Communication method and device

Abstract

A communication method and device, in the communication method, a first network element receives first information and a first service identifier from an application function network element, the first information being used for instructing a server to re-discover. And the first network element sends the first service identifier to the second network element. And the first network element receives the domain name or the address corresponding to the first service identifier from the second network element. And the first network element sends a first message to the terminal device, the first message comprising a domain name or an address corresponding to the first service identifier, and the first message being used for instructing the terminal device to clear server information corresponding to the domain name or the address corresponding to the first service identifier. According to the method, the terminal equipment can clear the server information corresponding to the domain name or the address corresponding to the first service identifier, so that the terminal equipment can acquire a new application server, the new application server provides services for the terminal equipment, and the service quality of the terminal equipment is improved.

Description

Technical Field

[0001] This application relates to the field of communication technologies, and in particular, to a communication method and apparatus. Background Art

[0002] With the growth of mobile service traffic, the industry has proposed the concept of edge computing (EC). By moving the user plane function and service processing capabilities to the network edge, EC can make devices with user plane function and service processing capabilities closer to the terminal device, thereby shortening the distance of the backhaul network and reducing the end-to-end (E2E) delay and jitter of user packets.

[0003] In the edge computing scenario, through the edge application server (EAS) discovery process, the terminal device can obtain the address of the EAS close to the terminal device, so that the terminal device can access the EAS close to the terminal device. When the EAS accessed by the terminal device is overloaded, the quality of service provided by the EAS to the terminal device deteriorates. Summary of the Invention

[0004] Embodiments of this application provide a communication method and apparatus, which are beneficial to improving the quality of service of terminal devices.

[0005] In a first aspect, this application provides a communication method. This method can be applied to a first network element, or to a chip in the first network element, or to a logical module or software that can implement all or part of the functions of the first network element. The following describes it taking the first network element as an example. The method includes: The first network element receives first information from an application function network element and a first service identifier. The first information is used to indicate server rediscovery. The first network element sends the first service identifier to a second network element. The first network element receives a domain name or address corresponding to the first service identifier from the second network element. The first network element sends a first message to the terminal device. The first message includes the domain name or address corresponding to the first service identifier, and the first message is used to instruct the terminal device to clear the server information corresponding to the domain name or address corresponding to the first service identifier.

[0006] It can be seen that in this method, the first network element obtains the domain name or address corresponding to the first service identifier from the second network element, so that the first network element sends a first message to the terminal device, causing the terminal device to clear the server information corresponding to the domain name or address corresponding to the first service identifier, so that the terminal device can obtain the address of a new server, and then the new server provides services to the terminal device to improve the quality of service of the terminal device.

[0007] In an alternative embodiment, the server is an edge application server. The first information is specifically used to indicate the rediscovery of the edge application server, and the first message is specifically used to instruct the terminal device to clear the edge application server information corresponding to the domain name or address of the first service identifier.

[0008] In an alternative manner, the domain name corresponding to the first service identifier is: the domain name of the edge application server corresponding to the first service identifier. The address corresponding to the first service identifier is: the address of the edge application server corresponding to the first service identifier.

[0009] In an alternative embodiment, the first network element sends the first service identifier to the second network element, including: the first network element sends the first service identifier to the second network element when the first condition is met; the first condition includes: the server deployment information of the first network element does not include the domain name and address corresponding to the first service identifier.

[0010] In an alternative embodiment, the method further includes: the first network element receives the data network access identifier corresponding to the first information from the application function network element. The first network element sends the first service identifier to the second network element, including: the first network element sends the first service identifier to the second network element when the second condition is met; the second condition includes: the server deployment information of the first network element does not include the data network access identifier.

[0011] In an alternative embodiment, the first network element belongs to the home public land mobile network of the terminal device, and the second network element belongs to the visited public land mobile network of the terminal device. The first network element sends the first service identifier to the second network element, including: the first network element sends the first service identifier to the second network element when the third condition is met; the third condition includes: the first network element does not store the server deployment information of the visited public land mobile network.

[0012] In an alternative embodiment, the method further includes: the first network element receives the third information from the second network element, where the third information is used to indicate the data network access identifier supported by the second network element; the first network element receives the data network access identifier corresponding to the first information from the application function network element. The first network element sends the first service identifier to the second network element, including: the first network element sends the first service identifier to the second network element when the fourth condition is met; the fourth condition includes: the data network access identifier corresponding to the first information is the data network access identifier supported by the second network element.

[0013] In an alternative embodiment, the method further includes: the first network element sends the fourth information to the second network element, where the fourth information is used to request the domain name or address corresponding to the first service identifier.

[0014] In an alternative embodiment, the first network element is a home domain session management function network element, and the second network element is a visited domain session management function network element. Alternatively, the first network element is a session management function network element, and the second network element is an intermediate session management function network element. Alternatively, the first network element is a session management function network element, and the second network element is used to assist the session management function network element in processing server-related information.

[0015] In an alternative embodiment, the first network element and the second network element serve the terminal device. Additionally, the first network element and the second network element serving the terminal device can also be understood as: the sessions of the first network element and the second network element serving the terminal device.

[0016] In an alternative manner, when the domain name or address corresponding to the first service identifier received by the first network element from the second network element is empty, or when the first network element receives information from the second network element indicating that the domain name or address corresponding to the first service identifier cannot be obtained, the first message sent by the first network element to the terminal device is used to instruct the terminal device to clear the server information related to the first session, where the first session is used by the terminal device to access the service corresponding to the first service identifier. And in this case, the domain name or address corresponding to the first service identifier sent by the first network element to the terminal device is empty, or the first network element does not send the domain name or address corresponding to the first service identifier to the terminal device.

[0017] In an alternative manner, the first network element receiving the first information and the first service identifier from the application function network element can be: the first network element receives the first information and the first service identifier from the application function network element through the forwarding of an intermediate network element. Exemplarily, the intermediate network element can directly forward the first information and the first service identifier from the application function network element to the first network element. Or, the intermediate network element generates a new message based on the first information and the first service identifier received from the application function network element, and sends the message to the first network element. Optionally, the intermediate network element can also modify the form of the first information and / or the first service identifier, and what the intermediate network element sends to the first network element can be the modified first information and / or the modified first service identifier.

[0018] In an alternative manner, the intermediate network element may be a Policy Control Function (PCF) network element. The Policy Control Function network element receives the first information and the first service identifier from the Application Function network element, and creates a Policy and Charging Control rule (PCC rule) based on the received first information and the first service identifier. The Policy Control Function network element sends the Policy and Charging Control rule to the first network element. The Policy and Charging Control rule includes the ninth information and the first service identifier. The ninth information is determined based on the first information. The ninth information may be the same as or different from the first information, but both the ninth information and the first information are used to indicate server rediscovery.

[0019] In an alternative manner, the intermediate network element may be a Policy Control Function network element and a Network Exposure Function (NEF) network element. Exemplarily, the Policy Control Function network element may directly receive the first information and the first service identifier from the Application Function network element, or indirectly receive the first information and the first service identifier from the Application Function network element through the Network Exposure Function network element.

[0020] Optionally, the Policy Control Function network element and the Network Exposure Function network element may also forward data through a Unified Data Repository (UDR). Exemplarily, the Network Exposure Function network element stores the first information and the first service identifier received from the Application Function network element in the Unified Data Repository, and the Policy Control Function network element obtains the first information and the first service identifier from the Unified Data Repository.

[0021] In an alternative manner, the first information may be "Indication for EAS relocation", and the first service identifier may be one or more "Application Identifiers (APPIDs)". The ninth information may be the same as the first information. Alternatively, the ninth information may be different from the first information, and the ninth information may be "EAS Rediscovery Indication (or, Indication of EAS rediscovery)". The first service identifier may be part of the "Service Dataflow Template" in the PCC rule.

[0022] In an alternative manner, the first message includes second information, where the second information is used to instruct the terminal device to clear the server information corresponding to the domain name or address of the first service identifier. For example, the second information may be "EAS rediscovery indication", and the domain name or address corresponding to the first service identifier may be sent to the terminal device as an impact field.

[0023] In an alternative manner, instructing the terminal device to clear the server information corresponding to the domain name or address of the first service identifier may be: instructing the terminal device to clear the cached server information, and the domain name or address corresponding to the first service identifier is used to indicate the server information to be cleared. Additionally, "clear" may be replaced with "delete", "refresh", etc.

[0024] In a second aspect, the present application provides a communication method. This method can be applied to a second network element, or to a chip in the second network element, or to a logical module or software that can implement all or part of the functions of the second network element. Hereinafter, the second network element will be taken as an example for description. The method includes: The second network element receives a first service identifier from the first network element. The second network element sends the domain name or address corresponding to the first service identifier to the first network element based on the stored server deployment information.

[0025] It can be seen that in this method, the second network element provides the domain name or address corresponding to the first service identifier for the first network element, enabling the first network element to instruct the terminal device to clear the server information corresponding to the domain name or address of the first service identifier, so that the terminal device clears the server information corresponding to the domain name or address of the first service identifier, in order for the terminal device to obtain the address of a new server, and then the new server provides services for the terminal device to improve the service quality of the terminal device.

[0026] In an alternative embodiment, the server is an edge application server.

[0027] In an alternative manner, the method further includes: The second network element determines the domain name or address corresponding to the first service identifier based on the stored server deployment information.

[0028] In an alternative manner, the domain name corresponding to the first service identifier is: the domain name of the server corresponding to the first service identifier. The address corresponding to the first service identifier is: the address of the server corresponding to the first service identifier.

[0029] In an alternative embodiment, the method further includes: The second network element receives fourth information from the first network element, where the fourth information is used to request the domain name or address corresponding to the first service identifier.

[0030] In an alternative embodiment, the first network element is a home domain session management function network element, and the second network element is a visited domain session management function network element. Alternatively, the first network element is a session management function network element, and the second network element is an intermediate session management function network element. Alternatively, the first network element is a session management function network element, and the second network element is used to assist the session management function network element in processing server-related information.

[0031] In an alternative embodiment, the first network element and the second network element serve a terminal device. Additionally, the first network element and the second network element serving the terminal device can also be understood as: the sessions of the first network element and the second network element serving the terminal device.

[0032] In a third aspect, the present application provides a communication method. This method can be applied to the first network element, or to a chip in the first network element, or to a logic module or software that can implement all or part of the functions of the first network element. The following describes it taking the first network element as an example. The method includes: The first network element receives fifth information from the second network element. The fifth information is used to indicate the correspondence between the first service identifier and the domain name, or the fifth information is used to indicate the correspondence between the first service identifier and the address. The first network element receives first information and the first service identifier from the application function network element. The first information is used to indicate the rediscovery of the edge application server. The first network element, based on the fifth information and the first service identifier, sends a first message to the terminal device. The first message includes the domain name or address corresponding to the first service identifier, and the first message is used to instruct the terminal device to clear the server information corresponding to the domain name or address corresponding to the first service identifier.

[0033] It can be seen that through this method, the first network element sends a first message to the terminal device, enabling the terminal device to clear the server information corresponding to the domain name or address corresponding to the first service identifier, so that the terminal device can obtain the address of a new server, and then the new server provides services for the terminal device to improve the service quality of the terminal device.

[0034] In an alternative embodiment, the server is an edge application server. The first information is specifically used to indicate the rediscovery of the edge application server, and the first message is specifically used to instruct the terminal device to clear the edge application server information corresponding to the domain name or address corresponding to the first service identifier. In an alternative manner, the domain name corresponding to the first service identifier is: the domain name of the server corresponding to the first service identifier. The address corresponding to the first service identifier is: the address of the server corresponding to the first service identifier.

[0035] In an alternative embodiment, the first network element sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier, including: when a first condition is satisfied, the first network element sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier; the first condition includes: the server deployment information of the first network element does not include the domain name and address corresponding to the first service identifier.

[0036] In an alternative embodiment, the method further includes: the first network element receives the data network access identifier corresponding to the first information from the application function network element. The first network element sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier, including: when a second condition is satisfied, the first network element sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier; the second condition includes: the server deployment information of the first network element does not include the data network access identifier.

[0037] In an alternative embodiment, the first network element belongs to the home public land mobile network of the terminal device, and the second network element belongs to the visited public land mobile network of the terminal device. The first network element sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier, including: when a third condition is satisfied, the first network element sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier; the third condition includes: the first network element does not store the server deployment information of the visited public land mobile network.

[0038] In an alternative embodiment, the method further includes: the first network element receives the third information from the second network element, where the third information is used to indicate the data network access identifier supported by the second network element; the first network element receives the data network access identifier corresponding to the first information from the application function network element. The first network element sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier, including: when a fourth condition is satisfied, the first network element sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier; the fourth condition includes: the data network access identifier corresponding to the first information is the data network access identifier supported by the second network element.

[0039] In an alternative embodiment, the first network element is a home domain session management function network element, and the second network element is a visited domain session management function network element. Alternatively, the first network element is a session management function network element, and the second network element is an intermediate session management function network element. Alternatively, the first network element is a session management function network element, and the second network element is used to assist the session management function network element in processing server-related information.

[0040] In an alternative embodiment, the first network element and the second network element serve a terminal device. Additionally, the first network element and the second network element serving the terminal device can also be understood as: the sessions of the first network element and the second network element serving the terminal device.

[0041] In an alternative manner, the first network element receives a first piece of information and a first service identifier from an application function network element. For the alternative manners of "the first network element receives a first piece of information and a first service identifier from an application function network element" in the first aspect, reference can also be made to the description. For example, the first network element receives the first piece of information and the first service identifier from the application function network element through the forwarding of an intermediate network element. Additionally, for the alternative manners of the intermediate network element, the first piece of information, the first service identifier, the first message, etc., reference can also be made to the description in the first aspect, which will not be elaborated here.

[0042] In a fourth aspect, the present application provides a communication method. This method can be applied to the second network element, or to a chip in the second network element, or to a logic module or software that can implement all or part of the functions of the second network element. The following describes it taking the second network element as an example. The method includes: the second network element receives a domain name or an address from an edge application server discovery function network element. The second network element sends a fifth piece of information to the first network element based on the domain name or the address. The fifth piece of information is used to indicate the correspondence between the first service identifier and the domain name, or the fifth piece of information is used to indicate the correspondence between the first service identifier and the address.

[0043] It can be seen that in this method, the second network element provides the fifth piece of information to the first network element so that the first network element can instruct the terminal device to clear the server information corresponding to the domain name or the address corresponding to the first service identifier, enabling the terminal device to clear the server information corresponding to the domain name or the address corresponding to the first service identifier, so that the terminal device can obtain the address of a new server, and then the new server can provide services to the terminal device to improve the service quality of the terminal device. In an alternative embodiment, the server is an edge application server.

[0044] In an alternative manner, the second network element sending the fifth piece of information to the first network element based on the domain name or the address includes: the second network element sends the fifth piece of information to the first network element based on the domain name or the address and the stored server deployment information.

[0045] In an alternative manner, the method further includes: a second network element determines a first service identifier corresponding to a domain name or an address based on stored server deployment information.

[0046] In an alternative manner, the domain name corresponding to the first service identifier is: the domain name of the server corresponding to the first service identifier. The address corresponding to the first service identifier is: the address of the server corresponding to the first service identifier.

[0047] In an alternative embodiment, the second network element sends fifth information to the first network element based on the domain name or the address, including: the second network element sends the fifth information to the first network element based on the domain name or the address when a fifth condition is satisfied; the fifth condition includes: the second network element has stored the identifier of the access and mobility management function network element.

[0048] In an alternative embodiment, the second network element sends fifth information to the first network element based on the domain name or the address, including: the second network element sends the fifth information to the first network element based on the domain name or the address when a sixth condition is satisfied; the sixth condition includes: the second network element has not sent the correspondence between the first service identifier and the domain name to the first network element, and the second network element has not sent the correspondence between the first service identifier and the address to the first network element.

[0049] In an alternative embodiment, the first network element is a home domain session management function network element, and the second network element is a visited domain session management function network element. Or, the first network element is a session management function network element, and the second network element is an intermediate session management function network element. Or, the first network element is a session management function network element, and the second network element is used to assist the session management function network element in processing server-related information.

[0050] In an alternative embodiment, the first network element and the second network element serve a terminal device. Additionally, the first network element and the second network element serving the terminal device can also be understood as: the sessions of the first network element and the second network element serving the terminal device.

[0051] In a fifth aspect, the present application provides a communication method. This method can be applied to the first network element, or to a chip in the first network element, or to a logic module or software that can implement all or part of the functions of the first network element. The following describes it taking the first network element as an example. The method includes: the first network element receives first information and a first service identifier from an application function network element, where the first information is used to indicate server rediscovery. The first network element sends sixth information to the application function network element, and the sixth information is used to request the domain name or address corresponding to the first service identifier. The first network element receives the domain name or address corresponding to the first service identifier from the application function network element. The first network element sends a first message to the terminal device, and the first message includes the domain name or address corresponding to the first service identifier. The first message is used to instruct the terminal device to clear the server information corresponding to the domain name or address corresponding to the first service identifier.

[0052] It can be seen that in this method, the first network element obtains the domain name or address corresponding to the first service identifier from the application function network element, so that the first network element sends a first message to the terminal device, causing the terminal device to clear the server information corresponding to the domain name or address of the first service identifier, so that the terminal device can obtain the address of a new server, and then the new server provides services for the terminal device to improve the service quality of the terminal device.

[0053] In an alternative embodiment, the server is an edge application server. The first information is specifically used to indicate edge application server rediscovery, and the first message is specifically used to instruct the terminal device to clear the edge application server information corresponding to the domain name or address of the first service identifier.

[0054] In an alternative manner, the domain name corresponding to the first service identifier is: the domain name of the server corresponding to the first service identifier. The address corresponding to the first service identifier is: the address of the server corresponding to the first service identifier.

[0055] In an alternative embodiment, the first network element sends sixth information to the application function network element, including: the first network element sends the sixth information to the application function network element when a first condition is met; the first condition includes: the server deployment information of the first network element does not include the domain name and address corresponding to the first service identifier.

[0056] In an alternative embodiment, the method further includes: the first network element receives the data network access identifier corresponding to the first information from the application function network element. The first network element sends sixth information to the application function network element, including: the first network element sends the sixth information to the application function network element when a second condition is met; the second condition includes: the server deployment information of the first network element does not include the data network access identifier.

[0057] In an alternative embodiment, the first network element belongs to the home public land mobile network of the terminal device, and the second network element belongs to the visited public land mobile network of the terminal device. The first network element sends sixth information to the application function network element, including: the first network element sends the sixth information to the application function network element when a third condition is met; the third condition includes: the first network element does not store the server deployment information of the visited public land mobile network.

