Communication method, and apparatus

Abstract

A communication method, and an apparatus. In the method, a first network device receives a first message, the first message comprising a first data network access identifier (DNAI) and a second DNAI and being used for instructing to establish a tunnel between a first DN corresponding to the first DNAI and a second DN corresponding to the second DNAI, the first DN being within the management scope of the first network device; when the second DN is not within the management scope of the first network device, but is within the management scope of a second network device, the first network device interacts with the second network device to establish a tunnel between the first DN and the second DN. The described method achieves establishing a node-level forwarding tunnel between DNs; in the case where two DNs are not within the management scope of a same session management network element, two session management network elements may together control establishment of a node-level forwarding tunnel between the first DN and the second DN, thereby solving the problem in the prior art that since only one session management network element controls establishment of a forwarding tunnel, a forwarding tunnel fails to be established when two DNs are not managed by a same session management network element.

Description

Communication method and apparatus

[0001] Cross-reference to Related Applications

[0002] This application claims priority to the Chinese Patent Application No. 202411100279.0, filed on August 9, 2024, and entitled "A Communication Method and Apparatus", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] Embodiments of the present application relate to the field of wireless communication technology, and in particular to a communication method and apparatus. BACKGROUND

[0004] With the explosive growth of mobile traffic, in order to support this rapidly growing mobile traffic model, the industry proposes the concept of edge computing (EC). In the EC deployment scenario, some services may be provided by multiple edge application servers (EASs) deployed at the edge of the network.

[0005] A local data network (L-DN) is a new concept proposed to support edge computing. The L-DN allows a local operator or enterprise to provide specific services (such as industrial automation, intelligent building systems, or high-speed data transmission within a limited area) within a limited geographical area (such as a building, a campus, or an industrial park), and at the same time, the L-DN can be connected to a central data network (C-DN) through a 5G network to provide access to external data services and resources.

[0006] However, there is currently no complete standard for how to build a node-level forwarding tunnel between the L-DN and the C-DN, and in particular, when the L-DN and the C-DN are managed by different session management functions (SMFs), how to build a forwarding tunnel is a technical problem that needs to be solved urgently. SUMMARY

[0007] Embodiments of the present application provide a communication method and apparatus for implementing the construction of a node-level forwarding tunnel between DNs.

[0008] In a first aspect, embodiments of the present application provide a communication method, which can be executed by a network device, or by a module (such as a chip, a chip system, or a processor) applied to the network device, or by a logic node, a logic module, or software implementing all or part of the function of an access network device.

[0009] Taking the method applied to the network device as an example, the method comprises: a first network device receiving a first message, the first message comprising a first data network access identifier (DNAI) and a second DNAI, the first message being used to indicate that a tunnel is established for a first data network (DN) corresponding to the first DNAI and a second DN corresponding to the second DNAI, the first DN belonging to a management range of the first network device; when the second DN does not belong to the management range of the first network device and belongs to a management range of a second network device, the first network device interacts with the second network device to establish a tunnel of the first DN and the second DN.

[0010] Optionally, the first network device and the second network device can be a first session management network element and a second session management network element respectively.

[0011] Through the above method, a node-level forwarding tunnel between DNs is constructed; for the case that two DNs do not belong to the management range of the same session management network element, the embodiments of the present application provide a node-level forwarding tunnel between the first DN and the second DN which can be created by two session management network elements, thereby solving the problem that the forwarding tunnel cannot be created when two DNs do not belong to the management of the same session management network element due to the control of creating the forwarding tunnel by only one session management network element.

[0012] In a possible implementation, the first network device and the second network device interact to establish the tunnel of the first DN and the second DN, comprising: the first network device sends a second message to the second network device, the second message comprising the second DNAI, the second message being used to indicate that a second PDU session anchor point (PSA) of the second DN is selected and a first tunnel identifier is allocated for the selected PSA of the first network device; the first network device receives a third message sent by the second network device, the third message comprising the first tunnel identifier; the first network device sends a fourth message to the selected first PSA of the first DN, the fourth message comprising the first tunnel identifier, the fourth message being used to instruct the first PSA to establish a tunnel with the second PSA according to the first tunnel identifier; the first network device sends a fifth message to the second network device, the fifth message comprising a second tunnel identifier allocated for the second PSA, so that the second network device instructs the second PSA to establish a tunnel with the first PSA according to the second tunnel identifier.

[0013] The implementation manner provides an interaction process of a first network device and a second network device, so as to construct a forwarding tunnel between a first DN and a second DN. In the interaction process of the first network device and the second network device, the first network device sends a second DNAI of the second DN to the second network device, so that the first network device controls the first PSA to establish a tunnel, the second network device controls the second PSA to establish a tunnel, and the first network device and the second network device implement interaction of tunnel identifiers, so as to complete tunnel establishment between the first PSA and the second PSA.

[0014] In a possible implementation manner, the first message further includes address information of the second network device; and the first network device sends a second message to the second network device, including: the first network device sends the second message to the second network device according to the address information of the second network device.

[0015] In this implementation manner, the first message received by the first network device further includes address information of the second network device. On one hand, the first network device can determine whether the second network device managing the second DN and the first network device are the same network device according to the address information of the second network device. On the other hand, in the case that the first network device and the second network device are not the same network device, the first network device does not need to obtain the address information of the second network device through cumbersome steps, and can send a second message to the second network device.

[0016] In a possible implementation manner, the first message further includes single-network slice selection support information (S-NSSAI), and the first network device selects the first PSA according to the S-NSSAI; and the second message further includes the S-NSSAI, and the second network device selects the second PSA according to the S-NSSAI.

[0017] In this implementation manner, the first message received by the first network device further includes S-NSSAI, so that the first network device can select the first PSA capable of supporting a corresponding slice / service type network slice according to the S-NSSAI; and the first network device further sends the S-NSSAI to the second network device, so that the second network device can also select the second PSA capable of supporting a corresponding slice / service type network slice according to the S-NSSAI, thereby meeting the requirements of the first DN and the second DN on the network slice.

[0018] In a possible implementation manner, the first message further includes an IP address of an application server corresponding to the first DNAI and / or the second DNAI; the fourth message further includes the IP address; and / or, the second message further includes the IP address.

[0019] In the implementation, the first message received by the first network device can further include an IP address of an application server of the first DN and / or the second DN, so that the first network device can generate a PDR and a FAR according to the IP address of the application server of the first DN and / or the second DN, thereby causing the first PSA to establish a tunnel according to the PDR and the FAR; further, the first network device can further send the IP address of the application server of the first DN and / or the second DN to the second network device, so that the second network device generates a PDR and a FAR according to the IP address, to control the second PSA to establish a tunnel according to the PDR and the FAR.

[0020] In a possible implementation, the first message is further used to instruct the first network device to determine whether the first DN and the second DN belong to a same management range of a network device.

[0021] In the implementation, the first message can include explicit indication information, to instruct the first network device to determine whether the first DN and the second DN belong to a same management range of a network device, so that the first network device does not default that the first DN and the second DN belong to a same management range of the first network device according to a traditional technical solution, and only discovers that the first DN and the second DN do not belong to a same management range of a network device in a tunnel establishment process.

[0022] In a possible implementation, the first message is further used to instruct the first network device to determine that the first DN and the second DN do not belong to a same management range of a network device.

[0023] In the implementation, the first message can include explicit indication information, to instruct the first network device to determine that the first DN and the second DN do not belong to a same management range of a network device, so that the first network device does not default that the first DN and the second DN belong to a same management range of the first network device according to a traditional technical solution, and does not need to determine whether the first DN and the second DN belong to a same management range of a network device, and can control the establishment of a forwarding tunnel together with the second network device.

[0024] In a second aspect, an embodiment of the present application provides a communication method, which can be executed by a network device, or by a module (for example, a chip, a chip system, or a processor) applied to the network device, or by a logic node, a logic module, or software realizing all or part of access network device functions.

[0025] With the method applied to the network device as an example, the method comprises: the second network device receiving a second message sent by the first network device, the second message comprising a second data network access identifier DNAI; the second network device selecting a second PDU session anchor point PSA of a second data network corresponding to the second DNAI, and obtaining a first tunnel identifier allocated to a first PSA selected for the first network device; the second network device sending a third message to the first network device, the third message comprising the first tunnel identifier; the second network device receiving a fifth message sent by the first network device, the fifth message comprising a second tunnel identifier allocated to the second PSA; and the second network device sending a sixth message to the second PSA, the sixth message comprising the second tunnel identifier, the sixth message being used to instruct the second PSA to establish a tunnel with the first PSA according to the second tunnel identifier.

[0026] Optionally, the first network device and the second network device can be a first SMF and a second SMF respectively.

[0027] In a possible implementation, the second message further comprises single network slice selection support information S-NSSAI, and the second network device selects the second PSA according to the S-NSSAI.

[0028] In a possible implementation, the second message further comprises an IP address of an application server corresponding to the first DNAI and / or the second DNAI; and the sixth message further comprises the IP address.

[0029] In a third aspect, an embodiment of the present application provides a communication method, which can be executed by a network device, a module (such as a chip, a chip system, or a processor) applied to the network device, or a logic node, a logic module, or software realizing all or part of an access network device function.

[0030] With the method applied to the network device as an example, the method comprises: the third network device receiving a seventh message, the seventh message comprising information of a first data network DN and information of a second DN; the third network device sending an eighth message to a fourth network device, the eighth message comprising a first data network access identifier DNAI corresponding to the first DN and not comprising a second DNAI corresponding to the second DN; the third network device receiving a ninth message sent by the fourth network device, the ninth message comprising address information of a first network device, and the first DN belonging to a management range of the first network device; and the third network device sending a first message to the first network device according to the address information, the first message comprising a first data network access identifier DNAI corresponding to the first DN and a second DNAI corresponding to the second DN.

[0031] Optionally, the third network device can be a NEF.

[0032] In the above method, after the NEF receives the related information of the first DN and the second DN, the NEF can select one of the first DN and the second DN (for example, the first DN is selected) and query the address information of the corresponding SMF through the fourth network device. The NEF does not need to judge whether the first DN and the second DN belong to the management range of the same network device, which can be judged by the SMF, so that the load of the NEF is not increased.

[0033] In a possible implementation, the first message is further used to instruct the first network device to judge whether the first DN and the second DN belong to the management range of the same network device. In this case, the third network device can instruct the first network device to judge whether the first DN and the second DN belong to the management range of the same network device through explicit indication information, so as to avoid that the first network device defaults that the first DN and the second DN belong to the management range of the first network device according to the traditional technical solution.

[0034] In a possible implementation, the seventh message further includes a data network name (DNN) and / or an application function service identifier; and the method further includes: determining, by the third network device, a single network slice selection support information (S-NSSAI) corresponding to the DNN according to the DNN and / or the application function service identifier; and the first message further includes the S-NSSAI, which is used to instruct to select a PDU session anchor (PSA) according to the S-NSSAI. In this implementation, the related information of the DN received by the third network device further includes the DNN and / or the application function service identifier, so that the third network device can obtain the S-NSSAI corresponding to the DNN and / or the application function service identifier and send the S-NSSAI to the first network device, so that the first network device selects the PSA capable of supporting a network slice of a corresponding slice / service type according to the S-NSSAI, so that the established tunnel can meet the demand of the first DN and the second DN for the network slice.

[0035] In a possible implementation, the seventh message further includes an S-NSSAI; and the first message further includes the S-NSSAI, which is used to instruct to select a PSA according to the S-NSSAI. In this implementation, the related information of the DN received by the third network device further includes the S-NSSAI, so that the third network device does not need to obtain the S-NSSAI by itself; the third network device sends the S-NSSAI to the first network device, so that the first network device selects the PSA capable of supporting a network slice of a corresponding slice / service type according to the S-NSSAI, so that the established tunnel can meet the demand of the first DN and the second DN for the network slice.

[0036] In a possible implementation, the seventh message further comprises an IP address of an application server corresponding to the first DNAI and / or the second DNAI; or, the method further comprises: the third network device obtaining the IP address from a fifth network device; and the first message further comprises the IP address. In this implementation, if the IP address of the application server of the first DN and / or the second DN is not included in the seventh message received by the third network device, the third network device can obtain the corresponding IP address from the fifth network device; if the IP address is included, the third network device can directly obtain the corresponding IP address from the seventh message, so that the third network device can send the IP address to the first network device, to enable the first network device to control establishment of the tunnel according to the IP address.

[0037] In a fourth aspect, an embodiment of the present application provides a communication method, which can be executed by a network device, or by a module (for example, a chip, a chip system, or a processor) applied to the network device, or by a logic node, a logic module, or software realizing all or part of access network device functions.

