Communication method and related device

Abstract

Provided in the embodiments of the present application are a communication method, device, and system. The method comprises: a first network element receives a first query message from a first anchor point of a session of a terminal device, the first query message comprising a domain name, and the first query message being used for querying an address of a server which provides, to the terminal device, a service corresponding to the domain name; the first network element obtains an address of a first server on the basis of the first query message, the first server being used for providing, to the terminal device, a service corresponding to the domain name; the first network element determines a data network access identifier corresponding to the address of the first server; and the first network element sends a first message used for determining a branching point to a session management network element, the first message comprising the address of the first server and the data network access identifier, and the branching point being used for sending session data to the first server via a second anchor point. The method facilitates data transmission between a terminal device and a server.

Description

A communication method and related device

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on January 11, 2024, application number 202410050267.5, and application name “A Communication Method, Device and System”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communications, and more particularly, to a communication method, device, and system. Background Art

[0003] After connecting to a network, a terminal device establishes a session with the network. It then uses the session's anchor point to transmit data for a specific service to a server on the data network, thereby consuming the service provided by that server. When a terminal device wants to use a new service, the network can select a server that provides the new service for the terminal device. However, the session's anchor point may not guarantee the quality of data transmission between the terminal device and the server providing the new service. Summary of the Invention

[0004] The embodiments of the present application provide a communication method, apparatus, and system that facilitate data transmission between a terminal device and a server.

[0005] In a first aspect, a communication method is provided. The method may be executed by a first network element, or may be executed by a chip or circuit of the first network element, which is not limited in this application. For ease of description, the following description is based on an example of execution by the first network element.

[0006] The method includes: a first network element receives a first query message from a first user plane network element, the first query message includes a domain name, the first query message is used to query the address of a server that provides services corresponding to the domain name to a terminal device, and the first user plane network element serves the session of the terminal device; the first network element obtains the address of the first server according to the first query message; the first network element determines the data network access identifier corresponding to the address of the first server; the first network element sends a first message for determining a second user plane network element to a session management network element, the first message includes the address of the first server and the data network access identifier, and the second user plane network element is used to forward a data packet belonging to the session sent by the terminal device to the first server to the first server.

[0007] Based on this method, the first network element can provide the session management network element with a first message for determining the second user plane network element based on the address of the first server providing services to the terminal device, so that the data sent by the terminal device in the session to the first server can be forwarded to the first server by the second user plane network element rather than the first user plane network element, which is conducive to data transmission between the terminal device and the first server.

[0008] In combination with the first aspect, in certain implementations of the first aspect, the first user plane network element is the anchor point of the session, and the second user plane network element includes a diversion point and a local anchor point of the session, and the diversion point is used to send the data packet of the session to the server via the local anchor point.

[0009] In a second aspect, a communication method is provided. The method may be executed by a first network element, or may be executed by a chip or circuit of the first network element, which is not limited in this application. For ease of description, the following description is based on an example of execution by the first network element.

[0010] The method includes: a first network element receiving a first query message from a first anchor point of a session of a terminal device, the first query message including a domain name, the first query message being used to query the address of a server providing a service corresponding to the domain name for the terminal device; the first network element obtaining the address of a first server based on the first query message, the first server being used to provide the service corresponding to the domain name for the terminal device; the first network element determining a data network access identifier corresponding to the address of the first server; and the first network element sending a first message to a session management network element for determining a diversion point, the first message including the address of the first server and the data network access identifier, the diversion point being used to send data of the session to the first server via a second anchor point. The first anchor point and the second anchor point are different.

[0011] Based on this method, the first network element can provide a first message for determining a diversion point to the session management network element according to the address of the first server providing services to the terminal device. Under the processing of this diversion point, the data of the session, such as the data sent by the terminal device to the first server, can be sent to the first server via the second anchor point rather than the first anchor point, which is conducive to data transmission between the terminal device and the first server.

[0012] The first message is used to determine the diversion point, which may be that the data network access identifier in the first message is used to determine the diversion point.

[0013] In combination with the second aspect, in certain implementations of the second aspect, the first anchor point is an anchor point configured by the session management network element for data transmission between the terminal device and the data network, and the first server is a server in the data network.

[0014] In combination with the first aspect and the second aspect, in certain implementations of the first aspect and the second aspect, the first message is further used to determine the second anchor point. For example, the data network access identifier in the first message is also used to determine the second anchor point.

[0015] In combination with the first and second aspects, in certain implementations of the first and second aspects, the server deployment information includes a correspondence between each of one or more data network access identifiers and an address of a server, the one or more data network access identifiers include the data network access identifier, and the address of the server includes the address of the first server; and the first network element determining the data network access identifier corresponding to the address of the first server includes: the first network element determining the data network access identifier corresponding to the address of the first server based on the server deployment information. The data network access identifier determined by the first network element based on the server deployment information facilitates selection of a transmission path with higher session quality.

[0016] Optionally, the server deployment information is pre-configured in the first network element, or is received by the first network element from other network elements.

[0017] Optionally, the first network element determines the data network access identifier corresponding to the address of the first server in combination with the server deployment information and the location of the terminal device, which helps to obtain a data network access identifier that is more suitable for the terminal device.

[0018] In combination with the first and second aspects, in certain implementations of the first and second aspects, before the first network element sends the first message for determining a diversion point to the session management network element, the method further includes: the first network element determining, based on a processing rule (e.g., a DNS processing rule), to send the first message to the session management network element, wherein the processing rule matches the domain name or the address of the first server, and the processing rule indicates that the first message needs to be sent to the session management network element. The first network element may communicate with the session management network element based on a management mechanism of the processing rule.

[0019] In combination with the first and second aspects, in certain implementations of the first and second aspects, the first network element obtains the address of the first server based on the first query message, including: the first network element determining, based on a processing rule, that the second query message includes option information, wherein the option information is used to determine the address of the first server; the processing rule matches the domain name and corresponds to the session, and the processing rule indicates that the query message sent to the domain name server must include option information; the first network element sends a second query message to the domain name server, the second query message including the domain name and the option information, the second query message being used to query the address of the server corresponding to the domain name; and the first network element receiving the address of the first server from the domain name server. Based on the clear indication of the processing rule, the first network element can accurately determine whether the option information needs to be included in the second query message.

[0020] In combination with the first and second aspects, in certain implementations of the first and second aspects, the first network element obtaining the address of the first server based on the first query message includes: the first network element sending a second query message to the domain name server based on a processing rule, wherein the processing rule matches the domain name and corresponds to the session, the processing rule includes the address of the domain name server, the second query message includes the domain name, and the second query message is used to query the address of the server corresponding to the domain name; and the first network element receiving the address of the first server from the domain name server. Based on the processing rule, the first network element can quickly determine which domain name server to send the second query message to.

[0021] In combination with the first and second aspects, in certain implementations of the first and second aspects, the method further includes: the first network element generating the processing rule based on server deployment information and / or feature information, the server deployment information indicating how each server is deployed in the data network, the first server being a server in the data network, and the feature information describing features of the session or the terminal device. The processing rule generated by the method facilitates the first network element to determine information related to the transmission path of the session.

[0022] In combination with the first and second aspects, in certain implementations of the first and second aspects, before the first network element generates the processing rule based on the server deployment information and / or feature information, the method further includes: the first network element receiving instruction information from the session management network element, the instruction information being used to instruct the first network element to generate a processing rule corresponding to the session; or the method further includes: the first network element receiving the processing rule from the session management network element, the processing rule including identification information of a baseline processing rule, the baseline processing rule being generated by the first network element based on the server deployment information and / or feature information, the server deployment information indicating how each server is deployed in the data network, the first server being a server in the data network, and the feature information being used to describe features of the session or the terminal device. The first network element can accept the instruction or rule from the session management network element to facilitate network management of the session.

[0023] In a third aspect, a communication method is provided. The method may be executed by a session management network element, or by a chip or circuit of the session management network element, which is not limited in this application. For ease of description, the following description is based on an example of execution by a session management network element.

[0024] The method includes: a session management network element selecting a first anchor point for a session of a terminal device, the first anchor point being used to transmit data between the terminal device and a data network, the data including a first query message including a domain name, the first query message being used to query the address of a server providing a service corresponding to the domain name for the terminal device; the session management network element receiving a first message from a first network element, the first message including the address of the first server and a data network access identifier, the first server being a server in the data network; the session management network element determining a diversion point based on the first message; and the session management network element instructing the diversion point to send the data of the session to the first server via a second anchor point. The first anchor point and the second anchor point are different.

[0025] Based on this method, the session management network element determines the diversion point according to the first message provided by the first network element, and configures the diversion point to send the data of the session, such as the data sent by the terminal device to the first server, to the first server via the second anchor point rather than the first anchor point, which is conducive to data transmission between the terminal device and the first server.

[0026] The session management network element may determine the diversion point according to the data network access identifier in the first message.

[0027] In conjunction with the third aspect, in certain implementations of the third aspect, the method further includes: the session management network element determining the second anchor point based on the first message, for example, the session management network element determining the second anchor point based on a data network access identifier in the first message. The session management network element can simultaneously determine the diversion point and the second anchor point based on the same message, which can improve the processing efficiency of the session management network element, thereby quickly establishing a data transmission path between the terminal device and the first server.

[0028] In conjunction with the third aspect, in certain implementations of the third aspect, the first query message further includes an address of the first network element, and the method further includes: the session management network element sending the address of the first network element to the terminal device when at least one of the following conditions is met: the terminal device is outside the service range of the session management network element; the data network access identifier of the session is a data network access identifier not supported by the session management network element; the terminal device is within the service range of the first network element; the data network access identifier of the session corresponds to the first network element; or the domain name in the first query message corresponds to the first network element. The session management network element determines, based on the condition, that the first network element provide query services for the terminal device, thereby helping to improve query reliability.

[0029] In conjunction with the third aspect, in certain implementations of the third aspect, if the at least one condition is met, the session management network element sends instruction information to the first network element, where the instruction information is used to instruct the first network element to generate a processing rule corresponding to the session, where the processing rule is used to obtain the address of the server, or where the processing rule is used to indicate that the first message needs to be sent to the session management network element. The session management network element instructs the first network element to generate the processing rule, thereby facilitating network management of the session.

[0030] In conjunction with the third aspect, in certain implementations of the third aspect, the session management network element sends characteristic information to the first network element, where the characteristic information is used to describe characteristics of the session or the terminal device, and the characteristic information is used to generate the processing rule. The session management network element provides the first network element with the characteristic information used to generate the processing rule, so that the first network element generates a processing rule for determining information related to the transmission path of the session that better matches the characteristics of the session or the terminal device.

[0031] In combination with the third aspect, in certain implementations of the third aspect, the method further includes: when at least one of the conditions is met, the session management network element sends a processing rule corresponding to the session to the first network element, the processing rule is used to obtain the address of the server, or the processing rule is used to indicate that the first message needs to be sent to the session management network element; wherein the processing rule includes identification information of a baseline processing rule, the baseline processing rule is generated by the first network element based on server deployment information and / or feature information, the server deployment information indicates how each server is deployed in the data network, the first server is a server in the data network, and the feature information is used to describe the features of the session or the terminal device. The session management network element sends the processing rule to the first network element to facilitate the network's management of the session.

[0032] In conjunction with the third aspect, in certain implementations of the third aspect, the method further includes: before the session management network element receives the first message from the first network element, the method further includes: the session management network element receiving the domain name from a second network element, the second network element being used to provide a server address for the terminal device; and the session management network element sending a second message to the second network element based on the domain name, the second message being used to instruct the second network element to send a query message including the domain name to the first network element. The session management network element explicitly instructing the second network element to forward the query message to the first network element facilitates session management by the session management network element.

[0033] In conjunction with the third aspect, in certain implementations of the third aspect, the method further includes: before the session management network element receives the first message from the first network element, the method further includes: the session management network element sending a second processing rule to a second network element, the second network element being configured to provide the terminal device with a server address, the second processing rule corresponding to the session and matching the domain name, the second processing rule further including: sending a query message including the domain name to the first network element. The session management network element configuring the processing rule for the second network element facilitates the session management network element's management of the session.

[0034] In a fourth aspect, a communication device is provided, which is configured to execute the method in the first aspect or any possible implementation of the first aspect. The communication device includes a unit configured to execute the method in the first aspect or any possible implementation of the first aspect.

[0035] In a fifth aspect, a communication device is provided, which is configured to execute the method in the second aspect or any possible implementation of the second aspect. The communication device includes a unit configured to execute the method in the second aspect or any possible implementation of the second aspect.

[0036] In a sixth aspect, a communication device is provided, wherein the communication device is configured to execute the method in the third aspect or any possible implementation of the third aspect. The communication device includes a unit configured to execute the method in the third aspect or any possible implementation of the third aspect.

[0037] In the fourth, fifth, or sixth aspects, the communication device may include a transceiver unit and a processing unit. For a detailed description of the transceiver unit and the processing unit, reference may be made to the device embodiments described below. The beneficial effects of the fourth to sixth aspects may be referenced to the relevant descriptions of the first to third aspects, and are not further elaborated here.

[0038] In a seventh aspect, a communication device is provided, comprising a processor configured to execute the method described in the first aspect, the second aspect, the third aspect, or any possible implementation of any one of these aspects. Alternatively, the processor is configured to execute a program stored in a memory, and when the program is executed, the method described in the first aspect, the second aspect, the third aspect, or any possible implementation of any one of these aspects is executed.

[0039] In combination with the seventh aspect, in a possible implementation, the memory is located outside the above-mentioned communication device.

[0040] In combination with the seventh aspect, in a possible implementation, the memory is located within the above-mentioned communication device.

[0041] In the present application, the processor and the memory may also be integrated into one device, that is, the processor and the memory may also be integrated together.

[0042] In combination with the seventh aspect, in a possible implementation, the communication device further includes a transceiver, and the transceiver is used to send or receive information.

[0043] In an eighth aspect, a communication device is provided, which may include a processor and an interface circuit, and the processor is connected to the interface circuit. The interface circuit is used to interact (or transmit and receive or input and output) information or data, and the processor is used to run program instructions so that the communication device executes the method described in any possible implementation of the first aspect, the second aspect, or the third aspect, or any of the aspects above. The interface circuit may be a communication interface or a transceiver. The transceiver may be a radio frequency module in a communication device, or a combination of a radio frequency module and an antenna, or an input and output interface of a chip or circuit.

[0044] In the ninth aspect, a readable storage medium is provided, which stores program instructions. When the readable storage medium is run on a computer, the computer executes the method described in the first aspect, the second aspect, the third aspect, or any possible implementation of any one of the aspects.

[0045] In the tenth aspect, a program product containing program instructions is provided, which, when executed, enables the method described in the first aspect, the second aspect, the third aspect, or any possible implementation of any of the aspects to be executed.

[0046] In the eleventh aspect, a device is provided, which can be implemented in the form of a chip or in the form of a device, and the device includes a processor. The processor is used to read and execute a program stored in a memory to execute one or more of the first aspect, the second aspect, or the third aspect, or one or more of the communication methods provided in any possible implementation of any of the aspects. Optionally, the device also includes a memory, which is connected to the processor via a circuit. Further optionally, the device also includes a communication interface, and the processor is connected to the communication interface. The communication interface is used to receive information to be processed, and the processor obtains the information from the communication interface, processes the information, and outputs the processing results through the communication interface. The communication interface can be an input and output interface.

[0047] In a possible implementation, the processor and memory may be physically independent units, or the memory may be integrated with the processor.

[0048] In the twelfth aspect, a communication system is provided, which includes a first network element and a session management network element; optionally, the communication system further includes one or more of a diversion point, a first anchor point, or a second anchor point. The first network element can be used to execute the method described in the first aspect, the second aspect, or any possible implementation of any one of the aspects. The session management network element can execute the method described in the third aspect, or any possible implementation of any one of the aspects. The diversion point is used to send data of a session of a terminal device to a first server via the second anchor point; the first anchor point is used to transmit data between the terminal device and a data network, and the first server is a server in the data network; the second anchor point is used to send data of the session from the diversion point to the first server.

