Communication method and apparatus

Abstract

The present application relates to the technical field of wireless communications, and provides a communication method and apparatus. The method comprises: a first session management network element receives first domain name information, the first domain name information being used by a terminal to query the address of at least one application server; the first session management network element sends first address information to a second session management network element, the first address information being determined on the basis of the first domain name information; the first session management network element receives second address information from the second session management network element, the second address information being an address of a first application server determined on the basis of the first address information, and the first application server being an application server close to a terminal among at least one application server; and on the basis of the second address information, the first session management network element determines a first user plane network element. According to the present application, a first session management network element can quickly determine an accurate first user plane network element on the basis of second address information, thereby improving the selection efficiency of the first user plane network element.

Description

Communication method and apparatus

[0001] Cross-reference to Related Applications

[0002] This application claims priority to the Chinese Patent Application No. 202410971635.X, filed on July 18, 2024, and entitled “A communication method and apparatus”, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to the technical field of wireless communication, and in particular to a communication method and apparatus. BACKGROUND

[0004] In an edge computing (EC) deployment scenario, some services can be provided by multiple edge application servers (EASs) deployed at the edge of a network. The multiple EASs deployed at the edge of the network can provide the same services and content, but different EASs can have different address information, for example, different IP addresses of different EASs.

[0005] When a terminal needs to access a service, a session management function (SMF) network element can discover an EAS corresponding to the service to be accessed by the terminal, and can assist the terminal to access the EAS. However, in an enhancing topolocy of SMF and UPF in 5G network (ETSUN) scenario, the SMF network element corresponds to a service area, and the SMF can serve one or more specific data network access points (or referred to as data network access identifiers (DNAIs)), and for other data network access points, the SMF network element can not be able to efficiently select a UPF network element serving the terminal when the terminal accesses the EAS. SUMMARY

[0006] The present application provides a communication method and apparatus to improve the efficiency of selecting a UPF network element when selecting the UPF network element serving a terminal when the terminal accesses an EAS.

[0007] In a first aspect, an embodiment of the present application provides a communication method, which can be applied to a first session management network element or a chip in the first session management network element. Taking the case that the method is applied to the first session management network element as an example, the method comprises the following steps: the first session management network element receives first domain name information, the first domain name information being used for a terminal to query an address of at least one application server, the at least one application server being a server providing a service corresponding to the first domain name information; the first session management network element sends first address information to a second session management network element, the first address information being determined according to the first domain name information, the first session management network element and the second session management network element serving the terminal; the first session management network element receives second address information from the second session management network element, the second address information being determined according to the first address information, the second address information being an address of a first application server, the first application server being an application server closest to the terminal among the at least one application server; and the first session management network element determines a first user plane network element according to the second address information, the first user plane network element being a user plane network element serving the terminal when the terminal accesses the first application server.

[0008] Through the above method, after the first session management network element receives the first domain name information, the first address information is determined according to the first domain name information, and the first address information is sent to the second session management network element. The first address information can be used to determine the second address information of the application server closest to the terminal. After the first session management network element receives the second address information, the accurate first user plane network element can be quickly determined based on the second address information, thereby improving the selection efficiency of the first user plane network element.

[0009] Optionally, the second session management network element is a network element managing a session of the terminal, and the first session management network element is an intermediate session management network element of the session of the terminal. For example, the first session management network element is an I-SMF network element, and the second session management network element is an SMF network element.

[0010] Through the above design, when the first user plane network element serving the terminal when the terminal accesses the EAS is selected, the I-SMF network element and the SMF network element are inserted to cooperate with each other to determine the first user plane network element. The first user plane network element can be accurately determined, and the suitable user plane network element can be selected after repeated selection, thereby improving the efficiency of selecting the first user plane network element.

[0011] Optionally, the first application server close to the terminal is at least one application server close to the location of the terminal; for example, the first application server can be the one closest to the location of the terminal, or one of the N closest application servers to the location of the terminal. Alternatively, the first application server close to the terminal is determined from the at least one application server according to the location of the terminal and reference information; for example, the reference information can be the load information of the application servers, such as the application server closest to the location of the terminal and with the smallest load. Alternatively, the first application server close to the terminal is at least one application server within a first set range from the location of the terminal; for example, the first set range can be a real distance range, or the first set range can be a range in the network topology (e.g., the number of network elements in the network topology).

[0012] Optionally, the location of the terminal can be a geographical location or a location in the network topology.

[0013] In a possible design, the first session management network element receives the first domain name information from the second session management network element; or, the first session management network element receives the first domain name information from the access management network element.

[0014] Through the above design, the first session management network element can flexibly receive the first domain name information in multiple different ways.

[0015] In a possible design, the first session management network element receives a session management context reply message from the second session management network element, and the session management context reply message includes the first domain name information.

[0016] Through the above design, the second session management network element can send the first domain name information to the first session management network element through the session management context reply message, without the need to increase additional messages, thereby reducing the signaling overhead.

[0017] Optionally, the session management context reply message further includes first indication information, and the first indication information is used to indicate that the first address information is determined according to the first domain name information.

[0018] Through the above design, after receiving the first indication information in the session management context reply message, the first session management network element can determine that the first address information needs to be determined according to the first domain name information, so that the first session management network element is clear about the subsequent actions, and the efficiency of selecting the user plane network element is improved.

[0019] In a possible design, the first session management network element receives a context creation message from the access management network element, where the context creation message is used to indicate creation of session management context information of the terminal, and the context creation message includes the first domain name information.

[0020] Through the above design, the access management network element can send the first domain name information to the first session management network element through the context creation message, without the need to increase additional messages, thereby reducing signaling overhead.

[0021] Optionally, the context creation message further includes first indication information, where the first indication information is used to indicate that the first address information is determined according to the first domain name information.

[0022] Through the above design, after receiving the first indication information in the context creation message, the first session management network element can determine that the first address information needs to be determined according to the first domain name information, so that the first session management network element is clear about subsequent actions, and the efficiency of selecting the user plane network element is improved.

[0023] In a possible design, the first session management network element determines the first user plane network element according to the second address information, deployment information of the first application server, and location information of the terminal.

[0024] Through the above design, the first session management network element can accurately determine the first user plane network element according to the second address information, the deployment information of the application server, and the location of the terminal.

[0025] In a second aspect, an embodiment of the present application provides a communication method, which can be applied to a first session management network element or a chip in the first session management network element. Taking the case that the method is applied to the first session management network element as an example, the method includes: the first session management network element receives first domain name information, where the first domain name information is used for the terminal to query addresses of at least one application server, and the at least one application server is a server providing a service corresponding to the first domain name information; and the first session management network element determines a first user plane network element according to the first domain name information, where the first user plane network element is a user plane network element serving the terminal when the terminal accesses the application server.

[0026] Through the above method, after the first session management network element receives the first domain name information, the first user plane network element can be directly determined according to the first domain name information, so that the first user plane network element can be quickly selected, and the efficiency of selecting the user plane network element is improved.

[0027] Optionally, the second session management network element is a network element managing a session of the terminal, and the first session management network element is an intermediate session management network element of the session of the terminal. For example, the first session management network element is an I-SMF network element, and the second session management network element is an SMF network element.

[0028] Through the above design, when the first user plane network element serving the terminal accessing the EAS is selected, the I-SMF network element and the SMF network element are cooperated with each other to determine the first user plane network element, so that the first user plane network element can be accurately determined, and the efficiency of selecting the first user plane network element is improved.

[0029] In a possible design, the first session management network element determines the first user plane network element according to the first domain name information, the deployment information of the at least one application server, and the location information of the terminal.

[0030] Through the above design, the first session management network element can accurately determine the first user plane network element according to the first domain name information, the deployment information of the application server, and the location of the terminal.

[0031] In a possible design, the first session management network element sends first address information to the second session management network element, the first address information being determined according to the first domain name information, and the first session management network element and the second session management network element serving the terminal; receives second address information from the second session management network element, the second address information being determined according to the first address information, and the second address information being an address of a first application server, the first application server being an application server close to the terminal in the at least one application server; and updates the first user plane network element to a second user plane network element according to the second address information, the second user plane network element being a user plane network element serving the terminal when the terminal accesses the first application server.

[0032] Through the above design, after the first session management network element selects the first user plane network element, it can determine whether the selected user plane network element needs to be updated. For example, the first session management network element determines first address information according to the first domain name information, and sends the first address information to the second session management network element, the first address information being used to determine second address information of an application server close to the terminal; after the first session management network element receives the second address information, the second user plane network element can be determined based on the second address information, and in a case where it is determined that the first user plane network element needs to be updated, the first user plane network element can be updated to the second user plane network element, so as to further ensure that an accurate user plane network element is selected.

[0033] In a possible design, the first session management network element determines the second user plane network element according to the second address information, the deployment information of the first application server, and the location information of the terminal; and if the data network access point corresponding to the first user plane network element is different from the data network access point corresponding to the second user plane network element, the first session management network element updates the first user plane network element to the second user plane network element.

[0034] Through the above design, when the data network access point determined according to the first domain name information is different from the data network access point determined according to the second address information, the first session management network element can update the first user plane network element to the second user plane network element, so as to ensure that the accurate user plane network element is selected.

[0035] In a third aspect, a communication apparatus is provided. The communication apparatus can implement the functions of any of the first aspect or the second aspect. The communication apparatus can include modules or units or means corresponding to the operations of any of the first aspect or the second aspect. The modules or units or means can be implemented by software or by hardware, or by a combination of software and hardware. For example, the communication apparatus includes a communication unit and a processing unit. The communication unit is configured to perform the functions of any of the first aspect or the second aspect. The processing unit is configured to perform the processing operations.

[0036] In one design, the communication apparatus is a communication chip. The processing unit can be one or more processors or processor cores. The communication unit can be input / output circuits, input / output interfaces, or antenna ports of the communication chip.

[0037] In another design, the communication unit can be a transmitter and a receiver. Or the communication unit can be a transmitter and a receiver.