[0038] For example, the method is applied to a network device, and the method comprises: a third network device receiving a seventh message, the seventh message comprising information of a first data network DN and information of a second DN; the third network device sending a tenth message to a fourth network device, the tenth message comprising a first data network access identifier DNAI corresponding to the first DN and a second DNAI corresponding to the second DN; and the third network device receiving an eleventh message sent by the fourth network device, the eleventh message comprising address information of a first network device and address information of a second network device, the first DN belonging to a management range of the first network device, and the second DN belonging to a management range of the second network device; when the first network device and the second network device are different network devices, the third network device sending a first message to the first network device according to the address information of the first network device, the first message comprising the first DNAI corresponding to the first DN and the second DNAI corresponding to the second DN.

[0039] In the above method, after the third network device receives the related information of the first DN and the second DN, the third network device can query the address information of the first network device managing the first DN and the address information of the second network device managing the second DN through the fourth network device, and determine whether the first network device and the second network device are the same network device by the NEF; when it is determined that the first network device and the second network device are not the same network device, the first DNAI and the second DNAI can be sent to the first network device, so that the first network device and the second network device interact with each other to jointly complete the tunnel establishment between the first DN and the second DN.

[0040] Optionally, the third network device can be an NEF.

[0041] In a possible implementation, the first message is further used to indicate that the first DN and the second DN do not belong to the management range of the same network device. In this implementation, since the third network device has determined that the first DN and the second DN do not belong to the management range of the same network device, the first network device can be notified by explicit indication information, so that the first network device does not need to determine again.

[0042] In a possible implementation, the method further includes: determining, by the third network device, whether the first network device and the second network device are the same network device according to the address information of the first network device and the address information of the second network device.

[0043] In a possible implementation, the method further includes: when the first network device and the second network device are the same network device, sending, by the third network device, a first message to the first network device according to the address information of the first network device, the first message including a first data network access identifier DNAI corresponding to the first DN and a second DNAI corresponding to the second DN. When the third network device determines that the first DN and the second DN belong to the management range of the same network device, the third network device can send the first DNAI and the second DNAI to the first network device (which is also the second network device), so that the first network device controls to establish a tunnel between the first DN and the second DN.

[0044] In a possible implementation, the first message is further used to indicate that the first DN and the second DN belong to the management range of the same network device. When the third network device determines that the first DN and the second DN belong to the management range of the same network device, the first network device can be notified by explicit indication information, so that the first network device does not need to determine again.

[0045] In a possible implementation, the first message further includes address information of the second network device. The third network device can further send the address information of the second network device to the first network device, so that the first network device can determine whether the second network device managing the second DN and the first network device are the same network device according to the address information of the second network device, and the first network device can send the second message to the second network device without obtaining the address information of the second network device through complicated steps.

[0046] In a possible implementation, the seventh message further includes a data network name (DNN) and / or an application function service identifier; and the method further includes: determining, by the third network device, single network slice selection assistance information (S-NSSAI) corresponding to the DNN according to the DNN and / or the application function service identifier; and the first message further includes the S-NSSAI, which is used to indicate that a PDU session anchor (PSA) is selected according to the S-NSSAI. In this implementation, the seventh message received by the third network device can further include the DNN and / or the application function service identifier, so that the third network device can obtain the S-NSSAI corresponding to the DNN and / or the application function service identifier, and send the S-NSSAI to the first network device, so that the first network device can select a PSA that can support a network slice of a corresponding slice / service type according to the S-NSSAI, thereby meeting the requirements of the first DN and the second DN for the network slice.

[0047] In a possible implementation, the seventh message further includes S-NSSAI; and the first message further includes the S-NSSAI, which is used to indicate that a PSA is selected according to the S-NSSAI. In this implementation, the seventh message received by the third network device can further include the S-NSSAI, and the third network device sends the S-NSSAI to the first network device, so that the first network device can select a PSA that can support a network slice of a corresponding slice / service type according to the S-NSSAI, thereby meeting the requirements of the first DN and the second DN for the network slice.

[0048] In a possible implementation, the seventh message further comprises an IP address of an application server corresponding to the first DNAI and / or the second DNAI; or, the method further comprises: the third network device obtaining the IP address from a fifth network device; and the first message further comprises the IP address. In this implementation, the seventh message received by the third network device can further comprise the IP address of the application server of the first DN and / or the second DN, or the third network device obtains the IP address of the application server of the first DN and / or the second DN according to the related information of the DN, and sends the IP address to the first network device, so that the first network device can generate the PDR and the FAR according to the IP address of the application server of the first DN and / or the second DN, thereby enabling the first PSA to establish the tunnel according to the PDR and the FAR.

[0049] In a fifth aspect, an apparatus is provided, which can implement the method in the first aspect or any possible implementation of the first aspect. The apparatus comprises corresponding units or modules for performing the method described above. The units or modules included in the apparatus can be implemented by software and / or hardware. The apparatus can be, for example, a terminal, a chip, a chip system, or a processor supporting the terminal to implement the method described above, and can also be a logic node, a logic module, or software capable of implementing all or part of the terminal functions.

[0050] In a sixth aspect, an apparatus is provided, which can implement the method in the second aspect or any possible implementation of the second aspect. The apparatus comprises corresponding units or modules for performing the method described above. The units or modules included in the apparatus can be implemented by software and / or hardware. The apparatus can be, for example, an access network device, a chip, a chip system, or a processor supporting the access network device to implement the method described above, and can also be a logic node, a logic module, or software capable of implementing all or part of the access network functions.

[0051] In a seventh aspect, an apparatus is provided, which can implement the method in the third aspect or any possible implementation of the third aspect. The apparatus comprises corresponding units or modules for performing the method described above. The units or modules included in the apparatus can be implemented by software and / or hardware. The apparatus can be, for example, an access network device, a chip, a chip system, or a processor supporting the access network device to implement the method described above, and can also be a logic node, a logic module, or software capable of implementing all or part of the access network functions.

[0052] In an eighth aspect, an embodiment of the present application provides a device, which can implement the method in the fourth aspect or any possible implementation manner of the fourth aspect. The device comprises corresponding units or modules for performing the method described above. The units or modules included in the device can be implemented by software and / or hardware. The device can be, for example, an access network device, a chip, a chip system, or a processor supporting the access network device to implement the method described above, and can also be a logic node, a logic module or software capable of implementing all or part of the access network function.

[0053] In a ninth aspect, an embodiment of the present application provides a communication device, which comprises a processor and a memory coupled to the processor, wherein the memory is configured to store programs or instructions, and when the programs or instructions are executed by the processor, the device performs the method in the first aspect and any possible implementation manner of the first aspect.

[0054] In a tenth aspect, an embodiment of the present application provides a communication device, which comprises a processor and a memory coupled to the processor, wherein the memory is configured to store programs or instructions, and when the programs or instructions are executed by the processor, the device performs the method in the second aspect and any possible implementation manner of the second aspect.

[0055] In an eleventh aspect, an embodiment of the present application provides a communication device, which comprises a processor and a memory coupled to the processor, wherein the memory is configured to store programs or instructions, and when the programs or instructions are executed by the processor, the device performs the method in the third aspect and any possible implementation manner of the third aspect.

[0056] In a twelfth aspect, an embodiment of the present application provides a communication device, which comprises a processor and a memory coupled to the processor, wherein the memory is configured to store programs or instructions, and when the programs or instructions are executed by the processor, the device performs the method in the fourth aspect and any possible implementation manner of the fourth aspect.

[0057] In a thirteenth aspect, an embodiment of the present application provides a communication system, which comprises the communication devices in the fifth aspect, the sixth aspect, the seventh aspect and the eighth aspect.

[0058] In a fourteenth aspect, an embodiment of the present application provides a communication system, which comprises the communication devices in the fifth aspect, the sixth aspect, the seventh aspect and the eighth aspect.

[0059] In a fifteenth aspect, an embodiment of the present application provides a chip, which comprises a processor and a memory coupled to the processor, wherein the memory is configured to store programs or instructions, and when the programs or instructions are executed by the processor, the chip implements the method in the first aspect to the fourth aspect and any possible implementation manner thereof.

[0060] In a sixteenth aspect, an embodiment of the present application provides a computer readable storage medium, which stores instructions, when the instructions are executed on a computer, cause the computer to perform the method according to the first aspect to the fourth aspect and any possible implementation thereof.

[0061] In a seventeenth aspect, an embodiment of the present application provides a computer program product containing instructions, when the instructions are executed on a computer, cause the computer to perform the method according to the first aspect to the fourth aspect and any possible implementation thereof. BRIEF DESCRIPTION OF DRAWINGS

[0062] Fig. 1 is a schematic diagram of a network architecture of a communication system according to an embodiment of the present application;

[0063] Fig. 2 is a schematic diagram of a process of constructing a forwarding tunnel according to an embodiment of the present application;

[0064] Fig. 3 is a schematic diagram of a process of a communication method according to an embodiment of the present application;

[0065] Fig. 4 is a schematic diagram of an interaction between a first network device and a second network device according to an embodiment of the present application;

[0066] Fig. 5 is a schematic diagram of a process of another communication method according to an embodiment of the present application;

[0067] Fig. 6 is a schematic diagram of a process of another communication method according to an embodiment of the present application;

[0068] Fig. 7 is a schematic diagram of a process of another communication method according to an embodiment of the present application;

[0069] Fig. 8 is a schematic diagram of a process of another communication method according to an embodiment of the present application;

[0070] Fig. 9 is a schematic diagram of a process of another communication method according to an embodiment of the present application;

[0071] Fig. 10 is a schematic diagram of a process of another communication method according to an embodiment of the present application;

[0072] Fig. 11 is a schematic diagram of a structure of a communication apparatus according to an embodiment of the present application;

[0073] Fig. 12 is a schematic diagram of a structure of another communication apparatus according to an embodiment of the present application. DETAILED DESCRIPTION

[0074] The techniques 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 evolved communication system such as a 6th generation (6G) mobile communication system, and the like.

[0075] The present application will present various aspects, embodiments or features around systems that can include a plurality of devices, components, modules, and the like. It should be understood and appreciated that various systems can include additional devices, components, modules, and the like, and / or can not include all of the devices, components, modules, and the like, discussed in connection with the figures. Additionally, a combination of these approaches can be used.

[0076] In addition, in the embodiments of the present application, the words "exemplary", "for example", "such as", and the like are used only to mean example, instance, or illustration, and not "preferred" over other embodiments or designs. In fact, the use of any of these terms is intended to present concepts in a concrete manner. In the embodiments of the present application, "of", "corresponding", and "corresponding" are sometimes mixed. It should be pointed out that when there is no emphasis on their differences, the meanings expressed are consistent.

[0077] A network element in a communication system can send a signal to another network element or receive a signal from another network element. Wherein 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, and the like. In the embodiments of the present application, the network element is taken as an example for description.

[0078] Referring to FIG. 1, a network architecture diagram of a communication system to which embodiments of the present application are applicable is shown. The system contains network functions and entities mainly including: a terminal (user equipment, UE), a (radio) access network (R)AN network element, a user plane function (UPF) network element, a data network (DN), 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 network element (EASDF) network element, and the like.

[0079] The terminal can be a device or module with corresponding communication functions for accessing the communication system and having corresponding communication functions. The terminal can also be referred to as a 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 device. The terminal is usually provided with a communication module, circuit or chip for performing corresponding communication functions, and is also configured with program instructions for performing 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 treatment, 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 consoles, smart televisions, smart speakers, smart refrigerators and fitness equipment, etc.), a transport vehicle 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.

[0080] The (R)AN network element 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. The (R)AN network element can also be an open RAN (O-RAN).

[0081] The (R)AN network element involved in the embodiments of the present application can be a RAN node. The RAN node, also referred to as a radio access network device, a RAN entity or an access node, is used to help the terminal 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 NodeB 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.

[0082] In another application scenario, the terminal can access the wireless network through the cooperation of multiple RAN nodes, and different RAN nodes implement part of the functions of the base station. For example, the RAN node can be a central unit (CU), a distributed unit (DU) or a radio unit (RU). The CU here implements the functions of the radio resource control protocol and the packet data convergence protocol (PDCP) of the base station, and can also implement the function of the service data adaptation protocol (SDAP); the DU implements the functions of the radio link control layer and the medium access control (MAC) layer of the base station, and can also implement part of the physical layer or all the physical layer functions. For specific descriptions of the above protocol layers, reference can be made to the relevant technical specifications of 3GPP. The RU can be used to implement the functions of transmitting and receiving radio frequency signals. The CU and the DU can be two independent RAN nodes, or can be integrated in the same RAN node, such as in a baseband unit (BBU). The RU can be included in a radio frequency device, such as a remote radio unit (RRU) or an active antenna unit (AAU). The CU can be further divided into two types of RAN nodes: CU-control plane and CU-user plane.

