CN113473569B

CN113473569B - Discovery method of application server and related device

Info

Publication number: CN113473569B
Application number: CN202010247659.2A
Authority: CN
Inventors: 周晓云
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2020-03-31
Filing date: 2020-03-31
Publication date: 2023-05-12
Anticipated expiration: 2040-03-31
Also published as: CN113473569A; WO2021197175A1

Abstract

The embodiment of the application provides a discovery method of an application server and a related device. The method comprises the following steps: the method comprises the steps that first information of second network equipment is received by first network equipment, wherein the first information comprises identification of an application; the first network equipment determines at least one first access position according to at least the first information, wherein the first access position is a candidate access position for the user equipment to access the application; the first network equipment sends the identification information of the at least one first access position to the second network equipment; the second network device determines the address of the server of the application according to the identification information of the at least one first access position. By implementing the method and the device, the configuration of the DNS AF can be simplified.

Description

Discovery method of application server and related device

Technical Field

The present invention relates to the field of mobile communications, and in particular, to a method and related apparatus for discovering an application server.

Background

In a fifth generation (5 th-generation, 5G) communication system, a User Equipment (UE) establishes a protocol data unit (protocol data unit, PDU) session after accessing a network, and accesses an external Data Network (DN) through the PDU session to interact with an application server deployed in the DN. The application server of the same application can be deployed at a plurality of positions, so that the network can select PDU session anchor points (PDU session anchor, PSA) which are close to the UE and support the UE to access DN according to the access position of the UE, thereby reducing routing detour and network delay.

If the UE accesses the application server, the address of the UE needs to be queried by a domain name system (domain name system, DNS) application function (application function, AF), a preferred access location is determined according to the address of the UE, and the DNS server is queried according to the access location to obtain the address of the application server. This results in a complicated DNS AF configuration.

Disclosure of Invention

The embodiment of the application provides a discovery method of an application server and a related device, which can simplify DNS AF configuration.

In a first aspect, an embodiment of the present application provides a discovery method of an application server, where the method includes: the method comprises the steps that first information of second network equipment is received by first network equipment, wherein the first information comprises identification of an application; the first network equipment determines at least one first access position according to at least the first information, wherein the first access position is a candidate access position for the user equipment to access the application; the first network device sends the identification information of the at least one first access location to the second network device, where the identification information of the at least one first access location is used for determining an address of a server of the application.

In this embodiment of the present application, the second network device is DNS AF, and the candidate access location of the application may be determined by the first network device and sent to the second network device, so that the second network device determines, according to identification information of the candidate access location, an address of a server of the application. By implementing the embodiment of the application, the configuration of the DNS AF can be simplified. In addition, the first network device may determine at least one candidate access location, improving reliability of servers of the DNS-ultimately selected application.

In one possible implementation manner, the first network device is a session management network element; the method further comprises the following steps: the first network receives request information sent by the second network device, where the request information is used to request the first network device to select a user plane network element for the user device to access the application.

In the embodiment of the application, the first network device is a session management network element (session management function, SMF), and since the SMF has configured the topology of the entire network, the SMF determines candidate access locations, and may select an application server for the UE nearby.

In a possible implementation manner, the request information further includes identification information of a second access location, and the at least one first access location includes the second access location.

In this embodiment of the present invention, when the candidate access location is not unique, the second network device may carry the identification information of the access location in the request information, so that the first network device selects, for the user equipment, the user plane network element for accessing the application according to the identification information.

In one possible implementation manner, the determining, by the first network device, at least one first access location according to the first information includes: the first network device determines the at least one first access location according to at least one of data steering control information corresponding to the application, current location information of the user device, an operator policy, and a load condition of a current network.

In the embodiment of the application, the SMF may comprehensively determine the candidate access location according to at least one of the data steering control information corresponding to the application, the current location information of the user equipment, the operator policy, and the load condition of the current network, so that the success rate of the finally selected user plane network element may be improved, the routing detour may be reduced, and the network delay may be reduced.

In one possible implementation manner, the data-oriented control information corresponding to the application is obtained by the first network device from a unified data repository or a policy control network element.

In one possible implementation manner, the first network device is a policy control network element; the first network device determining at least one first access location based at least on the first information, including: the first network device sends second information to the session management network element, wherein the second information is used for requesting the user device to access the access position of the application; the first network device receives the identification information of the at least one access location sent by the session management network element.