[0049] In a thirteenth aspect, a communication system is provided, comprising a session management network element, a diversion point, a first anchor point, and a second anchor point; optionally, the communication system further comprises a first network element. The session management network element can execute the method described in any possible implementation of the third aspect or any of the aspects above. The diversion point is used to send data of a session of a terminal device to a first server via the second anchor point; the first anchor point is used to transmit data between the terminal device and a data network, and the first server is a server in the data network; the second anchor point is used to send data of the session from the diversion point to the first server. The first network element can be used to execute the method described in any possible implementation of the first aspect or the second aspect or any of the aspects above.

[0050] In a fourteenth aspect, a communication method is provided, the method comprising: a session management network element selects a first anchor point for a session of a terminal device, the first anchor point being used to transmit data between the terminal device and a data network, the data comprising a first query message, the first query message comprising a domain name, the first query message being used to query the address of a server that provides services corresponding to the domain name for the terminal device; the first network element receives the first query message from the first anchor point; the first network element obtains the address of a first server according to the first query message, the first server being a server in the data network; the first network element determines a data network access identifier corresponding to the address of the first server; the first network element sends a first message to the session management network element, the first message comprising the address of the first server and the data network access identifier; the session management network element determines a diversion point according to the first message; the session management network element instructs the diversion point to send the data of the session to the first server via a second anchor point.

[0051] In combination with the fourteenth aspect, in certain implementations of the fourteenth aspect, the method also includes: the first anchor point sends the first query message to the first network element; the diversion point sends the data of the session to the second anchor point; the second anchor point receives the data of the session from the diversion point and sends the data of the session to the first server.

[0052] In a fifteenth aspect, a communication method is provided, the method comprising: a session management network element selects a first anchor point for a session of a terminal device; the first anchor point sends a first query message to the first network element, the first query message including a domain name, the first query message being used to query the address of a server that provides services corresponding to the domain name for the terminal device; the session management network element receives a first message from the first network element, the first message including an address and a data network access identifier of the first server, the first server being a server in the data network; the session management network element determines a diversion point based on the first message; the session management network element instructs the diversion point to send data of the session to the first server via a second anchor point; the diversion point sends the data of the session to the second anchor point; the second anchor point receives the data of the session from the diversion point, and sends the data of the session to the first server.

[0053] In combination with the fifteenth aspect, in certain implementations of the fifteenth aspect, the method further includes: the first network element receives a first query message from the first anchor point of the session of the terminal device, the first query message includes a domain name, and the first query message is used to query the address of the server that provides the terminal device with the service corresponding to the domain name; the first network element obtains the address of the first server according to the first query message, and the first server is used to provide the terminal device with the service corresponding to the domain name; the first network element determines the data network access identifier corresponding to the address of the first server; the first network element sends a first message to the session management network element for determining a diversion point, the first message including the address of the first server and the data network access identifier, and the diversion point is used to send the data of the session to the first server via the second anchor point.

[0054] The technical effects achieved in the above-mentioned aspects can be referred to each other or to the beneficial effects in the method embodiments shown below, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] FIG1 is a schematic diagram of a network architecture 100 applicable to an embodiment of the present application.

[0056] FIG2 is a flow chart of a communication method 200 provided in an embodiment of the present application.

[0057] FIG3 is a flow chart of a communication method 300 provided in an embodiment of the present application.

[0058] FIG4 is a flow chart of a communication method 400 provided in an embodiment of the present application.

[0059] FIG5 is a flow chart of a communication method 500 provided in an embodiment of the present application.

[0060] FIG6 is a schematic block diagram of a communication device 1000 provided in an embodiment of the present application.

[0061] FIG7 is a schematic block diagram of another communication device 2000 provided in an embodiment of the present application.

[0062] FIG8 is a schematic diagram of a chip system 3000 provided in an embodiment of the present application. DETAILED DESCRIPTION

[0063] Various communication systems involve data transmission. For example, a common operator network, also known as a public land mobile network (PLMN), is a network established and operated by the government or an operator approved by it, such as a mobile network operator (MNO), for the purpose of providing land mobile communication services to the public, which involves data transmission. The embodiments of the present application may be based on PLMN or a network that meets the requirements of the third generation partnership project (3GPP) standards, referred to as a 3GPP network. Among them, the 3GPP network includes but is not limited to the fifth generation (5th-generation, 5G) mobile communication network, the fourth generation (4G) mobile communication network (also known as the long term evolution (LTE) network), and other future communication systems, such as the sixth generation (6th-generation, 6G) mobile communication network.

[0064] Figure 1 provides a schematic diagram of a network architecture 100 applicable to embodiments of the present application, using a 5G network based on a service-based architecture (SBA) in a 3GPP non-roaming scenario as an example. As shown in Figure 1 , network architecture 100 may include a terminal device 110, a data network (DN) 140, and a carrier network component. The carrier network may include, but is not limited to, a (radio) access network (R)AN 120 and a core network (CN). The following briefly describes the devices or network elements in each component.

[0065] Among them, (R)AN 120 may include one or more access network elements or access network devices, and the following description will be made using the access network device as an example. The interface between the access network device and the terminal device may be a Uu interface (or air interface). Of course, in future communications, the interface name may remain unchanged or may be replaced by other names, and this application does not limit this. An access network device is a device that provides wireless communication functions for a terminal device, and can connect the terminal device to a node or device in the network, that is, a network device. (R)AN can be regarded as a subnetwork of the operator network, and is an implementation system between a service node and a terminal device in the operator network. For example, a terminal device can connect to a service node of the operator network through the (R)AN, thereby obtaining the services provided by the service node. The access network equipment in (R)AN includes but is not limited to: the next generation node base station (gNB) in the 5G system, the evolved node B (eNB) in the long term evolution (LTE), the radio network controller (RNC), the node B (NB), the base station controller (BSC), the base transceiver station (BTS), the home base station (for example, home evolved nodeB, or home nodeB, HNB), the base band unit (BBU), the transmitting and receiving point (TRP), the transmitting point (TP), the small base station equipment, the mobile switching center, or the network equipment in the future network. The access network equipment can also be a module or unit that performs the functions of a base station, such as a centralized unit (CU) and a distributed unit (DU); in a possible network structure, the CU can be used to support communications under protocols such as radio resource control (RRC), packet data convergence protocol (PDCP), and service data adaptation protocol (SDAP); the DU can be used to support communications under the radio link control (RLC) layer protocol, the medium access control (MAC) layer protocol, and the physical layer protocol.The embodiments of this application do not limit the specific technologies and device forms used by access network devices. In systems using different wireless access technologies, the names of devices that provide access network device functions may vary. For ease of description, in all embodiments of this application, devices that provide wireless communication functions for terminal devices are collectively referred to as access network devices. In the embodiments of this application, access network devices can be replaced with access network network elements. It should be understood that the embodiments of this application do not limit the specific types of access network devices.

[0066] The data network DN 140, also known as a packet data network (PDN), is typically a network located outside of the operator's network, such as a third-party network. The DN may include one or more servers that provide services to the terminal device by transmitting data with the terminal device. A portion of the DN may be deployed at a location closer to the terminal device, which is referred to as the local portion of the DN. One or more EASs 141 are deployed in the local portion of the DN. Since the transmission path between these EASs and the terminal device is shorter, the data transmission latency can be reduced.

[0067] The core network may include, but is not limited to, the following network elements: a user plane function (UPF) network element, an access and mobility management function (AMF) network element 132, a session management function (SMF) network element 133, a policy control function (PCF) network element 134, a network exposure function (NEF) network element 135, a network function repository function (NRF) network element 136, a unified data management function (UDM) network element 137, a unified data repository (UDR) network element 138, and an edge application server discovery function (EASDF) network element 139. A network element may also be referred to as a network function (NF), which is not limited in this embodiment of the present application. The following briefly describes some network elements in the core network.

[0068] 1. The UPF network element 131 is used to support a session of a terminal device, which is used for data transmission between the terminal device and the DN 140. That is, the UPF network element is used to forward service data between the terminal device and the DN. The session can be a protocol data unit (PDU) session. The UPF network element can be used to implement user-plane related functions such as data packet routing and transmission, data packet detection, service usage reporting, quality of service (QoS) processing, legal monitoring, uplink data packet detection, downlink data packet storage, etc. For example, during the session establishment process, the SMF network element selects a UPF network element for the session. The UPF network element can be called the anchor point of the session, such as a PDU session anchor (PSA).

[0069] The network architecture 100 may also include a UPF network element 131-1, which is configured to support data transmission between the terminal device and the local portion of the DN (e.g., EAS 141). Alternatively, it may be configured to support terminal device access to the local portion of the DN, or to support local access of the terminal device. The UPF network element 131-1 may be referred to as a local anchor point for a session, such as a local PSA (L-PSA). Compared to the UPF network element 131, the UPF network element 131-1 is typically closer to the terminal device, which helps reduce the end-to-end latency of data transmission between the terminal device and the local portion of the DN.

[0070] The network architecture 100 may also include a UPF network element 131-2, which is used to divert data transmitted in the session, that is, the UPF network element 131-2 can send the data transmitted in the session to different anchor points. For example, the UPF network element 131-2 can identify the data sent by the terminal device to the local part of the DN and send the data to the UPF network element 131-2. The UPF network element 131-2 is an uplink classifier (UL CL) and diverts data according to the destination address of the data packet; or, the UPF network element 131-2 is a branching point (BP) and diverts data according to the source address of the data packet. The UPF network element 131-2 can be recorded as UL CL / BP.

[0071] 2. The AMF network element 132 is responsible for access control and mobility management of terminal devices accessing the operator's network, such as mobile status management, allocation of user temporary identity identifiers, authentication and authorization of terminal devices, etc.

[0072] 3. The SMF network element 133 is used to manage sessions of terminal devices, such as session establishment, modification, and release. It is also used for the selection and reselection of UPF network elements, the allocation of Internet Protocol (IP) addresses for terminal devices, and Quality of Service (QoS) control. The SMF network element is also used to implement edge application server (EAS) discovery, including the selection of EASDF network elements and the configuration of domain name system (DNS) processing rules for EASDF network elements.

[0073] 4. PCF 134 is used to support a unified policy framework to govern network behavior, provide policy rules to other control functions, and provide contract information related to policy decisions.

[0074] 5. The NEF network element 135 is used to enable third parties to use the services provided by the operator's network, support the network to open its capabilities, event and data analysis, provide PLMN security configuration information from external applications, and convert interactive information within and outside the PLMN.

[0075] 6. The NRF network element 136 is a control plane function provided by the operator and is used to maintain real-time information about network functions and services in the network. For example, it supports network service discovery, maintains the NF configuration data (NF profile) of NF instances and the services they support, supports SCP service discovery, maintains the SCP configuration data (SCP profile) of SCP instances, sends notifications about newly registered, deregistered, and updated NFs and SCPs, and maintains the health status of NF and SCP operations.

[0076] 7. The UDM network element 137 is a control plane function provided by the operator and is responsible for storing information such as the subscriber permanent identifier (SUPI), the generic public subscription identifier (GPSI), and credentials of subscribers in the operator's network.

[0077] 8. The UDR network element 138 is a control plane function provided by the operator. It provides the UDM with the functions of storing and retrieving subscription data, the PCF with the functions of storing and retrieving policy data, and the user's NF group ID information.

[0078] 9. The EASDF network element 139 assists in edge application server (EAS) discovery. For example, the EASDF network element can receive a DNS query message from a terminal device, obtain the EAS address based on the DNS query message, and send the EAS address to the terminal device. The EASDF network element can also process the DNS query message and DNS response message according to the processing rules configured by the SMF network element, such as the DNS processing rules.

[0079] Optionally, the network architecture 100 further includes an application function (AF) network element for providing application layer services. The AF network element may belong to the operator network or may be a third-party network element outside the operator network.

[0080] It should be understood that the above-mentioned network elements can be physical entities in hardware devices, software instances running on dedicated hardware, or virtualized functions instantiated on a shared platform (e.g., a cloud platform). In terms of form, the above-mentioned network elements can be independent devices or integrated into the same device to implement different functions.

[0081] Terminal device 110 is a device with wireless transceiver capabilities that provides voice and / or data connectivity to users and can communicate with one or more network elements in the core network via the (R)AN. Terminal devices may also be referred to as user equipment (UE), access terminal, terminal, subscriber unit, subscriber station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, user agent, or user device. Terminal devices can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; on water (e.g., ships); or in the air (e.g., airplanes, balloons, and satellites). Terminal devices may be cellular phones, cordless phones, Session Initiation Protocol (SIP) phones, smartphones, mobile phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), etc. Terminal devices may also be handheld devices with wireless communication capabilities, computing devices, or other devices connected to a wireless modem, vehicle-mounted devices, wearable devices, drones, or terminals in the Internet of Things or Internet of Vehicles, or relay user devices. The relay user equipment may be a 5G residential gateway (RG). The terminal device may also be a virtual reality (VR) terminal, an augmented reality (AR) terminal, a wireless terminal for industrial control, a wireless terminal for unmanned driving, a wireless terminal for telemedicine, a wireless terminal for smart grids, a wireless terminal for transportation safety, a wireless terminal for smart cities, a wireless terminal for smart homes, etc. The embodiments of the present application do not limit the type or category of the terminal device.

[0082] It should be understood that the network architecture applicable to the embodiments of the present application is not limited to network architecture 100, and any network architecture that can realize the functions of the above-mentioned network elements or devices is applicable to the embodiments of the present application. In addition, the above-mentioned naming is only defined for the convenience of distinguishing different functions and should not constitute any limitation on the embodiments of the present application. This application does not exclude the possibility of adopting other naming in 5G networks and future networks. For example, in a 6G network, some or all of the above-mentioned network elements or devices may use the terminology in 5G, or may adopt other names, etc.

[0083] After connecting to a network, a terminal device establishes a session with the network. It then uses the session's anchor point to transmit data for a specific service to a server on the data network, thereby consuming the service provided by that server. When a terminal device wishes to use a new service, the network may select a server that provides the new service for the terminal device. However, the current anchor point for the session may not guarantee the quality of data transmission between the terminal device and the server selected by the network.

[0084] Figure 2 is a flow chart of a communication method 200 provided in an embodiment of the present application. As shown in Figure 2, the communication method 200 can be executed by a session management network element, a first network element, a first anchor point, and a diversion point, or can be executed by modules and / or devices (e.g., chips or integrated circuits, etc.) with corresponding functions installed in the session management network element, the first network element, the first anchor point, and the diversion point, and this application is not limited thereto. For ease of description, the following description is based on the session management network element, the first network element, the first anchor point, and the diversion point as the execution entities. The communication method 200 can be applied to the network architecture 100 shown in Figure 1. For example, the terminal device is the terminal device 110, the first network element is the EASDF network element 139 or AF, the first anchor point is the UPF network element 131, and the diversion point is the UPF network element 131-3. For parts not fully described in the embodiments of the present application, reference can be made to existing protocols. As shown in Figure 2, the communication method 200 includes the following steps.

[0085] S210. The session management network element selects a first anchor point for the session of the terminal device, where the first anchor point is used to transmit data between the terminal device and the data network.

[0086] The first anchor point may be considered as an anchor point configured by a session management network element for a session of a terminal device, where the session is used for data transmission between the terminal device and a data network. Exemplarily, the session of the terminal device may be a protocol data unit (PDU) session, and the anchor point may be a PDU session anchor (PSA).

[0087] For example, during the establishment of the session, the session management network element selects an anchor point for the session. For specific implementation, reference may be made to existing protocols and will not be described in detail here.

[0088] S220. The first network element receives a first query message from the first anchor point. Correspondingly, the first anchor point sends the first query message to the first network element.