[0083] 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 embodiments of the present application can be implemented by 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 embodiments of the present application do not limit the specific technology and specific equipment form adopted by the RAN node. For ease of description, a base station is described as an example of the RAN node in the following.

[0084] Data Network (DN): a data network providing service for a user, generally a client is located at a terminal and a server is located at a data network. The data network can be a private network such as a local area network, can be an external network not controlled by an operator, for example, the Internet, or can be a dedicated network jointly deployed by operators, for example, a network providing IP Multimedia Core Network Subsystem (IMS) services.

[0085] The functions of the network elements in the core network are briefly introduced as follows:

[0086] SMF network element: mainly used for session management, IP address allocation and management of a terminal, selection of a manageable user equipment plane function, policy control, or termination of a charging function interface, and downlink data notification, etc.

[0087] AMF network element: mainly used for mobility management and access management, for example, it can be a mobility management entity (MME) function in a 4G communication network or an AMF network element in a 5G network.

[0088] 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.).

[0089] UDM network element: used for processing user identification, subscription, access authentication, registration, or mobility management, etc.

[0090] AF network element: used for interacting with other control network elements of the 5G network on behalf of the application.

[0091] UPF network element: used for packet routing and forwarding, or quality of service (QoS) processing of user plane data, etc.

[0092] NEF network element: used for securely opening services and capabilities provided by 3GPP network functions to the outside, etc.

[0093] 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.

[0094] EASDF network element: a network element used for assisting in discovering edge application servers (EAS), which mainly functions to process domain name system (DNS) messages according to the instructions of the SMF.

[0095] It can be understood that other network elements can also be included in the above network architecture in actual applications, which are not limited in the present application.

[0096] It should be noted that in the present application, the names of the various network elements are only examples, and the present application does not exclude the case where the various network elements are given other names in the future, 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 above-mentioned network elements is within the protection scope of the present application. The interface names between the various network elements in FIG. 1 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 above-mentioned various network elements are also only examples, and do not constitute any limitation on the functions of the messages themselves.

[0097] It should be understood that the embodiments introduced hereinafter in the present application can be implemented by all the network elements in FIG. 1, or can be implemented by part of the network elements in FIG. 1, which are not limited in the present application.

[0098] 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”, etc.

[0099] The terms related to the present application are introduced as follows.

[0100] 1. Content delivery network (CDN) addressing

[0101] CDN addressing technology helps to avoid bottlenecks and links on the Internet that can affect the speed and stability of data transmission, making content transmission faster and more stable. CDN caches the content of a website at the edge of the network (the closest place to the user's access network), and then when the user accesses the website content, the user's request is routed or directed to the cache server closest to the user's access network or the best access effect by the scheduling system, and the cache server provides content services for the user; compared with direct access to the source station, this way shortens the network distance between the user and the content, thereby achieving the effect of acceleration.

[0102] 2. EAS deployment information (EDI):

[0103] The EAS deployment information reflects the deployment of the network at the edge. The EAS deployment information can include address information of the EAS deployed by the business provider (such as EAS IP address range), DNS server information, full address domain name (FQDN) information, and the like; the EAS deployment information can also include the identity of the edge service to the 5G core network (5G core network, 5GC), such as data network access identifier (data network access identifier, DNAI), data network name (data network name, DNN) corresponding to the EAS, Single Network Slice Selection Assistance Information (Single Network Slice Selection Assistance Information, S-NSSAI) and the like.

[0104] For detailed information about EAS deployment information, please refer to 3GPP TS23.548.

[0105] The DNAI can be used to represent a network access point, that is, an access point for accessing a DN from a core network (such as a UPF network element); the DNAI can include or correspond to one or more UPFs and EASs. The DNAI can be related to a geographical location, for example, the DNAI has a corresponding relationship with a tracking area (tracking area, TA).

[0106] The EAS deployment information can be provided by an AF network element; the AF network element is a network element controlled by a business provider; for example, the AF network element provides the EAS deployment information to the operator.

[0107] The EAS deployment information can be stored in a unified data repository (UDR) network element; the SMF network element can obtain the EAS deployment information from the UDR network element through the NEF network element. For example, the SMF network element provides a DNN and / or S-NSSAI to the NEF network element, the NEF network element obtains and notifies the SMF network element from the UDR network element, and the SMF network element thereby obtains the EAS deployment information related to the DNN and / or S-NSSAI.

[0108] In the discussion of constructing a node-level forwarding tunnel to meet the data interconnection requirement between the L-DN and the C-DN, one solution is that the UE first sends the data packet to the EAS in the L-DN for processing (which can reuse the PDU session of the UE itself), and after the EAS finishes processing, the EAS in the L-DN further sends the data packet to the application server (AS) in the C-DN through the 5GC network side for processing; in the downlink data packet transmission process, the AS in the C-DN sends the data packet to the EAS in the L-DN, and the EAS sends the data packet to the UE after processing the data packet, or the EAS directly forwards the data packet to the UE. Wherein, the source and destination addresses of the uplink data packet sent by the EAS to the AS are EAS IP and AS IP respectively; the source and destination addresses of the downlink data packet sent by the AS to the EAS are AS IP and EAS IP respectively.

[0109] The specific process can be as shown in FIG. 2, including the following steps:

[0110] Step 201, the AF sends information related to the construction of the forwarding tunnel between the L-DN and the C-DN to the 5GC.

[0111] The AF can send the information related to the construction of the forwarding tunnel between the L-DN and the C-DN to the SMF through the NEF. Specifically, the AF can reuse the operation process of EDI issuance / update / deletion to issue the related information.

[0112] Step 202, the SMF retrieves the information provided by the AF.

[0113] Specifically, the SMF can retrieve the DNAI corresponding to the L-DN and the C-DN respectively. The SMF can determine to establish the forwarding tunnel between the L-DN and the C-DN based on the retrieved information.

[0114] Step 203, the SMF selects a UPF as a local PDU session anchor (L-PSA) and a UPF as a central PDU session anchor (C-PSA) according to the retrieved information respectively.

[0115] Step 204, the SMF sends an N4 session establishment message to the C-PSA UPF.

[0116] The N4 session establishment message can include a packet detection rule (PDR) 1 and a forwarding action rule (FAR) 1 for up link (UL).

[0117] After receiving the N4 session establishment message, the C-PSA UPF selects a tunnel endpoint identifier (TEID) for UL, which is used to forward the data stream of the L-PSA UPF to the C-DN through the C-PSA UPF.

[0118] Step 205, the C-PSA UPF sends an N4 session establishment response message to the SMF.

[0119] The N4 session establishment response message includes the UL TEID selected in step 204.

[0120] Step 206, the SMF sends an N4 session establishment message to the L-PSA UPF.

[0121] The N4 session establishment message includes the UL TEID, a PDR-2 and a FAR-2 for UL.

[0122] After receiving the N4 session establishment message, the L-PSA UPF selects a TEID for down link (DL), which is used to forward the data stream of the C-PSA UPF to the L-DN through the L-PSA UPF.

[0123] Step 207, the L-PSA UPF sends an N4 session establishment response message to the SMF.

[0124] The N4 session establishment response message can include the DL TEID.

[0125] Step 208, the SMF sends an N4 session update request message to the L-PSA UPF.

[0126] The N4 session update request message can include a PDR-3 and a FAR-3 for down link.

[0127] Step 209, the L-PSA UPF sends an N4 session update response message to the SMF.

[0128] Step 210, the SMF sends an N4 session update request message to the C-PSA UPF.

[0129] The N4 session update request message can include the above-mentioned DL TEID, the PDR-4 for downlink, and the FAR-4.

[0130] Step 211, the C-PSA UPF sends an N4 session update response message to the SMF.

[0131] In the above technical solution, it is considered that there is one SMF in the whole network, and the SMF is responsible for controlling and managing all PSAs accessing different DNs; however, if the PSAs accessing the L-DN and the C-DN are controlled and managed by different SMFs respectively, the above-mentioned solution cannot complete the establishment of the forwarding tunnel in this scenario.

[0132] Therefore, the embodiments of the present application provide a communication method for establishing a node-level forwarding tunnel between an L-DN and a C-DN, so that the establishment of the forwarding tunnel can be completed even if the PSAs accessing the L-DN and the C-DN are managed by different SMFs.

[0133] Referring to FIG. 3, it is a flowchart of the communication method provided by the embodiments of the present application, as shown in the figure, the method can include the following steps:

[0134] Step 301, a first network device receives a first message, the first message includes a first DNAI and a second DNAI, and the first message is used to indicate that a tunnel is established for a first DN corresponding to the first DNAI and a second DN corresponding to the second DNAI.

[0135] The first network device is a network device with a session management function. For example, in a 5G communication system, the first network device can be an SMF.

[0136] The first message received by the first network device can come from a third network device. The third network device can be a network device used to provide services and capabilities to an external open communication system. For example, in a 5G communication system, the first SMF can receive the first message from the NEF.

[0137] Optionally, in addition to the first DNAI and the second DNAI, the first message can further include indication information used to indicate whether the first DN and / or the second DN is an L-DN or a C-DN. For example, the first message can include a data network type field, if the value of the data network type field corresponding to the first DNAI is "1", it indicates that the first DN corresponding to the first DNAI is an L-DN; if the value of the data network type field corresponding to the second DNAI is "0", it indicates that the second DN corresponding to the second DNAI is a C-DN.

[0138] Optionally, the first message can further include indication information for indicating to establish a forwarding tunnel between the first DN and the second DN, i.e., the first message indicates the first network device to establish the forwarding tunnel between the first DN and the second DN in an explicit manner. For example, for the L-DN, a field can be set for indicating whether to establish a tunnel with the C-DN. In a specific example, the first DN corresponding to the first DNAI is the L-DN, and the second DN corresponding to the second DNAI is the C-DN. The field for indicating whether to establish a tunnel with the C-DN can be set for the first DNAI. If the field takes a value of "1", it indicates to establish the forwarding tunnel between the first DN corresponding to the first DNAI and the second DN corresponding to the second DNAI. If the field takes a value of "0", it indicates not to establish the forwarding tunnel between the first DN corresponding to the first DNAI and the second DN corresponding to the second DNAI.

[0139] Alternatively, the first message can also indicate to establish the forwarding tunnel between the first DN corresponding to the first DNAI and the second DN corresponding to the second DNAI in an implicit manner. For example, when the first network device receives a message conforming to a preset format and containing the first DNAI and the second DNAI, it is considered that the message is for indicating to establish a tunnel for the first DN corresponding to the first DNAI and the second DN corresponding to the second DNAI.

[0140] Step 302: When the second DN does not belong to the management range of the first network device and belongs to the management range of the second network device, the first network device interacts with the second network device to establish the tunnel between the first DN and the second DN.

[0141] In some embodiments, the first message received by the first network device can further include first indication information for indicating that the first DN corresponding to the first DNAI and the second DN corresponding to the second DNAI do not belong to the management range of the same network device. In some specific examples, it can be defaulted that the first DN belongs to the management range of the first network, and thus the first indication information can be used to indicate that the second DN does not belong to the management range of the first network device.

[0142] In some other embodiments, the first message received by the first network device can also include second indication information for indicating that the first network device needs to determine whether the first DN corresponding to the first DNAI belongs to the management range of the first network device, and / or determine whether the second DN corresponding to the second DNAI belongs to the management range of the first network device. In some specific examples, it can be defaulted that the first DN belongs to the management range of the first network device, and thus the first indication information can be used to indicate to determine the second DN.

[0143] When the first message can also not include the first indication information, regardless of whether the first message packet includes the second indication information, after receiving the first message, the first network device judges whether the first DN corresponding to the first DNAI belongs to the management range of the first network device, that is, whether the first network device manages the PSA (in the 5G communication system, the PSA can be a UPF) capable of accessing the first DN; and / or, the first network device judges whether the second DN corresponding to the second DNAI belongs to the management range of the first network device, that is, whether the first network device manages the PSA capable of accessing the second DN. In some special cases, it can also be defaulted that the first DN belongs to the management range of the first network device, and the second network device can only judge whether the second DN belongs to the management range of the first network device.

[0144] If the first network device manages the PSA capable of accessing the first DN and also manages the PSA capable of accessing the second DN, the first network device can refer to the flowchart shown in FIG. 2 (such as steps 204 to 211) to control the PSA capable of accessing the first DN and the PSA capable of accessing the second DN to establish a forwarding tunnel. Alternatively, the first message can also include third indication information for indicating that the first DN and the second DN both belong to the management range of the first network device; in this case, the first network device does not need to perform the above judgment process and can refer to the flowchart shown in FIG. 2 (such as steps 204 to 211).