In the embodiment of the application, the first network device is a policy control network element (policy control function, PCF), and the PCF initiates third information to the SMF, and then the SMF determines the candidate access location and sends the candidate access location to the PCF. Since the SMF has configured the topology of the entire network, the candidate access locations are determined by the SMF, and an application server may be selected for the UE nearby.

In one possible implementation manner, the identification information of the at least one first access location is determined by the session management network element according to at least one of data steering control information corresponding to the application, current location information of the user equipment, an operator policy, and a load condition of the current network.

In one possible implementation manner, the first network device provides the session management network element with data-oriented control information corresponding to the application.

In one possible implementation manner, the method further includes: the first network device receives request information of the second network device, where the request information is used to request the session management network element to select a user plane network element for the user device to access the application.

In a possible implementation, the identification information of the at least one first access location is at least one data network access identification DNAI and/or subnet information.

In one possible implementation manner, the at least one DNAI is a DNAI corresponding to a user plane network element that may be used by the user equipment to access the application.

In one possible implementation manner, the at least one piece of subnet information is subnet information corresponding to a user plane network element that may be used by the user equipment to access the application.

In one possible implementation, the subnet information includes IPv6 subnet information or IPv4 subnet information.

In one possible implementation, the address of the server of the application is an address sent by a DNS server of a domain name system to the second network device.

In a second aspect, an embodiment of the present application provides a discovery method of an application server, including: the second network equipment sends first information to the first network equipment, wherein the first information comprises an identification of an application; the second network device receives first identification information of at least one first access position sent by the first network device; the first access position is a candidate access position for the user equipment to access the application; the second network device determines an address of the first server of the application according to the first identification information of the at least one first access location.

In one possible implementation manner, the determining, by the second network device, the address of the first server of the application according to the first identification information of the at least one first access location includes: the second network device sends third information to the first Domain Name System (DNS), wherein the third information comprises second identification information of at least one first access position, and the second identification information of the at least one first access position is determined according to the first identification information of the at least one first access position; the second network device receives an address of at least one server of the application corresponding to second identification information of the at least one first access location sent by the first DNS server; the second network device determines an address of the first server from the addresses of the at least one server.

In this embodiment of the present application, the first DNS server is a centralized DNS server, and the DNS AF sends identification information of at least one candidate access location to the DNS server, where the DNS server returns an application server corresponding to the at least one candidate access location.

In one possible implementation manner, the method further includes: the second network device receives first priority information of first identification information of the at least one first access position sent by the network device; the second network device determining an address of the first server of the application according to the first identification information of the at least one first access location, including: the second network device sends third information to the first DNS server, wherein the third information comprises second identification information of at least one first access position, and the second identification information of the at least one first access position is determined according to the first identification information of the at least one first access position; the second network device receives at least one server address of the application corresponding to the second identification information of the at least one first access position sent by the first DNS server; and the second network equipment determines the address of the first server according to the first priority information and at least one server address of the application corresponding to the second identification information of the at least one first access position.

In the embodiment of the application, the second network device can select at least one application server with better performance according to the priority information of the candidate access position, so that the user device can quickly access the application server, and network delay is reduced.

In a possible implementation manner, the third information further includes second priority information corresponding to second identification information of the at least one first access location, where the second priority information is determined according to the first priority information; the address of the at least one first server transmitted by the first DNS server is determined by the first DNS server according to the second priority information.

In the embodiment of the application, the centralized DNS server can perform preliminary screening on at least one candidate access position according to the priority information, and then the second network device screens one or more application servers returned by the centralized DNS server according to the priority information, so that the user device can quickly access the application server, and network delay is reduced.

In one possible implementation manner, the determining, by the second network device, the address of the first server of the application according to the first identification information of the at least one first access location includes: the second network device determines a second DNS server corresponding to a second access position according to the first identification information of the at least one first access position, and sends fourth information to the second DNS server; the fourth information is used for acquiring the address of the first server; the first identification information of the at least one first access location includes first identification information of the second access location; the second network device receives the address of the first server sent by the second DNS server.