[0089] The first query message includes a domain name (hereinafter referred to as the first domain name). The first query message is used to query the address of a server that provides a service corresponding to the first domain name for the terminal device. In other words, the first query message is used to query the terminal device for the address of the server that provides the service corresponding to the first domain name. The first query message may be a Domain Name System (DNS) query message, and the first domain name may be a fully qualified domain name (FQDN).

[0090] The data between the terminal device and the data network includes a first query message. Specifically, the terminal device sends the first query message via the session. After being sent from the terminal device, the first query message reaches the first network element via the first anchor point. Correspondingly, the first network element receives the first query message from the terminal device via the first anchor point. The source address information of the first query message indicates the address of the terminal device, which corresponds to the session. Therefore, the first query message can be considered to be related to the session.

[0091] In one implementation method (method 2-1), the first query message includes the address of the first network element. If the destination address information of the first query message indicates the address of the first network element, the first anchor point can send the first query message to the first network element based on the address of the first network element.

[0092] In this implementation, the communication method 200 further includes the following steps S221.

[0093] S221. The session management network element sends the address of the first network element to the terminal device.

[0094] The session management network element may send the address of the first network element to the terminal device if at least one of the following conditions is met:

[0095] (1) The terminal device is outside the service range of the session management network element;

[0096] (2) The data network access identifier of the session is not supported by the session management network element;

[0097] (3) The terminal device is within the service range of the first network element;

[0098] (4) The data network access identifier of the session corresponds to the first network element; or

[0099] (5) The domain name from the second network element corresponds to the first network element, wherein the second network element is used to provide the address of the server.

[0100] The session management network element can determine whether the above conditions are met according to the following methods 2-1-1 to 2-1-7.

[0101] Mode 2-1-1: The session management network element receives a notification message from the mobility management network element, wherein the notification message is used to notify the session management network element that the terminal device is outside the service range of the session management network element, that is, the notification message is used to indicate that the above condition (1) is met. The session management network element determines that condition (1) is met based on the notification message. The notification message may also include location information of the terminal device, such as user location information (URI) of the terminal device, identification information of the tracking area (TA) where the terminal device is located, or identification information of the cell where the terminal device is located.

[0102] Mode 2-1-2: The session management network element receives a notification message from the mobility management network element, which is used to notify the terminal device of a location change. The notification message may include updated location information of the terminal device. Based on the location information of the terminal device, the session management network element determines that the terminal device is outside the service range of the session management network element, that is, determines that the above condition (1) is met.

[0103] Mode 2-1-3: The session management network element receives the location information of the terminal device from the mobility management network element. For example, the session management network element receives the notification message in mode 2-1-1 or mode 2-1-2, and the notification message includes the location information of the terminal device. The session management network element determines the corresponding data network access identifier (DNAI) based on the location information of the terminal device. Then, the session management network element determines that the DNAI is a DNAI that the session management network element does not support, that is, it determines that the DNAI is a DNAI that the session management network element cannot serve, that is, the above condition (2) is met.

[0104] For example, the session management network element determines the DNAI corresponding to the TA indicated by the location information of the terminal device based on the correspondence between the TA and the DNAI. The session management network element then determines whether the DNAI corresponding to the TA belongs to a list of DNAIs supported by the session management network element, or whether the DNAI corresponding to the TA belongs to a list of DNAIs not supported by the session management network element, thereby determining whether the DNAI is a DNAI that the session management network element cannot serve. The correspondence between the TA and the DNAI, the list of DNAIs supported by the session management network element, or the list of DNAIs not supported by the session management network element may be pre-configured in the session management network element.

[0105] Method 2-1-4: The session management network element receives rule information from the policy control network element, such as policy and charging control (PCC) rules. The rule information includes DNAI. The session management network element determines that the DNAI is a DNAI that the session management network element does not support, that is, it determines that the DNAI is a DNAI that the session management network element cannot serve, that is, condition (2) is met.

[0106] For example, after receiving the DNAI from the policy control network element, the session management network element determines whether the DNAI belongs to a list of DNAIs supported by the session management network element, or whether the DNAI belongs to a list of DNAIs not supported by the session management network element. The list of DNAIs supported by the session management network element or the list of DNAIs not supported by the session management network element may be pre-configured in the session management network element.

[0107] Method 2-1-5: The session management network element receives a notification message from the mobility management network element. The notification message is the same as the notification message in method 2-1-1 or method 2-1-2. The session management network element determines that the terminal device is within the service range of the first network element based on the location information of the terminal device in the notification message, that is, condition (3) is met.

[0108] For example, the location information of the terminal device indicates the TA where the terminal device is located. The session management network element determines that condition (3) is satisfied based on the fact that the service range of the first network element includes the TA where the terminal device is located. Exemplarily, the session management network element is locally configured with a list, and the list includes one or more TAs that are covered by the service range of the first network element. When the TA where the terminal device is located belongs to the list, it means that the service range of the first network element includes the TA where the terminal device is located, that is, the terminal device is within the service range of the first network element.

[0109] Mode 2-1-6: The session management network element determines that the first network element corresponds to the DNAI based on the DNAI corresponding to the location information of the terminal device (refer to mode 2-1-3), or the session management network element determines that the first network element corresponds to the DNAI based on the DNAI from the policy control network element (refer to mode 2-1-4), that is, condition (4) is met. For example, the session management network element is locally configured with a list that includes one or more DNAIs corresponding to the first network element, and the one or more DNAIs include a DNAI corresponding to the location information of the terminal device or a DNAI from the policy control network element. If the first network element corresponds to the DNAI, it can be considered that the service range of the first network element includes the location represented by the DNAI.

[0110] Method 2-1-7: The session management network element receives the second domain name from the second network element and determines that the second domain name corresponds to the first network element, that is, condition (5) is satisfied. For example, the session management network element is locally configured with a list that includes one or more domain names corresponding to the first network element. When the list includes the second domain name, condition (5) is satisfied. If the first network element corresponds to the second domain name, it can be considered that the service scope of the first network element includes the address of the server that provides the service corresponding to the second domain name.

[0111] Based on method 2-1-7, before step S221, the communication method also includes the following steps S222 and S223.

[0112] S222. The terminal device sends a third query message to the second network element. Correspondingly, the second network element receives the third query message from the terminal device.

[0113] The third query message includes the second domain name and is used to query the address of a server that provides the service corresponding to the second domain name to the terminal device. The second network element may be a network element selected by the session management network element for the terminal device's session to provide the server address. Prior to step S222, the session management network element may send the address of the second network element to the terminal device.

[0114] S223: The second network element sends the second domain name to the session management network element. Correspondingly, the session management network element receives the second domain name from the second network element.

[0115] For example, the second network element sends the second domain name to the session management network element according to a fourth processing rule. The fourth processing rule corresponds to the session and matches the domain name. The fourth processing rule instructs the second network element to send the second domain name to the session management network element. The fourth processing rule may be sent by the session management network element to the second network element before step S222. The processing rule in this embodiment of the present application may be a DNS processing rule.

[0116] Before step S221, the communication method 200 further includes: the session management network element obtains the address of the first network element. For example, if at least one of the above conditions (1) to (5) is met, the session management network element obtains the address of the first network element and then executes step S221.

[0117] Optionally, the session management network element obtains the address of the first network element by using the following steps S224 and S225.

[0118] S224. The session management network element sends a fourth query message to the third network element. Correspondingly, the third network element accepts the fourth query message from the session management network element.

[0119] S225. The third network element sends the address of the first network element to the session management network element. Correspondingly, the session management network element receives the address of the first network element from the third network element.

[0120] For example, the third network element sends a fourth response to the fourth query message to the session management network element, where the fourth response includes the address of the first network element. The third network element can be any one of an NRF network element, a UDR network element, a NEF network element, a PCF network element, a BSF network element, and a UDM network element.

[0121] In an example, the fourth query message includes DNAI, and the fourth query message is used to query the address of the first network element corresponding to the DNAI.

[0122] For example, based on methods 2-1-1 to 2-1-6, the DNAI included in the fourth query message is the DNAI corresponding to the location information of the terminal device or the DNAI of the policy control network element. Based on method 2-1-7, the DNAI included in the fourth query message is the DNAI corresponding to the second domain name. For example, the session management network element has a correspondence between one or more domain names and DNAIs, and the one or more domain names include the second domain name. The session management network element determines the DNAI corresponding to the second domain name based on the correspondence.

[0123] The third network element is locally configured with a correspondence between the DNAI and the address of the first network element. The third network element determines the address of the first network element based on the DNAI in the fourth query message and the correspondence.

[0124] In another example, the fourth query message includes location information of the terminal device, and the fourth query message is used to query the address of the first network element corresponding to the location information of the terminal device.

[0125] For example, based on methods 2-1-1 to 2-1-3, or 2-1-5, the session management network element receives the location information of the terminal device from the mobility management network element, and sends the location information to the third network element in a fourth query message. The third network element is locally configured with a correspondence between the location information of the terminal device and the address of the first network element. The third network element determines the address of the first network element based on the correspondence and the location information of the terminal device in the fourth query message.

[0126] In yet another example, the fourth query message includes the second domain name, and the fourth query message is used to query the address of the first network element corresponding to the second domain name.

[0127] For example, based on method 2-1-7, the session management network element carries the second domain name received from the second network element in a fourth query message and sends it to the third network element. The third network element is locally configured with a correspondence between the domain name and the address of the first network element, and the third network element determines the address of the first network element based on the correspondence and the second domain name.

[0128] Optionally, steps S224 and S225 may be replaced by step S224 - a: the session management network element determines the address of the first network element.

[0129] For example, based on method 2-1-1 to method 2-1-7, the session management network element is locally configured with a correspondence between one or more DNAIs and the address of the first network element. The one or more DNAIs include a DNAI corresponding to the location information of the terminal device, a DNAI from the policy control network element, or a DNAI corresponding to the second domain name. The session management network element determines the address of the first network element based on the correspondence.

[0130] For another example, based on methods 2-1-1 to 2-1-3, or 2-1-5, the session management network element is locally configured with a correspondence between the terminal device's location information and the address of the first network element. The session management network element receives the terminal device's location information from the mobility management network element, and determines, based on the correspondence, the address of the first network element corresponding to the terminal device's location information.

[0131] For example, based on method 2-1-7, the session management network element is locally configured with a correspondence between the domain name and the address of the first network element. The session management network element determines the address of the first network element corresponding to the second domain name based on the correspondence and the second domain name received from the second network element.

[0132] In another implementation manner (method 2-2), the first network element receives the first query message from the first anchor point, including: the first network element receives the first query message from the first anchor point via the second network element.

[0133] For example, the first network element receiving the first query message from the first anchor point includes the following steps S226 to S229.

[0134] S226. The terminal device sends a first query message to the second network element. Correspondingly, the second network element receives the first query message from the terminal device.

[0135] Among them, the terminal device sends a first query message to the second network element through the first anchor point, and correspondingly, the second network element receives the first query message through the first anchor point.

[0136] For example, during the process of establishing a session with a terminal device, the session management network element sends the address of a second network element to the terminal device. The second network element is used to provide the terminal device with the address of a server. When the terminal device desires to access a service corresponding to the first domain name, the terminal device sends a first query message through the session. The destination address of the first query message is the address of the second network element. The first anchor point can send the first query message to the second network element based on the destination address.

[0137] S227 . The second network element sends the first domain name to the session management network element. Correspondingly, the session management network element receives the first domain name from the second network element.

[0138] For example, the second network element sends the first domain name to the session management network element according to a fifth processing rule. The fifth processing rule corresponds to the session and matches the first domain name. The fifth processing rule instructs the second network element to send the first domain name to the session management network element. Exemplarily, the action included in the fifth processing rule is reporting. The fifth processing rule may be sent by the session management network element to the second network element.

[0139] S228. The session management network element sends a second message to the second network element. Correspondingly, the second network element receives the second message from the session management network element.

[0140] The second message is used to instruct the second network element to send the first query message to the first network element, and the second message may further include the address of the first network element. For example, the second message includes a sixth processing rule, and the sixth processing rule includes: sending the first query message to the first network element, and the sixth processing rule may further include the address of the first network element.

[0141] For example, if the first domain name corresponds to the first network element, the session management network element sends a second message to the second network element. Exemplarily, the session management network element is locally configured with a correspondence between one or more domain names and the first network element, where the one or more domain names include the first domain name. After receiving the first domain name, the session management network element determines that the first domain name corresponds to the first network element based on the correspondence, and then sends the second message to the second network element.

[0142] S229. The second network element sends a first query message to the first network element according to the second message. Correspondingly, the first network element receives the first query message from the second network element.

[0143] S230. The first network element obtains the address of the first server according to the first query message.

[0144] The first server is a server in the above data network, and the first server may be an edge application server (EAS).

[0145] In one implementation manner (method 2-3), the first network element obtains the address of the first server according to the first query message, including the following steps S221 and S222.

[0146] S221. The first network element sends a second query message to the first domain name server according to the first query message. Correspondingly, the first domain name server receives the second query message from the first network element.

[0147] The second query message includes the first domain name, and is used to query the address of the server corresponding to the first domain name. The second query message may be a DNS query message.

[0148] S222. The first domain name server sends the address of the first server to the first network element. Correspondingly, the first network element receives the address of the first server from the domain name server.

[0149] The first server is used to provide the terminal device with a service corresponding to the first domain name. For example, the first domain name server sends a second response to the second query message to the first network element, and the second response includes the address of the first server and may also include the first domain name.

[0150] Optionally, the second query message also includes option information, which is used to determine the address of the first server. The option information is constructed based on the first domain name. For example, the second query message conforms to a certain message format, which may be specified by a protocol. According to this message format, a fixed field of the second query message is used to carry the option information. That is, the option information occupies a fixed field of the second query message, and the recipient of the second query message can obtain the option information from this fixed field.

[0151] For example, the first network element constructs option information based on the first domain name, and modifies the first query message into the second query message in the following manner: including the option information in the first query message, or replacing the option information in the first query message with the option information. Exemplarily, when the first query message and the second query message are DNS query messages, the option information may be a client subnet option (ECS option) of an extended mechanism for DNS (EDNS). Exemplarily, the option information may be information indicating the location of the terminal device, so that the first domain name server may select a server that is closer to the terminal device as the first server based on the option information, thereby shortening the transmission path between the terminal device and the first server and reducing the transmission delay. Exemplarily, the first network element may construct option information in accordance with the following method 2-3-1 or method 2-3-2.

[0152] Method 2-3-1: When the first domain name meets the conditions, the first network element determines that the second query message includes option information.

[0153] For example, the condition includes: the first domain name belongs to a first list, wherein the first list includes at least one domain name, and when the first list includes a domain name, when the first network element sends a query message including the domain name to the domain name server, the query message needs to include option information.

[0154] Exemplarily, the server deployment information includes a first list. The server deployment information indicates how each server (or each service) is deployed in the data network, that is, the server deployment information indicates the deployment of servers (or services) in the data network, wherein the servers in the data network include the first server, and the servers in the data network can provide services corresponding to the domain names in the first list.

[0155] The server deployment information may be pre-configured in the first network element, or may be obtained by the first network element from another network element. For example, the first network element obtains the server deployment information from the NEF network element. The server deployment information may be EAS deployment information (EDI). The specific implementation of the first network element obtaining the server deployment information from the NEF network element can refer to the implementation method of the SMF network element obtaining EDI from the NEF network element in the existing protocol, and will not be repeated here.

[0156] Optionally, the option information is constructed based on at least one of the following: the data network name (DNN) corresponding to the session, the single network slice selection assistance information (S-NSSAI) corresponding to the session, or the data network access identifier (DNAI) corresponding to the first domain name (referred to as the first DNAI).

[0157] Exemplarily, the first network element locally stores information corresponding to each DNN or S-NSSAI for constructing option information. The first network element determines the information for constructing option information based on the DNN or S-NSSAI corresponding to the session, and then constructs the option information.