[0038] Optionally, the communication apparatus further includes various modules that can be used to perform any of the first aspect or the second aspect, or perform any possible implementation of the first aspect or the second aspect.

[0039] In a fourth aspect, a communication apparatus is provided. The communication apparatus can be the first session management network element. The communication apparatus can include a processor and a memory to perform any of the first aspect or the second aspect, or perform any possible implementation of the first aspect or the second aspect. Optionally, the communication apparatus further includes a transceiver. The memory is configured to store computer programs or instructions. The processor is configured to invoke and run the computer programs or instructions in the memory. When the processor executes the computer programs or instructions in the memory, the communication apparatus performs any of the first aspect or the second aspect, or performs any possible implementation of the first aspect or the second aspect.

[0040] Optionally, the processor is one or more processors, and the memory is one or more memories.

[0041] Optionally, the memory can be integrated with the processor, or the memory can be arranged separately from the processor.

[0042] Optionally, the transceiver can include a transmitter (transmitter) and a receiver (receiver).

[0043] In a fifth aspect, a communication apparatus is provided, which can be the first session management network element. The communication apparatus can include a processor to implement any of the first aspect or the second aspect, or any possible implementation of the first aspect or the second aspect. The processor is coupled to a memory. Optionally, the communication apparatus further includes the memory. Optionally, the communication apparatus further includes a communication interface, and the processor is coupled to the communication interface.

[0044] In an implementation, when the communication apparatus is the first session management network element, the communication interface can be a transceiver, or an input / output interface. Optionally, the transceiver can be a transceiver circuit. Optionally, the input / output interface can be an input / output circuit.

[0045] In yet another implementation, when the communication apparatus is a chip or a chip system, the communication interface can be an input / output interface, an interface circuit, an output circuit, an input circuit, a pin, or related circuitry, etc. on the chip or the chip system. The processor can also be embodied as a processing circuit or a logic circuit.

[0046] In a sixth aspect, the present application provides a communication apparatus, which includes a processor, and can further include a storage medium storing a computer program or instructions, which are executed by the processor to implement the method in any possible design of the first aspect or the second aspect. The communication apparatus can be a chip system. The chip system can be composed of a chip, or can include a chip and other discrete devices.

[0047] In a seventh aspect, the present application further provides a chip including a processor coupled to a memory, for reading and executing computer programs or instructions stored in the memory, so as to enable the chip to implement the method in any possible design of the first aspect or the second aspect.

[0048] In an eighth aspect, the present application provides a computer readable storage medium, which stores computer programs or instructions, and when a computer reads and executes the computer programs or instructions, the computer executes the method in any possible design of the first aspect or the second aspect.

[0049] In a ninth aspect, the present application provides a computer program product, and when a computer reads and executes the computer program product, the computer executes the method in any possible design of the first aspect or the second aspect.

[0050] The technical effects that can be achieved by each of the third aspect to the ninth aspect and each aspect are described above in relation to the technical effects that can be achieved by each of the possible solutions of the first aspect or the second aspect, and thus will not be repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0051] Fig. 1 is a schematic diagram of a multi-anchor session architecture according to an embodiment of the present application;

[0052] Fig. 2 is a network architecture diagram of a communication system according to an embodiment of the present application;

[0053] Fig. 3 is a flow diagram of a communication method according to an embodiment of the present application;

[0054] Fig. 4 is a flow diagram of a communication method according to an embodiment of the present application;

[0055] Fig. 5 is a flow diagram of a communication method according to an embodiment of the present application;

[0056] Fig. 6 is a flow diagram of a communication method according to an embodiment of the present application;

[0057] Fig. 7 is a flow diagram of a communication method according to an embodiment of the present application;

[0058] Fig. 8 is a flow diagram of a communication method according to an embodiment of the present application;

[0059] Fig. 9 is a schematic diagram of a structure of a communication apparatus according to an embodiment of the present application;

[0060] Fig. 10 is a schematic diagram of a structure of a communication apparatus according to an embodiment of the present application. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the embodiments of the present application will be further described in detail below with reference to the drawings.

[0062] At least one (item) to which the embodiments of the present application relate indicates one (item) or multiple (items). Multiple (items) means two (items) or more than two (items). The “and / or” describes the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can mean that there are three cases of A alone, A and B together, and B alone. The character “ / ” generally represents an “or” relationship between the front and rear associated objects. In addition, it should be understood that although the terms first, second, etc. can be used to describe various objects in the embodiments of the present application, these objects should not be limited to these terms. These terms are only used to distinguish each object from each other.

[0063] The ordinal numbers, such as the first, the second, etc., mentioned in the embodiments of the present application are used to distinguish a plurality of objects, and are not used to limit the order, the time sequence, the priority, or the importance of the plurality of objects. For example, the first indication information and the second indication information are only used to distinguish different information, and do not represent that the contents, the priorities, or the importance of the two kinds of information are different.

[0064] The terms “comprise”, “comprising”, “have”, “having”, “include”, “including” and any variations thereof in the description and in the claims of the present application are intended to cover the non-exclusive inclusion such that processes, methods, articles, or apparatuses that comprise, have, include or include the recited elements, but also those that further comprise, have, include or include other elements. It is to be noted that the words “exemplary” and “for example” in the description of the embodiments of the present application are used to present examples, instances, or illustrations. Any method or design scheme described as “exemplary” or “for example” in the embodiments of the present application should not be interpreted as more preferred or more advantageous than other methods or design schemes. Rather, the words “exemplary” or “for example” are used to present the relevant concept in a specific manner.

[0065] The technology provided by the embodiments of the present application can be applied to various communication systems, such as a universal mobile telecommunications system (UMTS), a wireless local area network (WLAN), a wireless fidelity (Wi-Fi) system, a 4th generation (4G) mobile communication system (such as a long term evolution (LTE) system), a 5th generation (5G) mobile communication system (such as a new radio (NR) system), and a future communication system.

[0066] The present application will present various aspects, embodiments or features around a system that can include a plurality of devices, components, modules, etc. It should be understood and appreciated that each system can include additional devices, components, modules, etc., and / or can not include all of the devices, components, modules, etc. discussed in conjunction with the figures. Moreover, combinations of these aspects can also be used.

[0067] In addition, in the embodiments of the present application, the words "exemplary", "for example", "for instance", etc. are used herein to mean an example or illustration rather than a preference or requirement. Any embodiment or design solution described as "example" in the present application should not be interpreted as being more preferred or advantageous than other embodiments or design solutions. In fact, the use of the word "example" is intended to present concepts in a concrete manner. In the embodiments of the present application, "of", "corresponding" and "corresponding" are sometimes used interchangeably, and it should be pointed out that when their differences are not emphasized, their meanings are consistent.

[0068] A network element in a communication system can send a signal to another network element or receive a signal from another network element. The signal can include information or data, etc.; the network element can also be referred to as an entity, a network entity, a device, a communication device, a communication module, a node, a communication node, etc. In the embodiments of the present application, the network element is taken as an example for description.

[0069] In order to support selective traffic routing to a data network or support a session continuity mode, the SMF network element can insert multiple UPF network elements controlled by the SMF network element in the user plane of a protocol data unit (PDU) session to control the user plane path of the PDU session, so that one PDU session can access a data network (DN) through multiple N6 interfaces at the same time. Each UPF network element accessing the DN needs to support the PDU session anchor function, that is, one PDU session needs to access the same DN through multiple anchors.

[0070] As shown in the multi-anchored session architecture (see 3GPP TS 23.501, 23.548 for details) in FIG. 1, the architecture contains network functions and entities, including: a terminal, a (radio) access network (R) AN network element, an access and mobility management function (AMF) network element, a session management function (SMF) network element, a policy control function (PCF) network element, an application function (AF) network element, a unified data management (UDM) network element, a network exposure function (NEF) network element, a network repository function (NRF) network element, an edge application server discovery function (EASDF) network element, at least one user plane function (UPF) network element, a DN, and the like.

[0071] The PDU session of the terminal has a splitting point UPF network element (such as the ULCL / BP in FIG. 1), which has the function of splitting user plane messages according to the destination / source IP address of the user plane message. The splitting rule can be configured by the SMF network element. For example, the uplink classifier (ULCL) UPF network element splits according to the destination IP address of the uplink message. According to the destination IP address, the user plane message is forwarded to the C-PSA or L-PSA through different tunnels (such as the tunnel between the ULCL and the central-PSA (C-PSA) in FIG. 1, or the tunnel between the ULCL and the local-PSA (L-PSA)). The C-PSA can also be referred to as a PSA. For example, the branching point (BP) UPF network element splits according to the source IP address of the uplink message. According to the source IP address, the user plane message is forwarded to the C-PSA or L-PSA through different tunnels. When using BP splitting, the SMF network element generates a routing rule and sends it to the terminal. The terminal selects different source IPs when accessing services according to the routing rule. Further, the BP UPF network element splits according to the source IP.

[0072] The splitting rule of the splitting point is configured by the SMF network element, and the SMF network element can control the insertion, modification, removal, and configuration / modification of the splitting rule of the UPF network element through the N4 interface between the SMF network element and the UPF network element.

[0073] For example, in the scenario of a public network, the local DN and the DN in FIG. 1 are the internet network, and the two DNs can interwork. That is, the data packet of the UE can reach any one of the servers in the L-DN / DN, regardless of whether the data packet enters the L-DN / DN from the L-PSA or the C-PSA. For example, the deployment locations of the L-PSA and the L-DN are A, the deployment location of the C-PSA is B, and the deployment location of the server corresponding to a service is C. The routing mode of the data packet of the terminal includes: mode 1, the data packet of the terminal can enter the internet through the C-PSA with the deployment location B, and be routed to the server with the deployment location C in the internet; and mode 2, the data packet of the terminal can directly enter the internet from the L-PSA with the deployment location A, and be routed to the server with the deployment location C in the internet.