[0058] In an alternative embodiment, the method further includes: a first network element receives third information from a second network element, where the third information is used to indicate a data network access identifier supported by the second network element; the first network element receives the data network access identifier corresponding to the first information from an application function network element. The first network element sends sixth information to the application function network element, including: the first network element sends the sixth information to the application function network element when a fourth condition is satisfied; the fourth condition includes: the data network access identifier corresponding to the first information is the data network access identifier supported by the second network element.

[0059] In an alternative embodiment, the first network element is a home domain session management function network element, and the second network element is a visited domain session management function network element. Alternatively, the first network element is a session management function network element, and the second network element is an intermediate session management function network element. Alternatively, the first network element is a session management function network element, and the second network element is used to assist the session management function network element in processing server-related information.

[0060] In an alternative embodiment, the first network element and the second network element serve a terminal device. Additionally, the first network element and the second network element serving the terminal device can also be understood as: the sessions of the first network element and the second network element serving the terminal device.

[0061] In an alternative manner, the first network element receives the first information and the first service identifier from the application function network element. For the alternative manners of "the first network element receives the first information and the first service identifier from the application function network element" in the first aspect, reference can also be made. For example, the first network element receives the first information and the first service identifier from the application function network element through the forwarding of an intermediate network element. Additionally, for the alternative manners of the intermediate network element, the first information, the first service identifier, the first message, etc., reference can also be made to the descriptions in the first aspect, which will not be elaborated herein.

[0062] In a sixth aspect, the present application provides a communication method, which can be applied to an application function network element, or a chip in the application function network element, or a logic module or software capable of implementing all or part of the functions of the application function network element. The following describes it taking the application function network element as an example. The method includes: the application function network element sends the first information and the first service identifier to the first network element, where the first information is used to indicate the rediscovery of an edge application server. The application function network element receives sixth information from the first network element, where the sixth information is used to request the domain name or address corresponding to the first service identifier. The application function network element sends the domain name or address corresponding to the first service identifier to the first network element.

[0063] It can be seen that in this method, the application function network element sends the domain name or address corresponding to the first service identifier to the first network element, so that the first network element instructs the terminal device to clear the server information corresponding to the domain name or address corresponding to the first service identifier, enabling the terminal device to clear the server information corresponding to the domain name or address corresponding to the first service identifier, so that the terminal device can obtain the address of a new server, and then the new server provides services for the terminal device to improve the service quality of the terminal device.

[0064] In an alternative embodiment, the server is an edge application server. The first information is specifically used to indicate the rediscovery of the edge application server.

[0065] In an alternative manner, the application function network element sending the first information and the first service identifier to the first network element may be: the application function network element sends the first information and the first service identifier to the first network element through an intermediate network element. Exemplarily, the intermediate network element may directly forward the first information and the first service identifier from the application function network element to the first network element. Or, the intermediate network element generates a new message based on the first information and the first service identifier received from the application function network element and sends the message to the first network element. Optionally, the intermediate network element may also modify the form of the first information and / or the first service identifier, and what the intermediate network element sends to the first network element is the modified first information and / or the modified first service identifier.

[0066] In addition, the alternative manners regarding the intermediate network element, the first information, the first service identifier, etc. can also refer to the descriptions in the first aspect and will not be elaborated here.

[0067] In an alternative manner, the application function network element sending the domain name or address corresponding to the first service identifier to the first network element may be: the application function network element sends the domain name or address corresponding to the first service identifier to the first network element through an intermediate network element. Similar to the aforementioned application function network element sending the first information and the first service identifier to the first network element, it will not be elaborated here.

[0068] In an alternative manner, the domain name corresponding to the first service identifier is: the domain name of the edge application server corresponding to the first service identifier. The address corresponding to the first service identifier is: the address of the edge application server corresponding to the first service identifier.

[0069] In a seventh aspect, the present application provides a communication method. This method can be applied to a first network element, or to a chip in the first network element, or to a logic module or software that can implement all or part of the functions of the first network element. The following describes it taking the first network element as an example. The method includes: The first network element receives first information and a first service identifier from an application function network element, where the first information is used to indicate server rediscovery. When the first network element is unable to obtain the domain name or address corresponding to the first service identifier, it sends second information to the terminal device, and the second information is used to instruct the terminal device to clear all server information related to the first session, and the first session is used for the terminal device to access the service corresponding to the first service identifier.

[0070] In an optional implementation manner, the server is an edge application server. The first information is specifically used to indicate edge application server rediscovery, and the second information is specifically used to instruct the terminal device to clear the edge application server information corresponding to the domain name or address of the first service identifier.

[0071] In an optional manner, the situation where the first network element is unable to obtain the domain name or address corresponding to the first service identifier includes:

[0072] The server deployment information of the first network element does not include the domain name and address corresponding to the first service identifier; or,

[0073] The first network element does not store the server deployment information of the visited public land mobile network; or,

[0074] The server deployment information of the first network element does not include a data network access identifier; or,

[0075] The data network access identifier corresponding to the first information is a data network access identifier supported by a second network element; or,

[0076] The first network element is a home domain session management function network element, and the second network element is a visited domain session management function network element; or,

[0077] The first network element is a session management function network element, and the second network element is an intermediate session management function network element; or,

[0078] The first network element is a session management function network element, and the second network element is used to assist the session management function network element in processing server-related information.

[0079] In an alternative manner, the first network element receives the first information and the first service identifier from the application function network element. For the alternative manner of "the first network element receives the first information and the first service identifier from the application function network element" in the first aspect, reference can also be made to the description in the first aspect. For example, the first network element receives the first information and the first service identifier from the application function network element through the forwarding of an intermediate network element. In addition, for the alternative manners of the intermediate network element, the first information, the first service identifier, the second information, etc., reference can also be made to the description in the first aspect and will not be elaborated here.

[0080] In an alternative manner, in the expression of instructing the terminal device to clear all server information related to the first session, "clear" can also be replaced with "delete", "refresh", etc.

[0081] In a eighth aspect, the present application provides a communication method, which includes: the first network element receives the first information and the first service identifier from the application function network element, and the first information is used to indicate server rediscovery. The first network element sends the first service identifier to the second network element; the second network element receives the first service identifier from the first network element. The second network element sends the domain name or address corresponding to the first service identifier to the first network element based on the stored edge application server deployment information; the first network element receives the domain name or address corresponding to the first service identifier from the second network element. The first network element sends a first message to the terminal device, and the first message includes the domain name or address corresponding to the first service identifier, and the first message is used to instruct the terminal device to clear the edge application server information corresponding to the domain name or address corresponding to the first service identifier.

[0082] In addition, in this aspect, other alternative implementation manners included in the method can refer to the relevant content of the above first aspect and second aspect, and also have the beneficial effects described in the first aspect and second aspect, which will not be elaborated here.

[0083] In a ninth aspect, the present application provides a communication method, which includes: the second network element receives the domain name or address from the edge application server discovery function network element. The second network element sends fifth information to the first network element based on the domain name or address, and the fifth information is used to indicate the correspondence between the first service identifier and the domain name, or the fifth information is used to indicate the correspondence between the first service identifier and the address; the first network element receives the fifth information from the second network element. The first network element receives the first information and the first service identifier from the application function network element, and the first information is used to indicate edge application server rediscovery. The first network element sends a first message to the terminal device based on the fifth information and the first service identifier, and the first message includes the domain name or address corresponding to the first service identifier, and the first message is used to instruct the terminal device to clear the edge application server information corresponding to the domain name or address corresponding to the first service identifier.

[0084] In addition, in this aspect, for other optional implementation manners included in this method, reference may be made to the relevant content of the third aspect and the fourth aspect above, and the beneficial effects described in the third aspect and the fourth aspect are also achieved, which will not be elaborated here.

[0085] In a tenth aspect, the present application provides a communication method, which includes: an application function network element sends first information and a first service identifier to a first network element, where the first information is used to indicate re-discovery of an edge application server; the first network element receives the first information and the first service identifier from the application function network element. The first network element sends sixth information to the application function network element, where the sixth information is used to request a domain name or an address corresponding to the first service identifier; the application function network element receives the sixth information from the first network element. The application function network element sends the domain name or the address corresponding to the first service identifier to the first network element; the first network element receives the domain name or the address corresponding to the first service identifier from the application function network element. The first network element sends a first message to a terminal device, where the first message includes the domain name or the address corresponding to the first service identifier, and the first message is used to instruct the terminal device to clear the edge application server information corresponding to the domain name or the address corresponding to the first service identifier.

[0086] In addition, in this aspect, for other optional implementation manners included in this method, reference may be made to the relevant content of the fifth aspect and the sixth aspect above, and the beneficial effects described in the fifth aspect and the sixth aspect are also achieved, which will not be elaborated here.

[0087] In an eleventh aspect, the present application provides a communication system, which includes a first network element and a second network element. In another possible design, the system may further include other devices that interact with the first network element in the solution provided by the present application, and / or other devices that interact with the second network element.

[0088] In an implementation manner, the first network element is configured to receive the first information and the first service identifier from the application function network element, where the first information is used to indicate re-discovery of an edge application server. The first network element is further configured to send the first service identifier to the second network element. The second network element is configured to receive the first service identifier from the first network element. The second network element is further configured to send the domain name or the address corresponding to the first service identifier to the first network element based on the stored edge application server deployment information. The first network element is further configured to receive the domain name or the address corresponding to the first service identifier from the second network element. The first network element is further configured to send a first message to a terminal device, where the first message includes the domain name or the address corresponding to the first service identifier, and the first message is used to instruct the terminal device to clear the edge application server information corresponding to the domain name or the address corresponding to the first service identifier.

[0089] In addition, in this aspect, for other optional implementation manners of the first network element, reference may be made to the relevant content of the first aspect above, and for other optional implementation manners of the second network element, reference may be made to the relevant content of the second aspect above, which will not be elaborated here.

[0090] In another implementation, a second network element is configured to receive a domain name or an address from an edge application server discovery function network element. The second network element is further configured to send a fifth piece of information to a first network element based on the domain name or the address, where the fifth piece of information is used to indicate the correspondence between a first service identifier and the domain name, or the fifth piece of information is used to indicate the correspondence between the first service identifier and the address. The first network element is configured to receive the fifth piece of information from the second network element. The first network element is further configured to receive a first piece of information and a first service identifier from an application function network element, where the first piece of information is used to indicate rediscovery of an edge application server. The first network element is further configured to send a first message to a terminal device based on the fifth piece of information and the first service identifier, where the first message includes the domain name or the address corresponding to the first service identifier, and the first message is used to instruct the terminal device to clear the edge application server information corresponding to the domain name or the address corresponding to the first service identifier.

[0091] In addition, in this aspect, for other optional implementations of the first network element, reference may be made to the relevant content of the third aspect above, and for other optional implementations of the second network element, reference may be made to the relevant content of the fourth aspect above, which will not be elaborated here.

[0092] In a twelfth aspect, the present application provides a communication system, which includes an application function network element and a first network element. In another possible design, the system may further include other devices that interact with the application function network element in the solution provided by the present application, and / or other devices that interact with the first network element.

[0093] Among them, the application function network element is configured to send a first piece of information and a first service identifier to the first network element, where the first piece of information is used to indicate rediscovery of an edge application server. The first network element is configured to receive the first piece of information and the first service identifier from the application function network element. The first network element is further configured to send a sixth piece of information to the application function network element, where the sixth piece of information is used to request the domain name or the address corresponding to the first service identifier. The application function network element is further configured to receive the sixth piece of information from the first network element. The application function network element is further configured to send the domain name or the address corresponding to the first service identifier to the first network element. The first network element is further configured to receive the domain name or the address corresponding to the first service identifier from the application function network element. The first network element is further configured to send a first message to a terminal device, where the first message includes the domain name or the address corresponding to the first service identifier, and the first message is used to instruct the terminal device to clear the edge application server information corresponding to the domain name or the address corresponding to the first service identifier.

[0094] In addition, in this aspect, for other optional implementations of the first network element, reference may be made to the relevant content of the fifth aspect above, which will not be elaborated here.

[0095] In a thirteenth aspect, the present application further provides a communication device. The communication device may be a first network element, or a chip in the first network element, or a logical module or software capable of implementing all or part of the functions of the first network element. The communication device has the functions of implementing some or all of the embodiments described in the first aspect, the third aspect, the fifth aspect, or the seventh aspect above. Alternatively, the communication device may be a second network element, or a chip in the second network element, or a logical module or software capable of implementing all or part of the functions of the second network element. The communication device has the functions of implementing some or all of the embodiments described in the second aspect or the fourth aspect above. Alternatively, the communication device may be an application function network element, or a chip in the application function network element, or a logical module or software capable of implementing all or part of the functions of the application function network element. The communication device has the functions of implementing some or all of the embodiments described in the sixth aspect above. The functions may be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more units or modules corresponding to the above functions.

[0096] In a possible design, the structure of the communication device may include a processing unit, and the processing unit is configured to support the communication device to execute the corresponding functions in the above method. Optionally, the communication device further includes a communication unit, and the communication unit is used to support the communication between the communication device and other communication devices. Optionally, the communication device may further include a storage unit, and the storage unit is used to be coupled with the processing unit and the communication unit, and stores necessary program instructions and data of the communication device. In addition, the processing unit may be used to control the communication unit to perform data / signaling transceiver.

[0097] In one embodiment, the communication unit is configured to receive first information and a first service identifier from an application function network element, where the first information is used to indicate rediscovery of an edge application server. The communication unit is further configured to send the first service identifier to a second network element. The communication unit is further configured to receive a domain name or address corresponding to the first service identifier from the second network element. The communication unit is further configured to send a first message to a terminal device, where the first message includes the domain name or address corresponding to the first service identifier, and the first message is used to instruct the terminal device to clear the edge application server information corresponding to the domain name or address.

[0098] In addition, in this aspect, for other optional embodiments of the communication device, reference may be made to the relevant content of the first aspect above, which will not be elaborated here.

[0099] In another embodiment, the communication unit is configured to receive a first service identifier from a first network element. The communication unit is further configured to send a domain name or address corresponding to the first service identifier to the first network element based on stored edge application server deployment information.

[0100] In addition, in this aspect, for other optional embodiments of the communication device, reference may be made to the relevant content of the second aspect above, which will not be elaborated here.

[0101] In another embodiment, a communication unit is configured to receive fifth information from a second network element, where the fifth information is used to indicate the correspondence between a first service identifier and a domain name, or the fifth information is used to indicate the correspondence between the first service identifier and an address. The communication unit is further configured to receive first information and a first service identifier from an application function network element, where the first information is used to indicate re-discovery of an edge application server. The communication unit is further configured to send a first message to a terminal device based on the fifth information and the first service identifier, where the first message includes the domain name or address corresponding to the first service identifier, and the first message is used to instruct the terminal device to clear the edge application server information corresponding to the domain name or address corresponding to the first service identifier.

[0102] In addition, in this aspect, for other optional embodiments of the communication device, reference may be made to the relevant content of the third aspect above, which will not be elaborated here.

[0103] In another embodiment, a communication unit is configured to receive a domain name or an address from an edge application server discovery function network element. The communication unit is further configured to send fifth information to a first network element based on the domain name or address, where the fifth information is used to indicate the correspondence between a first service identifier and a domain name, or the fifth information is used to indicate the correspondence between the first service identifier and an address.

[0104] In addition, in this aspect, for other optional embodiments of the communication device, reference may be made to the relevant content of the fourth aspect above, which will not be elaborated here.

[0105] In another embodiment, a communication unit is configured to receive first information and a first service identifier from an application function network element, where the first information is used to indicate re-discovery of an edge application server. The communication unit is further configured to send sixth information to the application function network element, where the sixth information is used to request the domain name or address corresponding to the first service identifier. The communication unit is further configured to receive the domain name or address corresponding to the first service identifier from the application function network element. The communication unit is further configured to send a first message to a terminal device, where the first message includes the domain name or address corresponding to the first service identifier, and the first message is used to instruct the terminal device to clear the edge application server information corresponding to the domain name or address corresponding to the first service identifier.

[0106] In addition, in this aspect, for other optional embodiments of the communication device, reference may be made to the relevant content of the fifth aspect above, which will not be elaborated here.

[0107] In another implementation, a communication unit is configured to send a first piece of information and a first service identifier to a first network element. The first piece of information is used to indicate the rediscovery of an edge application server. The communication unit is further configured to receive sixth information from the first network element, where the sixth information is used to request a domain name or an address corresponding to the first service identifier. The communication unit is further configured to send the domain name or the address corresponding to the first service identifier to the first network element.

[0108] In addition, in this aspect, for other optional implementations of the communication device, reference may be made to the relevant content of the sixth aspect above, which will not be elaborated here.

[0109] As an example, the communication unit may be a transceiver or a communication interface, the storage unit may be a memory, and the processing unit may be a processor. The processor is coupled to the memory, and the memory is used to store programs or instructions for the processor. The processor can be used to cause the communication device to execute the method described in the first aspect above when the programs or instructions are executed by the processor. The transceiver or the communication interface can be used to transmit and receive signals and / or data.

[0110] In one implementation, a transceiver is configured to receive a first piece of information and a first service identifier from an application function network element. The first piece of information is used to indicate the rediscovery of an edge application server. The transceiver is further configured to send the first service identifier to a second network element. The transceiver is further configured to receive a domain name or an address corresponding to the first service identifier from the second network element. The transceiver is further configured to send a first message to a terminal device. The first message includes the domain name or the address corresponding to the first service identifier, and the first message is used to instruct the terminal device to clear the edge application server information corresponding to the domain name or the address corresponding to the first service identifier.

[0111] In addition, in this aspect, for other optional implementations of the communication device, reference may be made to the relevant content of the first aspect above, which will not be elaborated here.

[0112] In another implementation, a transceiver is configured to receive a first service identifier from a first network element. The transceiver is further configured to send the domain name or the address corresponding to the first service identifier to the first network element based on the stored edge application server deployment information.

[0113] In addition, in this aspect, for other optional implementations of the communication device, reference may be made to the relevant content of the second aspect above, which will not be elaborated here.

[0114] In another implementation, a transceiver is configured to receive fifth information from a second network element, where the fifth information is used to indicate the correspondence between a first service identifier and a domain name, or the fifth information is used to indicate the correspondence between the first service identifier and an address. The transceiver is further configured to receive first information and a first service identifier from an application function network element, where the first information is used to indicate rediscovery of an edge application server. The transceiver is further configured to send a first message to a terminal device based on the fifth information and the first service identifier, where the first message includes the domain name or address corresponding to the first service identifier, and the first message is used to instruct the terminal device to clear the edge application server information corresponding to the domain name or address corresponding to the first service identifier.

[0115] In addition, in this aspect, other optional implementations of the communication device can refer to the relevant content of the third aspect above, which will not be elaborated here.

[0116] In another implementation, a transceiver is configured to receive a domain name or an address from an edge application server discovery function network element. The transceiver is further configured to send fifth information to a first network element based on the domain name or address, where the fifth information is used to indicate the correspondence between a first service identifier and the domain name, or the fifth information is used to indicate the correspondence between the first service identifier and the address.