[0158] Exemplarily, the first network element locally stores a first correspondence between a domain name and a DNAI, and a second correspondence between each DNAI and information used to construct option information. The first network element determines a first DNAI based on the first domain name and the second correspondence, and then determines information used to construct option information based on the DNAI and the second correspondence, thereby constructing the option information. Among them, DNAI can be used to identify a connection between a core network and one or more data networks for transmitting data, and can also be used to indicate the location where the core network accesses the one or more data networks, that is, to indicate the location of a server in the one or more data networks. The correspondence between the first domain name and the first DNAI indicates that a server providing the service corresponding to the first domain name exists at the location indicated by the first DNAI. The first correspondence may be included in the server deployment information.

[0159] Method 2-3-2: The first network element determines that the second query message includes option information according to the second processing rule. The second processing rule corresponds to the session and matches the first domain name. The second processing rule indicates that the query message sent to the domain name server needs to include option information.

[0160] The second processing rule corresponds to the session and matches the first domain name, that is, the second processing rule matches the first query message; the second processing rule corresponds to the session and the source address information included in the second processing rule indicates the address of the terminal device, and the address corresponds to the session. Exemplarily, the detection template of the second processing rule includes source address information and domain name range, wherein the source address information indicates the address of the terminal device and the domain name range includes the domain name in the first query message; the action of the second processing rule indicates that the query message sent to the domain name server needs to include option information; or, the action of the second processing rule indicates the construction of option information. The second processing rule can adopt the following format:

[0161] Exemplarily, after receiving the first query message, the first network element searches for a second processing rule that matches the first query message (i.e., corresponds to the session and matches the first domain name), such as searching for a second processing rule whose detection template matches the first query message, and then constructs option information according to the second processing rule, such as constructing option information according to the actions included in the second processing rule.

[0162] Optionally, the second processing rule further includes first information for constructing option information, and the first network element may construct the option information according to the first information.

[0163] In one example, the first information is related to a session. Specifically, for a processing rule where the source address information indicates the address of a terminal device, i.e., a processing rule corresponding to the session, if the processing rule includes information for constructing option information, then the information is identical to the first information. The first information may be determined by the first network element based on the DNN or S-NSSAI corresponding to the session when generating the second processing rule. For specific implementation, see the description below.

[0164] In another example, the first information is related to DNAI, and the option information can be considered to be constructed based on the first DNAI. In this example, the second processing rule can also include the first DNAI. For example, after the first network element receives the first query message, it determines the first DNAI based on the first domain name and the first correspondence, and then searches for the second processing rule that matches the first query message, that is, searches for the second processing rule that corresponds to the session, matches the first domain name, and matches the first DNAI, and then constructs the option information based on the first information included in the second processing rule. Among them, the second processing rule including the first DNAI can be, the detection template of the second processing rule includes a DNAI range, and the DNAI range includes the first DNAI. The second processing rule including the first information can be, and the action of the second processing rule includes the first information. The second processing rule can adopt the following format:

[0165] In another example, the first network element locally stores a first correspondence between domain names and DNAIs, and a second correspondence between each DNAI and information used to construct the option information. After determining, based on the second processing rule, that the second query message includes option information, the first network element determines a first DNAI based on the first domain name and the first correspondence, determines first information based on the first DNAI and the second correspondence, and then constructs the option information based on the first information.

[0166] It should be noted that, in the first correspondence between domain names and DNAIs, a domain name can correspond to one or more DNAIs. When the first domain name corresponds to multiple DNAIs, the embodiment of the present application does not limit the implementation method of the first network element selecting the first DNAI from the multiple DNAIs. Exemplarily, the first network element can randomly select the first DNAI from the multiple DNAIs; the first network element can also select the first DNAI from the multiple DNAIs according to a predefined mechanism, which can be specified by the protocol or pre-configured in the first network element; the first network element can also select the first DNAI from the multiple DNAIs according to the location of the terminal device. For example, the first network element selects the DNAI whose location represented by the multiple DNAIs is closest to the location of the terminal device as the first DNAI.

[0167] Optionally, the first domain name server is determined based on the first domain name. Exemplarily, the first network element may determine the first domain name server according to the following method 2-3-3 or method 2-3-4.

[0168] Method 2-3-3: The first network element determines the first domain name server based on the first DNAI corresponding to the first domain name.

[0169] For example, the server deployment information includes an address of a domain name server corresponding to each DNAI in one or more DNAIs, the one or more DNAIs including a first DNAI, and the domain name server including a first domain name server. The address of the domain name server may be an Internet Protocol (IP) address and / or port of the domain name server. The first network element may determine the first domain name server based on the first DNAI and the server deployment information.

[0170] Exemplarily, the first network element determines the first DNAI corresponding to the first domain name based on the first corresponding relationship, and then determines the information of the first domain name server corresponding to the first DNAI based on the server deployment information, and then sends a second query message to the first domain name server based on the information of the first domain name server.

[0171] Method 2-3-4: The first network element determines the first domain name server according to the third processing rule, wherein the third processing rule matches the first domain name and corresponds to the session, and the third processing rule includes the address of the first domain name server.

[0172] The phrase "the third processing rule matches the first domain name and corresponds to the session" can refer to the description of the second processing rule in Method 2-3-2. For example, after receiving the first query message, the first network element searches for a third processing rule that matches the first query message, and then sends a second query message to the first domain name server based on the address of the first domain name server in the third processing rule.

[0173] It should be understood that any one of the methods 2-3-1 and 2-3-2 can be combined with any one of the methods 2-3-3 and 2-3-4. When the method 2-3-2 and the method 2-3-4 are combined, the second processing rule and the third processing rule can be one processing rule.

[0174] In one example (method 2-3-5), the second processing rule and / or the third processing rule may be generated by the first network element. For example, the first network element generates the second processing rule and / or the third processing rule based on the server deployment information and / or feature information. In this embodiment of the present application, generating a processing rule may also be referred to as creating or configuring a processing rule.

[0175] The server deployment information indicates how each server is deployed in the data network. For example, the server deployment information includes the domain names corresponding to the services provided by each server in the data network. Feature information describes the characteristics of the session or terminal device and may include one or more of the following: the DNN corresponding to the session, the S-NSSAI corresponding to the session, the terminal device's location information, the terminal device's group information, or the terminal device's policy information.

[0176] The first network element may also generate information for constructing option information based on the server deployment information and / or feature information, include the information for constructing option information in the second processing rule, or save the information for constructing option information locally, and use the information to construct option information in step S230 to obtain the address of the server.

[0177] For example, the first network element generates information for constructing option information based on the DNN corresponding to the session and / or the S-NSSAI corresponding to the session, and the information for constructing option information corresponds to the DNN and / or S-NSSAI.

[0178] When the first network element generates the second processing rule and / or the third processing rule according to the feature information, the communication method 200 further includes: the session management network element sends the feature information to the first network element, and correspondingly, the first network element receives the feature information from the session management network element.

[0179] Optionally, before the first network element generates the second processing rule and / or the third processing rule, the communication method 200 further includes: the session management network element sending instruction information (referred to as first instruction information) to the first network element, where the first instruction information is used to instruct the first network element to generate a processing rule corresponding to the session. Correspondingly, the first network element receives the first instruction information from the session management network element and generates a processing rule corresponding to the session based on the first instruction information, including the second processing rule and / or the third processing rule.

[0180] The processing rules corresponding to the session can be considered to be the processing rules for processing query messages related to the session and responses to the query messages. The query messages related to the session can be query messages sent by a terminal device through the session. For example, the source address information of these processing rules indicates the address of the terminal device corresponding to the session.

[0181] For example, when at least one of the above conditions (1) to (5) is met, the session management network element sends the first indication information to the first network element.

[0182] In another example (method 2-3-6), the second processing rule and / or the third processing rule may be sent by the second session management network element to the first network element. The second processing rule and / or the third processing rule include identification information of a baseline processing rule. The identification information of the baseline processing rule is used to indicate the baseline processing rule, which is generated by the first network element. The baseline processing rule is not specific to a particular session.

[0183] Among them, the second processing rule and / or the third processing rule includes the identification information of the baseline processing rule, and it can also be considered that the second processing rule and / or the third processing rule refers to the baseline processing rule. For example, the baseline processing rule includes at least one of the following: a baseline detection template, or baseline action information. The baseline detection template is used to determine whether the processing rule matches the query message, including the domain name range. When the second processing rule and / or the third processing rule refers to the baseline processing rule including the baseline detection template, the first network element determines whether the second processing rule and / or the third processing rule matches the first query message based on the domain name range included in the baseline detection template, that is, determines whether the first domain name belongs to the domain name range included in the baseline detection template.

[0184] The baseline action information indicates an action. When the second processing rule and / or the third processing rule references a baseline processing rule that includes the baseline action information, the first network element, upon determining that the first query message matches the second processing rule and / or the third processing rule, processes the second processing rule and / or the third processing rule according to the action indicated by the baseline action information. For example, the baseline action information referenced by the second processing rule indicates that the query message sent to the domain name server must include option information; the baseline action information referenced by the third processing rule includes the address of the first domain name server.

[0185] The first network element may generate a baseline processing rule based on the server deployment information and / or feature information. The server deployment information and feature information may refer to the description in method 2-3-5.

[0186] For example, if at least one of the above conditions (1) to (5) is met, the second session management network element sends the processing rules corresponding to the session to the first network element, including the second processing rule and / or the third processing rule. In this example, before the second session management network element sends the processing rules corresponding to the session to the first network element, the communication method 200 further includes: the second session management network element obtains identification information of the baseline processing rule. Exemplarily, the second session management network element can obtain the identification information of the baseline processing rule through the following steps S231 and S232.

[0187] S231. The second session management network element sends a fifth query message to the third network element. Correspondingly, the third network element accepts the fifth query message from the session management network element.

[0188] The fifth query message is used to query the baseline processing rules of the first network element. The fifth query message can be the same as the fourth query message, i.e., the session management network element queries the third network element for the address of the first network element and the baseline processing rules of the first network element through the same query message. The fifth query message can be different from the fourth query message. For example, after the session management network element obtains the address of the first network element based on the fourth query message, it further queries the baseline processing rules of the first network element through the fifth query message. The fifth query message includes information about the first network element, such as the address of the first network element.

[0189] S232. The third network element sends identification information of the baseline processing rule of the first network element to the session management network element. Correspondingly, the session management network element receives identification information of the baseline processing rule from the third network element.

[0190] For example, after generating baseline processing rules, the first network element assigns identification information to each baseline processing rule and sends the identification information of each baseline processing rule to the third network element. In response, the third network element receives the identification information of each baseline processing rule and stores the correspondence between the information of the first network element (such as the address of the first network element) and the identification information of each baseline processing rule, or stores the correspondence between one or more DNAIs, the address of the first network element, and the identification information of each baseline processing rule.

[0191] After receiving the fifth query message, the third network element determines the identification information of each baseline processing rule of the first network element based on the above correspondence and the DNAI or information of the first network element in the fifth query message, and sends the identification information of each baseline processing rule to the session management network element.

[0192] Optionally, steps S231 and S232 may be replaced by: the session management network element determines identification information of the baseline processing rule of the first network element.

[0193] For example, the session management network element locally configures the correspondence between the information of the first network element (such as the address of the first network element) and the identification information of each baseline processing rule. After the session management network element obtains the address of the first network element based on steps S224 and S225, it determines the identification information of each baseline processing rule according to the correspondence.

[0194] For example, in step S224-a, the correspondence between one or more DNAIs locally configured by the session management network element and the address of the first network element is the correspondence between one or more DNAIs, the address of the first network element, and the identification information of each baseline processing rule. In step S224-a, the session management network element determines the address of the first network element based on the DNAI, and also determines the identification information of the baseline processing rule of the first network element based on the correspondence.

[0195] In another implementation manner (method 2-4), the first network element obtains the address of the first server according to the first query message, including: the first network element determines the address of the first server according to the first query message.

[0196] For example, the first network element determines the address of the first server based on the first domain name in the first query message. Exemplarily, the first network element determines the address of the first server corresponding to the first domain name based on a third correspondence. The third correspondence includes a correspondence between each of one or more domain names and a server address, the one or more domain names including the first domain name, and the server address including the address of the first server. Exemplarily, the server deployment information includes the third correspondence.

[0197] In this implementation, the first network element may be a network element in the core network, or an application function (AF) of a third party.

[0198] S240. The first network element determines the DNAI corresponding to the address of the first server (referred to as the second DNAI).

[0199] For example, the first network element determines the second DNAI corresponding to the address of the first server based on the fourth correspondence, wherein the fourth correspondence includes the correspondence between each DNAI in one or more DNAIs and the address of the server, the one or more DNAIs include the second DNAI, and the address of the server includes the address of the first server. Exemplarily, when the first server is at the location represented by the second DNAI, the fourth correspondence includes the correspondence between the first server and the second DNAI.

[0200] Exemplarily, the server deployment information includes the above-mentioned corresponding relationship, and the first network element determines the second DNAI corresponding to the address of the first server according to the server deployment information.

[0201] Optionally, the first network element determines the second DNAI corresponding to the address of the first server based on the server deployment information and the location information of the terminal device. For example, in the fourth correspondence, the address of a server corresponds to one or more DNAIs. When the address of the first server corresponds to multiple DNAIs, the first network element can select the second DNAI from the multiple DNAIs based on the location information of the terminal device. Exemplarily, the first network element selects the DNAI representing the location closest to the location of the terminal device from the multiple DNAIs as the second DNAI. The location information of the terminal device can be the DNAI corresponding to the location of the terminal device, or it can be the identification information of the tracking area (TA) where the terminal device is located or the identification information of the cell (cell).

[0202] In this implementation, before the first network element determines the DNAI corresponding to the address of the first server, the communication method 200 further includes: the first network element obtains location information of the terminal device. For example, the first network element receives the address of the terminal device from the session management network element.

[0203] The first network element may also use other methods to select the second DNAI from the multiple DNAIs, and this embodiment of the present application does not limit this.

[0204] S250: The first network element sends a first message to the session management network element. Correspondingly, the session management network element receives the first message from the first network element.

[0205] The first message includes the address of the first server and the second DNAI. The first message is used to determine a diversion point, which is used to send the data of the session to the first server via the second anchor point. The first message can also be used to determine a second anchor point, which is used to send the data of the session from the diversion point to the first server.

[0206] Optionally, the first network element directly sends the first message to the session management network element. For example, there is an interface between the first network element and the session management network element, and the first network element directly sends the first message to the session management network element through the interface, which may be a service-based interface.

[0207] Optionally, the first network element sends the first message to the session management network element through other network elements. For example, in mode 2-4, when the first network element is an AF, the first network element may send the first message to the session management network element through one or more network elements selected from the group consisting of an NEF network element, a PCF network element, and a UDR network element. The first message may be an AF request.

[0208] In one implementation manner (method 2-5), the first network element sends a first message to the session management network element when the first domain name and / or the address of the first server meets the conditions.

[0209] For example, the first network element sending the first message to the session management network element when the first domain name meets a condition includes: the first network element sending the first message to the session management network element when the first domain name belongs to a second list. The second list includes at least one domain name. When the second list includes a domain name, the first network element obtains the address of a server providing a service corresponding to the domain name and sends the server address and corresponding DNAI to the session management network element. That is, the second list includes one or more domain names for which the server address and corresponding DNAI need to be sent to the session management network element, and the one or more domain names include the first domain name.

[0210] Similarly, the first network element sends a first message to the session management network element when the address of the first server meets the conditions, or the first network element sends a first message to the session management network element when the first domain name and the address of the first server meet the conditions. The specific implementation can be referred to the above description and will not be repeated here.

[0211] In another implementation manner (Method 2-6), the first network element sends a first message to the session management network element according to a first processing rule, wherein the first processing rule matches the first domain name and / or the address of the first server, and the first processing rule indicates that the first message needs to be sent to the session management network element, or the first processing rule indicates: there is a requirement to send the first message to the session management network element.