[0074] Referring to FIG. 2, a network architecture diagram of a communication system to which embodiments of the present application are applicable is shown. The system includes network functions and entities, mainly including: a terminal, a RAN network element, an AMF network element, an SMF network element, an I-SMF network element, an EASDF network element, and multiple UPF network elements, and the like. The SMF network element and the I-SMF network element are session management network elements for serving the terminal, the SMF network element is a network element for managing the PDU session of the terminal, and the I-SMF network element is an intermediate session management network element inserted by the AMF network element for the PDU session of the terminal. For example, the multiple UPF network elements can include the UPF1 network element, the UPF2 network element, and the UPF3 network element in FIG. 2. The UPF1 network element can be a ULCL / BP, the UPF2 network element can be a L-PSA, and the UPF3 network element can be a C-PSA. The C-PSA can be a user plane network element selected by the SMF network element for the UE, and the ULCL / BP and the L-PSA can be user plane network elements selected by the I-SMF network element for the UE.

[0075] The terminal in the network architecture diagram of the communication system in the present application can be a device or module with corresponding communication functions and accessing the above communication system. The terminal can also be referred to as user equipment (UE), terminal device, user apparatus, access terminal, subscriber unit, subscriber station, mobile station, mobile station (MS), remote station, remote terminal, mobile device, user terminal, terminal unit, terminal station, terminal apparatus, wireless communication device, user agent or user apparatus. The terminal is usually provided with a communication module, circuit or chip for executing corresponding communication functions. The terminal is also configured with program instructions for executing corresponding communication functions. For example, the terminal in the embodiments of the present application can be a mobile phone, a personal digital assistant (PDA) computer, a laptop computer, a tablet computer (Pad), a drone, a computer with wireless transceiver function, a machine type communication (MTC) terminal, a virtual reality (VR) terminal, an augmented reality (AR) terminal, an internet of things (IoT) terminal, a wireless terminal in industrial control, a wireless terminal in self driving, a wireless terminal in remote medical, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home (such as game console, smart TV, smart speaker, smart refrigerator and fitness equipment, etc.), a wireless terminal with wireless communication function, a communication module, a roadside unit (RSU) with terminal function. The embodiments of the present application do not limit the specific technology and specific device form of the terminal device.

[0076] The (R)AN network element in the network architecture diagram of the communication system of the present application can be an evolved universal terrestrial radio access (E-UTRA) system, an NR system, and a future wireless access system defined in the 3rd generation partnership project (3GPP). The RAN 100 can also include two or more different wireless access systems described above. The (R)AN network element can also be an open RAN (O-RAN).

[0077] The (R)AN network element involved in the embodiments of the present application can be a RAN node. The RAN node, also known as a wireless access network device, a RAN entity, or an access node, is used to help terminals access the communication system through wireless means. In one application scenario, the RAN node can be a base station, an evolved NodeB (eNodeB), a transmission reception point (TRP), a next generation NodeB (gNB) in the 5th generation (5G) mobile communication system, a next generation base station in the 6th generation (6G) mobile communication system, or a base station in a future mobile communication system. The RAN node can be a macro base station, a micro base station, or an indoor station, and can also be a relay node or a donor node.

[0078] In another application scenario, wireless access can be realized for a terminal through cooperation of a plurality of RAN nodes, and different RAN nodes realize part of functions of a base station respectively. For example, a RAN node can be a central unit (CU), a distributed unit (DU), or a radio unit (RU). Here, the CU completes functions of a radio resource control protocol and a packet data convergence protocol (PDCP) of the base station, and can also complete a function of a service data adaptation protocol (SDAP); the DU completes functions of a radio link control layer and a medium access control (MAC) layer of the base station, and can also complete a function of part of a physical layer or all of the physical layer. For specific descriptions of the above protocol layers, refer to related technical specifications of the 3GPP. The RU can be used to realize a function of transceiving a radio frequency signal. The CU and the DU can be two independent RAN nodes, or can be integrated in a same RAN node, for example, integrated in a baseband unit (BBU). The RU can be included in a radio frequency device, for example, included in a remote radio unit (RRU) or an active antenna unit (AAU). The CU can be further divided into two types of RAN nodes of a CU-control panel and a CU-user panel.

[0079] In different systems, the RAN node can have different names. For example, in an O-RAN system, the CU can be referred to as an open CU (O-CU), the DU can be referred to as an open DU (O-DU), and the RU can be referred to as an open RU (O-RU). The CU-control panel (CU-CP) can also be referred to as an open CU-CP (O-CU-CP), and the CU-user panel (CU-UP) can also be referred to as an open CU-UP (O-CU-UP). The RAN node in the embodiment of the present application can be realized through a software module, a hardware module, or a combination of a software module and a hardware module. For example, the RAN node can be a server loaded with a corresponding software module. The embodiment of the present application does not limit specific technologies and specific device forms adopted by the RAN node. For ease of description, a base station is taken as an example of the RAN node in the following description.

[0080] DN: a data network providing service for users, generally, the client is located in the terminal, and the server is located in the data network. The data network can be a private network, such as a local area network, or an external network not under the control of an operator, for example, the Internet, or a dedicated network jointly deployed by operators, for example, a network providing IP multimedia network subsystem (IMS) services.

[0081] The functions of the network elements in the core network are briefly introduced as follows (for details, see 3GPP TS 23.501):

[0082] The SMF network element: mainly used for session management, IP address allocation and management of the terminal, selection of a manageable user equipment plane function, termination of a policy control or charging function interface, and downlink data notification.

[0083] The AMF network element: mainly used for mobility management and access management, for example, it can be the mobility management entity (MME) function in the 4G communication network or the AMF network element in the 5G network.

[0084] The PCF network element: a unified policy framework for guiding network behavior, providing policy rule information for control plane function network elements (such as AMF, SMF, etc.).

[0085] The UDM network element: used for processing user identification, subscription, access authentication, registration, or mobility management, etc.

[0086] The AF network element: used for data routing for application influence, access network exposure function, or interaction with the policy framework for policy control, etc.

[0087] The UPF network element: used for packet routing and forwarding, or quality of service (QoS) processing of user plane data, etc.

[0088] The NEF network element: used for securely exposing services and capabilities provided by 3GPP network functions to the outside, etc.

[0089] The NRF network element: used for saving the description information of network function entities and the services they provide, and supporting service discovery, network element entity discovery, etc.

[0090] The EASDF network element: a network element used for assisting in discovering EAS, which mainly functions to process domain name system (DNS) messages according to the instructions of the SMF.

[0091] It can be understood that other network elements can be included in the network architecture described above in actual applications, which are not limited in the present application.

[0092] It should be noted that in the present application, the names of various network elements are only examples, and the present application does not exclude the case that the various network elements are named otherwise and the functions of the various network elements are merged. With the evolution of technology, any device or network element that can realize the functions of the various network elements described above is within the protection scope of the present application. The interface names between the various network elements in FIG. 2 are only examples, and the names of the interfaces in the specific implementation can be other names, which are not limited in the present application. In addition, the names of the messages (or signaling) transmitted between the various network elements described above are also only examples, and do not constitute any limitation on the functions of the messages themselves.

[0093] It should be understood that the embodiments introduced hereinafter can be implemented by all the network elements in FIG. 2, or can be implemented by part of the network elements in FIG. 2, which are not limited in the present application.

[0094] For ease of description, hereinafter, the various network elements can be represented by their corresponding English abbreviations, for example, the application function network element is represented by "AF", the session management function network element is represented by "SMF", and so on.

[0095] Based on the network architecture of the communication system of the embodiments of the present application described above, hereinafter, the scheme of selecting the UPF network element by the I-SMF network element when the terminal requests to access the EAS is introduced in detail.

[0096] The embodiments of the present application provide a communication method, when a terminal requests to access the service provided by an application server, if the data network access point (or DNAI) at the location of the terminal is not the data network access point in the service area corresponding to the SMF network element serving the terminal, the SMF network element triggers the insertion of the I-SMF network element, the I-SMF network element determines the user plane network element, and the user plane network element is the user plane network element serving the terminal when the terminal accesses the application server.

[0097] FIG. 3 is a flow diagram of a communication method provided by an embodiment of the present application, which mainly includes the following steps 300-303. It can be understood that the steps and the execution order shown in FIG. 3 are only examples, and in actual implementation, part of the steps or the remaining steps can be executed, and similarly, the execution order of the steps can also be adjusted, which is not limited in the embodiments of the present application.

[0098] Step 300: The first session management network element receives first domain name information.

[0099] The first session management network element and the second session management network element serve the terminal. Optionally, the first session management network element and the second session management network element are different network elements serving the terminal.

[0100] For example, the first session management network element can be an intermediate session management network element (I-SMF network element); for example, the first session management network element is an I-SMF network element inserted for a session (such as a PDU session) of the terminal; wherein the name of the first session management network element is not limited to I-SMF, and can also be other names, which are not limited by the present application. The second session management network element can be a network element managing the session of the terminal; for example, the second session management network element is an SMF network element or an anchor SMF network element, and the name of the second session management network element is not limited by the present application.

[0101] Alternatively, the first session management network element and the second session management network element can be network elements supporting different capabilities; for example, the first session management network element supports traffic routing of the session, and the second session management network element supports QoS control of the session; for another example, the first session management network element supports local traffic routing, and the second session management network element does not support local traffic routing. Alternatively, the first session management network element and the second session management network element can be network elements with different characteristics; for example, the first session management network element and the second session management network element support different data network names (DNNs) and / or single network slice selection assistance information (S-NSSAIs). Alternatively, the first session management network element and the second session management network element correspond to different service areas.

[0102] It should be noted that the above is only an example of the first session management network element and the second session management network element, and the first session management network element and the second session management network element can also be other session management network elements serving the terminal, which are not limited by the present application.