[0117] In addition, in this aspect, other optional implementations of the communication device can refer to the relevant content of the fourth aspect above, which will not be elaborated here.

[0118] In another implementation, a transceiver is configured to receive first information and a first service identifier from an application function network element, where the first information is used to indicate rediscovery of an edge application server. The transceiver is further configured to send sixth information to the application function network element, where the sixth information is used to request the domain name or address corresponding to the first service identifier. The transceiver is further configured to receive the domain name or address corresponding to the first service identifier from the application function network element. The transceiver is further configured to send a first message to a terminal device, where the first message includes the domain name or address corresponding to the first service identifier, and the first message is used to instruct the terminal device to clear the edge application server information corresponding to the domain name or address corresponding to the first service identifier.

[0119] In addition, in this aspect, other optional implementations of the communication device can refer to the relevant content of the fifth aspect above, which will not be elaborated here.

[0120] In another implementation, a transceiver is configured to send first information and a first service identifier to a first network element, where the first information is used to indicate rediscovery of an edge application server. The transceiver is further configured to receive sixth information from the first network element, where the sixth information is used to request the domain name or address corresponding to the first service identifier. The transceiver is further configured to send the domain name or address corresponding to the first service identifier to the first network element.

[0121] In addition, in this aspect, for other optional embodiments of the communication device, reference may be made to the relevant content of the sixth aspect above, which will not be elaborated here. In another embodiment, the communication device is a chip or a chip system. The processing unit may also be embodied as a processing circuit or a logic circuit; the transceiver unit may be an input / output interface, an interface circuit, an output circuit, an input circuit, a pin or a related circuit, etc. on the chip or the chip system.

[0122] In the implementation process, the processor can be used for, for example but not limited to, baseband-related processing, and the transceiver or communication interface can be used for, for example but not limited to, radio frequency transceiver. The above-mentioned devices can be respectively arranged on independent chips, or at least partially or entirely arranged on the same chip. For example, the processor can be further divided into an analog baseband processor and a digital baseband processor. Among them, the analog baseband processor can be integrated with the transceiver (or communication interface) on the same chip, and the digital baseband processor can be arranged on an independent chip. With the continuous development of integrated circuit technology, more and more devices can be integrated on the same chip. For example, the digital baseband processor can be integrated with multiple application processors (such as but not limited to a graphics processor, a multimedia processor, etc.) on the same chip. Such a chip can be called a system on a chip (SoC). Whether to arrange the above-mentioned devices independently on different chips or integrate them on one or more chips often depends on the needs of product design. The embodiments of the present application do not limit the implementation forms of the above-mentioned devices.

[0123] In a fourteenth aspect, the present application further provides a processor for executing the above various methods. In the process of executing these methods, the processes of sending the above information and receiving the above information in the above methods can be understood as the process of the processor outputting the above information and the process of the processor inputting the above information. When outputting the above information, the processor outputs the above information to the transceiver so that the transceiver (or communication interface) can transmit it. After the above information is output by the processor, other processing may be required before it reaches the transceiver (or communication interface). Similarly, when the processor receives the input above information, the transceiver (or communication interface) receives the above information and inputs it to the processor. Further, after the transceiver (or communication interface) receives the above information, the above information may need to be processed otherwise before it is input to the processor.

[0124] For operations such as sending and receiving involved in the processor, if there is no special description, or if it does not conflict with its actual role or internal logic in the relevant description, they can generally be understood as operations of the processor outputting, receiving, and inputting, rather than the sending and receiving operations directly performed by the radio frequency circuit and the antenna.

[0125] In the implementation process, the above-mentioned processor can be a processor dedicated to executing these methods, or a processor that executes computer instructions in a memory to execute these methods, such as a general-purpose processor. The above-mentioned memory can be a non-transitory memory, such as a read-only memory (ROM), which can be integrated with the processor on the same chip or separately provided on different chips. The embodiments of the present application do not limit the type of the memory and the setting manner of the memory and the processor.

[0126] In a fifteenth aspect, the present application provides a computer-readable storage medium storing a computer program, and when the computer program is run, the method described in any one of the first aspect to the seventh aspect is executed.

[0127] In a sixteenth aspect, the present application further provides a computer program product including instructions, and the computer program product includes: computer program code, and when the computer program code is run, the method described in any one of the first aspect to the seventh aspect is executed.

[0128] In a seventeenth aspect, the present application provides a chip system including a processor and an interface, where the interface is used to obtain a program or an instruction, and the processor is used to call the program or the instruction to implement the functions involved in any one of the first aspect to the seventh aspect. In a possible design, the chip system further includes a memory for storing necessary program instructions and data of the terminal. The chip system can be composed of chips or include chips and other discrete devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0129] Figure 1 is a schematic diagram of a network architecture;

[0130] Figure 2 is a schematic diagram of another network architecture;

[0131] Figure 3 is a schematic diagram of a communication system provided by an embodiment of the present application;

[0132] Figure 4 is a schematic diagram of another communication system provided by an embodiment of the present application;

[0133] Figure 5 is a schematic diagram of another communication system provided by an embodiment of the present application;

[0134] Figure 6 is a schematic diagram of another communication system provided by an embodiment of the present application;

[0135] Figure 7 It is a schematic diagram of an edge application server discovery process provided by an embodiment of the present application;

[0136] Figure 8 It is a schematic flowchart of a communication method 100 provided by an embodiment of the present application;

[0137] Figure 9 It is a schematic flowchart of a communication method 200 provided by an embodiment of the present application;

[0138] Figure 10 It is a schematic flowchart of a communication method 300 provided by an embodiment of the present application;

[0139] Figure 11 It is a schematic flowchart of a communication method 400 provided by an embodiment of the present application;

[0140] Figure 12 It is a schematic structural diagram of a communication device provided by an embodiment of the present application;

[0141] Figure 13 It is a schematic structural diagram of another communication device provided by an embodiment of the present application. Detailed implementation manners

[0142] The embodiments of the present application will be described below with reference to the accompanying drawings in the embodiments of the present application.

[0143] Before introducing the embodiments of the present application, the following points are first explained.

[0144] First, in the present application, if there is no special explanation and logical conflict, the terms and / or descriptions between different embodiments are consistent and can be mutually referred to, and the technical features in different embodiments can be combined to form new embodiments according to their internal logical relationships.

[0145] It can be understood that some optional features in the embodiments of the present application may not depend on other features in some scenarios, and may also be combined with other features in some scenarios, without limitation.

[0146] It can be understood that the solutions in the embodiments of the present application can be combined and used, and the explanations or descriptions of each term and the similar operations or steps appearing in the embodiments can be mutually referred to or explained in each embodiment, and the present application does not make any limitation thereto.

[0147] Second, in this application, "at least one" means one or more, and "a plurality" means two or more. "And / or" describes the relationship between related objects and indicates that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, or B exists alone, where A and B can be singular or plural. In the written description of this application, the character " / " generally represents an "or" relationship between the related objects before and after. "At least one (item)" or a similar expression refers to any combination of these items, including any combination of a single item or multiple items. For example, at least one (item) of a, b, and c can represent: a, or b, or c, or a and b, or a and c, or b and c, or a, b, and c. Where a, b, and c can be single or multiple respectively.

[0148] Third, in this application, "first", "second", and various numerical numbers are used for distinction for the convenience of description and do not limit the scope of the embodiments of this application. For example, to distinguish different messages, etc., rather than to describe a specific order or sequence. It should be understood that the objects described in this way can be interchanged under appropriate circumstances so as to be able to describe the solutions other than the embodiments of this application.

[0149] Fourth, in this application, the terms "comprise" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or are inherent to these processes, methods, products, or devices.

[0150] Fifth, in this application, "for indicating" can include for direct indication and for indirect indication. When describing that a certain indication information is used to indicate A, it can include that the indication information directly indicates A or indirectly indicates A, and it does not mean that A must be carried in the indication information.

[0151] Sixth, in this application, "sending information to XX (device / network element)" can be understood as the destination of this information is this device. It can include sending information to this device directly or indirectly. "Receiving information from XX (device / network element), or receiving information from XX (device / network element)" can be understood as the source of this information is this device, and it can include receiving information from this device directly or indirectly. The information may be processed as necessary, such as format change, etc., between the source and destination of the information sending, but the destination can understand the valid information from the source.

[0152] The network architecture and service scenarios described in the embodiments of this application are used to more clearly illustrate the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided by the embodiments of this application. Those of ordinary skill in the art will know that with the evolution of the network architecture and the emergence of new service scenarios, the technical solutions provided by the embodiments of this application are also applicable to similar technical problems.

[0153] The technical solutions of the embodiments of this application can be applied to various communication systems. For example, Global System for Mobile Communications (GSM), Long Term Evolution (LTE) system, Universal Mobile Telecommunications System (UMTS), 4th generation (4G) mobile communication system, 5th generation (5G) mobile communication system, and with the continuous development of communication technology, the technical solutions of the embodiments of this application can also be used in subsequent evolved communication systems, such as 6th generation (6G) mobile communication system, 7th generation (7G) mobile communication system, and so on.

[0154] Please refer to Figure 1 , Figure 1 which is a schematic diagram of a network architecture. This network architecture is a non-roaming scenario network architecture and is a 5G network architecture based on service-based interfaces. This network architecture includes a Network Repository Function (NRF) network element, a Policy Control Function (PCF) network element, an Application Function (AF) network element, a Unified Data Management (UDM) network element, an Access and Mobility Management Function (AMF) network element, a Session Management Function (SMF) network element, a Network Exposure Function (NEF) network element, an Edge Application Server Discovery Function (EASDF) network element, a terminal device, an Access Network (AN), a User Plane Function (UPF) network element, and a Data Network (DN).

[0155] Among them, the service - based interface provided by the NRF network element is the Nnrf interface. The service - based interface provided by the PCF network element is the Npcf interface. The service - based interface provided by the AF network element is the Naf interface. The service - based interface provided by the UDM network element is the Nudm interface. The service - based interface provided by the AMF network element is the Namf interface. The service - based interface provided by the SMF network element is the Nsmf interface. The service - based interface provided by the NEF network element is the Nnef interface. The service - based interface provided by the EASDF network element is the Neasdf interface. The terminal device communicates with the AMF network element through the N1 interface. The AN communicates with the AMF network element through the N2 interface. The AN communicates with the UPF network element through the N3 interface. The UPF network element communicates with the SMF network element through the N4 interface. The UPF network element communicates with the DN through the N6 interface.

[0156] Among them, the UPF network element acting as a splitting point can also be called an uplink classifier (ULCL) or a branching point (BP). The UPF network element acting as a splitting point communicates with the AN through the N3 interface. The UPF network element directly connected to the DN through the N6 interface in a protocol data unit (PDU) session can also be called a PDU session anchor (PSA). The central anchor UPF can also be called a central PDU session anchor (C - PSA). The C - PSA communicates with the UPF network element acting as a splitting point through the N9 interface and communicates with the central DN through the N6 interface. The local splitting anchor UPF can also be called a local PDU session anchor (L - PSA). The L - PSA communicates with the local part of the DN through the N6 interface. The local part of the DN includes an edge application server (EAS) and can also be called a local DN.

[0157] In addition, the embodiments of the present application can also be applied to a roaming scenario. The network in the roaming scenario includes a visited public land mobile network (VPLMN) and a home public land mobile network (HPLMN). Among them, the HPLMN is the public land mobile network (PLMN) subscribed by the terminal device at its home location, and the VPLMN is the PLMN accessed by the terminal device at the roaming location. When the terminal device leaves the coverage area of the HPLMN, the terminal device can access the VPLMN. The coverage area of the VPLMN can include the current location of the terminal device, and the operator of the VPLMN has signed a roaming agreement with the operator of the HPLMN, enabling the operator of the VPLMN to provide services and billing for the terminal device, etc. It is understandable that in the roaming scenario, the serving PLMN of the terminal device is the VPLMN.

[0158] Please refer to Figure 2 , Figure 2 which is a schematic diagram of another network architecture. This network architecture is an exemplary network architecture for the roaming scenario and is a 5G network architecture based on service-based interfaces. Figure 2 The network architecture shown includes the VPLMN and the HPLMN. Among them, the VPLMN includes network elements such as the NRF, PCF, AMF, SMF, NEF, EASDF, terminal device, AN, UL CL / BP, L-PAS, and the DN local part (including EAS), and the HPLMN includes network elements such as the UDM, NRF, PCF, AF, SMF, NEF, C-PSA, and the central DN. Figure 2 For the interfaces used for communication between network elements in Figure 1 the network architecture shown, reference can be made to the relevant description of the network architecture shown, which will not be elaborated here. In addition, in the embodiments of the present application, the "xx network element" in the VPLMN can also be referred to as the "visited xx network element" or the "visited domain xx network element". For example, the SMF network element in the VPLMN can also be referred to as the visited SMF network element or the visited domain SMF network element (V-SMF network element). The "xx network element" in the HPLMN can also be referred to as the "home xx network element" or the "home domain xx network element". For example, the SMF network element in the HPLMN can also be referred to as the home SMF network element or the home domain SMF network element (H-SMF network element).

[0159] In the embodiments of the present application, the terminal device may also be referred to as a user equipment (UE), a terminal, an access terminal, a user unit, a user station, a mobile station, a mobile device, a remote station, a remote terminal, a mobile device, a user terminal, a user agent, or a user device, and may be applied to 4G, 5G, or even 6G systems, etc. The terminal device in the embodiments of the present application may be a joint device for digital signal transmission and reception over a conventional telephone line, and may also be a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a mobile phone, a pad, a computer with wireless transceiver functions, a head mounted display (HMD), a virtual reality (VR) terminal device (such as VR glasses), an augmented reality (AR) terminal device (such as AR glasses), a mixed reality (MR) terminal device, a wireless terminal in industrial control, a processing device connected to a wireless modem, a tactile terminal device, a vehicle-mounted terminal device, a wireless terminal in self-driving, a wireless terminal in remote medical, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, a road side unit (RSU) of the aforementioned wireless terminal types, a wearable terminal device, and so on.

[0160] AN may be, for example, a radio access network (RAN). The access network device includes, but is not limited to: base station (BS), radio network controller (RNC), base station controller (BSC), base transceiver station (BTS), home network device (e.g., home evolved Node B, or home Node B, HNB), baseband unit (BBU), wireless relay node, wireless backhaul node, transmission and reception point (TRP; or, transmission point, TP). Among them, a base station is a device deployed in a radio access network that can provide wireless communication functions, and it can also be called a base station device. For example, an evolved base station (evolutional Node B, eNB or e-NodeB) in an LTE system, Node B, a base station (gNodeB or gNB) in a 5G system, a base station in a 6G system, etc. A base station may include a BBU and a remote radio unit (RRU). The BBU and the RRU can be placed in different locations. For example, the RRU is remote and placed in a high-traffic area, and the BBU is placed in the central computer room. The BBU and the RRU can also be placed in the same computer room. The BBU and the RRU can also be different components under a single rack. The base station can be in the following forms: macro base station, micro base station (also called small cell), pico base station, relay station, access point, balloon station, etc. Optionally, in some deployments of the access network device, the access network device may include a central unit (CU) and a distributed unit (DU), etc. In some other deployments of the access network device, the CU can also be divided into a CU-control plane (CP) and a CU-user plane (UP), etc. In some other deployments of the access network device, the access network device can also be an open radio access network (ORAN) architecture, etc. This application does not limit the specific deployment method of the access network device.

[0161] The AMF network element is responsible for the mobility management of the terminal device, including mobility state management, allocating a temporary identity identifier for the terminal device, and authenticating and authorizing the terminal device.

[0162] The UDM network element is responsible for managing the subscribed data and notifying the corresponding network elements when the subscribed data is modified.

[0163] The AF network element is used for the service provider to indicate requirements to the core network and subscribe to user plane events. Among them, the service provider can provide EAS content.

[0164] The SMF network element is mainly responsible for session management in the mobile network, such as session establishment, modification, and release. Specific functions include allocating Internet Protocol (IP) addresses for users, selecting UPFs that provide packet forwarding functions, etc.

[0165] Please refer to Figure 3 , Figure 3 , which is a schematic diagram of a communication system provided by an embodiment of the present application. The communication system includes an application function network element, a first network element, a second network element, and a terminal device. Among them, different network elements / devices can communicate directly with each other, or can also communicate indirectly through other network elements / devices, and this is not limited. Optionally, Figure 3 the shown communication system may further include an edge application server discovery function network element. The edge application server discovery function network element and the second network element can communicate directly with each other, or can also communicate indirectly through other network elements / devices.

[0166] In an optional implementation manner, the service scopes of the first network element and the second network element are different. In the embodiment of the present application, the service scopes of the first network element and the second network element are different. For example, it can be that the service scope of the first network element and the service scope of the second network element do not intersect, or it can also be that the service scope of the first network element and the service scope of the second network element have an intersection and the intersection is not empty, or it can also be that the service scope of the second network element is a subset of the service scope of the first network element. For example, in a non-roaming scenario, the service scopes of the first network element and the second network element are different. Another example is that in a roaming scenario, the service scope of the first network element belongs to the scope of the home public land mobile network, and the service scope of the second network element belongs to the scope of the visited public land mobile network.

[0167] In an optional implementation manner, the first network element and the second network element serve the terminal device. In the embodiment of the present application, the first network element and the second network element serve the terminal device, and it can also be understood as: the first network element and the second network element serve the session of the terminal device.

[0168] In an alternative embodiment, the first network element belongs to the home public land mobile network of the terminal device, and the second network element belongs to the visited public land mobile network of the terminal device. This approach can be applied to roaming scenarios. Optionally, the first network element is a home domain session management function network element, and the second network element is a visited domain session management function network element. Exemplarily, in the roaming scenario of a 5G system, the first network element may be the SMF network element in the HPLMN (i.e., the H-SMF network element), and the second network element may be the SMF network element in the VPLMN (i.e., the V-SMF network element). For example, as Figure 4 shown in the communication system.

[0169] In another alternative embodiment, the first network element is a session management function network element, and the second network element is an intermediate session management function network element. This approach can be applied to non-roaming scenarios. Exemplarily, in a 5G system, the first network element may be an SMF network element, and the second network element may be an intermediate SMF (intermediate SMF, I-SMF) network element. For example, as Figure 5 shown in the communication system.

[0170] In yet another alternative embodiment, the first network element is a session management function network element, and the second network element is used to assist the session management function network element in processing edge application server-related information. This approach can be applied to non-roaming scenarios. For example, the second network element can assist the first network element in completing edge application server discovery and session management to reduce the load on the first network element. Additionally, in this embodiment, the second network element may, for example, be another session management function network element that assists the session management function network element. The second network element may also be referred to as a local network element, and the local network element may be a local session management function network element, for example. However, the embodiments of the present application do not limit the naming of the second network element in the case where the second network element is used to assist the session management function network element in processing edge application server-related information. Exemplarily, in a 5G system, the first network element may be an SMF network element, and the second network element may be a local SMF (local SMF, L-SMF) network element. For example, as Figure 6 shown in the communication system.