[0212] The first processing rule matches the first domain name, which may be that the domain name range in the first processing rule includes the first domain name, for example, the domain name range in the detection template of the first processing rule includes the first domain name; the first processing rule matches the address of the first server, which may be that the server address range in the first processing rule includes the address of the first server, for example, the server address range in the detection template of the first processing rule includes the address of the first server. The first processing rule indicates that a first message needs to be sent to the session management network element, which may be that the action of the first processing rule includes: sending the address of the server and the corresponding DNAI to the session management network element. Exemplarily, the first processing rule may adopt the following format:

[0213] For example, after the first network element obtains the address of the first server, it searches for the first processing rule that matches the first domain name and / or the address of the first server, and then executes step S240 to determine the second DNAI according to the first processing rule, and then executes step S250 to send the first message to the session management network element.

[0214] The first processing rule is generated by the first network element; or the first processing rule is sent to the first network element by the session management network element. The first processing rule includes identification information of the baseline processing rule, and the baseline processing rule is generated by the first network element. For specific implementation, please refer to Method 2-3-5 and Method 2-3-6, which will not be repeated here.

[0215] It should be noted that when the first domain name and / or the address of the first server does not meet the conditions, or when the first network element does not find the first processing rule, the first network element sends the address of the first server to the terminal device. For example, the first network element sends a first response to the first query message to the terminal device, the first response including the address of the first server, and subsequent steps S250 to S290 can be skipped.

[0216] S260. The session management network element determines a diversion point (referred to as a first diversion point) according to the first message.

[0217] Since the session management network element determines the first branch point based on the first message, it can be considered that the first message is used to determine the first branch point. The first branch point is used to send the data of the session to the first server via the second anchor point. In other words, the first branch point is used to send the data sent by the terminal device to the first server to the second anchor point.

[0218] For example, the session management network element determines the first diversion point based on the second DNAI in the first message. Exemplarily, the session management network element determines the first diversion point corresponding to the second DNAI based on a fifth correspondence, wherein the fifth correspondence includes a correspondence between each DNAI in one or more DNAIs and a diversion point, the one or more DNAIs including the second DNAI, and the diversion point including the first diversion point.

[0219] Optionally, the session management network element further determines a second anchor point according to the first message, that is, the first message can also be used to determine the second anchor point, and the second anchor point is used to send the data of the session from the first diversion point to the first server.

[0220] For example, the session management network element determines the second anchor point based on the second DNAI in the first message. Exemplarily, the session management network element determines the second anchor point corresponding to the second DNAI based on the first flow correspondence, wherein the sixth correspondence includes a correspondence between each DNAI in one or more DNAIs and a user plane network element, the one or more DNAIs including the second DNAI, and the user plane network element including the second anchor point.

[0221] S270. The session management network element instructs the diversion point (ie, the first diversion point) to send the session data to the first server via the second anchor point.

[0222] For example, the session management network element sends a third message to the first diversion point, and the third message is used to instruct the first diversion point to send the data of the session to the first server via the second anchor point, that is, to forward the data sent by the terminal device to the first server to the second anchor point. The third message can be any one of the following: packet detection rules (PDR), forwarding action rules (FAR), multi-access rules (MAR), usage reporting rules (URR), quality of service (QoS) enforcement rules (QER), and session reporting rules (SRR). The interface between the session management network element and the first diversion point is called the N4 interface. The session management network element can configure the first diversion point through the N4 session. For example, the session management network element can configure the first diversion point by creating, updating, or deleting the N4 session context in the first diversion point.

[0223] In one implementation, the session management network element sends a third message to the first branch point, where the third message includes the address of the server. The third message is used to instruct the first branch point to send a data packet whose destination address is the address of the first server to the second anchor point. In this implementation, the first branch point may be an uplink classifier (UL CL). The session management network element also establishes a tunnel between the first branch point and the second anchor point for transmitting data for the session between the first branch point and the second anchor point. The tunnel may be a general packet radio service (GPRS) user plane tunneling protocol (GTP-U) tunnel. For specific implementation, reference may be made to existing protocols.

[0224] In another implementation, the session management network element sends a third message to the first branching point. The third message includes the first address of the terminal device. The third message is used to instruct the first branching point to send a data packet with the first address as the source address to the second anchor point. The first address is an address assigned to the terminal device by the second anchor point. The first address corresponds to the first server, that is, the source address information of the data packet sent by the terminal device to the first server is the first address. The session management network element may also instruct the second anchor point to assign an address to the terminal device. In this implementation, the first branching point may be a branching point (BP).

[0225] In this implementation, the session management network element further sends a fourth message to the terminal device. The fourth message includes the terminal device's address and the first address. The fourth message is used to instruct the terminal device to set the source address information of data packets sent to the first server to the first address. In other words, the fourth message is used to instruct the terminal device to use the first address as the source address of data packets sent to the first server. The fourth message can be a routing rule.

[0226] Optionally, the communication method 200 further includes the following steps S280 and S290 (not shown in the figure).

[0227] S280. The session management network element sends second indication information to the first network element. Correspondingly, the first network element receives the second indication information from the session management network element.

[0228] The second indication information is used to indicate the address of the first network element sending server;

[0229] Alternatively, the second indication information is used to indicate that the diversion point is configured successfully, or the second indication information is used to indicate that the connection between the terminal device and the first server is configured successfully, and the connection is used to transmit data of the service corresponding to the first domain name between the terminal device and the first server.

[0230] The session management network element may send the second indication information directly to the first network element, or may send the second indication information to the first network element through another network element. For example, if the first network element is an EASDF network element, and there is an interface (such as a service-based interface) between the session management network element and the first network element, the session management network element may send the second indication information directly to the first network element through the interface. For another example, if the first network element is an AF network element or a DNS server, or if the first network element may have some or all of the functions of an AF network element, a DNS server, or an SMF network element, the session management network element may send the second indication information to the first network element through a network exposure function network element (such as NEF network element 135).

[0231] S290. The first network element sends a first response to the first query message, where the first response includes the address of the first server.

[0232] For example, the first network element determines the address of the first server to be sent according to the second indication information.

[0233] Based on mode 2-1, the first network element sends a first response to the terminal device; based on mode 2-2, the first network element sends a first response to the second network element, and the second network element then sends a first response to the terminal device.

[0234] Optionally, the communication method 200 further includes the following steps S291 to S293 (not shown in the figure).

[0235] S291. The terminal device sends data of a service corresponding to a first domain name to a first diversion point. Correspondingly, the first diversion point receives the data from the terminal device.

[0236] S292. The first branch point sends the data to the second anchor point. Correspondingly, the second anchor point receives the data from the first branch point.

[0237] S293. The second anchor point sends the data to the first server.

[0238] For example, the terminal device sends a data packet to the first branching point through the session, and the data packet is used to carry data of the service.

[0239] Optionally, based on method 2-5, the destination address of the data packet is the address of the first server, and the first diversion point sends the data packet to the second anchor point according to the destination address of the data packet, and the second anchor point then sends the data packet to the first server.

[0240] Optionally, based on mode 2-6, the source address of the data packet is the address of the terminal device, and the address of the terminal device corresponds to the first server. The first branch point sends the data packet to the second anchor point based on the source address of the data packet, and the second anchor point further sends the data packet to the first server.

[0241] Based on this method, the first network element can provide a first message for determining a diversion point to the session management network element based on the address of the first server providing services to the terminal device. Under the processing of this diversion point, the data of the session, such as the data sent by the terminal device to the first server, can be sent to the first server via the second anchor point rather than the first anchor point, which facilitates data transmission between the terminal device and the first server.

[0242] Figure 3 is a flow chart of a communication method 300 provided in an embodiment of the present application. This example describes a possible implementation of the communication method 200, using as an example a first network element being an EASDF network element 139, a session management network element being an SMF network element 133, a first anchor point being an UPF network element 131, a diversion point being an UPF network element 131-2, and a second anchor point being an UPF network element 131-1. As shown in Figure 3, the communication method 300 can be executed by an EASDF network element, an SMF network element, or an UPF network element, or by modules and / or devices (e.g., chips or integrated circuits) with corresponding functions installed in the EASDF network element, SMF network element, or UPF network element, but this application does not limit this. For ease of description, the following description uses the EASDF network element, SMF network element, and UPF network element as the execution entities. For portions not fully described, reference can be made to existing protocols and the above description of the communication method 200.

[0243] S301. The SMF network element selects the UPF network element 131 as the session anchor point for the terminal device session.

[0244] For specific implementation, please refer to the existing protocol and will not be described here.

[0245] S302. The SMF network element determines that the first condition is met.

[0246] The first condition includes at least one of the following conditions:

[0247] (1) The terminal device is outside the service range of the SMF network element;

[0248] (2) The data network access identifier of the session is not supported by the SMF network element;

[0249] (3) The terminal device is within the service range of the EASDF network element;

[0250] (4) The data network access identifier of the session corresponds to the EASDF network element; or

[0251] (5) The domain name from EASDF network element 2 corresponds to the EASDF network element, where EASDF network element 2 is used to provide the address of the server.

[0252] The specific implementation of the SMF network element to judge the above conditions can be referred to Method 2-1-1 to Method 2-1-7, which will not be repeated here.

[0253] S303. The SMF network element obtains the address of the EASDF network element.

[0254] In one implementation, the SMF network element obtains the address of the EASDF network element, including: the SMF network element receives the address of the EASDF network element from the NRF network element. For specific implementation, refer to steps S224 and S225. In another implementation, the SMF network element obtains the address of the EASDF network element, including: the SMF network element locally determines the address of the EASDF network element. For specific implementation, refer to step S224-a.

[0255] Optionally, when the SMF network element obtains the address of the EASDF network element, it also obtains the identification information of the baseline DNS processing rule, which is generated by the EASDF network element. For example, the EASDF network element generates a baseline DNS processing rule based on the edge application server deployment information (EAS deployment information, EDI). The baseline DNS processing rule includes at least one of the baseline DNS detection template or the baseline DNS action information. The baseline DNS detection template is used to determine whether the DNS processing rule matches the DNS message. Exemplarily, when the DNS message type included in the baseline DNS detection template is a DNS query message, the baseline DNS detection template includes a domain name range. When the domain name in the DNS query message belongs to the domain name range included in the baseline DNS detection template, the baseline DNS detection template matches the DNS query message. Exemplarily, when the DNS message type included in the baseline DNS detection template is a DNS response message, the baseline DNS detection template includes a domain name range and / or an EAS server address range. When the domain name in the DNS response message falls within the domain name range included in the baseline DNS detection template, and / or the EAS server address in the DNS response message falls within the EAS server address range included in the baseline DNS detection template, the baseline DNS detection template matches the DNS response message. The baseline DNS action information is used to indicate the action performed by the EASDF network element, which is described in detail below.

[0256] The EDI indicates how the edge services in the local portion of the DN are deployed. The EDI includes at least one FQDN, where each FQDN corresponds to a service provided by the server in the local portion of the DN. The EDI may also include at least one of the following:

[0257] (1) At least one DNAI, where each DNAI can identify the location of the local portion of the core network access DN, or in other words, each DNAI can represent the location of one or more servers in the local portion of the DN. A DNAI can correspond to one or more FQDNs, and an FQDN can correspond to one or more DNAIs. The correspondence between FQDNs and DNAIs is hereinafter referred to as correspondence relationship 1.

[0258] (2) At least one EAS address, which is the address of the EAS deployed in the local portion of the DN. Each DNAI corresponds to one or more EAS addresses, and each EAS address can correspond to one or more DNAIs. Hereinafter, the correspondence between EAS addresses and DNAIs is referred to as correspondence relationship 2.

[0259] (3) Information about at least one DNS server, such as the IP address and port number of the DNS server. Each DNAI corresponds to information about one or more DNS servers. The correspondence between DNAIs and DNS servers is referred to as correspondence relationship 3.

[0260] EDI can also include other information, such as DNN, S-NSSAI, and service identifiers. For detailed descriptions, refer to existing protocols and are omitted here. EDI can be pre-configured in EASDF network elements or obtained from other network elements (such as NEF network elements). For specific implementations, refer to the existing protocols for SMF network elements to obtain EDI.

[0261] After the EASDF network element generates the baseline DNS processing rules, it assigns identification information to each baseline DNS processing rule and sends the identification information of each baseline DNS processing rule to the SMF network element or the NRF network element. Correspondingly, the SMF network element or the NRF network element saves the identification information of each baseline DNS processing rule, so that the SMF network element can locally determine the identification information of the baseline DNS processing rule generated by the EASDF network element, or the SMF network element can obtain the identification information of the baseline DNS processing rule generated by the EASDF network element from the NRF network element. For the specific implementation, please refer to steps S231 and S232, which will not be repeated here.

[0262] S304. The SMF network element sends indication information 1 to the EASDF network element. Correspondingly, the EASDF network element receives indication information 1 from the SMF network element.

[0263] Instruction information 1 is used to instruct the EASDF network element to generate a DNS processing rule corresponding to the session with the terminal device. The DNS processing rule corresponding to the session with the terminal device can also be considered as a processing rule for processing DNS messages related to the terminal device. The DNS message related to the terminal device includes a DNS query message A whose source address information indicates the address of the terminal device corresponding to the session; the DNS message related to the terminal device also includes a DNS response message to the DNS query message A.

[0264] Optionally, the SMF network element also sends feature information to the EASDF network element, where the feature information is used to describe the features of the session or terminal device. The feature information used to describe the features of the session may include the DNN or S-NSSAI corresponding to the session, etc. The feature information used to describe the features of the terminal device may include one or more of the terminal device's location information, the terminal device's group information, or the terminal device's policy information. The terminal device's location information may be the DNAI corresponding to the terminal device, or may be used to indicate the TA or cell where the terminal device is located.

[0265] S305. The EASDF network element generates a DNS processing rule corresponding to the session according to instruction information 1.

[0266] The EASDF network element can generate DNS processing rules based on one or more pieces of information in the server deployment information and feature information.

[0267] For example, the EASDF network element generates DNS processing rule 1, wherein the DNS processing rule 1 is used to process the DNS response message, and the DNS processing rule 1 includes the FQDN range and / or the address range of the EAS server. The DNS processing rule 1 indicates that the address of the EAS server and the DNAI corresponding to the address of the EAS server need to be sent to the SMF network element; for example, the action included in the DNS processing rule 1 is: sending the address of the EAS server and the DNAI corresponding to the address of the EAS server to the SMF network element.

[0268] For example, the EASDF network element generates DNS processing rule 2, where DNS processing rule 2 is used to process DNS query messages, the source address information included in DNS processing rule 2 indicates the address of the terminal device, DNS processing rule 2 includes an FQDN range, and DNS processing rule 2 indicates that the query message sent to the domain name server needs to include the ECS option.

[0269] Optionally, the EASDF network element further generates information K for constructing the ECS option. Information K may be included in DNS processing rule 2. In one example, information K corresponds to a session. For example, information K is determined based on the DNN or S-NSSAI corresponding to the session. In another example, information K corresponds to DNAI. When information K corresponds to DNAI and DNS processing rule 2 includes information K, DNS processing rule 2 also includes DNAI, such as when the detection template of DNS processing rule 2 includes DNAI.

[0270] For example, the EASDF network element generates a DNS processing rule 3, wherein the DNS processing rule 3 is used to process a DNS query message, the source address information included in the DNS processing rule 3 indicates the address of the terminal device, the DNS processing rule 3 includes an FQDN range, and the DNS processing rule 3 includes the address of the DNS server. Exemplarily, the EASDF network element may determine the address of the DNS server and include the address of the DNS server in the DNS processing rule 3 based on one or more of the following: the location information of the terminal device, the DNN, the S-NSSAI, the group information of the terminal device, and the policy information of the terminal device. For example, the EASDF network element selects a DNS server that is closer to the terminal device based on the location information of the terminal device (which may be called a local DNS server, and the local DNS server may provide the address of a server close to the terminal device). The EASDF network element may also determine a DNS server based on different DNNs and / or S-NSSAIs. In this case, the DNS servers supporting different DNNs and / or S-NSSAIs may be different. The EASDF network element may also determine a DNS server that complies with the group to which the terminal device belongs or complies with the policy of the terminal device (for example, a DNS server dedicated to gold users) based on the group information of the terminal device and / or the policy information of the terminal device. Based on this method, the EASDF network element can select a DNS server that meets the characteristics of the session or terminal device, such as a server close to the terminal device.