[0103] For example, the first session management network element serving the terminal can be understood as the first SMF network element serving the session of the terminal, or the first SMF network element is the I-SMF network element of the session of the terminal, or the first SMF network element is the I-SMF network element in the PDU session architecture of the terminal, or the first SMF network element stores the context of the session of the terminal, or the first SMF network element is the I-SMF network element inserted for the session of the terminal, or the first SMF is the I-SMF network element selected by the AMF network element in the session establishment / modification process of the terminal. The second session management network element serving the terminal can be understood as the second SMF network element serving the session of the terminal, or the second SMF network element is the SMF network element of the session of the terminal, or the second SMF network element is the SMF network element in the PDU session architecture of the terminal, or the second SMF network element stores the context of the session of the terminal, or the second SMF is the SMF network element selected by the AMF network element in the session establishment process of the terminal.

[0104] The first domain name information is used by the terminal to query the address of at least one application server, and the at least one application server is a server providing a service corresponding to the first domain name information.

[0105] For example, the first domain name information can be full qualified domain name (FQDN) information in a DNS request message sent by the terminal.

[0106] In the embodiment of the application, the first session management network element can receive the first domain name information in multiple different ways, which are described below.

[0107] The first domain name information receiving method one is as follows:

[0108] Optionally, the first session management network element receives the first domain name information from the second session management network element.

[0109] The process in which the first session management network element receives the first domain name information is as follows: when the terminal initiates a certain service, taking the first service as an example. The terminal sends a DNS request message to the EASDF network element, and the DNS request message includes the first domain name information, which is the domain name information of the application server providing the first service. The EASDF network element sends the first domain name information in the DNS request message to the second session management network element. The second session management network element sends the first domain name information to the first session management network element.

[0110] It should be understood that the first session management network element in the embodiment of the application can be a network element inserted for the session (such as a PDU session) of the terminal. Optionally, the first session management network element is inserted after the second session management network element receives the first domain name information sent by the EASDF network element.

[0111] After the second session management network element receives the first domain name information sent by the EASDF network element, the first session management network element can be inserted in a plurality of different ways. Exemplarily, two first session management network element insertion ways are introduced below; it should be understood that the two first session management network element insertion ways below are only examples of the embodiments of the present application, and the embodiments of the present application do not limit the specific first session management network element insertion way.

[0112] First session management network element insertion way 1:

[0113] The second session management network element sends first indication information to the access management network element, and the first indication information is used to indicate that the first session management network element is inserted according to the location information of the terminal.

[0114] In implementation, the second session management network element obtains a candidate FQDN set, wherein the candidate FQDN set includes a plurality of FQDN information, and the FQDN information included in the candidate FQDN set is the FQDN information corresponding to the service that needs I-SMF control. After the second session management network element receives the first domain name information sent by the EASDF network element, if it is determined that the first domain name information is included in the candidate FQDN set, the second session management network element sends notification information to the access management network element, notifying the access management network element to insert the first session management network element according to the location information of the terminal. Correspondingly, after the access management network element receives the notification information, the first session management network element is inserted according to the location of the terminal. Exemplarily, the access management network element can be an AMF network element.

[0115] First session management network element insertion way 2:

[0116] The second session management network element sends the target DNAI to the access management network element, and the access management network element inserts the first session management network element according to the target DNAI.

[0117] In implementation, the second session management network element obtains a candidate FQDN set and a DNAI set corresponding to each FQDN information in the candidate FQDN set. The candidate FQDN set includes a plurality of FQDN information, and the FQDN information included in the candidate FQDN set is the FQDN information corresponding to the service that needs I-SMF control; and the DNAI set corresponding to each FQDN information includes one or more DNAIs. After the second session management network element receives the first domain name information sent by the EASDF network element, if it is determined that the first domain name information is included in the candidate FQDN set, the second session management network element determines the target DNAI from the DNAI set corresponding to the first domain name information according to the location information of the terminal. The second session management network element sends the target DNAI to the access management network element; correspondingly, after the access management network element receives the target DNAI, the first session management network element is inserted according to the target DNAI. Exemplarily, the access management network element can be an AMF network element.

[0118] After the access management network element inserts the first session management network element, the first session management network element sends a session management context request message to the second session management network element, for requesting session context information from the second session management network element. After receiving the session management context request message, the second session management network element sends a session management context reply message to the first session management network element; correspondingly, the first session management network element receives the session management context reply message from the second session management network element, and optionally, the session management context reply message includes the first domain name information.

[0119] Based on this, the first session management network element obtains the first domain name information through the session management context reply message sent by the second session management network element.

[0120] Optionally, the session management context reply message further includes first indication information, and the first indication information is used to indicate that the first address information is determined according to the first domain name information. Correspondingly, after receiving the session management context reply message, the first session management network element determines, according to the first indication information included in the session management context reply message, that the first address information is determined according to the first domain name information.

[0121] It should be understood that the first indication information included in the session management context reply message is used to indicate that the first session management network element performs a subsequent step, such as determining the first address information according to the first domain name information. In the case that the first indication information is not included in the session management context reply message, when the first session management network element determines that the first domain name information is included in the session management context reply message, it can also determine to perform the subsequent step, such as determining the first address information according to the first domain name information.

[0122] Second receiving mode of the first domain name information:

[0123] Optionally, the first session management network element receives the first domain name information from the access management network element. Correspondingly, the access management network element sends the first domain name information to the first session management network element.

[0124] The process that the first session management network element receives the first domain name information is as follows: taking a first service as an example, when a terminal initiates a certain service. The terminal sends a DNS request message to the EASDF network element, and the DNS request message includes the first domain name information, which is the domain name information of an application server providing the first service; the EASDF network element sends the first domain name information in the DNS request message to the second session management network element; the second session management network element sends the first domain name information to the access management network element; after the access management network element receives the first domain name information, the first session management network element is determined, and the first domain name information is sent to the first session management network element; correspondingly, the first session management network element receives the first domain name information from the access management network element. Exemplarily, the access management network element can be an AMF network element.

[0125] It should be understood that the first session management network element in the embodiments of the present application is a network element inserted for a session (such as a PDU session) of a terminal. Optionally, after the access management network element receives the first domain name information, the first session management network element is inserted.

[0126] Optionally, the access management network element inserts the first session management network element according to the following manner:

[0127] After the access management network element receives the first domain name information from the second session management network element, the first session management network element is determined according to the first domain name information.

[0128] In the implementation, the second session management network element obtains a candidate FQDN set, wherein the candidate FQDN set includes a plurality of FQDN information, and the FQDN information included in the candidate FQDN set is FQDN information corresponding to a service that needs I-SMF control. After the second session management network element receives the first domain name information sent by the EASDF network element, if it is determined that the first domain name information is included in the candidate FQDN set, the first domain name information is sent to the access management network element. After the access management network element receives the first domain name information, the first domain name information and the location information of the terminal are sent to the NRF network element, and the NRF network element determines the first session management network element according to the first domain name information and the location information of the terminal; the NRF network element can send the identification information of the first session management network element to the access management network element, and the access management network element inserts the first session management network element according to the identification information of the first session management network element. Exemplarily, the identification information of the first session management network element can be an identity ID of the first session management network element, or the identification information of the first session management network element can be address information of the first session management network element.

[0129] Optionally, after the second session management network element receives the first domain name information sent by the EASDF network element, the second session management network element can also send first indication information to the access management network element, for indicating that the first address information is determined according to the first domain name information.

[0130] After the access management network element inserts the first session management network element, the access management network element sends a context creation message to the first session management network element. Correspondingly, the first session management network element receives the context creation message from the access management network element, and the context creation message is used to indicate the creation of the session management context information of the terminal; optionally, the context creation message includes the first domain name information.

[0131] Based on this, the first session management network element obtains the first domain name information through the context creation message of the access management network element.

[0132] Optionally, the context creation message further includes first indication information, and the first indication information is used to indicate that the first address information is determined according to the first domain name information. Correspondingly, after the first session management network element receives the context creation message, the first session management network element determines, according to the first indication information included in the context creation message, that the first address information is determined according to the first domain name information.

[0133] It should be understood that the first indication information included in the context creation message is used to indicate that the first session management network element performs a subsequent step, such as determining the first address information according to the first domain name information. In the case where the first indication information is not included in the context creation message, when the first session management network element determines that the context creation message includes the first domain name information, the first session management network element can also determine to perform the subsequent step, such as determining the first address information according to the first domain name information.

[0134] Step 301: The first session management network element sends the first address information to the second session management network element.

[0135] After the first session management network element receives the first domain name information, the first session management network element determines the first address information according to the first domain name information.

[0136] Optionally, the first address information can be used to construct an extension mechanism for the domain name system protocol (EDNS) client subnet option, which can be referred to as an ECS option. The first address information can be referred to as ECS option information; wherein the ECS option can be used as an extension item in a DNS request message to represent the location information of the terminal. For example, the ECS option information can be an IP address, for example, the first address information.

[0137] For example, the first session management network element can determine the first address information according to the following manner:

[0138] The first session management network element determines the first address information according to the first domain name information, the deployment information of the application server, and the location information of the terminal.

[0139] The first session management network element determines the first address information and sends the first address information to the second session management network element. Correspondingly, the second session management network element receives the first address information from the first session management network element. Optionally, the first session management network element sends a PDU session creation / update request message to the second session management network element, and the PDU session creation / update request message includes the first address information. The second session management network element obtains the first address information from the PDU session creation / update request message. Exemplarily, the PDU session creation / update request message can be an Nsmf_PDUSession_Create Request message or an Nsmf_PDUSession_Update Request message.

[0140] Step 302: The first session management network element receives the second address information from the second session management network element.

[0141] As introduced in step 301, the second session management network element receives the first address information from the second session management network element. After receiving the first address information, the second session management network element sends the first address information to the EASDF network element. Correspondingly, the EASDF network element receives the first address information from the second session management network element. Optionally, the second session management network element can send a DNS context update message to the EASDF network element, and the DNS context update message includes the first address information. The EASDF network element obtains the first address information from the DNS context update message. Exemplarily, the DNS context update message can be a Neasdf_DNSContext_Update message.