[0171] It can be understood that as the network architecture changes, the method provided by the embodiments of the present application can also be implemented by network elements with corresponding functions in the new network architecture.

[0172] It can be understood that for ease of explanation, the embodiments of the present application are described by taking the 5G system as an example. When the solutions of the embodiments of the present application are applied to a 6G system or other communication systems, the corresponding network element names, network element deployment methods, interfaces, etc. may change, and the present application does not make any limitations in this regard.

[0173] Secondly, a brief introduction to the related concepts involved in the embodiments of the present application is given.

[0174] 1. Edge Computing (EC)

[0175] Edge computing is a distributed computing model that realizes local processing of distributed service traffic by moving the user plane function and service processing capabilities to the network edge.

[0176] In a network architecture that deploys user plane devices using a tree topology, the uplink user packets need to pass through the base station, the backhaul network, and the centrally deployed anchor gateway to access the data network. These anchor gateways are generally centrally deployed at a relatively high position in the network (for example: the regional central computer room), resulting in excessive traffic concentration at the anchor gateway when the service traffic is large. Compared with the network architecture that deploys user plane devices using a tree topology, the network architecture deployed based on edge computing can reduce the excessive concentration of traffic at the anchor gateway, thereby reducing the requirements for the backhaul network bandwidth, computer room throughput, and gateway specifications.

[0177] Moreover, by moving the user plane function and service processing capabilities to the network edge, edge computing can make the devices with user plane function and service processing capabilities closer to the terminal devices, thereby shortening the distance of the backhaul network and reducing the end-to-end (E2E) delay and jitter of user packets. Figure 1 、 Figure 2 、 Figure 4 、 Figure 5 and Figure 6 The network architectures shown are all network architectures deployed using edge computing. For example, in the network architecture described in Figure 1 the UPF network element is deployed at the network edge, and the user plane path is for the terminal device to access the DN through the AN and the UPF network element, which can reduce the E2E delay and jitter of user packets.

[0178] 2. Edge Application Server Discovery

[0179] The edge application server discovery process can be used to return an edge application server address (for example, EAS IP address) to the terminal device in the case of a terminal device initiating a Domain Name Service (DNS) query. The edge application server discovery process can also be used to enable the data packets exchanged between the terminal device and the edge application server to be forwarded through the local path in the user plane, where the user plane local path is configured by the session management function network element, and the user plane local path includes the path from ULCL / BP to L-PSA. After the edge application server discovery process is completed, the terminal device can access the edge application server through the user plane local path.

[0180] Exemplarily, in combination with Figure 7, The edge application server discovery process may include: If a terminal device wants to access edge services, the terminal device sends a DNS query message, and the DNS query message carries the domain name that the terminal device wants to access. The domain name is, for example, a fully qualified domain name (FQDN). The edge application server discovery functional network element sends part of the information in the DNS query message (information from the DNS Query) to the session management functional network element. Part of the information in the DNS query message may include, for example, the domain name in the DNS query message. The session management functional network element sends the information indicating the location of the terminal device to the edge application server discovery functional network element. The edge application server discovery functional network element adds the information indicating the location of the terminal device to the DNS query message and sends the DNS query message with the added information indicating the location of the terminal device to the DNS server. The DNS server determines the current location of the terminal device based on the information indicating the location of the terminal device and sends a DNS response message to the edge application server discovery functional network element. The DNS response message carries the address of an edge application server close to the terminal device, and the address is, for example, an EAS IP address. The edge application server discovery functional network element sends the DNS response message to the terminal device.

[0181] In addition, in a roaming scenario, Figure 7 In the edge application server discovery process mentioned above, the "edge application server discovery functional network element" is the "visited domain edge application server discovery functional network element", and the "session management functional network element" is the "visited domain session management functional network element". In the case where the non-roaming scenario includes a session management network element and an intermediate session management network element, Figure 7 In the edge application server discovery process mentioned above, the "edge application server discovery functional network element" is the "intermediate edge application server discovery functional network element", and the "session management functional network element" is the "intermediate session management functional network element". In the case where the non-roaming scenario includes a session management network element and a local session management network element, Figure 7 In the edge application server discovery process mentioned above, the "edge application server discovery functional network element" is the "local edge application server discovery functional network element", and the "session management functional network element" is the "local session management functional network element".

[0182] In addition, after the terminal device obtains the address of the edge application server through the edge application server discovery process, the terminal device can also store the correspondence between the domain name carried in the DNS query message and the address of the edge application server carried in the DNS response message. When the terminal device accesses the domain name later, it can stop initiating DNS queries and directly send data packets to the edge application server corresponding to the address corresponding to the domain name based on the cached correspondence between the domain name and the address of the edge application server.

[0183] For example, the terminal device initiates a DNS query for FQDN#1. Through the edge application server discovery process, the terminal device receives EAS IP address#1. The terminal device stores the correspondence between FQDN#1 and EAS IP address#1. When the terminal device accesses FQDN#1 later, it can stop initiating DNS queries and directly send data packets to the edge application server corresponding to EAS IP address#1 based on the cached correspondence between FQDN#1 and EAS IP address#1.

[0184] 3. Edge Application Server Rediscovery (EAS rediscovery or EAS relocation)

[0185] The edge application server rediscovery process is triggered after the edge application server discovery process is completed. Through the edge application server discovery process, the terminal device can obtain the address of the edge application server, so that the terminal device can access the edge application server. When the edge application server accessed by the terminal device is no longer appropriate, the edge application server rediscovery process can be triggered, enabling the terminal device to obtain the address of a new edge application server. Herein, the terminal device performing edge application server rediscovery can also be understood as: the terminal device rediscovering the edge application server. The terminal device rediscovering the edge application server can include: the terminal device reinitiating a DNS query. Exemplarily, when the load of the edge application server is too high, the application function network element can trigger the edge application server rediscovery.

[0186] Before re - executing the edge application server discovery process, the terminal device also clears the DNS cache stored locally. Among them, the DNS cache stored locally by the terminal device includes the correspondence between the domain names stored by the terminal device and the addresses of the edge application servers. Understandably, after the terminal device obtains the address of the edge application server through the edge application server discovery process, the terminal device also stores the correspondence between the domain name and the address of the edge application server. If the terminal device wants to access the domain name subsequently, the terminal device directly sends a data packet to the corresponding edge application server based on this cached correspondence. Therefore, if you want the terminal device to access other edge application servers for a certain domain name, the terminal device needs to delete the DNS cache corresponding to the domain name, that is, to make the terminal device delete the correspondence between the domain name and the address of the edge application server. Then, when the terminal device wants to access the domain name again, it initiates a DNS query again, so as to re - execute the edge application server discovery process to discover the address of a new edge application server for the terminal device.

[0187] For example, the terminal device initiates a DNS query for FQDN#1. Through the edge application server discovery process, the terminal device receives EAS IP address#1. The terminal device stores the correspondence between FQDN#1 and EAS IP address#1. When the load of the edge application server corresponding to EAS IP address#1 is too high, the application function network element can trigger the edge application server re - discovery process. The terminal device deletes the correspondence between FQDN#1 and EAS IP address#1. When the terminal device wants to access FQDN#1 subsequently, it initiates a DNS query again so that the edge application server discovery process is re - executed to obtain the address of the edge application server.

[0188] 4. Edge Application Server Deployment Information (EDI)

[0189] Edge application server deployment information can be used to reflect the deployment of the network at the edge. The edge application server deployment information may include one or more of the following parameters: AF ID, data network name (DNN), single network slice selection assistance information (S-NSSAI), external group identifier / internal group identifier, application ID (APP ID), one or more FQDNs, one or more data network access identifiers (DNAIs), DNS server information, EAS IP address range information, N6 traffic routing information. Among them, the EAS IP address range information, DNS server information, and FQDN are deployed by the application service provider. The DNAI, DNN, and S-NSSAI are the identifications of the edge services by the network (e.g., 5G core network). For the description of the parameters that the edge application server deployment information may include, refer to Table 1.

[0190] Table 1

[0191]

[0192]

[0193] The edge application server deployment information is also used to reflect the correspondence relationship between these included parameters. For example, the edge application server deployment information can be used to reflect the correspondence relationship between the DNAI and one or more of the FQDN, EAS IP address range, and DNS server information. It can be understood that based on the edge application server deployment information, it is possible to determine one or more of the FQDN, EAS IP address range, and DNS server information corresponding to each DNAI in the edge application server deployment information; if the FQDN or EAS IP address of a certain service is within the above range, it means that the service is deployed at the local edge.

[0194] In addition, the edge application server deployment information can be stored in a unified data repository (UDR), and the first network element or the second network element can obtain the edge application server deployment information from the UDR. For example, the first network element can provide a DNN and / or an S-NSSAI to the UDR, so as to obtain the edge application server deployment information related to the DNN and / or the S-NSSAI.

[0195] In the embodiments of the present application, the first network element and the second network element can each configure the edge application server deployment information corresponding to their service scopes. Exemplarily, when the service scope of the first network element does not intersect with the service scope of the second network element, the first network element may not configure the edge application server deployment information corresponding to the service scope of the second network element. Exemplarily, when the service scope of the second network element is a subset of the service scope of the first network element, compared with the edge application server deployment information configured by the first network element, the edge application server deployment information configured by the second network element may be more accurate. For example, if the service scope of the first network element is City #1 and the service scope of the second network element is Street #1 in City #1, then the first network element configures the edge application server deployment information corresponding to City #1, and the second network element configures the edge application server deployment information corresponding to Street #1 in City #1.

[0196] In addition, when the first network element belongs to the home public land mobile network and the second network element belongs to the visited public land mobile network, the edge application server deployment information configured by the first network element can also be referred to as the home domain edge application server deployment information (HPLMN EDI), and the edge application server deployment information configured by the second network element can also be referred to as the visited domain edge application server deployment information (VPLMN EDI). When the second network element is a local network element, the edge application server deployment information configured by the second network element can also be referred to as the local edge application server deployment information (local EDI, L-EDI).

[0197] The embodiments of the present application are elaborated in detail below with reference to the accompanying drawings. In the embodiments of the present application, the first network element, the second network element, the terminal device, and the application function network element are used as the execution subjects to illustrate the corresponding methods, but the present application does not limit the execution subjects of the methods. For example, the network element / device in the method can also be a chip, a chip system, or a processor that supports the network element / device to implement the corresponding method, and can also be a logic module or software that can implement all or part of the functions of the network element / device.

[0198] Please refer to Figure 8 , Figure 8 which is a schematic flowchart of a communication method 100 provided by the embodiments of the present application. The communication method 100 includes the following steps.

[0199] S101. The application function network element sends a first message and a first service identifier to the first network element, where the first message is used to indicate the rediscovery of the server. Correspondingly, the first network element receives the first message and the first service identifier from the application function network element.

[0200] In an alternative embodiment, in the embodiments of the present application, the server may be an edge application server. In this case, for example, the first message is used to indicate the rediscovery of the server, which is: the first message is used to indicate the rediscovery of the edge application server. The "server" in the following text can be replaced by the "edge application server", and will not be elaborated further.

[0201] It can be understood that step S101 may be executed after the edge application server discovery process is completed. After the edge application server discovery process is completed, the application function network element sends a first message to the first network element to indicate the rediscovery of the edge application server, which is beneficial to trigger the edge application server rediscovery process. For the specific descriptions of the edge application server discovery process and the edge application server rediscovery process, reference can be made to the foregoing related descriptions, and will not be elaborated further.

[0202] In an alternative manner, the first message is used to indicate the rediscovery of the server can also be replaced by: the first message is used to trigger the rediscovery of the server. Optionally, the first message may be an "EAS relocation indication".

[0203] In an alternative manner, the first service identifier can also be understood as: the service identifier affected by the server rediscovery. Additionally, the service identifier may be represented by an APP ID, for example. Exemplarily, the first service identifier may be one or more APP IDs.

[0204] In an alternative manner, the first message and the first service identifier are carried in an application function request (AF request) message sent by the application function network element.

[0205] In an alternative manner, the application function network element sending the first message and the first service identifier to the first network element may be: the application function network element sends the first message and the first service identifier to the first network element through an intermediate network element. Exemplarily, the intermediate network element may directly forward the first message and the first service identifier from the application function network element to the first network element. Or, the intermediate network element generates a new message based on the first message and the first service identifier received from the application function network element, and sends the message to the first network element. Optionally, the intermediate network element may also modify the form of the first message and / or the first service identifier, and the intermediate network element sends the modified first message and / or the modified first service identifier to the first network element.

[0206] Optionally, the intermediate network element may be a policy control function (PCF) network element. The policy control function network element receives the first information and the first service identifier from the application function network element, and creates a policy and charging control rule (PCC rule) based on the received first information and the first service identifier. The policy control function network element sends the policy and charging control rule to the first network element. The policy and charging control rule includes the ninth information and the first service identifier, and the ninth information is determined based on the first information. The ninth information may be the same as or different from the first information, but the functions of the ninth information and the first information are both used to indicate server rediscovery.

[0207] For example, the first information is "indication for EAS relocation". The ninth information is the same as the first information. Alternatively, the ninth information is different from the first information, and the ninth information may be "EAS rediscovery indication" or "Indication of EAS rediscovery".

[0208] Optionally, the intermediate network element may be a policy control function network element and a network exposure function (NEF) network element. The application function network element sends the first information and the first service identifier to the first network element, including: the application function network element sends the first information and the first service identifier to the first network element through the network exposure function network element and the policy control function network element. This method can be applied to the scenario where the first network element is a session management function network element.

[0209] Exemplarily, the application function network element sends the first information and the first service identifier to the first network element, including: the application function network element sends an application function request message to the network exposure function network element, and the application function request message includes application function traffic influence request information (AF traffic influence request information), and the application function traffic influence request information includes the first information and the first service identifier; correspondingly, the network exposure function network element receives the application function request from the application function network element. The network exposure function network element sends the application function traffic influence request information to the policy control function network element; correspondingly, the policy control function network element receives the application function traffic influence request information from the network exposure function network element. The policy control function network element generates a policy and charging control (PCC) rule based on the application function traffic influence request information and sends the PCC rule to the first network element; correspondingly, the first network element receives the PCC rule from the policy control function network element. Among them, the manifestation form of the application function traffic influence request information in the PCC rule is: the influence of the application function on traffic routing enforcement control (application function influence on traffic routing enforcement control).

[0210] Among them, optionally, the network exposure function network element sending the application function traffic influence request information to the policy control function network element can be: the network exposure function network element directly sends the application function traffic influence request information to the policy control function network element. Or, it can also be: the network exposure function network element stores the application function traffic influence request information in the unified data repository, and the policy control function network element then subscribes to the application function traffic influence request information from the unified data repository.

[0211] Optionally, the first service identifier can be part of the "service dataflow template" in the PCC rule.

[0212] In an optional implementation manner, the application function network element sending the first information and the first service identifier to the first network element can be replaced with: the application function network element sends the first service identifier to the first network element. It can be understood that the application function network element may not send the first information to the first network element. In this case, the application function network element can indicate server rediscovery through the first service identifier.

[0213] S102. The first network element sends the first service identifier to the second network element. Correspondingly, the second network element receives the first service identifier from the first network element.

[0214] The following elaborates on step S102 as described in the following optional embodiments 1.1 to 1.4.

[0215] Embodiment 1.1, the first network element sends a first service identifier to the second network element, including: when a first condition is met, the first network element sends a first service identifier to the second network element; the first condition includes: the server deployment information of the first network element does not include the domain name and address corresponding to the first service identifier.

[0216] In the embodiments of the present application, the server deployment information of the first network element can also be understood as: the server deployment information stored by the first network element; or can also be understood as: the server deployment information configured by the first network element. Additionally, the server deployment information of the first network element can be: the server deployment information corresponding to the service scope of the first network element. The server deployment information of the second network element in the following text is similar and will not be elaborated further.

[0217] In the embodiments of the present application, the domain name and address corresponding to the first service identifier are: the domain name and address of the server corresponding to the first service identifier. Among them, the server corresponding to the first service identifier can also be understood as: the server that provides services for the service corresponding to the first service identifier. The domain name can be, for example, FQDN, and the address can be, for example, an EAS IP address. Additionally, the domain name or address corresponding to the first service identifier can also be understood as: the impact field corresponding to the first service identifier. The domain name or address corresponding to the first service identifier can be sent to the terminal device as an impact field.

[0218] It can be understood that the server deployment information of the first network element does not include the domain name and address corresponding to the first service identifier, indicating that the first network element cannot obtain the domain name and address corresponding to the first service identifier based on the server deployment information of the first network element. Then, the first network element sending the first service identifier to the second network element is beneficial for the first network element to obtain the domain name and address corresponding to the first service identifier from the second network element.

[0219] For example, the server deployment information of the first network element includes service identifier #1, service identifier #2, domain name #1, and domain name #2, where service identifier #1 corresponds to domain name #1, and service identifier #2 corresponds to domain name #2. The first service identifier received by the first network element is service identifier #3. It can be seen that the server deployment information of the first network element does not include service identifier #3, and the first network element cannot determine the domain name or address corresponding to service identifier #3 based on the server deployment information of the first network element. That is to say, the server deployment information of the first network element does not include the domain name or address corresponding to service identifier #3. Then, the first network element sends service identifier #3 to the second network element.

[0220] Optionally, when the first network element determines that the first condition is satisfied, the first network element may send a first service identifier to the second network element, specifically: the first network element determines whether the first condition is satisfied; if the first network element determines that the first condition is satisfied, the first network element sends the first service identifier to the second network element.

[0221] Optionally, when the first network element determines that the first condition is satisfied, the first network element may send a first service identifier to the second network element, which may also be replaced with: when the server deployment information of the first network element does not include the domain name and address corresponding to the first service identifier, the first network element sends the first service identifier to the second network element. In this method, the first network element may not perform the operation of determining whether the first condition is satisfied.

[0222] In Embodiment 1.2, the method further includes: the application function network element sends a data network access identifier corresponding to the first information to the first network element; correspondingly, the first network element receives the data network access identifier corresponding to the first information from the application function network element. The first network element sends the first service identifier to the second network element, including: when the second condition is satisfied, the first network element sends the first service identifier to the second network element; the second condition includes: the server deployment information of the first network element does not include the data network access identifier corresponding to the first information. Optionally, the sending path of the data network access identifier corresponding to the first information is the same as that of the first information. The data network access identifier corresponding to the first information may be carried by a potential locations of applications field, for example; it may also be understood that: the data network access identifier corresponding to the first information may be included in the potential locations of applications field, for example.

[0223] In the embodiments of the present application, the data network access identifier corresponding to the first information may also be understood as: the data network access identifier affected by server rediscovery. There is a corresponding relationship between the data network access identifier corresponding to the first information and the first service identifier, which may be understood as: the data network corresponding to the data network access identifier provides services for the service corresponding to the first service identifier. This will not be elaborated further hereinafter.

