second deployment information includes the domain name information of the service supported by the EAS in the second DN, and the second DN is the DN connected to the UPF network element controlled by each NF network element; the each NF network element includes the target NF network element; the each NF network element is the NF network element in the network to which the SMF network element belongs; The updated processing rules in the first EASDF context include the first processing rule, the third processing rule and the fifth processing rule, or the updated processing rules in the first EASDF context include the first processing rule, the third processing rule, the fifth processing rule and the sixth processing rule.

28. The method according to claim 27, characterized in that The method further comprises: Get the identifier of the first EASDF context, The updating of the processing rules in the first EASDF context based on the first processing rule and the third processing rule includes: The processing rule in the first EASDF context corresponding to the identifier of the first EASDF context is updated based on the first processing rule and the third processing rule.

29. The method according to claim 27 or 28, characterized in that The method further comprises: Obtain a third identifier and a second identifier, wherein the third identifier is used to indicate that the first processing rule and the third processing rule are processing rules generated by the target NF network element for the first DNS request message and the first DNS response message, respectively, and the second identifier is used to indicate that the sixth processing rule is a processing rule generated by the SMF network element for the fourth DNS message; The updating of the processing rules in the first EASDF context based on the first processing rule and the third processing rule includes: The sixth processing rule in the first EASDF context is updated to the first processing rule and the third processing rule based on the third identifier and the second identifier.

30. The method according to claim 26, wherein The processing rules of the second discovery function network element include the processing rules in the first EASDF context and the processing rules in the second EASDF context. Among them, the processing rules in the first EASDF context include the fifth processing rule and the sixth processing rule, and the processing rules in the first EASDF context include the first processing rule and the third processing rule; the fifth processing rule is the processing rule generated by the SMF network element for the third DNS message, and the third DNS message is a message whose domain name information belongs to the domain name information in the first deployment information; the sixth processing rule is the processing rule generated by the SMF network element for the fourth DNS message, and the fourth DNS message is a message whose domain name information belongs to the domain name information in the second deployment information; the domain name information in the first deployment information includes the domain name information of the EAS supported services in the first DN, and the first DN is the DN connected to the UPF network element controlled by the SMF network element; the domain name information in the second deployment information includes the domain name information of the EAS supported services in the second DN; the second DN is the DN connected to the UPF network element controlled by each NF network element; the each NF network element includes the target NF network element; the each NF network element is the NF network element in the network to which the SMF network element belongs.

31. The method according to any one of claims 27 to 30, characterized in that The method further comprises: receiving the fifth processing rule and the sixth processing rule from the SMF network element, wherein the matching priority of the sixth processing rule is higher than the priority of the fifth processing rule, matching the DNS request message from the UE with the sixth processing rule based on the matching priority of the sixth processing rule; If the DNS request message from the UE does not match the sixth processing rule, matching the DNS request message from the UE with the fifth processing rule based on the matching priority of the fifth processing rule; The first DNS request message is the message in the DNS request message from the UE that matches the fifth processing rule or the sixth processing rule.

32. The method according to any one of claims 26 to 31, characterized in that The processing of the first DNS request message and the first DNS response message based on the processing rule of the second discovery function network element includes: Matching the first DNS request message based on the first processing rule; if a match is found, sending the first DNS request message to a DNS server, and receiving the first DNS response message from the DNS server, where the first DNS response message includes an address of a first edge application server (EAS); and providing the UE with a first service corresponding to the first domain name information. Matching the first DNS response message with the third processing rule; if a match is found, sending the first EAS address to the target NF network element, where the first EAS address is used by the target NF network element to determine a first anchor point and a first diversion point; the first anchor point and the first diversion point are used to transmit data of the first service between the first EAS and the UE; When it is detected that the target NF network element executes the operation of notifying the second discovery function network element to send the first DNS response message to the UE, the first DNS response message is sent to the UE.

33. The method according to claim 32, characterized in that The target NF network element is determined by the SMF network element and the access and mobility management function AMF network element based on the location information of the UE; when the first domain name information does not belong to the domain name information in the EAS deployment information stored by the target NF network element, the forwarding action in the first processing rule includes the first information, and the method further includes: The ECS option of the first DNS request message is set to empty based on the first information.

34. The method according to claim 32 or 33, characterized in that The third processing rule includes second endpoint information, where the second endpoint information is used to indicate the target NF network element. The address of the first EAS is sent by the second discovery function network element to the target NF network element based on the second endpoint information.

35. The method according to claim 31, wherein The method further comprises: Sending a second DNS request message to the third discovery function network element, The second DNS request message is a message from the UE that matches the fifth processing rule or the sixth processing rule, excluding the first DNS request message.

36. A communication method, characterized in that: The method is applied to a third edge application server discovery function EASDF network element, and the method includes: receiving a fourth processing rule from a target network function NF network element, where the fourth processing rule is a processing rule of the target NF network element for the second DNS request message; Receiving a second DNS request message from a second discovery function network element or from a user equipment UE; The second DNS request message is processed based on the fourth processing rule.