[0145] If the first network device judges that only the first DN corresponding to the first DNAI belongs to the management range of the first network device, and the second DN corresponding to the second DNAI does not belong to the management range of the first network device, the first network device can establish a forwarding tunnel between the first DN and the second DN together with the second network device managing the second DN.

[0146] In a possible design, when the first network device determines that the second DN corresponding to the second DNAI does not belong to the management range of the first network device, the first network device can obtain the address information of the second network device capable of managing the second DN from other devices. For example, taking the 5G communication system as an example, the first SMF (i.e., the first network device) can send the second DNAI to the NRF, and the NRF queries the second SMF (i.e., the second network device) managing the UPF capable of accessing the second DN according to the second DNAI, and sends the address information of the second SMF to the first SMF.

[0147] In another possible design, the first message received by the first network device can also include address information of the second network device, and then the first network device can directly send the second message to the second network device according to the address information of the second network device. Still taking the first SMF receiving the first message sent by the NEF as an example, the address information of the second SMF to which the second DN belongs can be queried by the NEF, and the address information of the second SMF is sent to the first SMF together with the first DNAI and the second DNAI.

[0148] When the first network device needs to interact with the second network device to establish a forwarding tunnel between the first DN and the second DN, FIG. 4 exemplarily provides an interaction manner to implement the first network device and the second network device interacting to establish the forwarding tunnel between the first DN and the second DN. As shown in FIG. 4, the interaction process can include the following steps:

[0149] Step 401: The first network device sends a second message to the second network device, where the second message includes the second DNAI, and the second message is used to indicate selecting the second PSA of the second DN and allocating a first tunnel identifier for the PSA selected by the first network device.

[0150] The first network device sends the second DNAI to the second network device, indicating that a tunnel needs to be established for the second DN corresponding to the second DNAI, and the second PSA of the second DN needs to be selected by the second network device.

[0151] The second message indicates allocating the first tunnel identifier for the PSA selected by the first network device, which can be explicit indication, such as including explicit indication information in the second message to indicate that the first tunnel identifier needs to be allocated. The second message can also be implicit indication, such as conforming to a preset format, which indicates that the second PSA of the second DN needs to be selected and the first tunnel identifier needs to be allocated. It should be understood that although the second message can indicate allocating the first tunnel identifier for the PSA selected by the first network device, it does not mean that the first tunnel identifier must be allocated by the second network device, but the first tunnel identifier can be allocated by the second PSA selected by the second network device.

[0152] Step 402: The second network device sends a third message to the first network device, where the third message includes the first tunnel identifier allocated for the first PSA.

[0153] The second network device selects a corresponding PSA (the PSA of the second DN is referred to as the second PSA in the embodiments of the present application) for the second DN after receiving the second message; the second network device can obtain the first tunnel identifier allocated by the second PSA for the second PSA, and returns the allocated first tunnel identifier to the first network device.

[0154] For example, the second network device can send a session establishment request message to the second PSA after selecting the second PSA, the message can include the PDR, FAR and the like configured by the second network device for the second PSA; the second PSA performs relevant configuration according to the PDR, FAR and the like, and allocates a first tunnel identifier for the first PSA of the first DN, and then sends the first tunnel identifier to the second network device; the second network device returns the first tunnel identifier to the first network device.

[0155] Step 403, the first network device sends a fourth message to the selected first PSA of the first DN, the fourth message including the first tunnel identifier, and the fourth message is used to instruct the first PSA to establish a tunnel with the second PSA according to the first tunnel identifier.

[0156] Similarly, the first network device also needs to select a first PSA (the PSA of the first DN is referred to as the first PSA in the embodiment of the application) for the first DN, the selection step can be after step 402 or before step 402, and the embodiment of the application does not limit this. After receiving the third message, the first network device sends the first tunnel identifier to the first PSA, so that the first PSA establishes a tunnel with the second PSA according to the first tunnel identifier.

[0157] For example, the first network device can send a session establishment request message to the first PSA, the message can include the first tunnel identifier, the PDR, FAR and the like configured by the first network device for the first PSA; the first PSA performs relevant configuration according to the PDR, FAR and the like, and allocates a second tunnel identifier for the second PSA, and then sends the second tunnel identifier to the first network device.

[0158] Step 404, the first network device sends a fifth message to the second network device, the fifth message including the second tunnel identifier allocated for the second PSA.

[0159] As described above, the first network device can obtain the second tunnel identifier from the first PSA, and then send the second tunnel identifier to the second network device, so that the second network device instructs the second PSA to establish a tunnel with the first PSA according to the second tunnel identifier.

[0160] Step 405, the second network device sends a sixth message to the second PSA, the sixth message including the second tunnel identifier.

[0161] The second network device sends the second tunnel identifier allocated by the first network device to the second PSA after receiving the fifth message, so that the second PSA establishes a tunnel with the first PSA according to the second tunnel identifier.

[0162] Optionally, the first message received by the first network device further includes single network slice selection assistance information (S-NSSAI), and the first network device selects the first PSA for the first DN according to the S-NSSAI; in addition, the second message sent by the first network device to the second network device also includes the S-NSSAI, so that the second network device selects the second PSA for the second DN according to the S-NSSAI.

[0163] The S-NSSAI can include a slice / service type (SST) and a slice differentiator (SD). The SST is used to indicate the network slice behavior in terms of function and access; and the SD is optional information used to supplement the slice / service type to distinguish multiple network slices of the same slice / service type. The first network device can select the first PSA capable of supporting the corresponding slice / service type network slice according to the S-NSSAI, and the second network device can also select the second PSA capable of supporting the corresponding slice / service type network slice according to the S-NSSAI, so as to meet the network slice requirements of the first DN and the second DN.

[0164] Optionally, the first message can further include the IP address of the application server corresponding to the first DNAI and / or the second DNAI. The IP address of the application server corresponding to the first DNAI is the first IP address of the application server in the first DN; and the IP address of the application server corresponding to the second DNAI is the second IP address of the application server in the second DN. Taking the first DN as the L-DN and the second DN as the C-DN as an example, the first IP address is the EAS IP, and the second IP address is the AS IP.

[0165] If the first message does not include the IP address of the application server corresponding to the first DNAI and / or the second DNAI, the first network device can also obtain the IP address of the application server corresponding to the first DNAI and / or the second DNAI from other network devices. For example, in a 5G communication system, the SMF (the first network device) can obtain the IP address of the application server from the UDR.

[0166] After obtaining the first IP address of the application server in the first DN and / or the second IP address of the application server in the second DN, the first network device can send the first IP address and / or the second IP address to the second network device, so that the second network device can control the second PSA to establish a tunnel with the first PSA according to the first IP address and / or the second IP address.

[0167] In addition, the first network device can also send the first IP address and / or the second IP address to the first PSA, such as sending the first IP address and / or the second IP address to the first PSA in the fourth message described above, so that the first PSA establishes a tunnel with the second PSA according to the first IP address and / or the second IP address.

[0168] For example, the fourth message sent by the first SMF to the first PSA can include the first tunnel identifier, the PDR, and the FAR, wherein the first IP address and / or the second IP address are carried in the PDR and the FAR; or the first IP address and / or the second IP address can also not be sent through the fourth message, but sent to the first PSA through other messages. For another example, the sixth message sent by the second SMF to the second PSA can include the second tunnel identifier, the PDR, and the FAR, wherein the first IP address and / or the second IP address are carried in the PDR and the FAR; or the first IP address and / or the second IP address can also not be sent through the sixth message, but sent to the second PSA through other messages.

[0169] It should be understood that in the process of establishing the tunnel, the interaction between the first network device and the first PSA can also include other interaction processes, for example, the first network device sends the PDR and the FAR for UL to the first PSA, sends the PDR and the FAR for DL to the first PSA, etc. The interaction between the second network device and the second PSA can also include other interaction processes, for example, the second network device sends the PDR and the FAR for UL to the second PSA, sends the PDR and the FAR for DL to the second PSA, etc.

[0170] The embodiments of the present application also provide a communication method, which can be applied to a network device for providing services and capabilities to an external open communication system to establish a node-level forwarding tunnel between DNs.

[0171] Referring to FIG. 5, a flowchart of a communication method provided by the embodiments of the present application is shown. As shown in the figure, the method can include the following steps:

[0172] Step 501, the third network device receives a seventh message, and the seventh message includes information of a first DN and information of a second DN.

[0173] The third network device is a network device for providing services and capabilities to an external open communication system. For example, in a 5G communication system, the third network device can be a NEF.

[0174] The seventh message received by the third network device can come from an AF in a 5G communication system, or a network device with an AF function in a future communication system.

[0175] The information of the DN can include one or more of the following information: IP address of the application server, fully qualified domain name (FQDN), DNAI. When the first DN is an L-DN, the IP address of the corresponding application server can be an EAS IP; when the first DN is a C-DN, the IP address of the corresponding application server can be an AS IP. Similarly, the IP address of the application server corresponding to the second DN can also be an EAS IP or an AS IP.

[0176] When the information of the first DN does not include the first DNAI, the third network device can determine the corresponding first DNAI according to other information of the first DN. For example, if the information of the first DN includes the first FQDN corresponding to the first DN, the third network device can determine the DNAI of the first DN and the IP address of the application server according to the first FQDN.

[0177] Similarly, when the information of the second DN does not include the second DNAI, the third network device can determine the corresponding second DNAI and / or the IP address of the application server according to other information of the second DN.

[0178] Optionally, the third network device can find the corresponding DNAI from the information stored by itself, or can obtain the DNAI and / or the IP address of the application server from the fifth network device. For example, if the seventh message includes the first FQDN of the first DN but does not include the first DNAI, the IP address of the application server of the first DN, if the third network device stores the first DNAI corresponding to the first FQDN, the third network device can read the first DNAI corresponding to the first FQDN from the stored information; if the third network device does not store, the third network device can send the FQDN to the fifth network device, and the fifth network device queries the corresponding DNAI and the IP address of the application server according to the FQDN, and then sends the query result to the third network device. In the 5G communication system, the fifth network device can be a UDR.

[0179] In addition, the information of the first and / or second DN can further include indication information for indicating whether the first and / or second DN is an L-DN or a C-DN. For example, the seventh message can include a field of data network type, if the value of the data network type field corresponding to the first DNAI is "1", it indicates that the first DN corresponding to the first DNAI is an L-DN; if the value of the data network type field corresponding to the second DNAI is "0", it indicates that the second DN corresponding to the second DNAI is a C-DN.

[0180] Optionally, the seventh message can further include indication information for indicating to establish the forwarding tunnel between the first DN and the second DN, that is, the seventh message indicates to establish the forwarding tunnel between the first DNAI and the second DNAI in an explicit manner. For example, for the L-DN, a field can be set for indicating whether to establish the tunnel with the C-DN. In a specific example, the first DN corresponding to the first DNAI is the L-DN, and the second DN corresponding to the second DNAI is the C-DN. The field for indicating whether to establish the tunnel with the C-DN can be set for the first DNAI. If the field takes the value of "1", it indicates to establish the forwarding tunnel between the first DN and the second DN. If the field takes the value of "0", it indicates not to establish the forwarding tunnel between the first DN and the second DN.

[0181] Alternatively, the seventh message can also indicate to establish the tunnel between the first DN and the second DN in an implicit manner. For example, when the third network device receives a message conforming to a preset format and containing the first DNAI and the second DNAI, it is considered that the message is used to indicate to establish the tunnel for the first DN corresponding to the first DNAI and the second DN corresponding to the second DNAI.

[0182] Step 502, the third network device sends an eighth message to the fourth network device, the eighth message including the first DNAI corresponding to the first DN and not including the second DNAI corresponding to the second DN.

[0183] After obtaining the first DNAI and the second DNAI, the third network device can send an eighth message to query the address information of the network device managing the first DN or the second DN. Taking the address information of the first network device managing the first DN as an example, the third network device sends the eighth message including the first DNAI to the fourth network device to request the fourth network device to feed back the address information of the first network device managing the first DN.

[0184] The fourth network device can be a network device for saving network function entities and their service description information. For example, in the 5G communication system, the fourth network device can be the NRF, that is, the NEF queries the address information of the first SMF managing the first DN from the NRF.

[0185] Step 503, the fourth network device sends a ninth message to the third network device, the ninth message including the address information of the first network device. The first DN belongs to the management range of the first network device.

[0186] After receiving the eighth message, the fourth network device can determine the address information of the first network device managing the first DN according to the first DNAI in the eighth message, and send the address information of the first network device to the third network device.