In this embodiment of the present application, the second DNS server is a local DNS server, and the DNS AF selects an access location from at least one candidate access location, sends identification information of the access location to a corresponding local DNS server, and determines an address of a final application server by using the local DNS server.

In one possible implementation manner, the method further includes: the second network device receives priority information corresponding to first identification information of the at least one first access position sent by the first network device; the second network device determining a second DNS server corresponding to the second access location according to the first identification information of the at least one first access location, and sending fourth information to the second DNS server, including: the second network device determines the second DNS server corresponding to the second access location according to the priority information corresponding to the first identification information of the at least one first access location, and sends the fourth information to the second DNS server.

In the embodiment of the application, the DNS AF selects the second access position according to the priority of the candidate access position, and selects the current optimal access position, so that the user equipment can be quickly accessed to the application server, and the network delay is reduced.

In one possible implementation manner, the method further includes: and the second network equipment receives fourth information sent by the user equipment, wherein the fourth information is used for requesting the address of the server of the application.

In one possible implementation manner, the method further includes: and the second network equipment sends request information to the first network equipment, wherein the request information is used for requesting the first network equipment to select a user plane network element for accessing the application for the user equipment.

In one possible implementation manner, the request information further includes first identification information of a second access location, the at least one first access location includes the second access location, and the second access location corresponds to an address of the first server.

In one possible implementation manner, the method further includes: the second network device transmits the address of the first server to the user device.

In a possible implementation manner, the first identification information of the at least one first access location is at least one first data network access identification DNAI and/or first subnet information.

In one possible implementation manner, the at least one first DNAI is a DNAI corresponding to a user plane network element that may be used by the user equipment to access the application.

In one possible implementation manner, the one or more first subnet information is subnet information corresponding to a user plane network element that may be used by the user equipment to access the application.

In one possible implementation, the one or more first subnet information includes IPv6 subnet information or IPv4 subnet information.

In a possible implementation manner, the second identification information of the at least one first access location is at least one second DNAI and/or second subnet information, wherein the at least one second DNAI is determined according to the at least one first DNAI, and the at least one second subnet information is determined according to the at least one first DNAI or the first subnet information.

In a third aspect, an embodiment of the present application provides a discovery method of an application server, including: the method comprises the steps that first information of second network equipment is received by first network equipment, wherein the first information comprises identification of an application; the first network equipment determines at least one first access position according to at least the first information, wherein the first access position is a candidate access position for the user equipment to access the application; the first network device sends first identification information of the at least one first access position to the second network device; the second network device determines an address of the first server of the application according to the first identification information of the at least one first access location.

In one possible implementation manner, the first network device is a session management network element; the method further comprises the following steps: the first network device receives request information sent by the second network device, where the request information is used to request the first network device to select a user plane network element for the user device to access the application.

In a possible implementation manner, the request information further includes identification information of a second access location, and the at least one access location includes the second access location.

In one possible implementation manner, the method further includes: the first network device sends first priority information of first identification information of the at least one first access position to the second network device; the second network device determining an address of the first server of the application according to the first identification information of the at least one first access location, including: the second network device sends third information to the first DNS server, wherein the third information comprises second identification information of at least one first access position, and the second identification information of the at least one first access position is determined according to the first identification information of the at least one first access position; the second network device receives at least one server address of the application corresponding to the second identification information of the at least one first access position sent by the first DNS server; and the second network equipment determines the address of the first server according to the first priority information and at least one server address of the application corresponding to the second identification information of the at least one first access position.

In one possible implementation manner, the method further includes: the first network device sends priority information corresponding to first identification information of the at least one first access position to the second network device; the second network device determining a second DNS server corresponding to the second access location according to the first identification information of the at least one first access location, and sending fourth information to the second DNS server, including: the second network device determines the second DNS server corresponding to the second access location according to the priority information corresponding to the first identification information of the at least one first access location, and sends the fourth information to the second DNS server.

In one possible implementation manner, the method further includes: and the second network equipment receives fifth information sent by the user equipment, wherein the fifth information is used for requesting the address of the server of the application.

In a possible implementation manner, the first identification information of the one or more access locations is one or more first data network access identifications DNAI and/or first subnet information.

In one possible implementation manner, the at least one first subnet information is subnet information corresponding to a user plane network element that may be used by the user equipment to access the application.