[0271] The EASDF network element can establish a DNS context corresponding to the session. The DNS context includes the DNS processing rules generated by the EASDF network element and corresponding to the session.

[0272] S305a (not shown in the figure), the EASDF network element sends a message to the SMF network element to indicate that the generation of the DNS processing rules is completed. Correspondingly, the SMF network element receives the message from the EASDF network element.

[0273] Optionally, steps S304 to S305a may be replaced by steps S306 and S306a.

[0274] S306. The SMF network element sends at least one DNS processing rule to the EASDF network element. Correspondingly, the EASDF network element receives at least one DNS processing rule from the SMF network element.

[0275] The at least one DNS processing rule corresponds to a session, and the at least one DNS processing rule includes identification information of a baseline DNS processing rule generated by an EASDF network element, that is, the at least one DNS processing rule references the baseline DNS processing rule generated by the EASDF network element.

[0276] The at least one DNS processing rule may include DNS processing rule 1, and DNS processing rule 1 is used to process the DNS response message. DNS processing rule 1 may include identification information of baseline DNS detection template 1 and identification information of baseline DNS action information 1, wherein the baseline DNS detection template 1 includes the FQDN range and / or the address range of the EAS server; the baseline DNS action information 1 indicates that the address of the EAS server and the DNAI corresponding to the address of the EAS server need to be sent to the SMF network element, such as the action included in the baseline DNS action information 1 is: sending the address of the EAS server and the DNAI corresponding to the address of the EAS server to the SMF network element.

[0277] The at least one DNS processing rule may include DNS processing rule 2, which is used to process DNS query messages. DNS processing rule 2 may include identification information of baseline DNS detection template 2 and identification information of baseline DNS action information 2. Baseline DNS detection template 2 includes an FQDN range. Baseline DNS action information 2 indicates that the query message sent to the domain name server needs to include an ECS option. Baseline DNS action information 2 may also include information K for constructing the ECS option. DNS processing rule 2 also includes source address information indicating the address of the terminal device.

[0278] The at least one DNS processing rule may include DNS processing rule 3, wherein DNS processing rule 3 is used to process a DNS query message. DNS processing rule 3 may include identification information of a baseline DNS detection template 3 and identification information of baseline DNS action information 3, wherein baseline DNS detection template 3 includes an FQDN range; baseline DNS action information 3 includes an address of a DNS server. DNS processing rule 2 also includes source address information indicating the address of a terminal device.

[0279] S306a (not shown in the figure), the EASDF network element sends a message to the SMF network element to indicate the successful reception of the DNS processing rule. Correspondingly, the SMF network element receives the message from the EASDF network element.

[0280] Steps S304 to S305a, steps S306 and S306a are optional.

[0281] S307. The SMF network element sends the address of the EASDF network element to the terminal device. Correspondingly, the terminal device receives the address of the EASDF network element from the SMF network element.

[0282] The terminal device uses the EASDF network element as the default DNS server for the session.

[0283] It should be noted that step S307 can be executed before or after steps S304a to S306a, and can be executed before or after steps S304b and S305b, and this embodiment of the application does not limit this.

[0284] S308. The terminal device sends a DNS query message 1 to the EASDF network element. Correspondingly, the EASDF network element receives the DNS query message 1 from the terminal device.

[0285] For example, the terminal device sends a DNS query message 1 to the EASDF network element through the access network device and the session anchor point.

[0286] Among them, DNS query message 1 includes FQDN 1, DNS query message 1 is used to query the address of the server that provides the service corresponding to FQDN 1 to the terminal device, the source address information of DNS query message 1 indicates the address of the terminal device, and the destination address information indicates the address of the EASDF network element.

[0287] S309 . The EASDF network element sends a DNS query message 2 to the domain name server according to the DNS query message 1 . Correspondingly, the domain name server receives the DNS query message 2 from the EASDF network element.

[0288] Optionally, the DNS query message 2 includes an ECS option, and the ECS option is used to determine the address of the server.

[0289] In one example, if FQDN 1 meets a condition, the EASDF network element includes the ECS option in DNS query message 2. The condition can be that the EDI includes the address of EAS 1, or that the address of EAS 1 belongs to List 1, where List 1 includes one or more FQDNs. List 1 can be preconfigured in the EASDF network element.

[0290] For example, the EASDF network element locally stores a correspondence 4 between the terminal device's address and information K used to construct the ECS option. The EASDF network element determines information K based on this correspondence 4 and the terminal device's address indicated by the source address information in DNS query message 1, and then constructs the ECS option based on information K. For another example, the EASDF network element locally stores a correspondence 5 between DNAI and information K. The EASDF network element determines the DNAI corresponding to FQDN 1 based on correspondence 1, then determines information K based on correspondence 5, and then constructs the ECS option based on information K.

[0291] In another example, the EASDF network element includes the ECS option in the DNS query message 2 according to the DNS processing rule 2. If the EASDF network element determines that the DNS processing rule 2 matches the DNS query message 1, that is, the source address information included in the DNS processing rule 2 or the baseline DNS detection template 2 indicates the address of the terminal device, the included FQDN range includes FQDN 1, and optionally, the DNAI range included in the DNS processing rule 2 or the baseline DNS detection template 2 includes the DNAI corresponding to FQDN 1. Then, the EASDF network element includes the ECS option in the DNS query message 2 according to the instruction of the DNS processing rule 2 or the baseline DNS action information 2.

[0292] When DNS processing rule 2 includes information K, the EASDF network element constructs the ECS option according to the information K included in DNS processing rule 2. Alternatively, the EASDF network element determines information K according to correspondence 4 or correspondence 5. For specific implementation, please refer to the above description.

[0293] Optionally, before the EASDF network element sends the DNS query message 2 to the DNS server, the communication method 300 further includes: the EASDF network element determining the DNS server.

[0294] In one example, the EASDF network element determines a DNS server based on FQDN 1 and correspondence 3. In another example, the EASDF network element determines a DNS server based on DNS processing rule 3. If the EASDF network element determines that DNS processing rule 3 matches DNS query message 1, that is, the source address information included in DNS processing rule 3 or baseline DNS detection template 3 indicates the address of the terminal device, and the included FQDN range includes FQDN 1. Then, the EASDF network element determines that the DNS server included in DNS processing rule 3 or baseline DNS action information 3 is the target DNS server for sending DNS query message 2.

[0295] S310. The domain name server sends a DNS response message 2 to the EASDF network element. Correspondingly, the EASDF network element receives the DNS response message 2 from the domain name server.

[0296] The DNS response message 2 includes the address of EAS1.

[0297] S311. The EASDF network element determines DNAI 1 corresponding to the address of EAS1.

[0298] For example, the EASDF network element determines, based on correspondence relationship 2, that the DNAI corresponding to the address of EAS1 is DNAI 1. When, in correspondence relationship 2, the address of EAS1 corresponds to multiple DNAIs, the EASDF network element may select DNAI 1 from the multiple DNAIs based on the location information of the terminal device. Exemplarily, the EASDF network element may select, from the multiple DNAIs, a DNAI whose indicated location is closest to the location indicated by the location information of the terminal device as DNAI 1. The EASDF network element may also select DNAI 1 from the multiple DNAIs corresponding to the address of EAS1 in other ways, and this embodiment of the present application is not limited thereto.

[0299] S312. The EASDF network element sends message 1 to the SMF network element. Correspondingly, the SMF network element receives message 1 from the EASDF network element.

[0300] Message 1 includes the address of EAS1 and DNAI 1, and is used to determine the diversion point.

[0301] In one example, if the address of EAS1 satisfies a condition, the EASDF network element determines DNAI 1 corresponding to the address of EAS1 and sends Message 1 to the SMF network element. The condition may be that the EDI includes the address of EAS1, or that the address of EAS1 belongs to List 2, where List 2 includes the addresses of one or more EASs. List 2 may be preconfigured in the EASDF network element.

[0302] In another example, the EASDF network element determines the DNAI 1 corresponding to the address of EAS1 based on DNS processing rule 1, and sends message 1 to the SMF network element. For example, the EASDF network element determines that the DNS processing rule 1 matches the DNS response message 2, that is, the FQDN range included in the DNS processing rule 1 or the baseline DNS detection template 1 includes FQDN 1, and / or the EAS address range included in the DNS processing rule 1 or the baseline DNS detection template 1 includes the address of EAS1. Then, the EASDF network element determines the DNAI 1 corresponding to the address of EAS1 based on the instruction of the DNS processing rule 1 or the baseline DNS action information 1, and sends message 1 to the SMF network element.

[0303] Optionally, in step S311, the DNAI 1 corresponding to the address of EAS1 determined by the EASDF network element can be replaced by the diversion point corresponding to the address of EAS1 determined by the EASDF network element; the message 1 including DNAI 1 can be replaced by the message 1 including the identification information of the diversion point. The specific implementation method is similar and will not be repeated here.

[0304] S313. The SMF network element determines the diversion point according to message 1.

[0305] For example, when message 1 includes DNAI 1, the SMF network element stores a correspondence 6 between DNAI and UPF network elements. The SMF network element selects a UPF network element as a diversion point from the UPF network elements corresponding to DNAI 1 based on DNAI 1 and correspondence 6. The specific selection method is not limited in the embodiment of the present application.

[0306] Optionally, the SMF network element further determines a local session anchor point based on message 1. For example, the SMF network element selects another UPF network element from the UPF network element corresponding to DNAI 1 as the local session anchor point based on DNAI 1 and correspondence 6. The specific selection method is not limited in this embodiment of the application.

[0307] S314. The SMF network element instructs the diversion point to send the session data to EAS1 via the local session anchor point.

[0308] The implementation of step S314 can refer to the description of step S270 and will not be repeated here.

[0309] Optionally, the communication method 300 further includes the following steps S315 and S316 (not shown in the figure).

[0310] S315. The SMF network element sends indication information 3 to the EASDF network element. Correspondingly, the EASDF network element receives indication information 3 from the SMF network element.

[0311] Indication information 3 may be used to indicate that the split point configuration is complete, or to indicate that the connection between the terminal device and EAS1 is successfully configured. The connection is used to transmit data of the service corresponding to FQDN 1 between the terminal device and EAS1.

[0312] S316. The EASDF network element sends the EAS1 address to the terminal device according to instruction information 3. Correspondingly, the terminal device receives the EAS1 address from the EASDF network element.

[0313] For example, the EASDF network element sends a DNS response message 1 to the terminal device in response to the DNS query message 1, where the DNS response message 1 includes the address of EAS1.

[0314] Optionally, the communication method 300 further includes the following steps S317 to S319 (not shown in the figure).

[0315] S317: The terminal device sends data of the service corresponding to FQDN 1 to the diversion point. Correspondingly, the diversion point receives the data from the terminal device.

[0316] For example, the terminal device sends the data to the diversion point through the access network device.

[0317] The source address information of the data packet carrying the data indicates the address of the terminal device, and the destination address information indicates the address of EAS1. When the branch point is BP, the address of the terminal device corresponds to the address of EAS1.

[0318] S318. The diversion point sends the data to the local session anchor point. Correspondingly, the local session anchor point receives the data from the diversion point.

[0319] For example, if the branching point is a UL CL, the branching point forwards the data packet to the local session anchor point based on the destination address information of the data packet. For another example, if the branching point is a BP, the branching point forwards the data packet to the local session anchor point based on the source address information of the data packet.

[0320] S319. The local session anchor sends the data to EAS1. Correspondingly, EAS1 receives the data from the local session anchor.

[0321] Based on the above method, the data of the terminal device's session is originally sent to the data network through the session anchor point. When the terminal device needs to use the service corresponding to FQDN 1, it queries the EASDF network element for the address of the server that can provide this service. After obtaining the address of EAS1 based on the terminal device's query, the EASDF network element determines the DNAI corresponding to the EAS1 address and sends message 1 including the DNAI to the session management network element. The session management network element can then determine the diversion point based on message 1 and instruct the diversion point to send the data sent by the terminal device to EAS1 to EAS1 via the local session anchor point instead of the session anchor point. Data transmitted between the terminal device and EAS1 is forwarded via the local session anchor point, resulting in a short data transmission path, low transmission delay and jitter, and high data transmission quality between the terminal device and EAS1.

[0322] Figure 4 is a flow chart of a communication method 400 provided in an embodiment of the present application. Taking the session management network element as the SMF network element 133, the second network element as the EASDF network element, the first anchor point as the UPF network element 131, the diversion point as the UPF network element 131-2, and the second anchor point as the UPF network element 131-1 as an example, a possible implementation of the communication method 200 is described. In the communication method 400, the first network element may have some or all of the functions of an AF network element, a DNS server, or an SMF network element. As shown in Figure 4, the communication method 400 may be executed by the first network element, the EASDF network element, the SMF network element, and the UPF network element, or by modules and / or devices (e.g., chips or integrated circuits, etc.) with corresponding functions installed in the first network element, the EASDF network element, the SMF network element, and the UPF network element, and this application does not limit this. For the convenience of description, the following description is given with the first network element, EASDF network element, SMF network element and UPF network element as the execution entities. For parts not described in detail, reference can be made to the existing protocols and the above description of the communication method 200.

[0323] S401. The SMF network element selects the UPF network element 131 as the session anchor point for the terminal device session.

[0324] For specific implementation, please refer to the existing protocol and will not be described here.

[0325] S402. The SMF network element sends the address of the EASDF network element to the terminal device. Correspondingly, the terminal device receives the address of the EASDF network element from the SMF network element.

[0326] For example, the SMF network element selects the EASDF network element for the session of the terminal device, and the terminal device can use the EASDF network element as the default DNS server for the session. The specific implementation can refer to the existing protocol and will not be repeated here.

[0327] S403: The terminal device sends a DNS query message 1 to the EASDF network element. Correspondingly, the EASDF network element receives the DNS query message 1 from the terminal device.

[0328] Among them, DNS query message 1 includes FQDN 1, DNS query message 1 is used to query the address of the server that provides the service corresponding to FQDN 1 to the terminal device, the source address information of DNS query message 1 indicates the address of the terminal device, and the destination address information indicates the address of the EASDF network element.

[0329] S404. The EASDF network element sends FQDN 1 to the SMF network element. Correspondingly, the SMF network element receives FQDN 1 from the EASDF network element.

[0330] For example, the EASDF network element sends FQDN 1 to the SMF network element according to DNS processing rule 4. The source address information of DNS processing rule 4 indicates the address of the terminal device. The FQDN range of DNS processing rule 4 includes FQDN 1. DNS processing rule 4 indicates that FQDN 1 is sent to the SMF network element. For example, the action included in DNS processing rule 4 is reporting.

[0331] Exemplarily, the EASDF network element sends a DNS context notification request message (such as Neasdf_DNSContext_Notify Request) to the SMF network element, and the DNS context notification request message includes FQDN 1.

[0332] S405. The SMF network element instructs the EASDF network element to forward the DNS query message 1 to the first network element.

[0333] For example, if FQDN 1 satisfies a condition, the SMF network element instructs the EASDF network element to forward DNS query message 1 to the first network element. The condition may be that FQDN 1 corresponds to the first network element. For example, the SMF network element stores a list that includes at least one FQDN corresponding to the first network element. If FQDN 1 belongs to the list, the SMF network element instructs the EASDF network element to forward DNS query message 1 to the first network element.

[0334] In one example, the SMF network element sends indication information 2 to the EASDF network element. The indication information 2 is used to instruct the EASDF network element to forward the DNS query message 1 to the first network element. The SMF network element can also send the address of the first network element to the EASDF network element. In another example, the SMF network element sends DNS processing rule 5 to the EASDF network element. The DNS processing rule 5 includes: forwarding the DNS query message 1 to the first network element. For example, the action included in the DNS processing rule 5 is: forwarding the DNS query message 1 to the first network element. Optionally, the DNS processing rule 5 also includes the address of the first network element. For example, the SMF network element can send the DNS processing rule 5 to the EASDF network element through a DNS context update request message (such as Neasdf_DNSContext_Update Request).