[0187] In step 504, the third network device sends a first message to the first network device according to the address information of the first network device, where the first message includes the first DNAI and the second DNAI.

[0188] After obtaining the address information of the first network device, the third network device can send the first message including the first DNAI and the second DNAI to the first network device, so that the first network device establishes a forwarding tunnel between the first DN and the second DN, for example, so that the first network device performs the flow as shown in FIG. 3.

[0189] Optionally, the first message further includes an IP address of an application server of the first DN and an IP address of an application server of the second DN.

[0190] Optionally, the first message sent by the third network device further includes second indication information, which is used to indicate that the first network device needs to determine whether the first DN corresponding to the first DNAI belongs to the management range of the first network device, and / or determine whether the second DN corresponding to the second DNAI belongs to the management range of the first network device. In some specific cases, it can be defaulted that the first DN belongs to the management range of the first network device, and then the second indication information can be used to indicate to determine the second DN.

[0191] In a possible implementation, the seventh message received by the third network device in step 501 can further include a data network name (DNN) and / or an application function service identifier (AF service identifier) corresponding to the first DN and the second DN. The third network device determines the S-NSSAI that can meet the requirements of the first DN and the second DN according to the DNN and / or the application function service identifier. For example, the third network device can send the DNN and / or the application function service identifier to the fifth network device, the fifth network device determines the corresponding S-NSSAI according to the DNN and / or the application function service identifier, and then sends the determined S-NSSAI to the third network device. The fifth network device can be a UDR.

[0192] In another possible implementation, the seventh message received by the third network device in step 501 can include an S-NSSAI. Then the third network device can directly carry the S-NSSAI in the first message sent to the first network device, so that the first network device establishes the forwarding tunnel between the first DN and the second DN according to the S-NSSAI. Specifically, the first network device can select the first PSA capable of supporting the corresponding slice / service type network slice according to the S-NSSAI, and the first network device can also send the S-NSSAI to the second network device, so that the second network device also selects the second PSA capable of supporting the corresponding slice / service type network slice according to the S-NSSAI.

[0193] The embodiments of the present application also provide a communication method, which can also be applied to the network device for providing services and capabilities to the external open communication system, and can also realize the establishment of the node-level forwarding tunnel between the DNs.

[0194] Referring to FIG. 6, a flowchart of a communication method provided by the embodiments of the present application is shown. As shown in the figure, the method can include the following steps:

[0195] Step 601, the third network device receives a seventh message, and the seventh message includes information of a first DN and information of a second DN.

[0196] The third network device is a network device for providing services and capabilities to the external open communication system. For example, in the 5G communication system, the third network device can be a NEF.

[0197] The seventh message received by the third network device can come from an AF in the 5G communication system, or a network device with AF function in the future communication system.

[0198] The information of the DN can include one or more of the following information: IP address of the application server, FQDN, DNAI. When the first DN is an L-DN, the IP address of the corresponding application server can be an EAS IP; when the first DN is a C-DN, the IP address of the corresponding application server can be an AS IP. Similarly, the IP address of the application server corresponding to the second DN can also be an EAS IP or an AS IP.

[0199] When the information of the first DN does not include the first DNAI, the third network device can determine the corresponding first DNAI according to other information of the first DN. For example, if the information of the first DN includes the first FQDN corresponding to the first DN, the third network device can determine the DNAI of the first DN and the IP address of the application server according to the first FQDN.

[0200] Similarly, when the information of the second DN includes no second DNAI, the third network device can determine the corresponding second DNAI and / or the IP address of the application server according to other information of the second DN.

[0201] Optionally, the third network device can find the corresponding DNAI from the information stored by itself, or acquire the DNAI and / or the IP address of the application server from the fifth network device. For example, if the seventh message includes the first FQDN of the first DN but does not include the first DNAI and the IP address of the application server of the first DN, if the third network device stores the first DNAI corresponding to the first FQDN, the third network device can read the first DNAI corresponding to the first FQDN from the stored information; if the third network device does not store the information, the third network device can send the FQDN to the fifth network device, and the fifth network device queries the corresponding DNAI and the IP address of the application server according to the FQDN, and then sends the query result to the third network device. In the 5G communication system, the fifth network device can be a UDR.

[0202] In addition, the information of the first and / or second DN can further include indication information for indicating whether the first and / or second DN is an L-DN or a C-DN. For example, the seventh message can include a field of data network type, if the value of the data network type field corresponding to the first DNAI is "1", it indicates that the first DN corresponding to the first DNAI is an L-DN; if the value of the data network type field corresponding to the second DNAI is "0", it indicates that the second DN corresponding to the second DNAI is a C-DN.

[0203] Optionally, the seventh message can further include indication information for indicating the establishment of the forwarding tunnel between the first DNAI and the second DNAI. For example, for the L-DN, a field can be set for indicating whether to establish a tunnel with the C-DN. In a specific example, the first DN corresponding to the first DNAI is an L-DN, and the second DN corresponding to the second DNAI is a C-DN, a field for indicating whether to establish a tunnel with the C-DN can be set for the first DNAI, if the value of the field is "1", it indicates that the forwarding tunnel between the first DN and the second DN is established, and if the value of the field is "0", it indicates that the forwarding tunnel between the first DN and the second DN is not established.

[0204] Alternatively, the seventh message can also indicate the establishment of the tunnel between the first DN and the second DN in an implicit manner. For example, when the third network device receives a message conforming to a preset format and containing the first DNAI and the second DNAI, it is considered that the message is used to indicate the establishment of the tunnel for the first DN corresponding to the first DNAI and the second DN corresponding to the second DNAI.

[0205] Step 602, the third network device sends a tenth message to the fourth network device, the tenth message comprising the first DNAI corresponding to the first DN and the second DNAI corresponding to the second DN.

[0206] After obtaining the first DNAI and the second DNAI, the third network device can send the tenth message to query the address information of the network device managing the first DN and the address information of the network device managing the second DN.

[0207] The fourth network device can be a network device used for storing network function entities and their service description information. For example, in a 5G communication system, the fourth network device can be a NRF, i.e., the NEF queries the address information of the first SMF managing the first DN from the NRF.

[0208] Step 603, the fourth network device sends an eleventh message to the third network device, the eleventh message comprising the address information of the first network device and the address information of the second network device, wherein the first DN belongs to the management range of the first network device and the second DN belongs to the management range of the first network device.

[0209] After receiving the tenth message, the fourth network device can determine the address information of the first network device managing the first DN and the address information of the second network device managing the second DN according to the first DNAI and the second DNAI in the tenth message, and send the address information of the first network device and the address information of the second network device to the third network device.

[0210] Step 604, when the first network device and the second network device are different network devices, the third network device sends a first message to the first network device according to the address information of the first network device, the first message comprising the first DNAI and the second DNAI.

[0211] Optionally, after receiving the eleventh message, the third network device can determine whether the first network device and the second network device are the same device according to the address information of the first network device and the address information of the second network device. If the address information of the first network device is the same as the address information of the second network device, the third network device can consider that the first network device and the second network device are the same network device; if the address information of the first network device is not the same as the address information of the second network device, the third network device can consider that the first network device and the second network device are different network devices.

[0212] If the first network device and the second network device are the same network device, the third network device sends the first message to the first network device (i.e., the second network device), and the first message includes the first DNAI and the second DNAI. Optionally, the first message can further include third indication information, which is used to indicate that the first DN and the second DN both belong to the management range of the first network device.

[0213] If the first network device and the second network device are different network devices, the third network device can send the first message to the first network device, and the first message includes the first DNAI and the second DNAI, so that the first network device and the second network device interact to establish the forwarding tunnel between the first DN and the second DN. Alternatively, the third network device can also send the first message to the second network device, so that the second network device and the first network device interact to establish the forwarding tunnel between the first DN and the second DN. However, the following embodiments are exemplified by sending the first message to the first network device.

[0214] In a possible design, when the first network device and the second network device are different network devices, the first message sent by the third network device can further include first indication information, which is used to indicate that the first DN and the second DN do not belong to the management range of the same network device. In some specific cases, it can be defaulted that the first DN belongs to the management range of the first network, and therefore the first indication information can be used to indicate that the second DN does not belong to the management range of the first network device.

[0215] Optionally, the first message sent by the third network device can further include address information of the second network device. On one hand, after receiving the first message, the first network device can determine that the second DN does not belong to the management range of the first network device according to the address information of the second network device. On the other hand, the first network device does not need to query the address information of the second network device.

[0216] In addition, the third network device can also not need to determine whether the first network device and the second network device are the same network device, and the third network device can carry the address information of the second network device in the first message and send the first message to the first network device, so that the first network device determines whether the first network device and the second network device are the same network device according to the address information of the second network device, or determines whether the second DN belongs to the management range of the first network device.

[0217] In a possible implementation, the seventh message received by the third network device in step 601 can further include a DNN and / or an application function service identifier (AF service identifier) corresponding to the first DN and the second DN. The third network device determines the S-NSSAI that can meet the requirements of the first DN and the second DN according to the DNN and / or the application function service identifier. For example, the third network device can send the DNN and / or the application function service identifier to the fifth network device, and the fifth network device determines the corresponding S-NSSAI according to the DNN and / or the application function service identifier, and then sends the determined S-NSSAI to the third network device. In the 5G communication system, the fifth network device can be a UDR.

[0218] In another possible implementation, the seventh message received by the third network device in step 601 can include the S-NSSAI. Then the third network device can directly carry the S-NSSAI in the first message sent to the first network device, so that the first network device establishes the forwarding tunnel between the first DN and the second DN according to the S-NSSAI. Specifically, the first network device can select the first PSA that can support the corresponding slice / service type network slice according to the S-NSSAI, and the first network device can also send the S-NSSAI to the second network device, so that the second network device also selects the second PSA that can support the corresponding slice / service type network slice according to the S-NSSAI.

[0219] Optionally, the first message further includes the IP address of the application server of the first DN and the IP address of the application server of the second DN.

[0220] It should be understood that the embodiments shown in FIG. 5 and the embodiments described in FIG. 6 can be combined with the embodiments shown in FIG. 3 and FIG. 4.

[0221] In order to more clearly understand the above embodiments of the present application, the following will be illustrated in detail in combination with FIG. 7 to FIG. 10.

[0222] In FIG. 7, the embodiment shown in FIG. 5 is combined with the embodiments shown in FIG. 3 and FIG. 4, as shown in the figure, the communication method can include the following steps:

[0223] In step 701, the AF sends a seventh message to the NEF (i.e., the third network device in the foregoing embodiments), and the seventh message includes the related information of DN1 and DN2.

[0224] The related information of the DN can include an IP address (EAS IP or AS IP) of an application server corresponding to the DN, an FQDN, a DNAI, and the like. The related information of the DN1 and the related information of the DN2 can adopt the same parameters or different parameters. For example, the related information of the DN1 includes the DNAI 1 and the IP address 1 of the application server, and the related information of the DN2 includes the DNAI 2 and the IP address 2 of the application server; for another example, the related information of the DN1 includes the DNAI 1, and the related information of the DN2 includes the DNAI 2 and the IP address 2 of the application server.

[0225] Optionally, the seventh message can further include indication information used to indicate whether the first DN and / or the second DN is an L-DN or a C-DN. For example, the seventh message can include a field of a data network type. If the value of the data network type field corresponding to the first DNAI is “1”, it indicates that the first DN corresponding to the first DNAI is an L-DN; if the value of the data network type field corresponding to the second DNAI is “0”, it indicates that the second DN corresponding to the second DNAI is a C-DN.

[0226] Optionally, the seventh message can further include indication information used to indicate the establishment of the forwarding tunnel between the first DNAI and the second DNAI. For example, for the L-DN, a field of whether to establish a tunnel with the C-DN can be set.

[0227] Alternatively, the seventh message can also indicate the establishment of the tunnel between the first DN corresponding to the first DNAI and the second DN corresponding to the second DNAI in an implicit manner. For example, when the third network device receives a message conforming to a preset format and containing the first DNAI and the second DNAI, it is considered that the message is used to indicate the establishment of the tunnel for the first DN corresponding to the first DNAI and the second DN corresponding to the second DNAI.

[0228] Step 702a: If the related information does not include the DNAI 1 and the DNAI 2, the NEF obtains the corresponding DNAI 1 and DNAI 2 according to the related information of the DN.

[0229] Optionally, the NEF can find the corresponding DNAI from the information stored by itself, or obtain the DNAI and / or the IP address of the application server from the UDR.

[0230] Step 702a is an optional step. If the related information of the DN received by the NEF includes the DNAI 1 and the DNAI 2, the NEF can not perform the above step 702a, but perform step 702b.