[0224] It can be understood that the server deployment information of the first network element does not include the data network access identifier corresponding to the first information, indicating that the first network element does not support the data network access identifier corresponding to the first information. Then, when the server deployment information of the first network element does not include the data network access identifier corresponding to the first information, the first network element cannot obtain the domain name and address corresponding to the first service identifier based on the server deployment information of the first network element. Therefore, the first network element sending the first service identifier to the second network element is beneficial for the first network element to obtain the domain name and address corresponding to the first service identifier from the second network element.

[0225] In addition, in the embodiments of the present application, the data network access identifier supported by the network element can also be understood as: the data network access identifier that the network element can serve. The data network access identifier not supported by the network element can also be understood as: the data network access identifier that the network element cannot serve. For example, if network element #1 supports data network access identifier #1, it can be understood that network element #1 can serve data network access identifier #1. Another example, if network element #1 does not support data network access identifier #1, it can be understood that network element #1 cannot serve data network access identifier #1. This will not be elaborated further hereinafter.

[0226] Optionally, when the second condition is satisfied, the first network element sends the first service identifier to the second network element, which can be: the first network element determines whether the second condition is satisfied; if the first network element determines that the second condition is satisfied, it sends the first service identifier to the second network element.

[0227] Optionally, when the second condition is satisfied, the first network element sending the first service identifier to the second network element can also be replaced with: when the server deployment information of the first network element does not include the data network access identifier, the first network element sends the first service identifier to the second network element. In this method, the first network element may not perform the operation of determining whether the second condition is satisfied.

[0228] Embodiment 1.3: The first network element belongs to the home public land mobile network of the terminal device, and the second network element belongs to the visited public land mobile network of the terminal device. The first network element sending the first service identifier to the second network element includes: when the third condition is satisfied, the first network element sends the first service identifier to the second network element; the third condition includes: the first network element does not store the server deployment information of the visited public land mobile network.

[0229] Wherein, the terminal device is the terminal device that executes the service corresponding to the first service identifier, and the terminal device accesses the service corresponding to the first service identifier through the first session. It can be understood that in the roaming scenario, the serving public land mobile network of the terminal device is the visited public land mobile network, and the first service identifier belongs to the server deployment information of the visited public land mobile network. Then, when the first network element does not store the server deployment information of the visited public land mobile network, the first network element cannot obtain the domain name and address corresponding to the first service identifier based on the stored server deployment information. Therefore, the first network element sending the first service identifier to the second network element is beneficial for the first network element to obtain the domain name and address corresponding to the first service identifier from the second network element.

[0230] Optionally, when the third condition is satisfied, the first network element sends the first service identifier to the second network element, which can be: the first network element determines whether the third condition is satisfied; if the first network element determines that the third condition is satisfied, it sends the first service identifier to the second network element.

[0231] Optionally, when the first network element satisfies the third condition, it sends a first service identifier to the second network element, which can also be replaced with: when the first network element does not store the server deployment information of the visited public land mobile network, it sends a first service identifier to the second network element. In this method, the first network element may not perform the operation of determining whether the third condition is satisfied.

[0232] In Embodiment 1.4, the method further includes: the second network element sends third information to the first network element, and the third information is used to indicate the data network access identifiers supported by the second network element; correspondingly, the first network element receives the third information from the second network element. The application function network element sends the data network access identifier corresponding to the first information to the first network element; correspondingly, the first network element receives the data network access identifier corresponding to the first information from the application function network element. The first network element sends the first service identifier to the second network element, including: when the first network element satisfies the fourth condition, it sends the first service identifier to the second network element; the fourth condition includes: the data network access identifier corresponding to the first information is the data network access identifier supported by the second network element.

[0233] For example, the second network element sends third information #1 to the first network element, and the third information #1 is used to indicate that the data network access identifiers supported by the second network element are data network access identifier #1, data network access identifier #2, and data network access identifier #3. The application function network element sends the first information, the first service identifier, and the data network access identifier #2 to the first network element. It can be seen that the data network access identifier corresponding to the first information is the data network access identifier supported by the second network element, and the first network element can send the first service identifier to the second network element.

[0234] In addition, the embodiments of the present application do not limit the manifestation form of the data network access identifiers supported by the second network element indicated by the third information. For example, the third information includes the data network access identifiers supported by the second network element. Another example is that the third information is an interest data network access identifier list (interest DNAI list), and the interest data network access identifier list includes the data network access identifiers supported by the second network element.

[0235] Optionally, when the first network element satisfies the fourth condition, sending the first service identifier to the second network element may be: the first network element determines whether the fourth condition is satisfied; if the first network element determines that the fourth condition is satisfied, it sends the first service identifier to the second network element.

[0236] Optionally, when the fourth condition is satisfied, the first network element sends the first service identifier to the second network element. This can also be replaced with: when the data network access identifier corresponding to the first information is a data network access identifier supported by the second network element, the first network element sends the first service identifier to the second network element. In this method, the first network element may not perform the operation of determining whether the fourth condition is satisfied.

[0237] In addition, in an alternative implementation, any combination of the implementation manners 1.1 to 1.4 can be used. Specifically, the first network element sending the first service identifier to the second network element includes: the first network element sending the first service identifier to the second network element when at least two of the first condition, the second condition, the third condition, and the fourth condition are satisfied.

[0238] S103. The second network element sends the domain name or address corresponding to the first service identifier to the first network element based on the stored server deployment information. Correspondingly, the first network element receives the domain name or address corresponding to the first service identifier from the second network element.

[0239] In an alternative implementation, the second network element sending the domain name or address corresponding to the first service identifier to the first network element based on the stored server deployment information includes: the second network element determining the domain name or address corresponding to the first service identifier based on the stored server deployment information; and the second network element sending the domain name or address corresponding to the first service identifier to the first network element.

[0240] For example, the server deployment information stored by the second network element includes: service identifier #1, service identifier #2, domain name #1, domain name #2, where domain name #1 corresponds to service identifier #1, and domain name #2 corresponds to service identifier #2. The first service identifier received by the second network element from the first network element is service identifier #2. The second network element determines the corresponding domain name #2 based on the stored server deployment information and sends domain name #2 to the first network element.

[0241] In an alternative embodiment, for the case where multiple addresses correspond to the first service identifier in the server deployment information stored in the second network element, the second network element sends the addresses corresponding to the first service identifier to the first network element based on the stored server deployment information, including: the second network element determines multiple addresses corresponding to the first service identifier based on the stored server deployment information; the second network element can select one address from the multiple addresses corresponding to the first service identifier based on the session information of the terminal device; the second network element sends the selected address to the first network element. Wherein, the terminal device is a terminal device that executes the service corresponding to the first service identifier. Optionally, the session information includes one or more of the following: the location of the terminal device, the data splitting rule, and the packet detection result. In another alternative embodiment, the second network element can also send all the multiple addresses corresponding to the first service identifier to the first network element. In this case, the first network element sends the multiple addresses corresponding to the first service identifier received from the second network element to the terminal device.

[0242] In an alternative embodiment, the method further includes: the first network element sends fourth information to the second network element, and the fourth information is used to request the domain name or address corresponding to the first service identifier; correspondingly, the second network element receives the fourth information from the first network element. Optionally, the fourth information is used to request the domain name or address corresponding to the first service identifier can also be replaced with: the fourth information is used to request the second network element to provide the domain name or address corresponding to the first service identifier.

[0243] S104. The first network element sends a first message to the terminal device, the first message includes the domain name or address corresponding to the first service identifier, and the first message is used to instruct the terminal device to clear the server information corresponding to the domain name or address corresponding to the first service identifier. Correspondingly, the terminal device receives the second information and the domain name or address corresponding to the first service identifier from the first network element.

[0244] Wherein, the second information can be, for example, an EAS rediscovery indication. The second message can be a "PDU Session Modification Command", or a "network attached storage message (NAS message) non-access stratum message", or a "procedure control object (PCO)".

[0245] In an alternative embodiment, instructing the terminal device to clear the server information corresponding to the domain name or address of the first service identifier may be: instructing the terminal device to clear the cached server information, and the domain name or address corresponding to the first service identifier is used to indicate the server information to be cleared. Additionally, "clear" may be replaced with "delete", "refresh", etc.

[0246] In an alternative embodiment, the second information is carried by a protocol configuration option (PCO) field, and / or the domain name or address corresponding to the first service identifier is carried by the PCO field.

[0247] In an alternative embodiment, the server information corresponding to the domain name or address of the first service identifier includes: the correspondence between the domain name corresponding to the first service identifier and the address corresponding to the first service identifier.

[0248] It can be understood that after the terminal device obtains the address for the domain name through the server discovery process, the terminal device can access the server corresponding to the address to execute the service corresponding to the first service identifier, and the terminal device also stores the correspondence between the domain name and the address. Thereafter, the first network element sends the second information and the domain name or address corresponding to the first service identifier to the terminal device, which is beneficial for the terminal device to clear the correspondence between the domain name corresponding to the first service identifier and the address corresponding to the first service identifier, and thus beneficial for the terminal device to perform server re-discovery for the domain name corresponding to the first service identifier.

[0249] In an alternative embodiment, when the domain name or address corresponding to the first service identifier received by the first network element from the second network element is empty, or when the first network element receives information from the second network element indicating that the domain name or address corresponding to the first service identifier cannot be obtained, the second information sent by the first network element to the terminal device is used to instruct the terminal device to clear the server information related to the first session, and the first session is used for the terminal device to access the service corresponding to the first service identifier. And in this case, the domain name or address corresponding to the first service identifier sent by the first network element to the terminal device is empty, or the first network element does not send the domain name or address corresponding to the first service identifier to the terminal device.

[0250] Exemplarily, if the second network element cannot obtain / determine the domain name or address corresponding to the first service identifier, the second network element sends the domain name or address corresponding to the first service identifier to the first network element and the domain name or address is empty. The first network element sends the second information to the terminal device, and the second information is used to instruct the terminal device to clear the server information related to the first session. And the first network element sends the domain name or address corresponding to the first service identifier to the terminal device and the domain name or address is empty, or the first network element does not send the domain name or address corresponding to the first service identifier to the terminal device.

[0251] Exemplarily, if the second network element fails to obtain / determine the domain name or address corresponding to the first service identifier, the second network element sends information to the first network element indicating that it fails to obtain the domain name or address corresponding to the first service identifier, and the second network element may not send the domain name or address corresponding to the first service identifier to the first network element (the domain name or address is empty). The first network element sends second information to the terminal device, and the second information is used to instruct the terminal device to clear the server information related to the first session. Moreover, the first network element sends the domain name or address corresponding to the first service identifier to the terminal device and the domain name or address is empty, or the first network element does not send the domain name or address corresponding to the first service identifier to the terminal device. In an alternative embodiment, the first network element sending the second information and the domain name or address corresponding to the first service identifier to the terminal device may be replaced with: the first network element sends the domain name or address corresponding to the first service identifier to the terminal device. Understandably, the first network element may not send the second information to the terminal device. In this case, the first network element may instruct the terminal device to clear the server information corresponding to the domain name or address corresponding to the first service identifier through the domain name or address corresponding to the first service identifier.

[0252] In an alternative embodiment, the method further includes: the terminal device clears the server information corresponding to the domain name or address corresponding to the first service identifier. Understandably, the terminal device clears the server information corresponding to the cached domain name or address corresponding to the first service identifier.

[0253] For example, taking the domain name as FQDN and the address as EAS IP address as an example. The terminal device initiates a DNS query for FQDN#1. Through the server discovery process, the terminal device obtains EAS IP address#1. The terminal device accesses EAS IP address#1 to execute the service corresponding to the first service identifier, and the terminal device also stores the correspondence between FQDN#1 and EAS IP address#1. Thereafter, the application function network element sends the first information and the first service identifier to the first network element.

[0254] The first network element receives FQDN#1 corresponding to the first service identifier from the second network element. The first network element sends the second information and FQDN#1 to the terminal device, and the second information is used to instruct the terminal device to clear the server information corresponding to FQDN#1. The terminal device clears the server information corresponding to FQDN#1. Among them, the server information corresponding to FQDN#1 includes: the correspondence between FQDN#1 and EAS IP address#1.

[0255] Alternatively, the first network element receives the EAS IP address #1 corresponding to the first service identifier from the second network element. The first network element sends the second information and the EAS IP address #1 to the terminal device, where the second information is used to instruct the terminal device to clear the server information corresponding to the EAS IP address #1. The terminal device clears the server information corresponding to the EAS IP address #1. Among them, the server information corresponding to the EAS IP address #1 includes: the correspondence between the FQDN #1 and the EAS IP address #1.

[0256] Optionally, after the terminal device clears the server information corresponding to the domain name or address corresponding to the first service identifier, the terminal device performs server rediscovery. Among them, the terminal device performing server rediscovery can be executed when the terminal device wants to access the domain name corresponding to the first service identifier after clearing the server information corresponding to the domain name or address corresponding to the first service identifier.

[0257] For example, the domain name corresponding to the first service identifier is domain name #1, and the address corresponding to the first service identifier is address #1. The terminal device receives the second information and the domain name #1 or the address #1 from the first network element, and the terminal device clears the server information corresponding to the domain name #1 or the address #1. Thereafter, when the terminal device wants to access the domain name #1, the terminal device performs server rediscovery for the domain name #1.

[0258] In summary, in the communication method 100, the first network element receives the first information and the first service identifier from the application function network element, and the first information is used to indicate edge application server rediscovery. The first network element sends the first service identifier to the second network element. The second network element sends the domain name or address corresponding to the first service identifier to the first network element. The first network element sends the second information and the domain name or address corresponding to the first service identifier to the terminal device, and the second information is used to instruct the terminal device to clear the edge application server information corresponding to the domain name or address corresponding to the first service identifier.

[0259] It can be seen that in this method, the first network element obtains the domain name or address corresponding to the first service identifier from the second network element, so that the first network element sends the second information and the domain name or address corresponding to the first service identifier, the first message, to enable the terminal device to clear the edge application server information corresponding to the domain name or address corresponding to the first service identifier, so that the terminal device can obtain the address of the new edge application server, and then the new edge application server provides services for the terminal device to improve the service quality of the terminal device.

[0260] Please refer to Figure 9 , Figure 9 which is a schematic flowchart of a communication method 200 provided by an embodiment of the present application. The communication method 200 includes the following steps.

[0261] S201. The edge application server discovery functional network element sends a domain name or an address to the second network element. Correspondingly, the second network element receives the domain name or the address from the edge application server discovery functional network element.

[0262] Among them, step S201 can be executed during the edge application server discovery process or after the edge application server discovery process is completed, and there is no limitation on this.

[0263] In an alternative embodiment, the method further includes: the terminal device sends a DNS query message including a domain name to the edge application server discovery functional network element; correspondingly, the edge application server discovery functional network element receives the DNS query message from the terminal device. It can be seen that through this embodiment, the edge application server discovery functional network element can obtain the domain name, so that the edge application server discovery functional network element can send the domain name to the second network element. In addition, this embodiment can be executed during the edge application server discovery process.

[0264] For example, taking the domain name FQDN as an example. During the edge application server discovery process, the terminal device sends a DNS query message including FQDN#1 to the edge application server discovery functional network element. It can be seen that the edge application server discovery functional network element receives FQDN#1, so that the edge application server discovery functional network element can send FQDN#1 to the second network element.

[0265] In an alternative embodiment, the method further includes: the terminal device sends a DNS query message including a domain name to the edge application server discovery functional network element; correspondingly, the edge application server discovery functional network element receives the DNS query message from the terminal device. The edge application server discovery functional network element sends a DNS query message to the DNS server; correspondingly, the DNS server receives the DNS query message from the application server discovery functional network element. The DNS server sends a DNS response message including an address to the edge application server discovery functional network element; correspondingly, the edge application server discovery functional network element receives the DNS response message from the DNS server. It can be seen that through this embodiment, the edge application server discovery functional network element can obtain the domain name and / or the address, so that the edge application server discovery functional network element can send the domain name or the address to the second network element. In addition, this embodiment can be executed during the edge application server discovery process.

[0266] For example, take the FQDN as the domain name and the EAS IP address as the address. In the edge application server discovery process, the terminal device sends a DNS query message to the edge application server discovery function network element. The DNS query message includes FQDN#1. The edge application server discovery function network element sends a DNS query message to the DNS server. The DNS server sends a DNS response message to the edge application server discovery function network element. The DNS response message includes EAS IP address#1. It can be seen that the edge application server discovery function network element receives FQDN#1 and EAS IP address#1, so that the edge application server discovery function network element can send FQDN#1 or EAS IP address#1 to the second network element.

[0267] S202. The second network element sends fifth information to the first network element based on the domain name or the address. The fifth information is used to indicate the correspondence between the first service identifier and the domain name, or the fifth information is used to indicate the correspondence between the first service identifier and the address. Correspondingly, the first network element receives the fifth information from the second network element.

[0268] In an optional manner, the second network element sending fifth information to the first network element based on the domain name or the address includes: the second network element sending fifth information to the first network element based on the domain name or the address and the stored server deployment information.

[0269] In an optional implementation manner, the second network element sending fifth information to the first network element based on the domain name or the address and the stored edge application server deployment information includes: the second network element determining the first service identifier corresponding to the domain name or the address based on the stored edge application server deployment information; the second network element sending fifth information to the first network element.

[0270] For example, take the FQDN as the domain name. The second network element receives FQDN#1 from the edge application server discovery function network element. The second network element determines the service identifier#1 (service identifier#1 is the first service identifier) corresponding to FQDN#1 based on the stored edge application server deployment information. The second network element sends fifth information to the first network element. The fifth information is used to indicate the correspondence between service identifier#1 and FQDN#1.

[0271] Another example, take the EAS IP address as the address. The second network element receives EAS IP address#1 from the edge application server discovery function network element. The second network element determines the service identifier#1 (service identifier#1 is the first service identifier) corresponding to EAS IP address#1 based on the stored edge application server deployment information. The second network element sends fifth information to the first network element. The fifth information is used to indicate the correspondence between service identifier#1 and EAS IP address#1.

[0272] In addition, embodiments of the present application do not limit the manner in which the fifth information indicates the correspondence between the first service identifier and the domain name, or the manner in which the fifth information indicates the correspondence between the first service identifier and the address. For example, when the fifth information is used to indicate the correspondence between the first service identifier and the domain name, it may be expressed as: the fifth information includes the first service identifier and the domain name. Another example is that when the fifth information is used to indicate the correspondence between the first service identifier and the address, it may be expressed as: the fifth information includes the first service identifier and the address.

[0273] In addition, step S202 may also be as described in the following optional implementation manners 2.1 and 2.2.