[0142] After receiving the first address information, the EASDF network element sends the first address information to the DNS server. Optionally, the EASDF network element can send an updated DNS request message to the DNS server, and the updated DNS request message includes the first address information. For example, the EASDF network element creates or updates an ECS option in the DNS request message, and the first address information is used as the ECS option.

[0143] Correspondingly, the DNS server receives the first address information from the EASDF network element. Optionally, the DNS server can obtain the first address information from the updated DNS request message sent by the EASDF network element.

[0144] The DNS server determines the second address information according to the DNS request message; wherein the second address information is the address of the first application server, and the first application server is the application server closest to the terminal among the at least one application server. For example, the first application server is the application server closest to the first address information (e.g., closest in network topology), and the first address information is the address closest to the terminal.

[0145] For example, the DNS server determines the second address information according to the first domain name information and the first address information in the DNS request message.

[0146] After receiving the updated DNS request message, the DNS server can determine the at least one application server according to the first domain name information; wherein the at least one application server is the server providing the service corresponding to the first domain name information. After determining the at least one application server, the DNS server determines the first application server closest to the terminal from the at least one application server according to the first address information.

[0147] It should be understood that the first application server closest to the terminal can be the application server closest to the terminal location among the at least one application server. For example, the first application server can be the server closest to the terminal location among the at least one application server; or the first application server can be the application server closest to the terminal location determined by the DNS server according to the terminal location and other reference information (e.g., load information of each application server, etc.). The "closest to the terminal location" can be understood as the first application server being closest to the geographical location of the terminal, or can be understood as the first application server being closest to the terminal in network topology.

[0148] Optionally, after determining the first application server closest to the terminal from the at least one application server, the DNS server determines the address of the first application server as the second address information. The DNS server sends the second address information to the EASDF network element; correspondingly, the EASDF network element receives the second address information from the DNS server.

[0149] After receiving the second address information, the EASDF network element sends the second address information to the second session management network element. Correspondingly, the second session management network element receives the second address information from the EASDF network element. Optionally, the EASDF network element sends a DNS context notification message to the second session management network element, and the DNS context notification message includes the second address information; the second session management network element obtains the second address information from the DNS context notification message. For example, the DNS context notification message can be a Neasdf_DNSContext_Notify message.

[0150] In a possible implementation, after receiving the second address information, the second session management network element sends the second address information to the first session management network element.

[0151] Correspondingly, the first session management network element receives the second address information from the second session management network element. Optionally, the second session management network element sends a PDU session creation response message to the first session management network element, and the PDU session creation response message includes the second address information; the first session management network element obtains the second address information from the PDU session creation response message. For example, the PDU session creation response message can be an Nsmf_PDUSession_Create Response message.

[0152] In step 303, the first session management network element determines the first user plane network element according to the second address information. The first user plane network element is a user plane network element serving the terminal when the terminal accesses the first application server.

[0153] After receiving the second address information, the first session management network element can determine the first user plane network element according to the second address information.

[0154] Optionally, the first session management network element can determine the first user plane network element according to the following manner:

[0155] The first session management network element determines the first user plane network element according to the second address information, the deployment information of the first application server, and the location information of the terminal.

[0156] In the embodiment of the application, the first session management network element can determine a first data network access node (or referred to as a first DNAI) according to the second address information, the deployment information of the first application server, and the location information of the terminal; and the first session management network element determines the first user plane network element from the user plane network element corresponding to the first data network access node. For example, the first data network access node can correspond to multiple user plane network elements, and the first session management network element can determine the first user plane network element from the multiple user plane network elements corresponding to the first data network access node.

[0157] For example, the first user plane network element serves the terminal when the terminal accesses the first application server; for example, the first user plane network element provides services for the user plane service of the terminal.

[0158] For example, the user plane network element is a UPF network element, and the "user plane network element serving the terminal" can be understood as a UPF network element of the PDU session of the terminal, or can be understood as a UPF network element in the PDU session architecture of the terminal.

[0159] The first session management network element inserts a split point (ULCL / BP) and a local anchor point (L-PSA) according to the first user plane network element, and the inserted split point and local anchor point can be used to send user plane data of terminal service to a first application server corresponding to the service.

[0160] The communication method of the embodiment of the application shown in FIG. 3 will be described below in conjunction with examples.

[0161] Example 1

[0162] The first session management network element is taken as an I-SMF network element, the second session management network element is taken as an SMF network element, and the access management network element is taken as an AMF network element as an example for description.

[0163] The communication method flow shown in FIG. 4 shows only an example of steps and execution order, and in actual implementation, part of the steps or the remaining steps can be executed, and similarly, the execution order of the steps can be adjusted, which is not limited in the embodiment of the application.

[0164] Step 400: The terminal initiates a first service and sends a DNS request message for the first service to an EASDF network element.

[0165] Correspondingly, the EASDF network element receives the DNS request message from the terminal.

[0166] The DNS request message includes first domain name information; for example, the first domain name information can be FQDN information.

[0167] Step 401: The EASDF network element sends the first domain name information to an SMF network element.

[0168] Correspondingly, the SMF network element receives the first domain name information from the EASDF network element.

[0169] Optionally, the EASDF network element sends a DNS context notification message to the SMF network element, and the DNS context notification message includes the first domain name information; for example, the DNS context notification message can be a Neasdf_DNSContext_Notify message.

[0170] Step 402: The SMF network element sends a notification message to an AMF network element, for notifying the AMF network element to insert an I-SMF network element.

[0171] It should be noted that the manner of inserting the I-SMF network element in step 402 can refer to the description in the foregoing, such as the first session management network element insertion manner 1 and the first session management network element insertion manner 2 described above.

[0172] Step 403: The AMF network element selects an I-SMF network element, and sends a session management context creation request message to the I-SMF network element.

[0173] Correspondingly, the I-SMF network element receives the session management context creation request message from the AMF network element.

[0174] Illustratively, the session management context creation request message can be an Nsmf_PDUSession_CreateSMContext Request message.

[0175] Step 404: The I-SMF network element sends a session management context request message to the SMF network element, for requesting session context information from the second session management network element.

[0176] Correspondingly, the SMF network element receives the session management context request message from the I-SMF network element.

[0177] Illustratively, the session context request message can be an Nsmf_PDUSession_Context Request message.

[0178] Step 405: The SMF network element sends a session management context reply message to the I-SMF network element.

[0179] Correspondingly, the I-SMF network element receives the session management context reply message from the SMF network element. The session management context reply message can include first domain name information; or the session management context reply message can also include first indication information, which is used to indicate that the first address information is determined according to the first domain name information.

[0180] Illustratively, the session management context reply message can be an Nsmf_PDUSession_Context Response message.

[0181] Step 406: The I-SMF network element determines the first address information according to the first domain name information.

[0182] It should be noted that the manner in which the I-SMF network element determines the first address information according to the first domain name information can refer to the introduction of step 301 above, which will not be repeated here.

[0183] Step 407: The I-SMF network element sends the first address information to the SMF network element.

[0184] Correspondingly, the SMF network element receives the first address information from the I-SMF network element.

[0185] Optionally, the I-SMF network element sends a PDU session creation / update request message to the SMF network element, and the PDU session creation / update request message includes the first address information; and the second session management network element obtains the first address information from the PDU session creation / update request message. For example, the PDU session creation / update request message can be an Nsmf_PDUSession_Create Request message or an Nsmf_PDUSession_Update Request message.

[0186] Step 408: The SMF network element sends the first address information to the EASDF network element.

[0187] Correspondingly, the EASDF network element receives the first address information from the SMF network element.

[0188] Optionally, the SMF network element can send a DNS context update message to the EASDF network element, and the DNS context update message includes the first address information; and the EASDF network element obtains the first address information from the DNS context update message. For example, the DNS context update message can be a Neasdf_DNSContext_Update message.

[0189] Step 409: The EASDF network element sends the first address information to the DNS server.

[0190] Correspondingly, the DNS server receives the first address information from the EASDF network element.

[0191] Optionally, the EASDF network element can send an updated DNS request message to the DNS server, and the updated DNS request message includes the first address information; and the DNS server obtains the first address information from the updated DNS request message sent by the EASDF network element.

[0192] Optionally, the updated DNS request message received by the DNS server can also include first domain name information.

[0193] Step 410: The DNS server sends second address information to the EASDF network element.

[0194] Correspondingly, the EASDF network element receives the second address information from the DNS server.

[0195] It should be noted that the manner in which the DNS server determines the second address information can refer to the manner in which the DNS server determines the second address information described in step 302 above, which will not be repeated here.

[0196] Step 411: The EASDF network element sends the second address information to the SMF network element.

[0197] Correspondingly, the SMF network element receives the second address information from the EASDF network element.

[0198] Optionally, the EASDF network element sends a DNS context notification message to the SMF network element, and the DNS context notification message includes the second address information; and the SMF network element obtains the second address information from the DNS context notification message. Exemplarily, the DNS context notification message can be a Neasdf_DNSContext_Notify message.

[0199] Step 412: The SMF network element sends the second address information to the I-SMF network element.

[0200] Correspondingly, the I-SMF network element receives the second address information from the SMF network element.

[0201] Optionally, the SMF network element sends a PDU session creation response message to the I-SMF network element, and the PDU session creation response message includes the second address information; and the I-SMF network element obtains the second address information from the PDU session creation response message. Exemplarily, the PDU session creation response message can be a Nsmf_PDUSession_Create Response message.

[0202] Step 413: The I-SMF network element determines the first user plane network element according to the second address information.

[0203] The first user plane network element is a user plane network element serving the terminal when the terminal accesses the first application server. In FIG. 4, the first user plane network element is taken as an ULCL / BP network element and an L-PSA network element as an example.

[0204] It should be noted that the manner in which the I-SMF network element determines the first user plane network element can refer to the description of step 303 above, which will not be repeated here.