[0231] Step 702b: The NEF sends an eighth message to the NRF (i.e., the fourth network device in the foregoing embodiment), and the eighth message includes the DNAI 1.

[0232] The NEF can send the DNAI 1 to the NRF to query the address information of the first SMF managing the DN1, and can also send the DNAI 2 to the NRF to query the address information of the second SMF managing the DN2. FIG. 7 takes the sending of the DNAI 1 as an example for description.

[0233] Step 702c, the NRF sends an ninth message to the NEF, and the ninth message includes the address information of the first SMF.

[0234] Step 703, the NEF sends a first message to the first SMF, and the first message includes the DNAI 1 and the DNAI 2.

[0235] The first message is used to instruct the first SMF to establish a forwarding tunnel between the DN1 and the DN2.

[0236] Optionally, the first message can also include indication information used to indicate whether the first DN and / or the second DN is an L-DN or a C-DN.

[0237] Optionally, the first message can also include indication information used to instruct to establish a forwarding tunnel between the first DNAI and the second DNAI. Alternatively, the first message can also implicitly indicate to establish a tunnel between the first DN corresponding to the first DNAI and the second DN corresponding to the second DNAI.

[0238] Optionally, since the NEF does not judge whether the DN2 also belongs to the management range of the first SMF, the first message can include second indication information used to instruct the first SMF to judge whether the DN1 and the DN2 belong to the management range of the first SMF. In some examples, it can be defaulted that the DN1 belongs to the management range of the first SMF, and the second indication information can be used to instruct to judge the DN2.

[0239] Optionally, if the first message does not include explicit indication information indicating that the DN1 and the DN2 both belong to the management range of the first SMF, the first SMF judges whether the DN1 and the DN2 belong to the management range of the first SMF; or, in the case of defaulting that the DN1 belongs to the management range of the first SMF, the first SMF judges whether the DN2 belongs to the management range of the first SMF.

[0240] Step 704, the first SMF judges whether the DN1 and the DN2 belong to the management range of the first SMF.

[0241] That is, the first SMF judges whether it manages a UPF capable of accessing the DN1 and the DN2.

[0242] It should be understood that the first SMF can also only judge whether DN2 belongs to the management range of the first SMF.

[0243] If DN1 and DN2 both belong to the management range of the first SMF, the first SMF can control the PSA UPF capable of accessing DN1 and the PSA UPF capable of accessing DN2 to establish a forwarding tunnel with reference to the flow shown in FIG. 2 (such as steps 204 to 211).

[0244] Otherwise, the first SMF continues to perform step 705.

[0245] Optionally, if the first SMF does not obtain the IP address of the application server corresponding to DN1 and / or DN2, the first SMF can also obtain the IP address of the application server corresponding to DN1 and / or DN2 from the UDR. For example, the first SMF can send DNAI1 and / or DNAI2 to the UDR to request to obtain the IP address of the application server corresponding to DN1 and / or DN2; the UDR queries the IP address of the application server corresponding to DN1 and / or DN2 according to DNAI1 and / or DNAI2 after receiving the request message, and sends the result to the first SMF.

[0246] Step 705, the first SMF sends a request message to the NRF, the request message including DNAI2, to request to obtain the address information of the second SMF to which DN2 belongs.

[0247] Step 706, the NRF sends a response message to the first SMF, the response message including the address information of the second SMF.

[0248] The NRF queries the SMF capable of managing DN2, i.e. the second SMF, according to DNAI2, and sends the address information of the second SMF to the first SMF.

[0249] Step 707, the first SMF sends a second message to the second SMF, the second message including DNAI2.

[0250] The second message is used to indicate that a tunnel needs to be established with DN2 corresponding to DNAI2, to request to select a second PSA for DN2 and to allocate TEID1 for the first PSA selected by the first SMF. Optionally, the second message can indicate the selection of the second PSA for DN2 and / or the allocation of TEID1 by the second SMF in an explicit or implicit manner.

[0251] Optionally, the first PSA and the second PSA can be UPFs in a 5G communication system.

[0252] Optionally, the second message can further include the IP address of the application server corresponding to the DNAI 2 and / or the DNAI 1, for generating the PDR and / or the FAR.

[0253] Step 708, the second SMF determines the second PSA according to the DNAI 2.

[0254] Step 709, the second SMF configures the second PSA to establish a tunnel with the first PSA.

[0255] Optionally, the above configuration process can include: the second SMF can send an N4 session establishment request message to the second PSA, the request message can include the PDR 2 and the FAR 2 for the UL; the second PSA selects the TEID 1 after receiving the N4 session establishment request message, the TEID 1 is used to forward the data stream of the first PSA to the DN 2 through the second PSA; the second PSA sends an N4 session establishment response message to the second SMF, the N4 session establishment response message includes the TEID 1.

[0256] Step 710, the second SMF sends a third message to the first SMF, the third message includes the TEID 1.

[0257] Optionally, the third message can include indication information to indicate the first SMF to select the first PSA for the DN 1, send the TEID 1 to the first PSA, and allocate TEID for the second PSA.

[0258] Alternatively, the third message can also not include the above indication information, and the first SMF can determine according to the TEID 1 in the third message that the first PSA needs to be selected for the DN 1, the TEID 1 is sent to the first PSA, and the TEID is allocated for the second PSA.

[0259] Step 711, the first SMF determines the first PSA according to the DNAI 1.

[0260] Step 712, the first SMF configures the first PSA to establish a tunnel with the second PSA.

[0261] Optionally, the configuration process can include that the first SMF can send an N4 session establishment request message (i.e., the fourth message in the embodiment shown in FIG. 4) to the first PSA, the request message can include the TEID 1, and can further include the PDR1 and the FAR1 for the UL; the first PSA selects the TEID 2 after receiving the N4 session establishment request message, the TEID 2 is used for forwarding the data stream of the second PSA to the DN1 through the first PSA; the first PSA sends an N4 session establishment response message to the first SMF, the N4 session establishment response message includes the TEID 2; the first SMF sends an N4 session update request message to the first PSA, the request message includes the PDR3 and the FAR3 for the downlink; and the first PSA sends an N4 session update response message to the first SMF.

[0262] Step 713, the first SMF sends a fifth message to the second SMF, the fifth message includes the TEID 2.

[0263] Optionally, the fifth message can include indication information to indicate the second SMF to send the TEID 2 to the second PSA. Alternatively, the fifth message can not include the above-mentioned indication information, and the second SMF can determine that the TEI2 needs to be sent to the second PSA according to the TEID 2 in the fifth message.

[0264] Step 714, the second SMF sends an N4 session update response message to the second PSA (i.e., the sixth message in the embodiment shown in FIG. 4).

[0265] The N4 session update request message can include the above-mentioned TEID 2. Optionally, the N4 session update request message can further include the PDR4 and the FAR4 for the downlink.

[0266] Step 715, the second SMF sends tunnel establishment completion indication information to the first SMF, and the first SMF sends the tunnel establishment completion indication information to the AF.

[0267] Optionally, the first SMF can send the tunnel establishment completion indication information to the AF through the NEF.

[0268] In a specific embodiment shown in FIG. 8, the embodiment shown in FIG. 6 is combined with the embodiments shown in FIG. 3 and FIG. 4, as shown in the figure, the communication method can include the following steps:

[0269] Step 801, the AF sends a seventh message to the NEF (i.e., the third network device in the embodiment shown in FIG. 6), the seventh message includes the related information of the DN1 and the DN2.

[0270] The related information of the DN can include an IP address (EAS IP or AS IP) of an application server corresponding to the DN, an FQDN, a DNAI, and the like. The related information of the DN1 and the related information of the DN2 can use the same parameters or different parameters. For example, the related information of the DN1 includes the DNAI 1 and the IP address 1 of the application server, and the related information of the DN2 includes the DNAI 2 and the IP address 2 of the application server; for another example, the related information of the DN1 includes the DNAI 1, and the related information of the DN2 includes the DNAI 2 and the IP address 2 of the application server.

[0271] Optionally, the seventh message can further include indication information used to indicate whether the first DN and / or the second DN is an L-DN or a C-DN. For example, the seventh message can include a field of a data network type. If the value of the data network type field corresponding to the first DNAI is “1”, it indicates that the first DN corresponding to the first DNAI is an L-DN; if the value of the data network type field corresponding to the second DNAI is “0”, it indicates that the second DN corresponding to the second DNAI is a C-DN.

[0272] Optionally, the seventh message can further include indication information used to indicate the establishment of the forwarding tunnel between the first DNAI and the second DNAI. For example, for the L-DN, a field of whether to establish a tunnel with the C-DN can be set. Alternatively, the seventh message can also use an implicit manner to indicate the establishment of the tunnel between the first DN corresponding to the first DNAI and the second DN corresponding to the second DNAI.

[0273] Step 802: If the related information does not include the DNAI 1 and the DNAI 2, the NEF obtains the corresponding DNAI 1 and DNAI 2 according to the related information of the DN.

[0274] Optionally, the NEF can find the corresponding DNAI from the information stored by itself, or obtain the DNAI and / or the IP address of the application server from the UDR.

[0275] Step 802 is an optional step. If the related information of the DN received by the NEF includes the DNAI 1 and the DNAI 2, the NEF can not perform the above step 802, but perform step 803.

[0276] Step 803: The NEF sends a tenth message to the NRF (i.e., the fourth network device in the embodiment shown in FIG. 6), and the tenth message includes the DNAI 1 and the DNAI 2.

[0277] The tenth message is used to request to obtain the address information of the first SMF managing the DN1 and the address information of the second SMF managing the DN2.

[0278] Step 804, the NRF sends an eleventh message to the NEF, and the eleventh message includes the address information of the first SMF and the address information of the second SMF.

[0279] Step 805, the NEF determines whether the first SMF and the second SMF are the same SMF according to the address information of the first SMF and the address information of the second SMF.

[0280] If the first SMF and the second SMF are the same SMF, the NEF can send a first message to the first SMF, and the first message includes the DNAI1 and the DNAI2, and the first message is used to instruct the first SMF to establish a forwarding tunnel between the DN1 and the DN2. Specifically, the first message can include explicit indication information to instruct to establish the forwarding tunnel between the DN1 and the DN2; or, the first message can also implicitly instruct to establish the forwarding tunnel between the DN1 and the DN2. Optionally, the first message further includes the IP address of the application server corresponding to the DNAI1 and the DNAI2 respectively. Optionally, the first message further includes third indication information, which is used to indicate that the DN1 and the DN2 both belong to the management range of the first SMF.

[0281] After receiving the first message, the SMF can refer to the flow shown in FIG. 2 (such as steps 204 to 211) to control the PSA UPF capable of accessing the DN1 and the PSA UPF capable of accessing the DN2 to establish the forwarding tunnel, which will not be described herein again. If the first message does not include the third indication information, the first SMF can also determine whether the DN1 and / or the DN2 belong to the management range of the first SMF.

[0282] If the first SMF and the second SMF are not the same SMF, the NEF can continue to perform step 806 to make the first SMF and the second SMF interact to establish the forwarding tunnel between the DN1 and the DN2.

[0283] Step 806, the NEF sends a first message to the first SMF, and the first message includes the DNAI1 and the DNAI2. The first message is used to instruct the first SMF to establish the forwarding tunnel between the DN1 and the DN2.

[0284] Optionally, the first message can also include indication information indicating whether the first DN and / or the second DN is an L-DN or a C-DN.

[0285] Optionally, the first message can also include indication information indicating to establish the forwarding tunnel between the first DNAI and the second DNAI. Or, the first message can also implicitly indicate to establish the tunnel between the first DN corresponding to the first DNAI and the second DN corresponding to the second DNAI.

[0286] Optionally, the first message can further include address information of the second SMF. In this case, the first SMF can determine that DN2 does not belong to the management range of the first SMF according to the information of the second SMF.

[0287] If the address information of the second SMF is not included in the first message, the first SMF can obtain the address information of the second SMF according to the DNAI2. As described above, the first SMF can read the address information of the second SMF corresponding to the DNAI2 from the information stored by itself, or obtain the address information of the second SMF corresponding to the DNAI2 from the NRF.

[0288] Optionally, the first message can further include first indication information, which is used to indicate that the first DN and the second DN do not belong to the management range of the same network device, or to indicate that the second DN does not belong to the management range of the first SMF.

[0289] If there is no explicit indication information in the first message to indicate whether the first DN and the second DN belong to the management range of the first SMF, the first SMF can first determine whether DN1 and / or DN2 belong to the management range of the first SMF after receiving the first message.

[0290] Optionally, the first message can further include the IP address of the application server corresponding to the DNAI1 and the DNAI2 respectively.