[0274] Implementation manner 2.1: The second network element sends the fifth information to the first network element based on the domain name or the address, including: when the fifth condition is satisfied, the second network element sends the fifth information to the first network element based on the domain name or the address; the fifth condition includes: the second network element has stored the identifier of the access and mobility management function network element.

[0275] Optionally, the fifth condition includes: the second network element has stored the identifier of the access and mobility management function network element and the identifier of the first network element. Here, the identifier of the access and mobility management function network element is, for example, the ID of the access and mobility management function network element, and the identifier of the first network element is, for example, the ID of the first network element.

[0276] Optionally, when the fifth condition is satisfied, the second network element sends the fifth information to the first network element based on the domain name or the address, which may be: the second network element determines whether the fifth condition is satisfied; if the second network element determines that the fifth condition is satisfied, it sends the fifth information to the first network element based on the domain name or the address.

[0277] Optionally, when the fifth condition is satisfied, the second network element sending the fifth information to the first network element based on the domain name or the address may also be replaced by: when the second network element has stored the identifier of the access and mobility management function network element, it sends the fifth information to the first network element based on the domain name or the address. In this way, the second network element may not perform the operation of determining whether the fifth condition is satisfied.

[0278] Implementation manner 2.2: The second network element sends the fifth information to the first network element based on the domain name or the address, including: when the sixth condition is satisfied, the second network element sends the fifth information to the first network element based on the domain name or the address; the sixth condition includes: the second network element has not sent the correspondence between the first service identifier and the domain name to the first network element, and the second network element has not sent the correspondence between the first service identifier and the address to the first network element.

[0279] Understandably, if the second network element has not sent the correspondence between the first service identifier and the domain name and the correspondence between the first service identifier and the address to the first network element, the second network element may send the fifth information to the first network element. If the second network element has already sent the correspondence between the first service identifier and the domain name or the correspondence between the first service identifier and the address to the first network element, the second network element may not send the fifth information to the first network element, reducing signaling overhead.

[0280] Optionally, when the sixth condition is met, the second network element may send the fifth information to the first network element based on the domain name or the address, which may be: the second network element determines whether the sixth condition is met; if the second network element determines that the sixth condition is met, it sends the fifth information to the first network element based on the domain name or the address.

[0281] Optionally, when the sixth condition is met, the second network element may send the fifth information to the first network element based on the domain name or the address, which may also be replaced by: when the second network element has not sent the correspondence between the first service identifier and the domain name and the correspondence between the first service identifier and the address to the first network element, it sends the fifth information to the first network element based on the domain name or the address. In this method, the second network element may not perform the operation of determining whether the sixth condition is met.

[0282] In addition, in one implementation, implementation 2.1 and implementation 2.2 may be combined and used. Specifically, the second network element sends the fifth information to the first network element based on the stored edge application server deployment information, including: when the fifth condition and the sixth condition are met, the second network element sends the fifth information to the first network element based on the domain name or the address.

[0283] In an alternative implementation, the method further includes: the first network element stores the correspondence between the first service identifier and the domain name, or stores the correspondence between the first service identifier and the address, based on the fifth information.

[0284] S203. The application function network element sends the first information and the first service identifier to the first network element, and the first information is used to indicate server rediscovery. Correspondingly, the first network element receives the first information and the first service identifier from the application function network element.

[0285] For the specific elaboration of step S203, reference may be made to the relevant elaboration of step S101 in communication method 100, which will not be elaborated here.

[0286] S204. The first network element sends a first message to the terminal device based on the fifth information and the first service identifier. The first message includes the domain name or the address corresponding to the first service identifier, and the first message is used to instruct the terminal device to clear the server information corresponding to the domain name or the address corresponding to the first service identifier. Correspondingly, the terminal device receives the second information and the domain name or the address corresponding to the first service identifier from the first network element.

[0287] For the specific description of the first message, refer to the relevant description in communication method 100, which will not be elaborated here.

[0288] In an alternative embodiment, the first network element sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier, including: the first network element determines the domain name or address corresponding to the first service identifier based on the fifth information and the first service identifier; the first network element sends the second information and the domain name or address corresponding to the first service identifier to the terminal device.

[0289] In addition, step S204 can also be implemented as described in the following alternative embodiments 3.1 to 3.4.

[0290] Embodiment 3.1, the first network element sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier, including: the first network element, when the first condition is met, sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier; the first condition includes: the edge application server deployment information of the first network element does not include the domain name and address corresponding to the first service identifier. This embodiment 3.1 is similar to embodiment 1.1 in communication method 100. For specific details, reference can also be made to the relevant description of embodiment 1.1 above, which will not be elaborated here.

[0291] Optionally, when the first condition is met, the first network element sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier, which can be: the first network element determines whether the first condition is met; if the first network element determines that the first condition is met, it sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier.

[0292] Optionally, when the first condition is met, the first network element sending the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier can also be replaced with: when the edge application server deployment information of the first network element does not include the domain name and address corresponding to the first service identifier, the first network element sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier. In this way, the first network element may not perform the operation of determining whether the first condition is met.

[0293] Embodiment 3.2. The method further includes: a first network element receives a data network access identifier corresponding to first information from an application function network element. The first network element sends a domain name or address corresponding to the second information and the first service identifier to the terminal device based on the fifth information and the first service identifier, including: when a second condition is satisfied, the first network element sends a domain name or address corresponding to the second information and the first service identifier to the terminal device based on the fifth information and the first service identifier; the second condition includes: the edge application server deployment information of the first network element does not include the data network access identifier. Embodiment 3.2 is similar to Embodiment 1.2 in the communication method 100. For specific details, reference may also be made to the relevant description of Embodiment 1.1 above, and details will not be elaborated here.

[0294] Optionally, when a second condition is satisfied, the first network element sends a domain name or address corresponding to the second information and the first service identifier to the terminal device based on the fifth information and the first service identifier, which may be: the first network element determines whether the second condition is satisfied; if the first network element determines that the second condition is satisfied, it sends a domain name or address corresponding to the second information and the first service identifier to the terminal device based on the fifth information and the first service identifier.

[0295] Optionally, when a second condition is satisfied, the first network element sending a domain name or address corresponding to the second information and the first service identifier to the terminal device based on the fifth information and the first service identifier may also be replaced with: when the edge application server deployment information of the first network element does not include the data network access identifier, the first network element sends a domain name or address corresponding to the second information and the first service identifier to the terminal device based on the fifth information and the first service identifier. In this way, the first network element may not perform the operation of determining whether the second condition is satisfied.

[0296] Embodiment 3.3. The first network element belongs to the home public land mobile network of the terminal device, and the second network element belongs to the visited public land mobile network of the terminal device. The first network element sends a domain name or address corresponding to the second information and the first service identifier to the terminal device based on the fifth information and the first service identifier, including: when a third condition is satisfied, the first network element sends a domain name or address corresponding to the second information and the first service identifier to the terminal device based on the fifth information and the first service identifier; the third condition includes: the first network element does not store the edge application server deployment information of the visited public land mobile network. Embodiment 3.3 is similar to Embodiment 1.3 in the communication method 100. For specific details, reference may also be made to the relevant description of Embodiment 1.3 above, and details will not be elaborated here.

[0297] Optionally, when the third condition is satisfied, the first network element sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier. This can be: The first network element determines whether the third condition is satisfied; if the first network element determines that the third condition is satisfied, it sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier.

[0298] Optionally, when the third condition is satisfied, the first network element sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier, and it can also be replaced with: When the first network element does not store the edge application server deployment information of the visited public land mobile network, it sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier. In this method, the first network element may not perform the operation of determining whether the third condition is satisfied.

[0299] In Embodiment 3.4, the method further includes: The first network element receives the third information from the second network element, where the third information is used to indicate the data network access identifier supported by the second network element; the first network element receives the data network access identifier corresponding to the first information from the application function network element. The first network element sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier, including: When the fourth condition is satisfied, the first network element sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier; the fourth condition includes: The data network access identifier corresponding to the first information is the data network access identifier supported by the second network element. Embodiment 3.4 is similar to Embodiment 1.4 in the communication method 100, and for specific details, reference can also be made to the relevant description of Embodiment 1.1 above, which will not be elaborated here.

[0300] Optionally, when the fourth condition is satisfied, the first network element sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier. This can be: The first network element determines whether the fourth condition is satisfied; if the first network element determines that the fourth condition is satisfied, it sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier.

[0301] Optionally, when the fourth condition is satisfied, the first network element sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier. Alternatively, it may be replaced with: when the data network access identifier corresponding to the first information is the data network access identifier supported by the second network element, the first network element sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier. In this method, the first network element may not perform the operation of determining whether the fourth condition is satisfied.

[0302] In addition, in an optional implementation, any multiple of the implementation manners from implementation manner 3.1 to implementation manner 3.4 may be combined and used. Specifically, the first network element sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier, including: when at least two of the first condition, the second condition, the third condition, and the fourth condition are satisfied, the first network element sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier.

[0303] In an optional implementation, the method further includes: the second network element sends multiple seventh information to the first network element, and the multiple seventh information includes the fifth information. Each seventh information is used to indicate the correspondence between the service identifier and the domain name, or is used to indicate the correspondence between the service identifier and the address. The first network element sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier, including: the first network element determines the domain name or address corresponding to the first service identifier from the multiple seventh information based on the first service identifier; the first network element sends the second information and the domain name or address corresponding to the first service identifier to the terminal device.

[0304] It can be understood that each of the multiple seventh information is used to indicate the correspondence between the service identifier and the domain name. Or, each of the multiple seventh information is used to indicate the correspondence between the service identifier and the address. Or, some of the multiple seventh information are used to indicate the correspondence between the service identifier and the domain name, and the remaining seventh information are used to indicate the correspondence between the service identifier and the address.

[0305] In addition, the embodiments of the present application do not limit the manner in which the second network element sends multiple seventh information. For example, the second network element may send multiple seventh information at the same time, or the second network element may also perform the operation of sending each seventh information after determining one seventh information each time.

[0306] Optionally, the method further includes: the first network element stores the correspondence between the service identifier and the domain name indicated by each of the multiple seventh information, or the correspondence between the service identifier and the address indicated by each of the multiple seventh information.

[0307] For example, take the FQDN as the domain name and the APP ID as the service identifier.

[0308] In the edge application server discovery process for FQDN#1, the second network element receives FQDN#1 from the edge application server discovery function network element. The second network element can determine the corresponding APP ID#1 for FQDN#1 based on the stored edge application server deployment information and send the seventh piece of information #1 to the first network element. The seventh piece of information #1 is used to indicate the correspondence between FQDN#1 and APP ID#1.

[0309] In the edge application server discovery process for FQDN#2, the second network element receives FQDN#2 from the edge application server discovery function network element. The second network element determines the corresponding APP ID#2 for FQDN#2 based on the stored edge application server deployment information and sends the seventh piece of information #2 to the first network element. The seventh piece of information #2 is used to indicate the correspondence between FQDN#2 and APP ID#2.

[0310] In the edge application server discovery process for FQDN#1, the second network element receives FQDN#3 from the edge application server discovery function network element. The second network element determines the corresponding APP ID#3 for FQDN#3 based on the stored edge application server deployment information and sends the seventh piece of information #3 to the first network element. The seventh piece of information #3 is used to indicate the correspondence between FQDN#3 and APP ID#3.

[0311] The first network element receives the first piece of information from the application function network element and APP ID#2 (APP ID#2 is the first service identifier). The first network element determines the FQDN#2 corresponding to APP ID#2 from the seventh piece of information #1, the seventh piece of information #2, and the seventh piece of information #3 based on APP ID#2. The first network element sends the second piece of information and FQDN#2 to the terminal device.

[0312] In an alternative implementation, the method further includes: the terminal device clears the server information corresponding to the domain name or address of the first service identifier. Optionally, after the terminal device clears the server information corresponding to the domain name or address of the first service identifier, the terminal device performs server rediscovery. The specific elaboration of this implementation can be referred to the relevant elaboration in communication method 100 and will not be repeated here.

[0313] The specific elaboration of the first network element sending the first message to the terminal device can also be referred to the relevant elaboration in communication method 100 and will not be repeated here.

[0314] In summary, in the communication method 200, the second network element receives the domain name or address from the edge application server discovery function network element. The second network element sends the fifth information to the first network element based on the stored edge application server deployment information. The fifth information is used to indicate the correspondence between the first service identifier and the domain name, or the fifth information is used to indicate the correspondence between the first service identifier and the address. The first network element receives the first information and the first service identifier from the application function network element. The first information is used to indicate the rediscovery of the edge application server. The first network element sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier. The second information is used to instruct the terminal device to clear the edge application server information corresponding to the domain name or address corresponding to the first service identifier.

[0315] It can be seen that this method is beneficial to enabling the terminal device to clear the edge application server information corresponding to the domain name or address corresponding to the first service identifier, so that the terminal device can obtain the address of the new edge application server, and then the new edge application server provides services for the terminal device to improve the service quality of the terminal device.

[0316] Please refer to Figure 10 , Figure 10 which is a schematic flowchart of a communication method 300 provided by an embodiment of the present application. The communication method 300 includes the following steps.

[0317] S301. The application function network element sends the first information and the first service identifier to the first network element. The first information is used to indicate the rediscovery of the edge application server. Correspondingly, the first network element receives the first information and the first service identifier from the application function network element.

[0318] For the specific elaboration of step S301, reference can be made to the relevant elaboration of step S101 in the communication method 100, which will not be repeated here.

[0319] S302. The first network element sends the sixth information to the application function network element. The sixth information is used to request the domain name or address corresponding to the first service identifier. Correspondingly, the application function network element receives the sixth information from the first network element.

[0320] In an alternative embodiment, the sixth information is used to request the domain name or address corresponding to the first service identifier, and it can also be understood that: the sixth information is used to request the application function network element to provide the domain name or address corresponding to the first service identifier.

[0321] The following elaborates on step S302 as described in the following alternative embodiments 4.1 to 4.4.

[0322] Embodiment 4.1. The first network element sends the sixth information to the application function network element, including: the first network element sends the sixth information to the application function network element when the first condition is satisfied; the first condition includes: the edge application server deployment information of the first network element does not include the domain name and address corresponding to the first service identifier. This Embodiment 4.1 is similar to Embodiment 1.1 in the communication method 100. For specific details, reference can also be made to the relevant description of Embodiment 1.1 above, and details will not be repeated here.

[0323] Optionally, when the first condition is satisfied, the first network element sends the sixth information to the application function network element, which may be: the first network element determines whether the first condition is satisfied; if the first network element determines that the first condition is satisfied, it sends the sixth information to the application function network element.

[0324] Optionally, when the first condition is satisfied, the first network element sending the sixth information to the application function network element can also be replaced with: the first network element sends the sixth information to the application function network element when the edge application server deployment information of the first network element does not include the domain name and address corresponding to the first service identifier. In this method, the first network element may not perform the operation of determining whether the first condition is satisfied.

[0325] Embodiment 4.2. The method further includes: the first network element receives the data network access identifier corresponding to the first information from the application function network element. The first network element sends the sixth information to the application function network element, including: the first network element sends the sixth information to the application function network element when the second condition is satisfied; the second condition includes: the edge application server deployment information of the first network element does not include the data network access identifier. This Embodiment 4.2 is similar to Embodiment 1.2 in the communication method 100. For specific details, reference can also be made to the relevant description of Embodiment 1.1 above, and details will not be repeated here.

[0326] Optionally, when the second condition is satisfied, the first network element sends the sixth information to the application function network element, which may be: the first network element determines whether the second condition is satisfied; if the first network element determines that the second condition is satisfied, it sends the sixth information to the application function network element.

[0327] Optionally, when the second condition is satisfied, the first network element sending the sixth information to the application function network element can also be replaced with: the first network element sends the sixth information to the application function network element when the edge application server deployment information of the first network element does not include the data network access identifier. In this method, the first network element may not perform the operation of determining whether the second condition is satisfied.

[0328] Embodiment 4.3: The first network element belongs to the home public land mobile network, the second network element belongs to the visited public land mobile network, and the serving public land mobile network of the terminal device is the visited public land mobile network. The first network element sends sixth information to the application function network element, including: the first network element sends the sixth information to the application function network element when a third condition is met; the third condition includes: the first network element does not store the edge application server deployment information of the visited public land mobile network. This Embodiment 4.3 is similar to Embodiment 1.3 in the communication method 100. For specific details, reference can also be made to the relevant description of Embodiment 1.3 above, and details will not be repeated here.

[0329] Optionally, when the first network element sends the sixth information to the application function network element when the third condition is met, it may be: the first network element determines whether the third condition is met; if the first network element determines that the third condition is met, it sends the sixth information to the application function network element.

[0330] Optionally, when the first network element sends the sixth information to the application function network element when the third condition is met, it may also be replaced with: the first network element sends the sixth information to the application function network element when the first network element does not store the edge application server deployment information of the visited public land mobile network. In this way, the first network element may not perform the operation of determining whether the third condition is met.

[0331] Embodiment 4.4: The method further includes: the first network element receives third information from the second network element, where the third information is used to indicate the data network access identifier supported by the second network element; the first network element receives the data network access identifier corresponding to the first information from the application function network element. The first network element sends sixth information to the application function network element, including: the first network element sends the sixth information to the application function network element when a fourth condition is met; the fourth condition includes: the data network access identifier corresponding to the first information is the data network access identifier supported by the second network element. This Embodiment 4.4 is similar to Embodiment 1.4 in the communication method 100. For specific details, reference can also be made to the relevant description of Embodiment 1.1 above, and details will not be repeated here.

[0332] Optionally, when the first network element sends the sixth information to the application function network element when the fourth condition is met, it may be: the first network element determines whether the fourth condition is met; if the first network element determines that the fourth condition is met, it sends the sixth information to the application function network element.

[0333] Optionally, when the first network element sends the sixth information to the application function network element when the fourth condition is met, it may also be replaced with: the first network element sends the sixth information to the application function network element when the data network access identifier corresponding to the first information is the data network access identifier supported by the second network element. In this way, the first network element may not perform the operation of determining whether the fourth condition is met.

[0334] In addition, in an optional implementation, any combination of multiple implementations from Implementation 4.1 to Implementation 4.4 can be used. Specifically, the first network element sends sixth information to the application function network element, including: the first network element sends sixth information to the application function network element when at least two of the first condition, the second condition, the third condition, and the fourth condition are satisfied.

[0335] S303. The application function network element sends the domain name or address corresponding to the first service identifier to the first network element. Correspondingly, the first network element receives the domain name or address corresponding to the first service identifier from the application function network element.

[0336] In an optional implementation, the method further includes: the first network element sends eighth information to the application function network element, and the eighth information is used to request the application function network element to re-send the application function request message. This implementation can be applied to the case where the first information sent by the application function network element and the first service identifier are carried in the application function request message sent by the application function network element. In this case, the domain name or address corresponding to the first service identifier sent by the application function network element can be carried in the application function request message re-sent by the application function network element. In an optional manner, the sixth information sent by the first network element is carried in the eighth information sent by the first network element.