37. The method according to claim 36, wherein The second DNS request message includes second domain name information, and the processing of the second DNS request message based on the fourth processing rule includes: If the fourth processing rule matches the second DNS request message, sending the second DNS request message to the DNS server, and receiving a second DNS response message from the DNS server, where the second DNS response message is a response to the second DNS request message; the second DNS response message includes an address of a second EAS; and the second EAS provides the UE with a second service corresponding to the second domain name information; If the second DNS response message matches the fourth processing rule, sending the second EAS address to the target NF network element, where the second EAS address is used to determine a second anchor point and a second branch point, and the second anchor point and the second branch point are used to transmit data of the second service between the second EAS and the UE; When it is detected that the target NF network element executes the operation of notifying the third discovery function network element to send the second DNS response message to the UE, the second DNS response message is sent to the UE.

38. The method according to claim 37, wherein The fourth processing rule includes third endpoint information, where the third endpoint information is used to indicate the target NF network element. The address of the second EAS is sent by the third discovery function network element to the target NF network element based on the third endpoint information.

39. A communication method, characterized in that: The method is applied to a session management function (SMF) network element, and includes: Receiving first domain name information in a first domain name system DNS request message from a first discovery function network element or the second discovery function network element; the first DNS request message is a message transmitted between a user equipment UE and the first discovery function network element or the second discovery function network element; Determine a target DNAI based on the first domain name information, a correspondence between the domain name information and the data network access identifier DNAI, and the location information of the UE, wherein the distance between the data network DN identified by the target DNAI and the UE is less than the distance between the DN identified by other DNAIs corresponding to the first domain name information and the UE; If the target DNAI belongs only to the DNAI in the EAS deployment information stored by each network function NF network element, or the target DNAI belongs to both the DNAI in the EAS deployment information stored by each NF network element and the DNAI in the EAS deployment information stored by the SMF network element, the target DNAI is sent to the access and mobility management function AMF network element, and the target DNAI is used to determine the target NF network element; each NF network element is a NF network element in the network to which the SMF network element belongs; Receiving the address of the target NF network element from the AMF network element; The first domain name information is sent to the target NF network element based on the address of the target NF network element, where the first domain name information is used by the target NF network element to generate a processing rule for the first DNS request message based on the EAS deployment information stored in the target NF network element.

40. The method according to claim 39, wherein The method further comprises: Obtain first deployment information and second deployment information from the application function AF network element; wherein the first deployment information includes the domain name information of the EAS supported service in the first DN and the DNAI corresponding to the first DN; the first DN is the DN connected to the user plane function UPF network element controlled by the SMF network element; the second deployment information includes the domain name information of the EAS supported service in the second DN and the DNAI corresponding to the second DN; the second DN is the DN connected to the user plane function UPF network element controlled by each NF network element; Generating a fifth processing rule and a sixth processing rule based on the first deployment information and the second deployment information, respectively; the fifth processing rule is a processing rule for a third DNS message, wherein the third DNS message is a message whose domain name information belongs to the domain name information in the first deployment information; and the sixth processing rule is a processing rule for a fourth DNS message, wherein the fourth DNS message is a message whose domain name information belongs to the domain name information in the second deployment information; The fifth processing rule and the sixth processing rule are sent to the first discovery function network element or the second discovery function network element, and the fifth processing rule and the sixth processing rule are used to determine the first DNS request message from the DNS request message from the UE, and the first DNS request message is the message in the DNS request message from the UE that matches the fifth processing rule or the sixth processing rule.

41. A communication method, characterized in that: The method is applied to a session management function (SMF) network element, and includes: Receiving first domain name information in a first domain name system DNS request message from a first discovery function network element or a second discovery function network element; the first DNS request message is a message transmitted between a user equipment UE and the first discovery function network element or the second discovery function network element; If the first domain name information belongs to the domain name information of the service supported by the edge application server EAS in the second data network DN, the address of the target network function NF network element is determined from the access and mobility management function AMF network element by the AMF network element based on the location information of the UE; the second DN is the DN connected to the user plane function UPF network element controlled by each network function NF network element; each NF network element is an NF network element in the network to which the SMF network element belongs; The first domain name information is sent to the target NF network element based on the address of the target NF network element, where the first domain name information is used by the target NF network element to generate a processing rule for the first DNS request message based on the EAS deployment information stored by the target NF network element.

42. The method according to claim 41, wherein If the first domain name information belongs to the domain name information of the service supported by the EAS in the second DN, obtaining the address of the target NF network element based on the location information of the UE from the AMF network element, including: If the first domain name information belongs to the domain name information of the service supported by EAS in the second DN, and does not belong to the domain name information of the service supported by EAS in the first DN, then the address of the target NF network element determined by the AMF based on the location information of the UE is obtained from the AMF network element; the first DN is the DN connected to the UPF network element controlled by the SMF network element.