[0335] S406 . The EASDF network element sends a DNS query message 1 to the first network element. Correspondingly, the first network element receives the DNS query message 1 from the EASDF network element.

[0336] For example, the EASDF network element sends a DNS query message 1 to the first network element according to the instruction information 2 or the DNS processing rule 5.

[0337] Optionally, the above steps S404 to S406 can be replaced by the following step S407.

[0338] S407 . The EASDF network element sends a DNS query message 1 to the first network element according to the DNS processing rule 6 . Correspondingly, the first network element receives the DNS query message 1 from the EASDF network element.

[0339] DNS processing rule 6 matches DNS query message 1. For example, source address information in DNS processing rule 6 indicates the address of the terminal device, the FQDN range included in DNS processing rule 6 includes FQDN 1, and DNS processing rule 6 includes: sending a DNS query message including FQDN 1 to the first network element. DNS processing rule 6 may also include the address of the first network element.

[0340] After receiving the DNS query message 1 , the EASDF network element finds the DNS processing rule 6 that matches the DNS query message 1 , and then sends the DNS query message 1 to the first network element according to the DNS processing rule 6 .

[0341] In this implementation, before the EASDF network element sends the DNS query message 1 to the first network element according to the DNS processing rule 6, the communication method 400 further includes: the SMF network element sends the DNS processing rule 6 to the EASDF network element. For example, during the establishment of a session of the terminal device, the SMF network element selects the EASDF network element for the session and sends the DNS processing rule 6 to the EASDF network element.

[0342] The EASDF network element can establish a DNS context corresponding to the session and store DNS processing rule 6 in the DNS context corresponding to the session. The DNS context may include the address of the terminal device. After receiving DNS query message 1, the EASDF network element first determines that the DNS context corresponding to the session matches DNS query message 1. That is, the address of the terminal device included in the DNS context is the address of the terminal device indicated by the source address information of DNS query message 1. Next, the EASDF network element searches the DNS context for a DNS processing rule 6 that matches DNS query message 1.

[0343] The EASDF network element may send the DNS query message 1 directly to the first network element, or may send the DNS query message 1 to the first network element through other network elements (such as the NEF network element), and this embodiment of the present application does not impose any restrictions on this.

[0344] It should be noted that the DNS query message 1 sent by the above-mentioned EASDF network element to the first network element and the DNS query message 1 received by the EASDF network element may be the same or different. For example, the EASDF network element includes or replaces the ECS option in the received DNS query message 1, and then sends the DNS query message 1 with the added ECS option to the first network element. The DNS processing rule 6 may include information K for constructing the ECS option. The EASDF network element constructs the ECS option based on the information K in the DNS processing rule 6, adds the ECS option to the DNS query message 1, or uses the ECS option to replace the original ECS option in the DNS query message 1.

[0345] S408. The first network element obtains the address of EAS1 according to the DNS query message 1, and then determines the DNAI 1 corresponding to the address of EAS1.

[0346] For example, the first network element resolves FQDN 1 in DNS query message 1 to obtain the address of EAS1. For specific implementation, reference may be made to the implementation of the DNS server in the prior art, and the embodiment of the present application does not impose any limitation on this.

[0347] The first network element further includes a correspondence between one or more DNAIs and an address of an EAS, wherein the one or more DNAIs include DNAI 1 and the address of the EAS includes the address of EAS 1. The first network element determines DNAI 1 based on the correspondence and the address of EAS 1. The correspondence may be stored in the EDI of the first network element.

[0348] S409. The first network element sends the address of EAS1 and DNAI 1 to the SMF network element. Correspondingly, the SMF network element receives the address of EAS1 and DNAI 1 from the first network element.

[0349] DNAI 1 is used to determine the diversion point. DNAI 1 can also determine the local session anchor point. DNAI 1 can also be replaced with the identification information of the diversion point. For specific implementation, please refer to step S312.

[0350] Optionally, the first network element directly sends the address of EAS1 and DNAI 1 to the SMF network element, or the first network element sends the address of EAS1 and DNAI 1 to the SMF network element through other network elements, such as one or more network elements of NEF network element, PCF network element or UDR network element.

[0351] S410. The SMF network element determines the diversion point according to message 1.

[0352] For example, the SMF network element determines that the UPF network element 131-2 is the diversion point according to message 1. The SMF network element can also determine the local session anchor point according to message 1, such as determining that the UPF network element 131-1 is the local session anchor point.

[0353] S411. The SMF network element instructs the diversion point to send the session data to EAS1 via the local session anchor point.

[0354] The implementation of steps S410 and S411 may refer to steps S313 and S314 and will not be repeated here.

[0355] Optionally, the communication method 400 further includes steps S315 to S319.

[0356] Based on the above method, the data of the terminal device's session is originally sent to the data network through the session anchor point. When the terminal device needs to use the service corresponding to FQDN 1, it queries the EASDF network element for the address of the server that can provide the service. The EASDF network element forwards the terminal device's query message to the first network element, so that the first network element can parse the FQDN 1 in the query message, determine the address of EAS1 and the corresponding DNAI, and provide the address of EAS1 and the corresponding DNAI to the SMF network element. The SMF network element can determine and configure the separation point according to the information provided by the first network element, so that the data sent by the terminal device to EAS1 can be transmitted to EAS 1 via the local session anchor point instead of the session anchor point. The data transmitted between the terminal device and EAS1 is forwarded via the local session anchor point. The data transmission path is short, the transmission delay and jitter are low, and the data transmission quality is high.

[0357] In the communication method 300, the first condition may include: the domain name from the EASDF network element 2 corresponds to the EASDF network element, wherein the EASDF network element 2 is used to provide the address of the server. A possible implementation manner (denoted as communication method 500) is further described below in conjunction with FIG5.

[0358] S501. The SMF network element selects the UPF network element 131 as the session anchor point for the terminal device session.

[0359] S502. The SMF network element sends the address of EASDF network element 2 to the terminal device. Correspondingly, the terminal device receives the address of EASDF network element 2 from the SMF network element.

[0360] S503 : The terminal device sends a DNS query message 3 to the EASDF network element 2 . Correspondingly, the EASDF network element 2 receives the DNS query message 3 from the terminal device.

[0361] The DNS query message 3 includes the FQDN 2, and the DNS query message 3 is used to query the server that provides the service corresponding to the FQDN 2 for the terminal device.

[0362] S504. EASDF network element 2 sends FQDN 2 to the SMF network element. Correspondingly, the SMF network element receives FQDN 2 from EASDF network element 2.

[0363] The above steps S501 to S504 are similar to S401 to S404 and will not be repeated here.

[0364] S505. The SMF network element determines that FQDN 2 corresponds to the EASDF network element (ie, the first condition is met).

[0365] For example, the SMF network element is locally configured with a list that includes one or more FQDNs corresponding to the EASDF network element. When FQDN 2 belongs to the list, the SMF network element determines that FQDN 2 corresponds to the EASDF network element. The correspondence between FQDN 2 and the EASDF network element can indicate that a server capable of providing the service corresponding to FQDN 2 is deployed within the service range of the EASDF network element.

[0366] The communication method 500 further includes steps S303 to S317 , and the specific implementation thereof may refer to the description in the communication method 300 .

[0367] In step S308, the DNS query message 1 and the DNS query message 3 sent by the terminal device may be the same, that is, the FQDN 1 and the FQDN 2 may be the same. For example, in step S307, the terminal device receives the address of the EASDF network element, confirms that the default DNS server for the session has changed, and the DNS query message 3 that has been sent and has not received a response is invalidated. Then, the terminal device resends the DNS query message 3 to the EASDF network element in step S308.

[0368] Based on this method, the data of the terminal device's session is originally sent to the data network through the session anchor point. When the terminal device needs to use the service corresponding to FQDN 2, it queries EASDF network element 2 for the address of the server that can provide the service. The SMF network element determines that FQDN 1 corresponds to the EASDF network element based on FQDN 1 reported by EASDF network element 2, and then provides the address of the EASDF network element to the terminal device. The EASDF network element then provides the server discovery service for the terminal device. Subsequently, when the terminal device needs to use the service corresponding to FQDN 1, it queries the EASDF network element for the address of the server that can provide the service. After obtaining the address of EAS1 based on the query of the terminal device, the EASDF network element determines the DNAI corresponding to the address of EAS1 and sends message 1 including the DNAI to the session management network element. The session management network element can then determine the diversion point based on message 1 and instruct the diversion point to send the data sent by the terminal device to EAS1 to EAS 1 via the local session anchor point instead of the session anchor point. The data transmitted between the terminal device and EAS1 is forwarded via the local session anchor point, with a short data transmission path, low transmission delay and jitter, and high data transmission quality.

[0369] Figure 6 is a schematic diagram of the structure of a communication device 1000 provided in an embodiment of the present application. As shown in Figure 6, the device 1000 may include a transceiver unit 1010 and a processing unit 1020. The transceiver unit 1010 can implement corresponding communication functions, and the processing unit 1020 is used to perform data processing, or in other words, the transceiver unit 1010 is used to perform operations related to receiving and sending, and the processing unit 1020 is used to perform other operations in addition to receiving and sending. The transceiver unit 1010 can also be referred to as a communication interface or a communication unit.

[0370] In one possible design, the communication device 1000 may correspond to the first network element in the above method embodiment, or a component of the first network element (such as a chip).

[0371] The communication device 1000 can implement the steps or processes corresponding to those executed by the first network element in the above method embodiment, wherein the transceiver unit 1010 can be used to perform operations related to the transmission and reception of the first network element in the above method embodiment, and the processing unit 1020 can be used to perform operations related to the internal processing of the first network element in the above method embodiment.

[0372] Exemplarily, the transceiver unit 1010 is used to receive a first query message of a first anchor point of a session from a terminal device, the first query message including a domain name, and the first query message being used to query the address of a server that provides services corresponding to the domain name to the terminal device; the processing unit 1020 is used to obtain the address of a first server according to the first query message, and the first server is used to provide services corresponding to the domain name to the terminal device; the processing unit 1020 is also used to determine a data network access identifier corresponding to the address of the first server; the transceiver unit 1010 is also used to send a first message to a session management network element for determining a diversion point, the first message including the address of the first server and the data network access identifier, and the diversion point is used to send data of the session to the first server via a second anchor point.

[0373] In which, when the device 1000 is used to execute the method in Figure 2, the transceiver unit 1010 can be used to execute the steps of sending and receiving information in the method, such as step S220 or S250; the processing unit 1020 can be used to execute the internal processing steps in the method, such as step S230 or S240.

[0374] In which, when the device 1000 is used to execute the method in Figure 3, the transceiver unit 1010 can be used to execute the steps of sending and receiving information in the method, such as steps S304a, S304b, S308, S309, S310, or S312; the processing unit 1020 can be used to execute the internal processing steps in the method, such as steps S305a or S311.

[0375] In which, when the device 1000 is used to execute the method in Figure 4, the transceiver unit 1010 can be used to execute the steps of sending and receiving information in the method, such as steps S406, S407, S409, S411, S412, S414, or S415; the processing unit 1020 can be used to execute the internal processing steps in the method, such as step S408.

[0376] In which, when the device 1000 is used to execute the method in Figure 5, the transceiver unit 1010 can be used to execute the steps of sending and receiving information in the method, such as steps S304a, S304b, S308, S309, S310, or S312; the processing unit 1020 can be used to execute the internal processing steps in the method, such as steps S305a or S311.

[0377] It should be understood that the specific process of each unit executing the above steps can be found in the description of the above embodiment and will not be repeated here.

[0378] In another possible design, the communication device 1000 may correspond to the session management network element in the above method embodiment, or a component (such as a chip) of the session management network element.

[0379] The communication device 1000 can implement the steps or processes executed by the session management network element in the above method embodiment, wherein the transceiver unit 1010 can be used to perform operations related to sending and receiving of the session management network element in the above method embodiment, and the processing unit 1020 can be used to perform operations related to internal processing of the session management network element in the above method embodiment.

[0380] Exemplarily, the processing unit 1020 is used to select a first anchor point for a session of a terminal device, the first anchor point being used to transmit data between the terminal device and a data network, the data including a first query message, the first query message including a domain name, the first query message being used to query the address of a server that provides services corresponding to the domain name to the terminal device; the transceiver unit 1010 is used to receive a first message from a first network element, the first message including the address of the first server and a data network access identifier, the first server being a server in the data network; the processing unit 1020 is also used to determine a diversion point based on the first message; the processing unit 1020 is also used to instruct the diversion point through the transceiver unit 1010 to send the data of the session to the first server via a second anchor point.

[0381] In which, when the device 1000 is used to execute the method in Figure 2, the transceiver unit 1010 can be used to execute the steps of sending and receiving information in the method, such as step S250 or S270; the processing unit 1020 can be used to execute the internal processing steps in the method, such as step S210, S260, or S270.

[0382] In which, when the device 1000 is used to execute the method in Figure 3, the transceiver unit 1010 can be used to execute the steps of sending and receiving information in the method, such as steps S304a, S304b, S307, S312, or S314; the processing unit 1020 can be used to execute the internal processing steps in the method, such as steps S301, S302, S303, S313, or S314.

[0383] In which, when the device 1000 is used to execute the method in Figure 4, the transceiver unit 1010 can be used to execute the steps of sending and receiving information in the method, such as steps S402, S404, S405, S409, or S411; the processing unit 1020 can be used to execute the internal processing steps in the method, such as steps S401, S410, or S411.

[0384] In which, when the device 1000 is used to execute the method in Figure 5, the transceiver unit 1010 can be used to execute the steps of sending and receiving information in the method, such as steps S502, S504, S304a, S304b, S307, S312, or S314; the processing unit 1020 can be used to execute the internal processing steps in the method, such as steps S501, S505, S303, S313, or S314.

[0385] It should be understood that the specific process of each unit executing the above steps can be found in the description of the above embodiment and will not be repeated here.

[0386] It should be understood that the device 1000 here is embodied in the form of a functional unit. The term "unit" here can refer to an application specific integrated circuit (ASIC), an electronic circuit, a processor (such as a shared processor, a dedicated processor or a group processor, etc.) and a memory for executing one or more software or firmware programs, a combined logic circuit and / or other suitable components that support the described functions. In an optional example, the above-mentioned transceiver unit 1010 can also be a transceiver circuit (for example, it can include a receiving circuit and a transmitting circuit), and the processing unit 1020 can be a processing circuit.

[0387] The apparatus 1000 of each of the above-mentioned solutions has the function of implementing the corresponding steps performed by the network element (such as the first network element or the session management network element) in the above-mentioned method. This function can be implemented by hardware, or by hardware executing the corresponding software implementation. The hardware or software includes one or more modules corresponding to the above-mentioned functions; for example, the transceiver module can be replaced by a transceiver (for example, the sending unit in the transceiver module can be replaced by a transmitter, and the receiving unit in the transceiver module can be replaced by a receiver), and other units, such as the processing module, can be replaced by a processor to respectively perform the transceiver operations and related processing operations in each method embodiment.

[0388] FIG7 is a schematic diagram of another communication device 2000 provided in an embodiment of the present application. The device 2000 includes one or more processors 2010 and one or more memories 2020. The processor 2010 is configured to execute computer programs or instructions stored in the memory 2020, or to read data / signaling stored in the memory 2020, to perform the methods described in the above method embodiments. The memory 2020 is configured to store computer programs or instructions and / or data. The memory 2020 may be integrated with the processor 2010, or may be provided separately.

[0389] Optionally, as shown in Figure 7, the apparatus 2000 further includes a transceiver 2030, which is configured to receive and / or transmit signals. For example, the processor 2010 is configured to control the transceiver 2030 to receive and / or transmit signals.