[0337] Exemplarily, the application function network element sends application function request message #1, and application function request message #1 includes the first information and the first service identifier. The first network element sends the eighth information and the sixth information to the application function network element, or the first network element sends the eighth information (the eighth information includes the sixth information) to the application function network element, where the eighth information is used to request the application function network element to re-send the application function request message, and the sixth information is used to request the domain name or address corresponding to the first service identifier. The application function network element sends application function request message #2, and application function request message #2 includes the domain name or address corresponding to the first service identifier.

[0338] S304. The first network element sends a first message to the terminal device, and the first message includes the domain name or address corresponding to the first service identifier. The first message is used to instruct the terminal device to clear the edge application server information corresponding to the domain name or address corresponding to the first service identifier.

[0339] For the specific elaboration of the first message, reference can be made to the relevant elaboration in Communication Method 100, which will not be repeated here.

[0340] For the specific elaboration of the first network element sending the first message to the terminal device, reference can also be made to the relevant elaboration in Communication Method 100, which will not be repeated here.

[0341] In an alternative embodiment, the method further includes: the terminal device clears the edge application server information corresponding to the domain name or address of the first service identifier. Optionally, after the terminal device clears the edge application server information corresponding to the domain name or address of the first service identifier, the terminal device performs edge application server rediscovery. For the specific description of this embodiment, reference can be made to the relevant description in the communication method 100, which will not be elaborated here.

[0342] In summary, in the communication method 300, the application function network element sends the first information and the first service identifier to the first network element, and the first information is used to indicate edge application server rediscovery. The first network element sends the sixth information to the application function network element, and the sixth information is used to request the domain name or address corresponding to the first service identifier. The application function network element sends the domain name or address corresponding to the first service identifier to the first network element. The first network element sends the second information and the domain name or address corresponding to the first service identifier to the terminal device, and the second information is used to indicate the terminal device to clear the edge application server information corresponding to the domain name or address of the first service identifier.

[0343] It can be seen that this method is beneficial for the terminal device to clear the edge application server information corresponding to the domain name or address of the first service identifier, thereby facilitating the terminal device to perform edge application server rediscovery to re-obtain the address of the edge application server, and then the edge application server corresponding to the re-obtained address provides services for the terminal device, that is, the re-discovered edge application server provides services for the terminal device.

[0344] This method can be applied to the scenario where the load of the edge application server accessed by the terminal device is too high. In this scenario, through this communication method, it is beneficial for the terminal device to clear the edge application server information corresponding to the domain name or address of the first service identifier, so that the terminal device can perform edge application server rediscovery, and then the re-discovered edge application server provides services for the terminal device, improving the service quality for the terminal device and improving the communication performance.

[0345] Please refer to Figure 11 , Figure 11 which is a schematic flowchart of a communication method 400 provided by an embodiment of the present application. The communication method 400 includes the following steps.

[0346] S401. The application function network element sends the first information and the first service identifier to the first network element, and the first information is used to indicate edge application server rediscovery. Correspondingly, the first network element receives the first information and the first service identifier from the application function network element.

[0347] For the specific description of S401, reference can be made to the relevant description in the communication method 100, which will not be elaborated here.

[0348] S402. When the first network element fails to obtain the domain name or address corresponding to the first service identifier, it sends second information to the terminal device. The second information is used to instruct the terminal device to clear all edge application server information related to the first session, and the first session is used for the terminal device to access the service corresponding to the first service identifier.

[0349] For the specific elaboration of the second information, refer to the relevant elaboration in communication method 100, which will not be repeated here.

[0350] In an optional manner, the situation where the first network element fails to obtain the domain name or address corresponding to the first service identifier includes: the edge application server deployment information of the first network element does not include the domain name and address corresponding to the first service identifier; or, the first network element does not store the edge application server deployment information of the visited public land mobile network; or, the edge application server deployment information of the first network element does not include the data network access identifier; or, the data network access identifier corresponding to the first information is the data network access identifier supported by the second network element; or, the first network element is a home domain session management function network element, and the second network element is a visited domain session management function network element; or, the first network element is a session management function network element, and the second network element is an intermediate session management function network element; or, the first network element is a session management function network element, and the second network element is used to assist the session management function network element in processing edge application server-related information. For the specific elaboration, refer to the relevant elaboration above, which will not be repeated here.

[0351] In an optional manner, in the expression of instructing the terminal device to clear all edge application server information related to the first session, "clear" can also be replaced with "delete", "refresh", etc.

[0352] In an optional implementation manner, the method further includes: the terminal device clears the edge application server information corresponding to the domain name or address of the first service identifier. Optionally, after the terminal device clears the edge application server information corresponding to the domain name or address of the first service identifier, the terminal device performs edge application server re-discovery. For the specific elaboration of this implementation manner, refer to the relevant elaboration in communication method 100, which will not be repeated here.

[0353] It can be seen that this method is beneficial to the edge application server information related to the first session of the terminal device, thereby facilitating the terminal device to perform edge application server re-discovery to re-obtain the address of the edge application server, and then the edge application server corresponding to the re-obtained address provides services for the terminal device, that is, the re-discovered edge application server provides services for the terminal device.

[0354] The method can be applied to the scenario where the edge application server accessed by the terminal device is overloaded. In this scenario, through this communication method, it is beneficial for the terminal device to clear the edge application server information related to the first session, so that the terminal device can perform rediscovery of the edge application server, and then the rediscovered edge application server provides services for the terminal device, improving the service quality for the terminal device and enhancing the communication performance.

[0355] To implement each function in the method provided in the embodiments of the present application above, the network element / device may include a hardware structure and / or a software module, and implement the above functions in the form of a hardware structure, a software module, or a combination of a hardware structure and a software module. Whether a certain function among the above functions is executed in the form of a hardware structure, a software module, or a combination of a hardware structure and a software module depends on the specific application and design constraints of the technical solution.

[0356] As Figure 12 shown, an embodiment of the present application provides a communication device 1200. The communication device 1200 may be a first network element, a second network element, or an application function network element, and may also be a component of the first network element (for example, an integrated circuit, a chip, etc.), may also be a component of the second network element (for example, an integrated circuit, a chip, etc.), and may also be a component of the application function network element (for example, an integrated circuit, a chip, etc.). The communication device 1200 may also be other communication units for implementing the method in the method embodiments of the present application. The communication device 1200 may include a processing unit 1201. Optionally, the communication device 1200 may further include a communication unit 1202. The processing unit 1201 is used to control the communication unit 1202 to perform data / signaling transceiver, and the communication unit 1202 may also be referred to as a transceiver unit. Optionally, the communication unit 1202 may include a sending unit and a receiving unit. The sending unit may be used to send data / signaling, and the receiving unit may be used to receive data / signaling. Optionally, the communication device 1200 may further include a storage unit 1203. The storage unit 1203 may be used to store information and / or data and / or instructions, etc. The storage unit 1203 may interact with the processing unit 1201 or may also interact with the communication unit 1202.

[0357] In a possible design, for the case where the communication device 1200 is used to implement the functions of the first network element in the above method embodiments:

[0358] The communication unit 1202 is configured to receive first information and a first service identifier from an application function network element, where the first information is used to indicate server rediscovery. The communication unit 1202 is further configured to send the first service identifier to a second network element. The communication unit 1202 is further configured to receive a domain name or an address corresponding to the first service identifier from the second network element. The communication unit 1202 is further configured to send a first message to a terminal device, where the first message includes the domain name or the address corresponding to the first service identifier, and the first message is used to instruct the terminal device to clear server information corresponding to the domain name or the address corresponding to the first service identifier.

[0359] In an alternative embodiment, the communication unit 1202 sending the first service identifier to the second network element is specifically configured to: send the first service identifier to the second network element when a first condition is satisfied; the first condition includes: the server deployment information of the communication device 1200 does not include the domain name and address corresponding to the first service identifier.

[0360] In an alternative embodiment, the communication unit 1202 is further configured to receive a data network access identifier corresponding to the first information from the application function network element. The communication unit 1202 sending the first service identifier to the second network element is specifically configured to: send the first service identifier to the second network element when a second condition is satisfied; the second condition includes: the server deployment information of the communication device 1200 does not include the data network access identifier.

[0361] In an alternative embodiment, the communication device 1200 belongs to the home public land mobile network of the terminal device, and the second network element belongs to the visited public land mobile network of the terminal device. The communication unit 1202 sending the first service identifier to the second network element is specifically configured to: send the first service identifier to the second network element when a third condition is satisfied; the third condition includes: the communication device 1200 does not store the server deployment information of the visited public land mobile network.

[0362] In an alternative embodiment, the communication unit 1202 is further configured to receive third information from the second network element, where the third information is used to indicate a data network access identifier supported by the second network element; the communication unit 1202 is further configured to receive a data network access identifier corresponding to the first information from the application function network element. The communication unit 1202 sending the first service identifier to the second network element is specifically configured to: send the first service identifier to the second network element when a fourth condition is satisfied; the fourth condition includes: the data network access identifier corresponding to the first information is the data network access identifier supported by the second network element.

[0363] In an alternative embodiment, the communication unit 1202 is further configured to send fourth information to the second network element, where the fourth information is used to request a domain name or an address corresponding to the first service identifier.

[0364] In an alternative embodiment, the communication device 1200 is a home domain session management function network element, and the second network element is a visited domain session management function network element. Alternatively, the communication device 1200 is a session management function network element, and the second network element is an intermediate session management function network element. Alternatively, the communication device 1200 is a session management function network element, and the second network element is used to assist the session management function network element in processing server-related information.

[0365] In another possible design, for the case where the communication device 1200 is used to implement the functions of the second network element in the above method embodiments:

[0366] The communication unit 1202 is configured to receive a first service identifier from a first network element. The communication unit 1202 is further configured to send a domain name or address corresponding to the first service identifier to the first network element based on the stored server deployment information.

[0367] In an alternative embodiment, the communication unit 1202 is further configured to receive fourth information from the first network element, where the fourth information is used to request a domain name or address corresponding to the first service identifier.

[0368] In an alternative embodiment, the first network element is a home domain session management function network element, and the communication device 1200 is a visited domain session management function network element. Alternatively, the first network element is a session management function network element, and the communication device 1200 is an intermediate session management function network element. Alternatively, the first network element is a session management function network element, and the communication device 1200 is used to assist the session management function network element in processing server-related information.

[0369] In another possible design, for the case where the communication device 1200 is used to implement the functions of the first network element in the above method embodiments:

[0370] The communication unit 1202 is configured to receive fifth information from the second network element, where the fifth information is used to indicate the correspondence between the first service identifier and a domain name, or the fifth information is used to indicate the correspondence between the first service identifier and an address. The communication unit 1202 is further configured to receive first information and the first service identifier from an application function network element, where the first information is used to indicate server rediscovery. The communication unit 1202 is further configured to send a first message to the terminal device based on the fifth information and the first service identifier, where the first message includes a domain name or address corresponding to the first service identifier, and the first message is used to instruct the terminal device to clear the server information corresponding to the domain name or address corresponding to the first service identifier.

[0371] In an alternative embodiment, the communication unit 1202 sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier, specifically for: when the first condition is satisfied, sending the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier; the first condition includes: the server deployment information of the communication device 1200 does not include the domain name and address corresponding to the first service identifier.

[0372] In an alternative embodiment, the communication unit 1202 is further configured to receive the data network access identifier corresponding to the first information from the application function network element. The communication unit 1202 sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier, specifically for: when the second condition is satisfied, sending the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier; the second condition includes: the server deployment information of the communication device 1200 does not include the data network access identifier.

[0373] In an alternative embodiment, the communication device 1200 belongs to the home public land mobile network of the terminal device, and the second network element belongs to the visited public land mobile network of the terminal device. The communication unit 1202 sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier, specifically for: when the third condition is satisfied, sending the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier; the third condition includes: the communication device 1200 does not store the server deployment information of the visited public land mobile network.

[0374] In an alternative embodiment, the communication unit 1202 is further configured to receive the third information from the second network element, where the third information is used to indicate the data network access identifier supported by the second network element; the communication unit 1202 is further configured to receive the data network access identifier corresponding to the first information from the application function network element. The communication unit 1202 sends the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier, specifically for: when the fourth condition is satisfied, sending the second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier; the fourth condition includes: the data network access identifier corresponding to the first information is the data network access identifier supported by the second network element.

[0375] In an alternative embodiment, the communication device 1200 is a home domain session management function network element, and the second network element is a visited domain session management function network element. Alternatively, the communication device 1200 is a session management function network element, and the second network element is an intermediate session management function network element. Alternatively, the communication device 1200 is a session management function network element, and the second network element is used to assist the session management function network element in processing server-related information.

[0376] In another possible design, for the case where the communication device 1200 is used to implement the functions of the second network element in the above method embodiments:

[0377] The communication unit 1202 is configured to receive a domain name or an address from a server discovery function network element. The communication unit 1202 is further configured to send a fifth piece of information to the first network element based on the domain name or the address, where the fifth piece of information is used to indicate the correspondence between the first service identifier and the domain name, or the fifth piece of information is used to indicate the correspondence between the first service identifier and the address.

[0378] In an alternative embodiment, the communication unit 1202 sends the fifth piece of information to the first network element based on the domain name or the address, specifically: when a fifth condition is met, the communication unit 1202 sends the fifth piece of information to the first network element based on the domain name or the address; the fifth condition includes that the communication device 1200 has stored the identifier of the access and mobility management function network element.

[0379] In an alternative embodiment, the communication unit 1202 sends the fifth piece of information to the first network element based on the domain name or the address, specifically: when a sixth condition is met, the communication unit 1202 sends the fifth piece of information to the first network element based on the domain name or the address; the sixth condition includes that the communication unit 1202 has not sent the correspondence between the first service identifier and the domain name to the first network element, and the communication unit 1202 has not sent the correspondence between the first service identifier and the address to the first network element.

[0380] In an alternative embodiment, the first network element is a home domain session management function network element, and the communication device 1200 is a visited domain session management function network element. Alternatively, the first network element is a session management function network element, and the communication device 1200 is an intermediate session management function network element. Alternatively, the first network element is a session management function network element, and the communication device 1200 is used to assist the session management function network element in processing server-related information.

[0381] In an alternative embodiment, the second network element sends the fifth piece of information to the first network element based on the domain name or the address, including: the second network element sends the fifth piece of information to the first network element based on the domain name or the address and the stored server deployment information.

[0382] In another possible design, for the case where the communication device 1200 is used to implement the functions of the first network element in the above method embodiments:

[0383] A communication unit 1202, configured to receive first information and a first service identifier from an application function network element, where the first information is used to indicate server rediscovery. The communication unit 1202 is further configured to send sixth information to the application function network element, where the sixth information is used to request a domain name or an address corresponding to the first service identifier. The communication unit 1202 is further configured to receive a domain name or an address corresponding to the first service identifier from the application function network element. The communication unit 1202 is further configured to send a first message to a terminal device, where the first message includes a domain name or an address corresponding to the first service identifier, and the first message is used to instruct the terminal device to clear server information corresponding to the domain name or the address corresponding to the first service identifier.

[0384] In an optional implementation manner, the communication unit 1202 sending the sixth information to the application function network element is specifically configured to: send the sixth information to the application function network element when a first condition is met; the first condition includes: the server deployment information of the communication device 1200 does not include a domain name and an address corresponding to the first service identifier.

[0385] In an optional implementation manner, the communication unit 1202 is further configured to receive a data network access identifier corresponding to the first information from the application function network element. The communication unit 1202 sending the sixth information to the application function network element is specifically configured to: send the sixth information to the application function network element when a second condition is met; the second condition includes: the server deployment information of the communication device 1200 does not include the data network access identifier.

[0386] In an optional implementation manner, the communication device 1200 belongs to the home public land mobile network of the terminal device, and the second network element belongs to the visited public land mobile network of the terminal device. The communication unit 1202 sending the sixth information to the application function network element is specifically configured to: send the sixth information to the application function network element when a third condition is met; the third condition includes: the communication device 1200 does not store server deployment information of the visited public land mobile network.

[0387] In an optional implementation manner, the communication unit 1202 is further configured to receive third information from a second network element, where the third information is used to indicate a data network access identifier supported by the second network element; the communication unit 1202 is further configured to receive a data network access identifier corresponding to the first information from the application function network element. The communication unit 1202 sending the sixth information to the application function network element is specifically configured to: send the sixth information to the application function network element when a fourth condition is met; the fourth condition includes: the data network access identifier corresponding to the first information is a data network access identifier supported by the second network element.

[0388] In an alternative embodiment, the communication device 1200 is a home domain session management function network element, and the second network element is a visited domain session management function network element. Alternatively, the communication device 1200 is a session management function network element, and the second network element is an intermediate session management function network element. Alternatively, the communication device 1200 is a session management function network element, and the second network element is used to assist the session management function network element in processing server-related information.

[0389] In another possible design, for the case where the communication device 1200 is used to implement the functions of the application function network element in the above method embodiments:

[0390] The communication unit 1202 is configured to send a first piece of information and a first service identifier to the first network element, where the first piece of information is used to indicate server rediscovery. The communication unit 1202 is further configured to receive a sixth piece of information from the first network element, where the sixth piece of information is used to request the domain name or address corresponding to the first service identifier. The communication unit 1202 is further configured to send the domain name or address corresponding to the first service identifier to the first network element.

[0391] The embodiments of the present application and the method embodiments shown above are based on the same concept, and the technical effects brought by them are also the same. For the specific principle, please refer to the description of the above embodiments and will not be elaborated here.

[0392] The embodiments of the present application further provide a communication device 1300, as Figure 13 shown. The communication device 1300 may be an SF network element or an SMF network element, or may be a chip, a chip system, or a processor that supports the SF network element or the SMF network element to implement the above method. This device can be used to implement the method described in the above method embodiments, and specifically, reference can be made to the description in the above method embodiments.

[0393] The communication device 1300 may include one or more processors 1301. The processor 1301 can be used to implement some or all of the functions of the above SF network element or SMF network element through logic circuits or by running computer programs. The processor 1301 may be a general-purpose processor or a dedicated processor, etc. For example, it may be a baseband processor, a digital signal processor, an application-specific integrated circuit, a field-programmable gate array, or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or a CPU. The baseband processor can be used to process communication protocols and communication data, and the central processing unit can be used to control the communication device, execute software programs, and process the data of the software programs, where the communication device is, for example, a base station, a baseband chip, a terminal, a terminal chip, a distributed unit (DU), or a centralized unit (CU), etc.

[0394] Optionally, the communication device 1300 may include one or more memories 1302, on which instructions 1304 may be stored and executable on the processor 1301, so that the communication device 1300 executes the methods described in the above method embodiments. Optionally, data may also be stored in the memory 1302. The processor 1301 and the memory 1302 may be provided separately or integrated together.