[0291] If the first SMF does not obtain the IP address of the application server corresponding to the DNAI1 and / or the DNAI2, the first SMF can further obtain the IP address of the application server corresponding to the DNAI1 and / or the DNAI2 from the UDR.

[0292] Steps 807 to 815 are similar to steps 707 to 715 in FIG. 7, and will not be described in detail here.

[0293] The specific embodiment shown in FIG. 9 combines the embodiment shown in FIG. 6 with the embodiments shown in FIGS. 3 and 4, and combines the S-NSSAI for selecting the PSA, which can specifically include the following steps:

[0294] Step 901, the AF sends a seventh message to the NEF (i.e., the third network device in the foregoing embodiment), and the seventh message includes the related information of DN1 and DN2, and the DNN and / or application function service identifier.

[0295] The related information of the DN can further include an IP address (EAS IP or AS IP) of an application server corresponding to the DN, an FQDN, a DNAI, and the like. The related information of the DN1 and the related information of the DN2 can adopt the same parameters or different parameters. For example, the related information of the DN1 includes the DNAI 1 and the IP address 1 of the application server, and the related information of the DN2 includes the DNAI 2 and the IP address 2 of the application server; or for example, the related information of the DN1 includes the DNAI 1, and the related information of the DN2 includes the DNAI 2 and the IP address 2 of the application server.

[0296] The DN1 and the DN2 can share the same DNN and application service identifier. The AF can send the DNN and / or the application service identifier common to the DN1 and the DN2 to the NEF, so that the 5G core network selects a network slice that can meet the requirement according to the DNN and / or the application service identifier to provide a service.

[0297] Optionally, the seventh message can further include indication information for indicating whether the first DN and / or the second DN is an L-DN or a C-DN.

[0298] Optionally, the seventh message can further include indication information for indicating to establish a forwarding tunnel between the first DNAI and the second DNAI. For example, for the L-DN, a field of whether to establish a tunnel with the C-DN can be set. Alternatively, the seventh message can also indicate to establish a tunnel between the first DN corresponding to the first DNAI and the second DN corresponding to the second DNAI in an implicit manner.

[0299] In step 902, the NEF obtains the S-NSSAI corresponding to the DNN and / or the application function service identifier from the UDR.

[0300] The NEF can send the DNN and / or the application function service identifier to the UDR; the UDR determines the S-NSSAI corresponding to the DN1 according to the DNN and / or the application function service identifier, and sends the S-NSSAI to the NEF.

[0301] Optionally, if the seventh message does not include the DNAI 1 and / or the DNAI 2, the NEF can further obtain the DNAI 1 and / or the DNAI 2 according to the related information of the DN1 and / or the DN2 in step 902.

[0302] Optionally, if the seventh message does not include the IP address of the application server of the DN1 and / or the DN2, the NEF can further obtain the IP address of the application server of the DN1 and / or the DN2 according to the related information of the DN1 and / or the DN2 in step 902.

[0303] Step 903, the NEF sends a tenth message to the NRF (i.e., the fourth network device in the embodiment shown in FIG. 6), and the tenth message includes the DNAI 1, the DNAI 2, and the S-NSSAI.

[0304] Step 904, the NRF sends an eleventh message to the NEF, and the eleventh message includes the address information of the first SMF and the address information of the second SMF.

[0305] Step 905, the NEF determines whether the first SMF and the second SMF are the same SMF according to the address information of the first SMF and the address information of the second SMF.

[0306] Step 906, the NEF sends a first message to the first SMF, and the first message includes the DNAI 1, the DNAI 2, and the S-NSSAI. The first message is used to instruct the first SMF to establish a forwarding tunnel between the DN 1 and the DN 2.

[0307] Optionally, the first message can further include the address information of the second SMF. In this case, the first SMF can determine that the DN 2 does not belong to the management range of the first SMF according to the address information of the second SMF.

[0308] If the address information of the second SMF is not included in the first message, the first SMF can obtain the address information of the second SMF according to the DNAI 2. As described above, the first SMF can read the address information of the second SMF corresponding to the DNAI 2 from the information stored by itself, or can obtain the address information of the second SMF corresponding to the DNAI 2 from the NRF.

[0309] Optionally, the first message can further include first indication information, which is used to indicate that the first DN and the second DN do not belong to the management range of the same network device, or is used to indicate that the second DN does not belong to the management range of the first SMF. Alternatively, the first message can include second indication information, which is used to instruct the first SMF to determine whether the DN 1 and the DN 2 belong to the management range of the first SMF.

[0310] If there is no indication information in the first message to indicate whether the first DN and the second DN belong to the management range of the first SMF, the first SMF can first determine whether the DN 1 and / or the DN 2 belong to the management range of the first SMF after receiving the first message.

[0311] Optionally, the first message can further include the IP address of the application server corresponding to the DNAI 1 and the DNAI 2 respectively.

[0312] If the first SMF does not obtain the IP address of the application server corresponding to the DNAI 1 and / or the DNAI 2, the first SMF can further obtain the IP address of the application server corresponding to the DNAI 1 and / or the DNAI 2 from the UDR.

[0313] Optionally, the first message can also include indication information for indicating whether the first DN and / or the second DN is an L-DN or a C-DN.

[0314] Optionally, the first message can also include indication information for indicating the establishment of the forwarding tunnel between the first DNAI and the second DNAI. Alternatively, the first message can also implicitly indicate the establishment of the tunnel between the first DN corresponding to the first DNAI and the second DN corresponding to the second DNAI.

[0315] Step 907, the first SMF sends a second message to the second SMF, and the second message includes the DNAI 2 and the S-NSSAI.

[0316] The second message is used to indicate the establishment of the tunnel with the DN 2 corresponding to the DNAI 2, to request the selection of the second PSA for the DN 2, and to allocate the TEID 1 for the first PSA selected by the first SMF.

[0317] The second message further includes the S-NSSAI, indicating that the second SMF needs to select the second PSA according to the S-NSSAI.

[0318] Step 908, the second SMF determines the second PSA according to the DNAI 2 and the S-NSSAI.

[0319] Step 909, the second SMF configures the second PSA to establish the tunnel with the first PSA.

[0320] Step 910, the second SMF sends a third message to the first SMF, and the third message includes the TEID 1.

[0321] Step 911, the first SMF determines the first PSA according to the DNAI 1 and the S-NSSAI.

[0322] Steps 912 to 915 are similar to steps 712 to 715 in FIG. 7, and will not be described here.

[0323] It should be understood that the embodiment shown in FIG. 5 can also be combined with the embodiments shown in FIGS. 3 and 4, and the S-NSSAI can be used for selecting the PSA.

[0324] The embodiment shown in FIG. 10 is similar to the embodiment shown in FIG. 9, and the difference is that the seventh information sent by the AF to the NEF directly contains the S-NSSAI in the embodiment shown in FIG. 10. Therefore, the NEF does not need to determine the corresponding S-NSSAI according to the DNN and / or application function service identifier, and it is not necessary to perform step 902 in the embodiment shown in FIG. 9. The other steps are consistent with the embodiment shown in FIG. 9.

[0325] FIG. 11 is a schematic diagram of a communication apparatus according to an embodiment of the present application. The communication apparatus includes a processing module 1101 and a transceiver module 1102. The processing module 1101 is configured to implement the processing of data by the communication apparatus. The transceiver module 1102 is configured to receive or send the content of the communication apparatus and other units or network elements. It should be understood that the processing module 1101 in the embodiments of the present application can be realized by a processor or a processor-related circuit component (or referred to as a processing circuit), and the transceiver module 1102 can be realized by a receiver / transmitter or a receiver / transmitter-related circuit component.

[0326] Exemplarily, the communication apparatus can be a communication apparatus device, or a chip applied to the communication apparatus device or other combination devices, components, etc. having the functions of the communication apparatus device.

[0327] When the communication apparatus is a first network device, the processing module 1101 is configured to receive, by the transceiver module 1102, a first message including a first data network access identifier (DNAI) and a second DNAI, the first message being used to indicate that a tunnel is established for a first data network (DN) corresponding to the first DNAI and a second DN corresponding to the second DNAI, and the first DN belongs to the management range of the first network device; when the second DN does not belong to the management range of the first network device and belongs to the management range of a second network device, the processing module 1101 interacts with the second network device to establish the tunnel of the first DN and the second DN by the transceiver module 1102.

[0328] In addition, the above-mentioned various modules can also be used to support other processes performed by the first network device in the embodiments shown in FIGS. 3 to 10. The beneficial effects can refer to the previous description, which will not be repeated here.

[0329] When the communication apparatus is the second network device, the processing module 1101 is configured to: receive, by the transceiver 1102, a second message sent by the first network device, the second message comprising a second data network access identifier DNAI; select a second PDU session anchor PSA of a second data network corresponding to the second DNAI, and obtain a first tunnel identifier allocated to a first PSA selected for the first network device; send, by the transceiver 1102, a third message to the first network device, the third message comprising the first tunnel identifier; receive, by the transceiver 1102, a fifth message sent by the first network device, the fifth message comprising a second tunnel identifier allocated to the second PSA; and send, by the transceiver 1102, a sixth message to the second PSA, the sixth message comprising the second tunnel identifier, the sixth message being used to instruct the second PSA to establish a tunnel with the first PSA according to the second tunnel identifier.

[0330] In addition, each of the above modules can also be used to support other processes performed by the second network device in the embodiments shown in FIGS. 3 to 10. The beneficial effects can be referred to the foregoing description, which will not be described here.

[0331] When the communication apparatus is the third network device, the processing module 1101 is configured to: receive, by the transceiver 1102, a seventh message, the seventh message comprising information of a first data network DN and information of a second DN; send, by the transceiver 1102, an eighth message to a fourth network device, the eighth message comprising a first data network access identifier DNAI corresponding to the first DN and not comprising a second DNAI corresponding to the second DN; receive, by the transceiver 1102, a ninth message sent by the fourth network device, the ninth message comprising address information of the first network device, the first DN belonging to a management range of the first network device; and according to the address information, send, by the transceiver 1102, a first message to the first network device, the first message comprising the first data network access identifier DNAI corresponding to the first DN and the second DNAI corresponding to the second DN.

[0332] In addition, each of the above modules can also be used to support other processes performed by the third network device in the embodiments shown in FIGS. 3 to 5 and 7. The beneficial effects can be referred to the foregoing description, which will not be described here.

[0333] When the communication apparatus is the third network device, the processing module 1101 is configured to: receive, by the transceiver module 1102, a seventh message, the seventh message comprising information of a first data network DN and information of a second DN; send, by the transceiver module 1102, a tenth message to a fourth network device, the tenth message comprising a first data network access identifier DNAI corresponding to the first DN and a second DNAI corresponding to the second DN; receive, by the transceiver module 1102, an eleventh message sent by the fourth network device, the eleventh message comprising address information of a first network device and address information of a second network device, the first DN belonging to a management range of the first network device, and the second DN belonging to a management range of the second network device; when the first network device and the second network device are different network devices, send, by the transceiver module 1102, a first message to the first network device according to the address information of the first network device, the first message comprising the first DNAI corresponding to the first DN and the second DNAI corresponding to the second DN.

[0334] In addition, each of the above modules can also be used to support other processes performed by the third network device in the embodiments shown in FIG. 3, FIG. 4, FIG. 6, FIG. 8 to FIG. 10. The beneficial effects can refer to the foregoing description, which will not be repeated here.

[0335] FIG. 12 is a schematic diagram of another communication apparatus according to an embodiment of the present application, which comprises a processor 1201, a communication interface 1202, and further can comprise a memory 1203, a bus 1204. Wherein, the processor 1201, the communication interface 1202 and the memory 1203 can be connected with each other through the bus 1204; the bus 1204 can be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The above bus 1204 can be divided into address bus, data bus and control bus, etc. For the convenience of indication, only one line is used in FIG. 12, but it does not mean that there is only one bus or one type of bus.

[0336] The processor 1201 can be a central processing unit (CPU), a network processor (NP), or a combination of the CPU and the NP. The processor can further include a hardware chip. The hardware chip can be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The PLD can be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a Generic Array Logic (GAL), or any combination thereof. The memory 1203 can be a volatile memory or a nonvolatile memory, or can include both volatile and nonvolatile memory. The nonvolatile 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.

[0337] The processor 1201 is configured to implement data processing operations of the communication device, and the communication interface 1202 is configured to implement receiving operations and sending operations of the communication device.

[0338] When the communication device is a first network device, the processor 1201 is configured to receive, through the communication interface 1202, a first message including a first data network access identifier (DNAI) and a second DNAI, the first message being used to indicate that a tunnel is established for a first data network (DN) corresponding to the first DNAI and a second DN corresponding to the second DNAI, the first DN belonging to a management range of the first network device; when the second DN does not belong to the management range of the first network device and belongs to a management range of a second network device, the processor 1201 is configured to interact with the second network device through the communication interface 1202 to establish the tunnel between the first DN and the second DN.