[0205] Step 414: The I-SMF network element obtains address information of the first user plane network element from the NRF network element.

[0206] Optionally, the I-SMF network element sends the first DNAI to the NRF network element, and obtains the address information of the first user plane network element from the NRF network element based on the first DNAI.

[0207] Step 415: The I-SMF network element establishes an N4 session with the first user plane network element.

[0208] Step 416: The I-SMF network element sends tunnel information of the first user plane network element and / or third indication information to the SMF network element; and the third indication information is used to instruct sending a DNS response message to the terminal.

[0209] Step 417: The SMF network element sends third indication information to the EASDF network element.

[0210] Step 418: The EASDF network element sends a DNS response message to the terminal.

[0211] Example 2

[0212] Taking the first session management network element as the I-SMF network element, the second session management network element as the SMF network element, and the access management network element as the AMF network element as an example for description.

[0213] As shown in the communication method flow of FIG. 5, the steps and the execution order shown in FIG. 5 are only as an example, and in actual implementation, part of the steps or the remaining steps can be executed, and similarly, the execution order of the steps can be adjusted, which is not limited in the embodiments of the present application.

[0214] Step 500: The terminal initiates a first service and sends a DNS request message for the first service to the EASDF network element.

[0215] Correspondingly, the EASDF network element receives the DNS request message from the terminal.

[0216] The DNS request message includes first domain name information; for example, the first domain name information can be FQDN information.

[0217] Step 501: The EASDF network element sends the first domain name information to the SMF network element.

[0218] Correspondingly, the SMF network element receives the first domain name information from the EASDF network element.

[0219] Optionally, the EASDF network element sends a DNS context notification message to the SMF network element, and the DNS context notification message includes the first domain name information; for example, the DNS context notification message can be Neasdf_DNSContext_Notify message.

[0220] Step 502: The SMF network element sends the first domain name information to the AMF network element.

[0221] Optionally, in step 502, the SMF network element can also send first indication information to the AMF network element. The first indication information is used to indicate that the first address information is determined according to the first domain name information. For example, the first address information can be ECS option information.

[0222] Step 503: The AMF network element acquires the identification information of the I-SMF network element from the NRF network element according to the first domain name information and the location information of the terminal, and inserts the I-SMF network element.

[0223] For example, the identity information of the first session management network element can be an identity ID of the first session management network element, or the identity information of the first session management network element can be address information of the first session management network element.

[0224] In step 504, the AMF network element sends first domain name information to the I-SMF network element.

[0225] Correspondingly, the I-SMF network element receives the first domain name information from the AMF network element.

[0226] Optionally, the AMF network element sends a context creation message to the I-SMF network element. Correspondingly, the I-SMF network element receives the context creation message from the AMF network element, and the context creation message is used to indicate the creation of session management context information of the terminal; the context creation message includes the first domain name information. For example, the context creation message can be an Nsmf_PDUSession_CreateSMContext Request message.

[0227] Optionally, the context creation message further includes first indication information, and the first indication information is used to indicate that the first address information is determined according to the first domain name information. Correspondingly, the first session management network element determines, according to the first indication information included in the context creation message, that the first address information is determined according to the first domain name information.

[0228] Steps 505-517 in FIG. 5 can refer to steps 406-418 in FIG. 4, which will not be repeated here.

[0229] The embodiment of the present application further provides a communication method, as shown in the flowchart of the communication method in FIG. 6, which mainly includes the following steps 600-601. It can be understood that the steps and the execution order shown in FIG. 6 are only as an example, and in actual implementation, part of the steps or the remaining steps can be executed, and similarly, the execution order of the steps can also be adjusted, which is not limited in the embodiment of the present application.

[0230] In step 600, the first session management network element receives first domain name information.

[0231] The first session management network element and the second session management network element of the embodiment of the present application serve the terminal. Optionally, the first session management network element and the second session management network element are different network elements serving the terminal.

[0232] Exemplarily, the first session management network element can be an intermediate session management network element (I-SMF network element); for example, the first session management network element is an I-SMF network element inserted for a session (such as a PDU session) of the terminal; wherein the name of the first session management network element is not limited to I-SMF, and can also be other names, which are not limited in the present application. The second session management network element can be a network element for managing the session of the terminal; for example, the second session management network element is an SMF network element or an anchor SMF network element, and the name of the second session management network element is not limited in the present application.

[0233] Alternatively, the first session management network element and the second session management network element can be network elements with different capabilities; for example, the first session management network element is responsible for traffic routing of the session, and the second session management network element is responsible for QoS control of the session. Alternatively, the first session management network element and the second session management network element can be network elements with different features. Alternatively, the first session management network element and the second session management network element correspond to different service areas.

[0234] It should be noted that the above is only an example of the first session management network element and the second session management network element, and the first session management network element and the second session management network element can also be other session management network elements for serving the terminal, which are not limited in the present application.

[0235] Taking the session management network element as an SMF network element as an example: “the first session management network element serves the terminal”, which can be understood as that the first SMF network element serves the session of the terminal, or the first SMF network element is an I-SMF network element of the terminal session, or the first SMF network element is an I-SMF network element in the PDU session architecture of the terminal, or the first SMF network element stores the context of the terminal session, or the first SMF is an I-SMF network element inserted for the terminal session, or the first SMF is an I-SMF network element selected by the AMF network element in the terminal session establishment / modification process. “The second session management network element serves the terminal”, which can be understood as that the second SMF network element serves the session of the terminal, or the second SMF network element is an SMF network element of the terminal session, or the second SMF network element is an SMF network element in the PDU session architecture of the terminal, or the second SMF network element stores the context of the terminal session, or the second SMF is an SMF network element selected by the AMF network element in the terminal session establishment process.

[0236] The first domain name information is used by the terminal to query the address of at least one application server, and the at least one application server is a server providing a service corresponding to the first domain name information.

[0237] Exemplarily, the first domain name information can be FQDN information in a DNS request message sent by the terminal.

[0238] In the embodiment of the present application, the first session management network element can receive the first domain name information in multiple different ways.

[0239] It should be noted that the first session management network element receiving the first domain name information can refer to the description in the foregoing, such as the first domain name information receiving manner one and the first domain name information receiving manner two in the foregoing. In addition, for different manners of receiving the first domain name information, the insertion manner of the first session management network element in each first domain name information receiving manner can also refer to the description in the foregoing; for example, the first session management network element insertion manner 1 and the first session management network element insertion manner 2 in the first domain name information receiving manner one and the insertion manner of the first session management network element in the first domain name information receiving manner two.

[0240] Step 601: The first session management network element determines a first user plane network element according to the first domain name information.

[0241] After receiving the first domain name information, the first session management network element can determine the first user plane network element according to a plurality of manners. Exemplarily, two different manners of determining the first user plane network element are taken as examples for description; it should be understood that the two manners of determining the first user plane network element are only examples of the embodiments of the present application, and the embodiments of the present application do not limit the specific manner of determining the first user plane network element.

[0242] First user plane network element determination manner 1:

[0243] The first session management network element determines the first user plane network element according to the first domain name information, deployment information of an application server and location information of a terminal. At least one application server can be a server providing a service corresponding to the first domain name information.

[0244] Optionally, the first session management network element can determine a second data network access node (or referred to as a second DNAI) according to the first domain name information, the deployment information of the application server and the location information of the terminal; and the first session management network element determines the first user plane network element from a user plane network element corresponding to the second data network access node. Exemplarily, the second data network access node can correspond to a plurality of user plane network elements, and the first session management network element can determine the first user plane network element from the plurality of user plane network elements corresponding to the second data network access node.

[0245] First user plane network element determination manner 2:

[0246] The first session management network element determines a second data network access node (or referred to as a second DNAI) according to the first domain name information; and the first session management network element determines the first user plane network element from a user plane network element corresponding to the second data network access node.

[0247] The first user plane network element serves the terminal when the terminal accesses an application server corresponding to the service.

[0248] The first user plane network element serves the terminal when the terminal accesses an application server corresponding to the service.

[0249] The first user plane network element serves the terminal when the terminal accesses an application server corresponding to the service.

[0250] The first session management network element can further determine whether the determined first user plane network element is accurate after determining the first user plane network element based on steps 600-601. The process of determining whether the determined first user plane network element is accurate by the first session management network element is described in detail below.

[0251] Optionally, the flowchart of the communication method shown in FIG. 6 can further include steps 602-604.

[0252] Step 602: The first session management network element sends first address information to the second session management network element.

[0253] The first session management network element determines the first address information according to the first domain name information after receiving the first domain name information.

[0254] Optionally, the first address information can be used to construct an extension mechanism for the domain name system protocol (EDNS) client subnet option, which can be referred to as an ECS option. The first address information can be referred to as ECS option information; wherein the ECS option can be an extension item in the DNS request message, which represents the location information of the terminal. For example, the ECS option information can be an IP address, such as the first address information.

[0255] It should be noted that the manner in which the first session management network element determines the first address information, and the manner in which the first session management network element sends the first address information to the second session management network element can be referred to the description of step 301 above, which will not be repeated here.

[0256] Step 603: The first session management network element receives second address information from the second session management network element.

[0257] Optionally, the second address information is determined according to the first address information, and the second address information is an address of the first application server, and the first application server is an application server closest to the terminal among the at least one application server.

[0258] The determination manner of the second address information in step 603 and the manner in which the first session management network element receives the second address information can be referred to the description of step 302, and will not be repeated here.

[0259] Step 604: The first session management network element determines whether to update the first user plane network element according to the second address information.

[0260] After the first session management network element receives the second address information, the third data network access node (or referred to as third DNAI) is determined according to the second address information; and it is determined whether to update the first user plane network element according to the third data network access node.