[0390] As a solution, the device 2000 is used to implement the operations performed by the first network element in each of the above method embodiments.

[0391] As another solution, the apparatus 2000 is used to implement the operations performed by the session management network element in each of the above method embodiments.

[0392] It should be understood that the processor mentioned in the embodiments of the present application may be a central processing unit (CPU), or may be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc.

[0393] It should also be understood that the memory mentioned in the embodiments of the present application may be a volatile memory and / or a non-volatile memory. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM). For example, RAM can be used as an external cache. By way of example and not limitation, RAM includes the following forms: static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM).

[0394] It should be noted that when the processor is a general-purpose processor, DSP, ASIC, FPGA or other programmable logic device, discrete gate or transistor logic device, or discrete hardware component, the memory (storage module) can be integrated into the processor. It should also be noted that the memory described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0395] 8 is a schematic diagram of a chip system 3000 according to an embodiment of the present application. The chip system 3000 (or also referred to as a processing system) includes a logic circuit 3010 and an input / output interface 1002 .

[0396] Logic circuit 3010 may be a processing circuit in chip system 3000. Logic circuit 3010 may be coupled to a storage unit and call instructions in the storage unit, so that chip system 3000 can implement the methods and functions of various embodiments of the present application. Input / output interface 3020 may be an input / output circuit in chip system 3000, outputting information processed by chip system 3000 or inputting data or signaling information to be processed into chip system 3000 for processing.

[0397] As a solution, the chip system 3000 is used to implement the operations performed by the first network element or the session management network element in each of the above method embodiments. For example, the logic circuit 3010 is used to implement the internal processing-related operations performed by the first network element or the session management network element in the above method embodiments; and the input / output interface 3020 is used to implement the sending and / or receiving-related operations performed by the first network element or the session management network element in the above method embodiments.

[0398] The explanation of the relevant contents and beneficial effects of any of the above-mentioned devices can be referred to the corresponding method embodiments provided above, which will not be repeated here.

[0399] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0400] An embodiment of the present application further provides a communication system, comprising a first network element and a session management network element, wherein the first network element is configured to implement the operations performed by the first network element in each of the above method embodiments, and the session management network element is configured to implement the operations performed by the session management network element in each of the above method embodiments. Optionally, the communication system further comprises one or more network elements selected from a diversion point, a first anchor point, or a second anchor point, wherein the diversion point is configured to implement the operations performed by the diversion point in each of the above method embodiments, the first anchor point is configured to implement the operations performed by the first anchor point in each of the above method embodiments, and the second anchor point is configured to implement the operations performed by the second anchor point in each of the above method embodiments.

[0401] An embodiment of the present application further provides a communications system, including a session management network element, a diversion point, a first anchor point, and a second anchor point. The session management network element is configured to implement the operations performed by the session management network element in each of the above method embodiments; the diversion point is configured to implement the operations performed by the diversion point in each of the above method embodiments; the first anchor point is configured to implement the operations performed by the first anchor point in each of the above method embodiments; and the second anchor point is configured to implement the operations performed by the second anchor point in each of the above method embodiments. Optionally, the communications system further includes a first network element, wherein the first network element is configured to implement the operations performed by the first network element in each of the above method embodiments.

[0402] The present application also provides a computer-readable storage medium storing computer instructions for implementing the methods performed by the first network element or the session management network element in each of the above-described method embodiments. For example, when the computer program is executed by a computer, the computer can implement the methods performed by the first network element or the session management network element in each of the above-described method embodiments.

[0403] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. For example, the computer can be a personal computer, a server, or a network device, etc. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrations. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a magnetic tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid state disk (SSD)). For example, the available medium includes, but is not limited to, various media that can store program code, such as a USB flash drive, a mobile hard disk, ROM, RAM, a magnetic disk, or an optical disk.

[0404] In order to facilitate understanding of the embodiments of the present application, the following explanations are made.

[0405] First, in the various embodiments of the present application, unless otherwise specified or logically conflicting, the terms and / or descriptions between different embodiments are consistent and can be referenced by each other. The technical features in different embodiments can be combined to form new embodiments based on their inherent logical relationships.

[0406] Second, in the embodiments of this application, "plurality" refers to two or more. "And / or" describes the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, and B exists alone, where A and B can be singular or plural. In the text description of this application, the character " / " generally indicates that the associated objects are in an "or" relationship.

[0407] Third, in the embodiments of the present application, "first," "second," and various numerical references (e.g., #1, #2, etc.) are used to distinguish between different messages for ease of description and are not intended to limit the scope of the embodiments of the present application. For example, they are used to distinguish between different messages, rather than to describe a specific order or precedence. It should be understood that the objects described in this manner can be interchanged where appropriate to describe scenarios other than the embodiments of the present application.

[0408] Fourth, in the embodiments of the present application, descriptions such as "when...", "in the case of...", and "if" all mean that the device will perform corresponding processing under certain objective circumstances. It does not limit the time, nor does it require the device to perform judgment actions when implemented, nor does it mean that there are other limitations.

[0409] Fifth, in the embodiments of the present application, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus that includes a series of steps or units is not necessarily 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 apparatuses.

[0410] Sixth, in the embodiments of the present application, "used for indication" may include direct indication and indirect indication. When describing that a certain indication information is used to indicate A, it may include that the indication information directly indicates A or indirectly indicates A, and does not necessarily mean that the indication information carries A.

[0411] The indication methods involved in the embodiments of this application should be understood to encompass various methods that enable the party to be indicated to obtain information to be indicated. The information to be indicated can be sent as a whole or divided into multiple sub-information and sent separately. The transmission period and / or timing of these sub-information can be the same or different. This application does not limit the specific transmission method.

[0412] In the embodiments of the present application, the "indication information" may be an explicit indication, i.e., a direct indication via signaling, or may be obtained based on parameters indicated by the signaling, in combination with other rules, other parameters, or by deduction. It may also be an implicit indication, i.e., based on a rule or relationship, or based on other parameters, or by deduction. This application does not impose specific limitations on this.

[0413] Seventh, in the embodiments of the present application, "storage" may refer to storage in one or more memories. The one or more memories may be provided separately or integrated into an encoder or decoder, a processor, or a communication device. The one or more memories may also be partially provided separately and partially integrated into a decoder, a processor, or a communication device. The type of memory may be any form of storage medium and is not limited by this application.

[0414] Eighth, in the embodiments of the present application, "communication" can also be described as "data transmission", "information transmission", "data processing", etc. "Transmission" includes "sending" and "receiving", which is not limited in the present application.

[0415] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A communication method, characterized in that, Including: A first network element receives a first query message from a first anchor point of a session of a terminal device, the first query message including a domain name, the first query message being used to query for an address of a server that provides a service corresponding to the domain name for the terminal device; The first network element obtains an address of a first server according to the first query message, the first server being used to provide a service corresponding to the domain name for the terminal device; The first network element determines a data network access identifier corresponding to the address of the first server; The first network element sends a first message for determining a split point to a session management network element, the first message including the address of the first server and the data network access identifier, the split point being used to send data of the session to the first server via a second anchor point.

2. The method according to claim 1, characterized in that The first anchor point is an anchor point configured by the session management network element for data transmission between the terminal device and a data network, and the first server is a server in the data network.

3. The method according to claim 1 or 2, characterized in that, The first message is further used to determine the second anchor point.

4. The method according to claim 3, wherein The data network access identifier is used to determine the split point and the second anchor point.

5. The method according to any one of claims 1-4, characterized in that Server deployment information includes a correspondence relationship between each of one or more data network access identifiers and an address of a server, the one or more data network access identifiers including the data network access identifier, and the address of the server including the address of the first server; The first network element determines a data network access identifier corresponding to the address of the first server, including: The first network element determines a data network access identifier corresponding to the address of the first server according to the server deployment information.

6. The method according to claim 5, characterized in that, The first network element determines a data network access identifier corresponding to the address of the first server according to the server deployment information, including: The first network element determines a data network access identifier corresponding to the address of the first server according to the server deployment information and location information of the terminal device.

7. The method according to any one of claims 1 to 6, characterized in that, Before the first network element sends a first message for determining a split point to a session management network element, it further includes: The first network element determines to send the first message to the session management network element according to a processing rule, where the processing rule matches the domain name or the address of the first server, and the processing rule indicates that the first message needs to be sent to the session management network element.

8. The method according to any one of claims 1-7, characterized in that, The first network element obtains the address of the first server according to the first query message, including: The first network element determines that the second query message includes option information according to a processing rule, where the option information is used to determine the address of the first server, the processing rule matches the domain name and corresponds to the session, and the processing rule indicates that a query message sent to a domain name server needs to include option information; The first network element sends a second query message to a domain name server, the second query message including the domain name and the option information, the second query message being used to query for an address of a server corresponding to the domain name; The first network element receives the address of the first server from the domain name server.

9. The method according to any one of claims 1-8, characterized in that, The first network element obtains the address of the first server according to the first query message, including: The first network element sends a second query message to the domain name server according to a processing rule, where the processing rule matches the domain name and corresponds to the session, the processing rule includes the address of the domain name server, the second query message includes the domain name, and the second query message is used to query the address of the server corresponding to the domain name; The first network element receives the address of the first server from the domain name server.

10. The method according to any one of claims 7-9, characterized in that, The method further includes: The first network element generates the processing rule according to server deployment information and / or feature information, where the server deployment information indicates how each server is deployed in the data network, the first server is a server in the data network, and the feature information is used to describe the features of the session or the terminal device.

11. The method according to claim 10, characterized in that, Before the first network element generates the processing rule according to server deployment information and / or feature information, the method further includes: The first network element receives indication information from the session management network element, and the indication information is used to indicate the first network element to generate a processing rule corresponding to the session.

12. The method according to any one of claims 7-9, characterized in that, The method further includes: The first network element receives the processing rule from the session management network element, where the processing rule includes identification information of a baseline processing rule, and the baseline processing rule is generated by the first network element according to server deployment information and / or feature information, the server deployment information indicates how each server is deployed in the data network, the first server is a server in the data network, and the feature information is used to describe the features of the session or the terminal device.

13. A communication method, characterized in that, including: The session management network element selects a first anchor point for the session of the terminal device, and the first anchor point is used to transmit data between the terminal device and the data network, the data includes a first query message, the first query message includes a domain name, and the first query message is used to query the address of the server that provides the service corresponding to the domain name for the terminal device; The session management network element receives a first message from the first network element, and the first message includes the address of the first server and a data network access identifier, and the first server is a server in the data network; The session management network element determines a shunt point according to the first message; The session management network element instructs the shunt point to send the data of the session to the first server via a second anchor point.

14. The method according to claim 13, wherein The method further includes: The session management network element determines the second anchor point according to the first message.

15. The method according to claim 14, wherein: The session management network element determines a shunt point according to the first message, including: the session management network element determines the shunt point according to the data network access identifier; The session management network element determines the second anchor point according to the first message, including: the session management network element determines the second anchor point according to the data network access identifier.

16. The method according to any one of claims 1 to 15, characterized in that, The first query message further includes the address of the first network element, and the method further includes: When at least one of the following conditions is satisfied, the session management network element sends the address of the first network element to the terminal device: The terminal device is outside the service range of the session management network element; The data network access identifier of the session is a data network access identifier not supported by the session management network element; The terminal device is within the service range of the first network element; The data network access identifier of the session corresponds to the first network element; or, The domain name in the first query message corresponds to the first network element.

17. The method according to claim 16, wherein The method further includes: When the at least one condition is satisfied, the session management network element sends indication information to the first network element, and the indication information is used to instruct the first network element to generate a processing rule corresponding to the session, where the processing rule is used to obtain the address of the server, or the processing rule is used to indicate that the first message needs to be sent to the session management network element.

18. The method according to claim 17, wherein The method further includes: The session management network element sends feature information to the first network element, and the feature information is used to describe the features of the session or the terminal device, and the feature information is used to generate the processing rule.

19. The method according to claim 16, wherein The method further includes: When the at least one condition is satisfied, the session management network element sends a processing rule corresponding to the session to the first network element, where the processing rule is used to obtain the address of the server, or the processing rule is used to indicate that the first message needs to be sent to the session management network element; Wherein, the processing rule includes identification information of a baseline processing rule, and the baseline processing rule is generated by the first network element according to server deployment information and / or feature information, the server deployment information indicates how each server is deployed in the data network, the first server is a server in the data network, and the feature information is used to describe the features of the session or the terminal device.

20. The method according to claim 13, wherein Before the session management network element receives the first message from the first network element, the method further includes: The session management network element receives the domain name from a second network element, and the second network element is used to provide the address of the server for the terminal device; The session management network element sends a second message to the second network element according to the domain name, and the second message is used to instruct the second network element to send a query message including the domain name to the first network element.

21. The method according to claim 13, wherein Before the session management network element receives the first message from the first network element, the method further includes: The session management network element sends a second processing rule to a second network element, and the second network element is used to provide the address of the server for the terminal device, the second processing rule corresponds to the session and matches the domain name, and the second processing rule further includes: sending a query message including the domain name to the first network element.

22. A communication device, characterized in that, It includes a module for executing the method according to any one of claims 1-21.

23. A communication device, characterized in that, Comprising a processor and a memory, the memory being used to store instructions, which when executed by the processor cause the processor to execute the method according to any one of claims 1-21.

24. A computer program product comprising instructions, characterized in that, When the instructions run on a computer, the computer is caused to execute the method according to any one of claims 1-21.

25. A communication system, characterized in that, Comprising a first network element and a session management network element, wherein: The first network element is used to execute the method according to any one of claims 1-12; The session management network element is used to execute the method according to any one of claims 13-21.

26. The system according to claim 25, wherein The system further comprises one or more of a shunt point, a first anchor point or a second anchor point, wherein: The shunt point is used to send the data of the session of the terminal device to a first server via the second anchor point; The first anchor point is used to transmit data between the terminal device and a data network, and the first server is a server in the data network; The second anchor point is used to send the data of the session from the shunt point to the first server.

27. A communication system, characterized in that, Comprising a session management network element, a shunt point, a first anchor point and a second anchor point, wherein: The session management network element is used to execute the method according to any one of claims 13-21; The shunt point is used to send the data of the session of the terminal device to a first server via the second anchor point; The first anchor point is used to transmit data between the terminal device and a data network, and the first server is a server in the data network; The second anchor point is used to send the data of the session from the shunt point to the first server.

28. A communication method, characterized in that, Comprising: The session management network element selects a first anchor point for the session of the terminal device. The first anchor point is used to transmit data between the terminal device and a data network. The data includes a first query message, and the first query message includes a domain name. The first query message is used to query the address of a server that provides services corresponding to the domain name for the terminal device; The first network element receives the first query message from the first anchor point; The first network element obtains the address of a first server according to the first query message. The first server is a server in the data network; The first network element determines a data network access identifier corresponding to the address of the first server; The first network element sends a first message to the session management network element. The first message includes the address of the first server and the data network access identifier; The session management network element determines a shunt point according to the first message; The session management network element instructs the shunt point to send the data of the session to the first server via a second anchor point.

29. The method according to claim 28, wherein The method further comprises: The first anchor point sends the first query message to the first network element; The shunt point sends the data of the session to the second anchor point; The second anchor point receives the data of the session from the shunt point and sends the data of the session to the first server.

30. A communication method, characterized in that Comprising: The session management network element selects a first anchor point for the session of the terminal device; The first anchor point sends a first query message to the first network element. The first query message includes a domain name, and the first query message is used to query the address of a server that provides services corresponding to the domain name for the terminal device; The session management network element receives a first message from the first network element. The first message includes the address of the first server and a data network access identifier, and the first server is a server in the data network; The session management network element determines a traffic splitting point according to the first message; The session management network element instructs the traffic splitting point to send the data of the session to the first server via the second anchor point; The traffic splitting point sends the data of the session to the second anchor point; The second anchor point receives the data of the session from the traffic splitting point and sends the data of the session to the first server.

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