[0395] The memory 1302 may include, but is not limited to, non-volatile memories such as a hard disk drive (HDD) or a solid-state drive (SSD), a random access memory (RAM), an erasable programmable ROM (EPROM), a ROM, or a compact disc read-only memory (CD-ROM), etc.

[0396] Optionally, the communication device 1300 may further include a transceiver 1305 and an antenna 1306. The transceiver 1305 may be referred to as a transceiver unit, a transceiver, or a transceiver circuit, etc., for implementing transceiver functions. The transceiver 1305 may include a receiver and a transmitter. The receiver may be referred to as a receiver or a receiving circuit, etc., for implementing receiving functions; the transmitter may be referred to as a transmitter or a transmitting circuit, etc., for implementing transmitting functions.

[0397] In a possible design, for the case where the communication device 1300 is used to implement the function of the first network element in the above method embodiments:

[0398] The transceiver 1305 is configured to receive a first piece of information and a first service identifier from an application function network element, where the first piece of information is used to indicate server rediscovery. The transceiver 1305 is further configured to send the first service identifier to a second network element. The transceiver 1305 is further configured to receive a domain name or an address corresponding to the first service identifier from the second network element. The transceiver 1305 is further configured to send a first message to a terminal device, where the first message includes a domain name or an address corresponding to the first service identifier, and the first message is used to instruct the terminal device to clear server information corresponding to the domain name or the address corresponding to the first service identifier.

[0399] In another possible design, for the case where the communication device 1300 is used to implement the function of the second network element in the above method embodiments:

[0400] The transceiver 1305 is configured to receive a first service identifier from a first network element. The transceiver 1305 is further configured to send a domain name or an address corresponding to the first service identifier to the first network element based on stored server deployment information.

[0401] In another possible design, for the case where the communication device 1300 is used to implement the function of the first network element in the above method embodiments:

[0402] The transceiver 1305 is configured to receive fifth information from a second network element, where the fifth information is used to indicate the correspondence between a first service identifier and a domain name, or the fifth information is used to indicate the correspondence between a first service identifier and an address. The transceiver 1305 is further configured to receive first information and a first service identifier from an application function network element, where the first information is used to indicate server rediscovery. The transceiver 1305 is further configured to send a first message to a terminal device based on the fifth information and the first service identifier, where the first message includes the domain name or address corresponding to the first service identifier, and the first message is used to instruct the terminal device to clear the server information corresponding to the domain name or address corresponding to the first service identifier.

[0403] In another possible design, for the case where the communication device 1300 is used to implement the function of the second network element in the above method embodiments:

[0404] The transceiver 1305 is configured to receive a domain name or an address from a server discovery function network element. The transceiver 1305 is further configured to send fifth information to a first network element based on the domain name or address, where the fifth information is used to indicate the correspondence between a first service identifier and a domain name, or the fifth information is used to indicate the correspondence between a first service identifier and an address.

[0405] In another possible design, for the case where the communication device 1300 is used to implement the function of the first network element in the above method embodiments:

[0406] The transceiver 1305 is configured to receive first information and a first service identifier from an application function network element, where the first information is used to indicate server rediscovery. The transceiver 1305 is further configured to send sixth information to the application function network element, where the sixth information is used to request the domain name or address corresponding to the first service identifier. The transceiver 1305 is further configured to receive the domain name or address corresponding to the first service identifier from the application function network element. The transceiver 1305 is further configured to send a first message to a terminal device, where the first message includes the domain name or address corresponding to the first service identifier, and the first message is used to instruct the terminal device to clear the server information corresponding to the domain name or address corresponding to the first service identifier.

[0407] In another possible design, for the case where the communication device 1300 is used to implement the function of the application function network element in the above method embodiments:

[0408] The transceiver 1305 is configured to send first information and a first service identifier to the first network element, wherein the first information is used to instruct the server to rediscover. The transceiver 1305 is also configured to receive sixth information from the first network element, wherein the sixth information is used to request a domain name or address corresponding to the first service identifier. The transceiver 1305 is also configured to send a domain name or address corresponding to the first service identifier to the first network element.

[0409] In another possible design, the processor 1301 may include a transceiver for implementing the receiving and sending functions. For example, the transceiver may be a transceiver circuit, or an interface, or an interface circuit. The transceiver circuit, interface, or interface circuit for implementing the receiving and sending functions may be separate or integrated. The above-mentioned transceiver circuit, interface, or interface circuit may be used for reading and writing code / data, or the above-mentioned transceiver circuit, interface, or interface circuit may be used for transmitting or delivering signals.

[0410] In another possible design, optionally, the processor 1301 may store an instruction 1303, and the instruction 1303 runs on the processor 1301, so that the communication device 1300 can perform the method described in the above method embodiment. The instruction 1303 may be solidified in the processor 1301, in which case the processor 1301 may be implemented by hardware.

[0411] In yet another possible design, the communication device 1300 may include circuitry that can implement the functions of transmitting, receiving, or communicating in the foregoing method embodiments. The processor and transceiver described in the embodiments of the present application can be implemented on an integrated circuit (IC), an analog IC, a radio frequency integrated circuit (RFIC), a mixed-signal IC, an application specific integrated circuit (ASIC), a printed circuit board (PCB), an electronic device, etc. The processor and transceiver can also be fabricated using various IC process technologies, such as complementary metal oxide semiconductor (CMOS), N-type metal oxide semiconductor (NMOS), P-type metal oxide semiconductor (PMOS), bipolar junction transistor (BJT), BiCMOS, silicon germanium (SiGe), gallium arsenide (GaAs), etc.

[0412] Those skilled in the art can also understand that the various illustrative logical blocks and steps listed in the embodiments of the present application can be implemented by electronic hardware, computer software, or a combination of both. Whether such a function is implemented by hardware or software depends on the specific application and the design requirements of the entire system. For a specific application, those skilled in the art can use various methods to implement the described function, but such implementation should not be construed as exceeding the scope of protection of the embodiments of the present application.

[0413] The embodiments of the present application and the foregoing method embodiments are based on the same concept and bring the same technical effects. For the specific principle, please refer to the description in the foregoing method embodiments and will not be elaborated herein.

[0414] The present application also provides a computer-readable storage medium for storing computer software instructions, which, when executed by a communication device, implement the functions of any of the foregoing method embodiments.

[0415] The present application also provides a computer program product for storing computer software instructions, which, when executed by a communication device, implement the functions of any of the foregoing method embodiments.

[0416] The present application also provides a computer program which, when running on a computer, implements the functions of any of the above method embodiments.

[0417] The present application also provides a chip which includes a processor. The processor is configured to execute code or instructions to implement the functions of any of the above method embodiments. Optionally, the chip further includes an interface, and the processor is coupled to the interface, and the interface is configured to receive or output signals.

[0418] In the above embodiments, all or part of them can be implemented by software, hardware, firmware or any combination thereof. When implemented using software, all or part of it can be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from a website, a computer, a server or a data center to another website, computer, server or data center by wire (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium accessible by a computer or a data storage device such as a server, a data center, etc. that includes one or more available media integrated. The available medium can be a magnetic medium (such as a floppy disk, a hard disk, a magnetic tape), an optical medium (such as a high-density digital video disc (DVD)), or a semiconductor medium (such as an SSD), etc.

[0419] As described above, the above are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, which should all be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A communication method, characterized in that, The method includes: A first network element receives first information from an application function network element and a first service identifier, where the first information is used to indicate server rediscovery; The first network element sends the first service identifier to a second network element; The first network element receives a domain name or address corresponding to the first service identifier from the second network element; The first network element sends a first message to a terminal device, where the first message includes the domain name or address corresponding to the first service identifier, and the first message is used to instruct the terminal device to clear server information corresponding to the domain name or address of the first service identifier.

2. The method according to claim 1, wherein The first network element sending the first service identifier to the second network element includes: The first network element sends the first service identifier to the second network element when a first condition is satisfied; The first condition includes: the server deployment information of the first network element does not include the domain name and address corresponding to the first service identifier.

3. The method according to claim 1, wherein The method further includes: The first network element receives a data network access identifier corresponding to the first information from the application function network element; The first network element sending the first service identifier to the second network element includes: The first network element sends the first service identifier to the second network element when a second condition is satisfied; The second condition includes: the server deployment information of the first network element does not include the data network access identifier.

4. The method according to claim 1, wherein The first network element belongs to the home public land mobile network of the terminal device, and the second network element belongs to the visited public land mobile network of the terminal device; The first network element sending the first service identifier to the second network element includes: The first network element sends the first service identifier to the second network element when a third condition is satisfied; The third condition includes: the first network element does not store the server deployment information of the visited public land mobile network.

5. The method according to claim 1, characterized in that, The method further includes: The first network element receives third information from the second network element, where the third information is used to indicate data network access identifiers supported by the second network element; The first network element receives a data network access identifier corresponding to the first information from the application function network element; The first network element sending the first service identifier to the second network element includes: The first network element sends the first service identifier to the second network element when a fourth condition is satisfied; The fourth condition includes: the data network access identifier corresponding to the first information is a data network access identifier supported by the second network element.

6. The method according to any one of claims 1 to 5, characterized in that, The method further includes: The first network element sends fourth information to the second network element, where the fourth information is used to request the domain name or address corresponding to the first service identifier.

7. The method according to any one of claims 1 to 6, wherein The first network element is a home domain session management function network element, and the second network element is a visited domain session management function network element; or, The first network element is a session management function network element, and the second network element is an intermediate session management function network element; or, The first network element is a session management function network element, and the second network element is used to assist the session management function network element in processing server-related information.

8. A communication method, characterized in that, The method includes: The first network element receives fifth information from the second network element, where the fifth information is used to indicate the correspondence between a first service identifier and a domain name, or the fifth information is used to indicate the correspondence between the first service identifier and an address; The first network element receives first information and a first service identifier from an application function network element, where the first information is used to indicate server rediscovery; Based on the fifth information and the first service identifier, the first network element sends a first message to the terminal device, where the first message includes the domain name or address corresponding to the first service identifier, and the first message is used to instruct the terminal device to clear the server information corresponding to the domain name or address corresponding to the first service identifier.

9. The method according to claim 8, wherein The first network element sends second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier, including: When a first condition is satisfied, the first network element sends second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier; The first condition includes: the server deployment information of the first network element does not include the domain name and address corresponding to the first service identifier.

10. The method according to claim 8, characterized in that, The method further includes: The first network element receives a data network access identifier corresponding to the first information from the application function network element; The first network element sends second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier, including: When a second condition is satisfied, the first network element sends second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier; The second condition includes: the server deployment information of the first network element does not include the data network access identifier.

11. The method according to claim 8, wherein The first network element belongs to the home public land mobile network of the terminal device, and the second network element belongs to the visited public land mobile network of the terminal device; The first network element sends second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier, including: When a third condition is satisfied, the first network element sends second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier; The third condition includes: the first network element does not store the server deployment information of the visited public land mobile network.

12. The method according to claim 8, wherein, The method further includes: The first network element receives third information from the second network element, where the third information is used to indicate the data network access identifiers supported by the second network element; The first network element receives a data network access identifier corresponding to the first information from the application function network element; The first network element sends second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier, including: When a fourth condition is satisfied, the first network element sends second information and the domain name or address corresponding to the first service identifier to the terminal device based on the fifth information and the first service identifier; The fourth condition includes: the data network access identifier corresponding to the first information is a data network access identifier supported by the second network element.

13. The method according to any one of claims 8 to 12, wherein the first network element is a home domain session management function network element, and the second network element is a visited domain session management function network element; or the first network element is a session management function network element, and the second network element is an intermediate session management function network element; or the first network element is a session management function network element, and the second network element is used to assist the session management function network element in processing server-related information.

14. A communication method, characterized in that, The method includes: The second network element receives a domain name or address from a server discovery function network element; The second network element sends fifth information to the first network element based on the domain name or address, where the fifth information is used to indicate the correspondence between the first service identifier and the domain name, or the fifth information is used to indicate the correspondence between the first service identifier and the address.

15. The method according to claim 14, wherein The second network element sending the fifth information to the first network element based on the domain name or address includes: When a fifth condition is satisfied, the second network element sends the fifth information to the first network element based on the domain name or address; The fifth condition includes: the second network element has stored the identifier of the access and mobility management function network element.

16. The method according to claim 14 or 15, characterized in that, The second network element sending the fifth information to the first network element based on the domain name or address includes: When a sixth condition is satisfied, the second network element sends the fifth information to the first network element based on the domain name or address; The sixth condition includes: the second network element has not sent the correspondence between the first service identifier and the domain name to the first network element, and the second network element has not sent the correspondence between the first service identifier and the address to the first network element.

17. The method according to any one of claims 14 to 16, characterized in that, The second network element sending the fifth information to the first network element based on the domain name or address includes: The second network element sends the fifth information to the first network element based on the domain name or address and the stored server deployment information.

18. The method according to any one of claims 14 to 17, wherein the first network element is a home domain session management function network element, and the second network element is a visited domain session management function network element; or the first network element is a session management function network element, and the second network element is an intermediate session management function network element; or the first network element is a session management function network element, and the second network element is used to assist the session management function network element in processing server-related information.

19. A communication method, characterized in that, The method includes: The first network element receives first information and a first service identifier from an application function network element, where the first information is used to indicate server rediscovery; The first network element sends sixth information to the application function network element, where the sixth information is used to request the domain name or address corresponding to the first service identifier; The first network element receives the domain name or address corresponding to the first service identifier from the application function network element; The first network element sends a first message to the terminal device, where the first message includes the domain name or address corresponding to the first service identifier, and the first message is used to instruct the terminal device to clear the server information corresponding to the domain name or address of the first service identifier.

20. The method according to claim 19, wherein The first network element sending sixth information to the application function network element includes: The first network element sends sixth information to the application function network element when a first condition is met; The first condition includes: the server deployment information of the first network element does not include the domain name and address corresponding to the first service identifier.

21. The method according to claim 19, wherein The method further includes: The first network element receives the data network access identifier corresponding to the first information from the application function network element; The first network element sending sixth information to the application function network element includes: The first network element sends sixth information to the application function network element when a second condition is met; The second condition includes: the server deployment information of the first network element does not include the data network access identifier.

22. According to the method described in claim 19, wherein, The first network element belongs to the home public land mobile network of the terminal device, and the second network element belongs to the visited public land mobile network of the terminal device; The first network element sending sixth information to the application function network element includes: The first network element sends sixth information to the application function network element when a third condition is met; The third condition includes: the first network element does not store the server deployment information of the visited public land mobile network.

23. The method according to claim 19, characterized in that, The method further includes: The first network element receives third information from the second network element, where the third information is used to indicate the data network access identifier supported by the second network element; The first network element receives the data network access identifier corresponding to the first information from the application function network element; The first network element sending sixth information to the application function network element includes: The first network element sends sixth information to the application function network element when a fourth condition is met; The fourth condition includes: the data network access identifier corresponding to the first information is the data network access identifier supported by the second network element.

24. A communication method, characterized in that, The method includes: A first network element receives first information and a first service identifier from an application function network element, where the first information is used to indicate server rediscovery; The first network element sends the first service identifier to a second network element; The second network element receives the first service identifier from the first network element; Based on the stored server deployment information, the second network element sends the domain name or address corresponding to the first service identifier to the first network element; The first network element receives the domain name or address corresponding to the first service identifier from the second network element; The first network element sends a first message to the terminal device. The first message includes the domain name or address corresponding to the first service identifier, and the first message is used to instruct the terminal device to clear the server information corresponding to the domain name or address corresponding to the first service identifier.

25. A communication method, characterized in that, The method includes: The second network element receives a domain name or address from the server discovery function network element; Based on the domain name or address, the second network element sends fifth information to the first network element. The fifth information is used to indicate the correspondence between the first service identifier and the domain name, or the fifth information is used to indicate the correspondence between the first service identifier and the address; The first network element receives the fifth information from the second network element; The first network element receives first information and a first service identifier from the application function network element. The first information is used to indicate server re-discovery; Based on the fifth information and the first service identifier, the first network element sends a first message to the terminal device. The first message includes the domain name or address corresponding to the first service identifier, and the first message is used to instruct the terminal device to clear the server information corresponding to the domain name or address corresponding to the first service identifier.

26. A communication system, characterized in that, The system includes a first network element and a second network element; The first network element is configured to receive first information and a first service identifier from the application function network element. The first information is used to indicate server re-discovery; The first network element is further configured to send the first service identifier to the second network element; The second network element is configured to receive the first service identifier from the first network element; The second network element is further configured to send the domain name or address corresponding to the first service identifier to the first network element based on the stored server deployment information; The first network element is further configured to receive the domain name or address corresponding to the first service identifier from the second network element; The first network element is further configured to send a first message to the terminal device. The first message includes the domain name or address corresponding to the first service identifier, and the first message is used to instruct the terminal device to clear the server information corresponding to the domain name or address corresponding to the first service identifier.

27. A communication system, characterized in that, The system includes a first network element and a second network element; The second network element is configured to receive a domain name or address from the server discovery function network element; The second network element is further configured to send fifth information to the first network element based on the domain name or address. The fifth information is used to indicate the correspondence between the first service identifier and the domain name, or the fifth information is used to indicate the correspondence between the first service identifier and the address; The first network element is configured to receive the fifth information from the second network element; The first network element is further configured to receive first information and a first service identifier from the application function network element. The first information is used to indicate server re-discovery; The first network element is further configured to send a first message to the terminal device based on the fifth information and the first service identifier, where the first message includes a domain name or an address corresponding to the first service identifier, and the first message is used to instruct the terminal device to clear server information corresponding to the domain name or the address corresponding to the first service identifier.

28. A communication device, characterized in that, The apparatus includes a module or unit for implementing the method according to any one of claims 1 to 7, or includes a module or unit for implementing the method according to any one of claims 8 to 13, or includes a module or unit for implementing the method according to any one of claims 14 to 18, or includes a module or unit for implementing the method according to any one of claims 19 to 23.

29. A communication device, characterized in that, including a memory and a processor; The memory is configured to store instructions or computer programs; The processor is configured to execute the computer programs or instructions stored in the memory, so that the communication apparatus executes the method according to any one of claims 1 to 7, or so that the communication apparatus executes the method according to any one of claims 8 to 13, or so that the communication apparatus executes the method according to any one of claims 14 to 18, or so that the communication apparatus executes the method according to any one of claims 19 to 23.

30. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, and when the computer program is run, it implements the method according to any one of claims 1 to 7, or implements the method according to any one of claims 8 to 13, or implements the method according to any one of claims 14 to 18, or implements the method according to any one of claims 19 to 23.

31. A computer program product, the computer program product comprising: Computer program code, when the computer program code is run, implements the method according to any one of claims 1 to 7, or implements the method according to any one of claims 8 to 13, or implements the method according to any one of claims 14 to 18, or implements the method according to any one of claims 19 to 23.

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