[0261] Optionally, the first session management network element determines whether the third data network access node is the same as the second data network access node; if the same, it is determined that the first user plane network element is not updated; if different, it is determined that the first user plane network element is updated. The second data network access node is a data network access node determined according to the first domain name information, the deployment information of the at least one application server and the location information of the terminal, such as the second DNAI in the foregoing.

[0262] In the case that the third data network access node is different from the second data network access node, the second user plane network element is determined according to the third data network access node, and the first user plane network element is updated to the second user plane network element, and the second user plane network element is a user plane network element serving the terminal when the terminal accesses the first application server.

[0263] The first session management network element inserts the split point (ULCL / BP) and the local anchor point (L-PSA) according to the second user plane network element, and the inserted split point and local anchor point can be used to send the user plane data of the terminal service to the application server corresponding to the service.

[0264] The communication method of the embodiment of the application shown in FIG. 6 will be introduced below in combination with examples.

[0265] Example 3:

[0266] Taking the first session management network element as an I-SMF network element, the second session management network element as an SMF network element, and the access management network element as an AMF network element as an example for description.

[0267] The communication method flow as shown in FIG. 7, the steps and the execution order shown in FIG. 7 are only as an example, and in actual implementation, part of the steps can be executed or other steps can also be executed, and similarly, the execution order of the steps can be adjusted, and the embodiments of the present application do not limit this.

[0268] Step 700: The terminal initiates a first service and sends a DNS request message for the first service to an EASDF network element.

[0269] Correspondingly, the EASDF network element receives the DNS request message from the terminal.

[0270] The DNS request message includes first domain name information; for example, the first domain name information can be FQDN information.

[0271] Step 701: The EASDF network element sends the first domain name information to an SMF network element.

[0272] Correspondingly, the SMF network element receives the first domain name information from the EASDF network element.

[0273] Optionally, the EASDF network element sends a DNS context notification message to the SMF network element, and the DNS context notification message includes the first domain name information; for example, the DNS context notification message can be a Neasdf_DNSContext_Notify message.

[0274] Step 702: The SMF network element sends a notification message to an AMF network element, for notifying the AMF network element to insert an I-SMF network element.

[0275] It should be noted that the manner of inserting the I-SMF network element in step 702 can refer to the introduction in the above, such as the first session management network element insertion manner 1 and the first session management network element insertion manner 2 introduced above.

[0276] Step 703: The AMF network element selects the I-SMF network element and sends a request message for creating a session management context to the I-SMF network element.

[0277] Correspondingly, the I-SMF network element receives the request message for creating a session management context from the AMF network element.

[0278] For example, the request message for creating a session management context can be a Nsmf_PDUSession_CreateSMContext Request message.

[0279] Step 704: The I-SMF network element sends a session management context request message to the SMF network element, for requesting session context information from the second session management network element.

[0280] Correspondingly, the SMF network element receives the session management context request message from the I-SMF network element.

[0281] Illustratively, the session context request message can be an Nsmf_PDUSession_Context Request message.

[0282] Step 705: The SMF network element sends a session management context reply message to the I-SMF network element.

[0283] Correspondingly, the I-SMF network element receives the session management context reply message from the SMF network element. The session management context reply message can include the first domain name information; or the session management context reply message can also include first indication information, which is used to indicate that the first address information is determined according to the first domain name information.

[0284] Illustratively, the session management context reply message can be an Nsmf_PDUSession_Context Response message.

[0285] Step 706: The I-SMF network element determines the first user plane network element according to the first domain name information.

[0286] The specific manner in which the I-SMF network element determines the first user plane network element can be referred to the description of step 601 above, which is not repeated here. In FIG. 7, the first user plane network element is taken as an ULCL / BP network element, and the L-PSA network element is taken as an example.

[0287] Step 707: The I-SMF network element obtains the address information of the first user plane network element from the NRF network element.

[0288] Optionally, the I-SMF network element sends a second DNAI to the NRF network element, and obtains the address information of the first user plane network element from the NRF network element based on the second DNAI.

[0289] Step 708: The I-SMF network element establishes an N4 session with the first user plane network element.

[0290] Step 709: The I-SMF network element determines the first address information according to the first domain name information.

[0291] It should be noted that the manner in which the I-SMF network element determines the first address information according to the first domain name information can be referred to the description of step 301 above, which is not repeated here.

[0292] Step 710: The I-SMF network element sends the first address information to the SMF network element.

[0293] Correspondingly, the SMF network element receives the first address information from the I-SMF network element.

[0294] Optionally, the I-SMF network element sends a PDU session creation / update request message to the SMF network element, and the PDU session creation / update request message includes the first address information; and the second session management network element obtains the first address information from the PDU session creation / update request message. For example, the PDU session creation / update request message can be an Nsmf_PDUSession_Create Request message or an Nsmf_PDUSession_Update Request message.

[0295] Optionally, the PDU session creation / update request message can further include tunnel information of the user plane network element.

[0296] Step 711: The SMF network element sends the first address information to the EASDF network element.

[0297] Correspondingly, the EASDF network element receives the first address information from the SMF network element.

[0298] Optionally, the SMF network element can send a DNS context update message to the EASDF network element, and the DNS context update message includes the first address information; and the EASDF network element obtains the first address information from the DNS context update message. For example, the DNS context update message can be a Neasdf_DNSContext_Update message.

[0299] Step 712: The EASDF network element sends the first address information to the DNS server.

[0300] Correspondingly, the DNS server receives the first address information from the EASDF network element.

[0301] Optionally, the EASDF network element can send an updated DNS request message to the DNS server, and the updated DNS request message includes the first address information; for example, the EASDF network element creates or updates an ECS option in the DNS request message, and takes the first address information as the ECS option. The DNS server obtains the first address information from the updated DNS request message sent by the EASDF network element.

[0302] Optionally, the updated DNS request message received by the DNS server can further include first domain name information.

[0303] Step 713: The DNS server sends second address information to the EASDF network element.

[0304] Correspondingly, the EASDF network element receives the second address information from the DNS server.

[0305] It should be noted that the manner in which the DNS server determines the second address information can refer to the manner in which the DNS server determines the second address information described in step 302 above, which will not be repeated here.

[0306] Step 714: The EASDF network element sends the second address information to the SMF network element.

[0307] Correspondingly, the SMF network element receives the second address information from the EASDF network element.

[0308] Optionally, the EASDF network element sends a DNS context notification message to the SMF network element, and the DNS context notification message includes the second address information; the SMF network element obtains the second address information from the DNS context notification message. Exemplarily, the DNS context notification message can be a Neasdf_DNSContext_Notify message.

[0309] Step 715: The SMF network element sends the second address information to the I-SMF network element.

[0310] Correspondingly, the I-SMF network element receives the second address information from the SMF network element.

[0311] Optionally, the SMF network element sends a PDU session creation response message to the I-SMF network element, and the PDU session creation response message includes the second address information; the I-SMF network element obtains the second address information from the PDU session creation response message. Exemplarily, the PDU session creation response message can be a Nsmf_PDUSession_Create Response message.

[0312] Optionally, the PDU session creation response message can also include tunnel information of the C-PSA network element.

[0313] Step 716: The I-SMF network element updates the first user plane network element to the second user plane network element according to the second address information.

[0314] Optionally, the I-SMF network element determines a third data network access node (or referred to as a third DNAI) according to the second address information; if the third data network access node is different from the second data network access node determined in step 706, the I-SMF network element determines the second user plane network element according to the third data network access node, and updates the first user plane network element to the second user plane network element.

[0315] Step 717: The I-SMF network element sends tunnel information of the second user plane network element and / or fourth indication information to the SMF network element; the fourth indication information is used to instruct sending a DNS response message to the terminal.

[0316] Step 718: The SMF network element sends the fourth indication information to the EASDF network element.

[0317] Step 719: The EASDF network element sends the DNS response message to the terminal.

[0318] Example 4:

[0319] Taking the first session management network element as the I-SMF network element, the second session management network element as the SMF network element, and the access management network element as the AMF network element as an example for description.

[0320] The communication method flow shown in FIG. 8, the steps shown in FIG. 8 and the execution order are only as an example, and in actual implementation, part of the steps can be executed or the remaining steps can also be executed, similarly, the execution order of the steps can be adjusted, and the embodiments of the present application do not limit this.

[0321] Step 800: The terminal initiates a first service and sends a DNS request message for the first service to the EASDF network element.

[0322] Correspondingly, the EASDF network element receives the DNS request message from the terminal.

[0323] The DNS request message includes first domain name information; for example, the first domain name information can be FQDN information.

[0324] Step 801: The EASDF network element sends the first domain name information to the SMF network element.

[0325] Correspondingly, the SMF network element receives the first domain name information from the EASDF network element.

[0326] Optionally, the EASDF network element sends a DNS context notification message to the SMF network element, and the DNS context notification message includes the first domain name information; for example, the DNS context notification message can be Neasdf_DNSContext_Notify message.

[0327] Step 802: The SMF network element sends the first domain name information to the AMF network element.

[0328] Optionally, in step 802, the SMF network element can also send first indication information to the AMF network element; the first indication information is used to instruct determining first address information according to the first domain name information; for example, the first address information can be ECS option information.

[0329] Step 803: The AMF network element acquires the identifier information of the I-SMF network element from the NRF network element according to the first domain name information and the location information of the terminal, and inserts the I-SMF network element.

[0330] For example, the identifier information of the first session management network element can be an identity ID of the first session management network element, or the identifier information of the first session management network element can be address information of the first session management network element.

[0331] Step 804: The AMF network element sends the first domain name information to the I-SMF network element.

[0332] Correspondingly, the I-SMF network element receives the first domain name information from the AMF network element.

[0333] Optionally, the AMF network element sends a context creation message to the I-SMF network element. Correspondingly, the I-SMF network element receives the context creation message from the AMF network element, and the context creation message is used to indicate the creation of the session management context information of the terminal; the context creation message includes the first domain name information. For example, the context creation message can be a Nsmf_PDUSession_CreateSMContext Request message.