43. The method according to claim 41 or 42, characterized in that The method further comprises: If the first domain name information belongs to the domain name information of the service supported by EAS in the second DN, and belongs to the domain name information of the service supported by EAS in the first DN, the operation of obtaining the address of the target NF network element from the AMF network element will not be performed.

44. The method according to any one of claims 41 to 43, wherein: The method further comprises: Obtain first deployment information and second deployment information from the application function AF network element; the first deployment information includes the domain name information of the EAS supported service in the first DN and the data network access identifier DNAI corresponding to the first DN; the first DN is the DN connected to the user plane function UPF network element controlled by the SMF network element, and the second deployment information includes the domain name information of the EAS supported service in the second DN; Generating a fifth processing rule and a sixth processing rule based on the first deployment information and the second deployment information, respectively; the fifth processing rule is a processing rule for a third DNS message, wherein the third DNS message is a message whose domain name information belongs to the domain name information of the EAS-supported service in the first DN; and the sixth processing rule is a processing rule for a fourth DNS message; wherein the fourth DNS message is a message whose domain name information belongs to the domain name information of the EAS-supported service in the second DN; The fifth processing rule and the sixth processing rule are sent to the first discovery function network element or the second discovery function network element, and the fifth processing rule and the sixth processing rule are used to determine the first DNS request message from the DNS request message from the UE, and the first DNS request message is the message in the DNS request message from the UE that matches the fifth processing rule or the sixth processing rule.

45. A communication method, characterized in that: The method comprises: The session management function SMF network element sends domain name information of a first domain name system DNS request message to the target network function NF network element, where the first DNS request message is a message transmitted between the user equipment UE and the first discovery function network element, wherein the first discovery function network element is the application server discovery function EASDF network element corresponding to the SMF network element; The target NF network element generates a first processing rule for the first DNS request message based on the first domain name information and the EAS deployment information stored by the target NF network element; generates a second processing rule for the second DNS message based on the EAS deployment information stored by the target NF network element; the second DNS message is a message transmitted between the UE and the first discovery function network element later than the first DNS request message; The target NF network element sends the first processing rule and the second processing rule to the first discovery function network element; The first discovery function network element generates a processing rule of the first discovery function network element based on the first processing rule and the second processing rule; and processes the first DNS request message / or the second DNS message based on the processing rule of the first discovery function network element.

46. A communication method, characterized in that: The method comprises: The session function network element SMF network element sends domain name information of a first domain name system DNS request message to the target network function NF network element, where the first DNS request message is a message transmitted between the user equipment UE and the second discovery function network element; wherein the second discovery function network element is the application server discovery function EASDF network element corresponding to the SMF network element; The target NF network element generates a first processing rule for the first DNS request message and a third processing rule for the first DNS response message based on the first domain name information and the edge application server EAS deployment information stored by the target NF network element, where the first DNS response message is a response to the first DNS request message; and generates a fourth processing rule for the second DNS request message and the second DNS response message based on the EAS deployment information stored by the target NF network element; the second DNS request message is a message transmitted between the UE and the second discovery function network element later than the first DNS request message, and the second DNS response message is a response to the second DNS request message; The target NF network element sends the first processing rule and the third processing rule to the second discovery function network element; and sends the fourth processing rule to the third discovery function network element; wherein the third discovery function network element is an EASDF network element corresponding to the target NF network element; The second discovery function network element generates a processing rule of the second discovery function network element based on the first processing rule and the third processing rule; and processes the first DNS request message and the first DNS response message based on the processing rule of the second discovery function network element; The third discovery function network element processes the second DNS request message and the second DNS response message based on the fourth processing rule.

47. A device, characterized in that Comprising a unit or module for implementing the method as described in any one of claims 1 to 16, or a unit or module for implementing the method as described in any one of claims 17 to 25, or a unit or module for implementing the method as described in any one of claims 26 to 35, or a unit or module for implementing the method as described in any one of claims 36 to 38, or a unit or module for implementing the method as described in any one of claims 39 to 40, or a unit or module for implementing the method as described in any one of claims 41 to 44.

48. A device, characterized in that The method comprises at least one processor and a memory, wherein the memory is used to store program code, so that when the at least one processor executes the program code, the method according to any one of claims 1 to 44 is implemented.

49. A communication system, characterized in that The communication system comprises: A target network function NF element for implementing the method according to any one of claims 1 to 16, A discovery function network element for implementing the method according to any one of claims 17 to 38, One or more of the session management function SMF network elements used to implement the method as described in any one of claims 39-44.

50. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 44 is implemented.

51. A computer program product, characterized in that When the computer program product is executed by a processor, the method according to any one of claims 1 to 44 is implemented.

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