[0339] Furthermore, the above-described various components can also be used to support other processes performed by the terminal device in the embodiments shown in FIGS. 3-10. The beneficial effects can be referred to the previous description and will not be repeated here.

[0340] When the communication apparatus is the second network device, the processor 1201 is configured to: receive, through the communication interface 1202, a second message sent by the first network device, the second message comprising a second data network access identifier DNAI; select a second PDU session anchor PSA of a second data network corresponding to the second DNAI, and obtain a first tunnel identifier allocated to a first PSA selected for the first network device; send, through the communication interface 1202, a third message to the first network device, the third message comprising the first tunnel identifier; receive, through the communication interface 1202, a fifth message sent by the first network device, the fifth message comprising a second tunnel identifier allocated to the second PSA; and send, through the communication interface 1202, a sixth message to the second PSA, the sixth message comprising the second tunnel identifier, the sixth message being used to instruct the second PSA to establish a tunnel with the first PSA according to the second tunnel identifier.

[0341] Furthermore, the above-described various components can also be used to support other processes performed by the second network device in the embodiments shown in FIGS. 3-10. The beneficial effects can be referred to the previous description and will not be repeated here.

[0342] When the communication apparatus is the third network device, the processor 1201 is configured to: receive, through the communication interface 1202, a seventh message, the seventh message comprising information of a first data network DN and information of a second DN; send, through the communication interface 1202, an eighth message to a fourth network device, the eighth message comprising a first data network access identifier DNAI corresponding to the first DN and not comprising a second DNAI corresponding to the second DN; receive, through the communication interface 1202, a ninth message sent by the fourth network device, the ninth message comprising address information of a first network device, the first DN belonging to a management range of the first network device; and according to the address information, send, through the communication interface 1202, a first message to the first network device, the first message comprising the first data network access identifier DNAI corresponding to the first DN and the second DNAI corresponding to the second DN.

[0343] Furthermore, the above-described various components can also be used to support other processes performed by the third network device in the embodiments shown in FIGS. 3-5 and 7. The beneficial effects can be referred to the previous description and will not be repeated here.

[0344] When the communication device is the third network device, the processor 1201 is configured to: receive, by the communication interface 1202, a seventh message including information of a first data network DN and information of a second DN; send, by the communication interface 1202, a tenth message to a fourth network device, the tenth message including a first data network access identifier DNAI corresponding to the first DN and a second DNAI corresponding to the second DN; receive, by the communication interface 1202, an eleventh message sent by the fourth network device, the eleventh message including address information of a first network device and address information of a second network device, the first DN belonging to a management range of the first network device, and the second DN belonging to a management range of the second network device; and when the first network device and the second network device are different network devices, send, by the communication interface 1202, a first message to the first network device according to the address information of the first network device, the first message including the first DNAI corresponding to the first DN and the second DNAI corresponding to the second DN.

[0345] In addition, the above-mentioned various components can also be used to support other processes performed by the third network device in the embodiments shown in FIG. 3, FIG. 4, FIG. 6, FIG. 8 to FIG. 10. The beneficial effects can refer to the foregoing description, which will not be repeated here.

[0346] Based on the same technical concept, the embodiments of the present application also provide a computer-readable storage medium, which stores computer-readable instructions, when the computer-readable instructions run on a computer, the above-mentioned method embodiments are executed.

[0347] Based on the same technical concept, the embodiments of the present application also provide a computer-readable storage medium, which stores computer-readable instructions, when the computer-readable instructions run on a computer, the above-mentioned method embodiments are executed.

[0348] It should be understood that, in the description of the present application, the words "first", "second", etc. are only used for distinguishing the purpose of description, and cannot be understood as indicating or implying relative importance, nor can it be understood as indicating or implying sequence. In the description of the present application, the reference "one embodiment" or "some embodiments" means that the specific features, structures or characteristics described in connection with the embodiment are included in one or more embodiments of the present application. Therefore, the statements "in one embodiment", "in some embodiments", "in other some embodiments", "in further some embodiments" appearing in different places in the specification are not necessarily all referring to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized. The terms "include", "contain", "have" and their variants mean "including but not limited to", unless otherwise specifically emphasized.

[0349] Those skilled in the art will appreciate that embodiments of the present application can be devised for a method, a system, or a computer program product. Accordingly, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application can take the form of a computer program product on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage devices, etc.) embodying computer-readable program code.

[0350] The present application is described in reference to the flowchart illustrations and / or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations 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, special purpose computer, embedded processor or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart illustrations and / or block diagrams block or blocks.

[0351] These computer program instructions can also be stored in a computer- readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions which implement the function specified in the flowchart illustrations and / or block diagrams block or blocks.

[0352] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart illustrations and / or block diagrams block or blocks.

[0353] While preferred embodiments of the application have been described, those skilled in the art will appreciate that other modifications and variations to the preferred embodiments are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the claims and their equivalents all modifications and variations of the preferred embodiments are intended to be covered.

[0354] Obviously, numerous modifications and variations of the present application are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims and their equivalents, the application can be practiced otherwise than as specifically described.

Claims

1. A communication method characterized by comprising: The method comprises: The first network device receives a first message, the first message comprising a first data network access identifier (DNAI) and a second DNAI, the first message being used to indicate that a tunnel is to be established for a first data network (DN) corresponding to the first DNAI and a second DN corresponding to the second DNAI, the first DN belonging to a management range of the first network device; When the second DN does not belong to the management range of the first network device and belongs to a management range of a second network device, the first network device interacts with the second network device to establish a tunnel between the first DN and the second DN.

2. The method of claim 1, wherein, The first network device interacts with the second network device to establish a tunnel between the first DN and the second DN, comprising: The first network device sends a second message to the second network device, the second message comprising the second DNAI, the second message being used to indicate that a second PDU session anchor (PSA) of the second DN is to be selected and a first tunnel identifier is to be allocated for the selected PSA of the first network device; The first network device receives a third message sent by the second network device, the third message comprising the first tunnel identifier; The first network device sends a fourth message to a first PSA of the first DN, the fourth message comprising the first tunnel identifier, the fourth message being used to instruct the first PSA to establish a tunnel with the second PSA according to the first tunnel identifier; The first network device sends a fifth message to the second network device, the fifth message comprising a second tunnel identifier allocated for the second PSA, so that the second network device instructs the second PSA to establish a tunnel with the first PSA according to the second tunnel identifier.

3. The method of claim 2, wherein, The first message further comprises address information of the second network device; The first network device sends a second message to the second network device, comprising: The first network device sends a second message to the second network device according to the address information of the second network device.

4. The method according to claim 2 or 3, characterized in that, The first message further comprises single network slice selection support information (S-NSSAI), which is used by the first network device to select the first PSA according to the S-NSSAI; The second message further comprises the S-NSSAI, which is used by the second network device to select the second PSA according to the S-NSSAI.

5. The method according to any one of claims 2-4, characterized in that, The first message further comprises an IP address of an application server corresponding to the first DNAI and / or the second DNAI; The fourth message further comprises the IP address; and / or, the second message further comprises the IP address.

6. The method according to any one of claims 1 to 5, characterized in that, The first message is further used to instruct the first network device to determine whether the first DN and the second DN belong to a management range of a same network device.

7. The method according to any one of claims 1 to 5, characterized in that, The first message is further used to instruct that the first DN and the second DN do not belong to a management range of a same network device.

8. A communication method characterized by comprising: The method comprises: The second network device receives a second message sent by a first network device, the second message comprising a second data network access identifier (DNAI); The second network device selects a second PDU session anchor (PSA) of a second data network corresponding to the second DNAI, and obtains a first tunnel identifier allocated to a first PSA selected for the first network device; The second network device sends a third message to the first network device, where the third message includes the first tunnel identifier; The second network device receives a fifth message sent by the first network device, where the fifth message includes a second tunnel identifier allocated to the second PSA; The second network device sends a sixth message to the second PSA, where the sixth message includes the second tunnel identifier, and the sixth message is used to instruct the second PSA to establish a tunnel with the first PSA according to the second tunnel identifier.

9. The method of claim 8, wherein, The second message further includes single network slice selection support information (S-NSSAI), which is used for the second network device to select the second PSA according to the S-NSSAI.

10. The method according to claim 8 or 9, characterized in that, The second message further includes an IP address of an application server corresponding to the first DNAI and / or the second DNAI. The sixth message further includes the IP address.

11. A communication method, comprising: The method comprises: The third network device receives a seventh message, where the seventh message includes information of a first data network (DN) and information of a second DN; The third network device sends an eighth message to a fourth network device, where the eighth message includes a first data network access identifier (DNAI) corresponding to the first DN and does not include a second DNAI corresponding to the second DN; The third network device receives a ninth message sent by the fourth network device, where the ninth message includes address information of a first network device, and the first DN belongs to a management range of the first network device; The third network device sends a first message to the first network device according to the address information, where the first message includes a first data network access identifier (DNAI) corresponding to the first DN and a second DNAI corresponding to the second DN.

12. The method of claim 11, wherein, The first message is further used to instruct the first network device to determine whether the first DN and the second DN belong to a same network device.

13. A method of communication, comprising: The method comprises: The third network device receives a seventh message, where the seventh message includes information of a first data network (DN) and information of a second DN; The third network device sends a tenth message to a fourth network device, where the tenth message includes a first data network access identifier (DNAI) corresponding to the first DN and a second DNAI corresponding to the second DN; The third network device receives an eleventh message sent by the fourth network device, where the eleventh message includes address information of a first network device and address information of a second network device, the first DN belongs to a management range of the first network device, and the second DN belongs to a management range of the second network device; When the first network device and the second network device are different network devices, the third network device sends a first message to the first network device according to address information of the first network device, the first message comprising a first data network access identifier, DNAI, corresponding to the first DN and a second DNAI corresponding to the second DN.

14. The method of claim 13, wherein, The first message is further used to indicate that the first DN and the second DN do not belong to the same network device.

15. The method according to claim 13 or 14, characterized in that, The method further comprises: The third network device determines whether the first network device and the second network device are the same network device according to address information of the first network device and address information of the second network device.

16. The method of claim 15, wherein, The method further comprises: When the first network device and the second network device are the same network device, the third network device sends a first message to the first network device according to address information of the first network device, the first message comprising a first data network access identifier, DNAI, corresponding to the first DN and a second DNAI corresponding to the second DN.

17. The method of claim 16, wherein, The first message is further used to indicate that the first DN and the second DN belong to the same network device.

18. The method according to any one of claims 13-15, characterized by, The first message further comprises address information of the second network device.

19. The method according to any one of claims 11-18, characterized in that, The seventh message further comprises a data network name, DNN, and / or an application function service identifier; The method further comprises: The third network device determines single network slice selection support information, S-NSSAI, corresponding to the DNN according to the DNN and / or the application function service identifier. The first message further comprises the S-NSSAI, which is used to indicate that a PDU session anchor, PSA, is selected according to the S-NSSAI.

20. The method according to any one of claims 11-18, characterized in that, The seventh message further comprises S-NSSAI. The first message further comprises the S-NSSAI, which is used to indicate that a PSA is selected according to the S-NSSAI.

21. The method according to any one of claims 11-20, characterized in that, The seventh message further comprises an IP address of an application server corresponding to the first DNAI and / or the second DNAI; or the method further comprises: the third network device acquires the IP address from a fifth network device. The first message further comprises the IP address.

22. A communications device, characterized by Comprise: A processor coupled to a memory, the memory being configured to store programs or instructions, when the programs or instructions are executed by the processor, the apparatus executes the method of any one of claims 1-7, or executes the method of any one of claims 8-10, or executes the method of any one of claims 11-21.

23. A computer-readable storage medium, characterized in that, The computer readable storage medium stores instructions, when the instructions are run on a computer, the computer executes the method of any one of claims 1-7, or the method of any one of claims 8-10, or the method of any one of claims 11-21.

24. A computer program product comprising instructions, characterized in that, When the instructions are executed on a computer, cause the computer to perform the method of any of claims 1-7, or the method of any of claims 8-10, or the method of any of claims 11-21.

25. A communications device, characterized by Comprising: A unit or module for performing the method of any of claims 1-7, or the method of any of claims 8-10, or the method of any of claims 11-21.

26. A communication system, characterized by Comprising at least one of: A communication device for performing the method of any of claims 1-7; A communication device for performing the method of any of claims 8-10; A communication device for performing the method of any of claims 11-21.

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