[0334] Optionally, the context creation message further includes first indication information, and the first indication information is used to indicate that the first address information is determined according to the first domain name information. Correspondingly, the first session management network element determines that the first address information is determined according to the first domain name information according to the first indication information included in the context creation message.

[0335] Steps 805-818 in FIG. 8 can refer to steps 706-719 in FIG. 7, which will not be repeated here.

[0336] Based on the same technical concept, the embodiment of the present application provides a communication device, which includes a module / unit / means for executing the method performed by any network function and entity in the above-mentioned method embodiments. The module / unit / means can be implemented by software or hardware, or by executing corresponding software by hardware.

[0337] For example, referring to FIG. 9, the communication device 900 can include a communication unit 901, and can further include a processing unit 902.

[0338] For example, when the communication device 900 is the first session management network element or is located in the first session management network element:

[0339] The communication unit 901 is configured to receive first domain name information, and the first domain name information is used for a terminal to query an address of at least one application server, and the at least one application server is a server providing a service corresponding to the first domain name information.

[0340] The communication unit 901 is further configured to send first address information to a second session management network element, the first address information being determined according to the first domain name information, the first session management network element and the second session management network element serving the terminal;

[0341] The communication unit 901 is further configured to receive second address information from the second session management network element, the second address information being determined according to the first address information, the second address information being an address of the first application server, the first application server being an application server closest to the terminal among the at least one application server;

[0342] The processing unit 902 is configured to determine a first user plane network element according to the second address information, the first user plane network element being a user plane network element serving the terminal when the terminal accesses the first application server.

[0343] For another example, when the communication apparatus 900 is or is located at the first session management network element:

[0344] The communication unit 901 is configured to receive first domain name information, the first domain name information being used for the terminal to query an address of at least one application server, the at least one application server being a server providing a service corresponding to the first domain name information;

[0345] The processing unit 902 is configured to determine a first user plane network element according to the first domain name information, the first user plane network element being a user plane network element serving the terminal when the terminal accesses the application server.

[0346] The communication unit 901 and the processing unit 902 are described in more detail above, and the description is directly referred to herein.

[0347] Based on the same technical concept, the embodiment of the present application further provides a communication apparatus, as shown in FIG. 10, the communication apparatus 1000 includes a processor 1001 and a memory 1002; the memory 1002 is configured to store computer execution instructions; the processor 1001 is configured to execute the computer execution instructions stored in the memory 1002, so that the communication apparatus realizes the functions of any network element in the above method embodiments, such as the functions of the first session management network element in the above method embodiments.

[0348] The number of the memory 1002 can be one or more. The memory 1002 can include a Read Only Memory (ROM), a Random Access Memory (RAM), and a disk memory, etc. The memory 1002 can be used to store program codes required by the processor 1001 to perform tasks, and can also be used to store data, etc. The memory 1002 is an optional functional module rather than a mandatory functional module.

[0349] The processor 1001 and the memory 1002 can be connected through a bus, or can also be connected with the processor through a dedicated connection line, which is not limited here.

[0350] The processor 1001 is designed and programmed to solidify the codes corresponding to the methods shown in the foregoing embodiments into the chip, so that the chip can execute the methods shown in the foregoing embodiments when running. How to design and program the processor 1001 is a technology known to those skilled in the art, which will not be described here.

[0351] It should be understood that the processor mentioned in the embodiments of the present application can be implemented by hardware or software. When implemented by hardware, the processor can be a logic circuit, an integrated circuit, etc. When implemented by software, the processor can be a general-purpose processor, which is implemented by reading the software codes stored in the memory.

[0352] For example, the processor can be a Central Processing Unit (CPU), and can also 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 gates or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc.

[0353] It should be understood that the memory mentioned in the embodiments of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a Read-Only Memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an Electrically EPROM (EEPROM), or a flash memory. The volatile memory can be a Random Access Memory (RAM) used as an external cache. By way of example and not limitation, many forms of RAM are available, such as Static RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDR SDRAM), Enhanced SDRAM (ESDRAM), Synchlink DRAM (SLDRAM), and Direct Rambus RAM (DR RAM).

[0354] It should be noted that when the processor is a general processor, a DSP, an ASIC, a FPGA or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, the memory (storage module) can be integrated in the processor.

[0355] It should be noted that the memory described in the present application is intended to include but not limited to these and any other suitable types of memory.

[0356] Based on the same technical concept, the embodiments of the present application also provide a computer readable storage medium for storing instructions, when the instructions are executed, the method performed by the function of any of the network elements in the above method embodiments is realized.

[0357] Based on the same technical concept, the embodiments of the present application also provide a chip coupled with a memory, for reading and executing program instructions stored in the memory, to realize the method performed by the function of any of the network elements in the above method embodiments.

[0358] Based on the same technical concept, the embodiment of the present application also provides a computer program product containing instructions, and the computer program product stores the instructions. When the instructions are executed on a computer, the computer executes the method performed by the functions of any network element in the above method embodiment.

[0359] Those skilled in the art will appreciate that embodiments of the present application can be in the form of hardware embodiments, software embodiments, or embodiments combining software and hardware aspects. Furthermore, embodiments of the present application can be in the form of a computer program product on one or more computer-usable storage media (including, but not limited to, disk memory, CD-ROMs, optical storage media, etc.) embodying computer-readable program code.

[0360] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of flows and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing apparatus to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing apparatus produce the functions specified in one or more flows in the flowcharts and / or one or more blocks in the block diagrams.

[0361] These computer program instructions can also be stored in a computer-readable memory that can direct the computer or other programmable data processing apparatus to work in a specific manner, so that the instructions stored in the computer-readable memory produce a product including instruction means, which implements the functions specified in one or more flows in the flowcharts and / or one or more blocks in the block diagrams.

[0362] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus, so that a series of operation steps are executed on the computer or other programmable data processing apparatus to produce a computer-implemented process, so that the instructions executed on the computer or other programmable data processing apparatus provide steps for implementing the functions specified in one or more flows in the flowcharts and / or one or more blocks in the block diagrams.

[0363] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the scope and spirit of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A communication method characterized by comprising: The method applied to a first session management network element comprises: receiving first domain name information, the first domain name information being used for a terminal to query an address of at least one application server, the at least one application server being a server providing a service corresponding to the first domain name information; sending the first address information to a second session management network element, the first address information being determined according to the first domain name information, the first session management network element and the second session management network element serving the terminal; receiving second address information from the second session management network element, the second address information being determined according to the first address information, the second address information being an address of a first application server, the first application server being an application server close to the terminal among the at least one application server; determining a first user plane network element according to the second address information, the first user plane network element being a user plane network element serving the terminal when the terminal accesses the first application server.

2. The method of claim 1, wherein, The receiving first domain name information comprises: receiving the first domain name information from the second session management network element; or receiving the first domain name information from an access management network element.

3. The method of claim 2, wherein, The receiving the first domain name information from the second session management network element comprises: receiving a session management context reply message from the second session management network element, the first domain name information being included in the session management context reply message.

4. The method of claim 3, wherein, The session management context reply message further comprises first indication information, the first indication information being used for indicating that the first address information is determined according to the first domain name information.

5. The method of claim 2, wherein, The receiving the first domain name information from the access management network element comprises: receiving a context creation message from the access management network element, the context creation message being used for indicating that session management context information of the terminal is created, the context creation message comprising the first domain name information.

6. The method of claim 5, wherein, The context creation message further comprises first indication information, the first indication information being used for indicating that the first address information is determined according to the first domain name information.

7. The method according to any one of claims 1 to 6, characterized in that, The determining a first user plane network element according to the second address information comprises: determining the first user plane network element according to the second address information, deployment information of the first application server and location information of the terminal.

8. The method according to any one of claims 1 to 7, characterized in that, The second session management network element is a network element managing a session of the terminal, and the first session management network element is an intermediate session management network element of the session of the terminal.

9. A communication method characterized by comprising: The method applied to a first session management network element comprises: receiving first domain name information, the first domain name information being used for a terminal to query an address of at least one application server, the at least one application server being a server providing a service corresponding to the first domain name information; determining a first user plane network element according to the first domain name information, the first user plane network element being a user plane network element serving the terminal when the terminal accesses the application server.

10. The method of claim 9, wherein, The determining a first user plane network element according to the first domain name information comprises: According to the first domain name information, deployment information of the at least one application server, and location information of the terminal, the first user plane network element is determined.

11. The method of claim 9 or 10, wherein, The method further comprises: sending first address information to a second session management network element, the first address information being determined according to the first domain name information, the first session management network element and the second session management network element serving the terminal; receiving second address information from the second session management network element, the second address information being determined according to the first address information, the second address information being an address of a first application server, the first application server being an application server of the at least one application server that is closest to the terminal; updating the first user plane network element to a second user plane network element according to the second address information, the second user plane network element being a user plane network element serving the terminal when the terminal accesses the first application server.

12. The method of claim 11, wherein, The updating the first user plane network element to a second user plane network element according to the second address information comprises: determining the second user plane network element according to the second address information, deployment information of the first application server, and location information of the terminal; if a data network access point corresponding to the first user plane network element is different from a data network access point corresponding to the second user plane network element, updating the first user plane network element to the second user plane network element.

13. A communications device, characterized by comprise a module or unit for performing the method of any one of claims 1-8, or comprise a module or unit for performing the method of any one of claims 9-12.

14. A communications device, characterized by comprise one or more processors; the one or more processors are configured to execute a computer program in a memory, so that the communication device performs the method of any one of claims 1-8, or so that the communication device performs the method of any one of claims 9-12.

15. A computer-readable storage medium, characterized in that, The storage medium stores a computer program or instructions, when the computer program or instructions are executed by a computer, the method of any one of claims 1-8 is implemented, or the method of any one of claims 9-12 is implemented.

16. A computer program product, characterised in that, When the computer reads and executes the computer program product, the computer executes the method of any one of claims 1-8, or the method of any one of claims 9-12.

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