The advantages of the third aspect can be seen from the advantages of the first aspect and the second aspect, and are not described in detail herein.

In a fourth aspect, embodiments of the present application provide a network device, including: a receiving unit, configured to receive first information sent by a second network device, where the first information includes an identifier of an application; a determining unit, configured to determine at least one first access location according to at least the first information, where the first access location is a candidate access location for the user equipment to access the application; and the sending unit is used for sending the identification information of the at least one first access position to the second network equipment, wherein the identification information of the at least one first access position is used for determining the address of the server of the application.

In one possible implementation manner, the network device is a session management network element; the receiving unit is further configured to: and receiving request information sent by the second network equipment, wherein the request information is used for requesting the network equipment to select a user plane network element for accessing the application for the user equipment.

In a possible implementation manner, the determining unit is specifically configured to: and determining the at least one first access position according to at least one of data guiding control information corresponding to the application, current position information of the user equipment, operator strategies and load conditions of the current network.

In one possible implementation, the data-oriented control information corresponding to the application is obtained by the network device from a unified data repository or a policy control network element.

In one possible implementation manner, the network device is a policy control network element; the above-mentioned determination unit is specifically for: sending second information to a session management network element, wherein the second information is used for requesting the user equipment to access the access position of the application; and receiving the identification information of the at least one access position sent by the session management network element.

In a possible implementation manner, the network device provides the session management network element with data-oriented control information corresponding to the application.

In a possible implementation manner, the receiving unit is further configured to: and receiving request information of the second network equipment, wherein the request information is used for requesting the session management network element to select a user plane network element for accessing the application for the user equipment.

The advantages of the fourth aspect may be seen in the advantages of the first aspect and are not described in detail herein.

In a fifth aspect, embodiments of the present application provide a network device, including: a sending unit, configured to send first information to a first network device, where the first information includes an identifier of an application; a receiving unit, configured to receive first identification information of at least one first access location sent by the first network device; the first access position is a candidate access position for the user equipment to access the application; and the determining unit is used for determining the address of the first server of the application according to the first identification information of the at least one first access position.

In a possible implementation manner, the determining unit is specifically configured to: transmitting third information to the first Domain Name System (DNS), wherein the third information comprises second identification information of at least one first access position, and the second identification information of the at least one first access position is determined according to the first identification information of the at least one first access position; receiving an address of at least one server of the application corresponding to second identification information of the at least one first access position sent by the first DNS server; and determining the address of the first server from the addresses of the at least one server.

In a possible implementation manner, the receiving unit is further configured to: receiving first priority information of first identification information of the at least one first access position sent by the network equipment; the above-mentioned determination unit is specifically for: transmitting third information to the first DNS server, wherein the third information comprises second identification information of at least one first access position, and the second identification information of the at least one first access position is determined according to the first identification information of the at least one first access position; receiving at least one server address of the application corresponding to second identification information of the at least one first access position sent by the first DNS server; and determining the address of the first server according to the at least one server address of the application corresponding to the first priority information and the second identification information of the at least one first access position.

In a possible implementation manner, the determining unit is specifically configured to: determining a second DNS server corresponding to the second access position according to the first identification information of the at least one first access position, and sending fourth information to the second DNS server; the fourth information is used for acquiring the address of the first server; the first identification information of the at least one first access location includes first identification information of the second access location; the second network device receives the address of the first server sent by the second DNS server.

In one possible implementation manner, the receiving unit is specifically configured to: receiving priority information corresponding to first identification information of the at least one first access position sent by the first network device; the above-mentioned determination unit is specifically for: and determining the second DNS server corresponding to the second access position according to the priority information corresponding to the first identification information of the at least one first access position, and sending the fourth information to the second DNS server.

In a possible implementation manner, the receiving unit is further configured to: and receiving fifth information sent by the user equipment, wherein the fifth information is used for requesting the address of the server of the application.

In a possible implementation manner, the sending unit is further configured to: and sending request information to the first network device, wherein the request information is used for requesting the first network device to select a user plane network element for accessing the application for the user device.

In a possible implementation manner, the sending unit is further configured to: and sending the address of the first server to the user equipment.

The advantages of the fifth aspect may be seen in the advantages of the second aspect and are not described in detail herein.

In a sixth aspect, embodiments of the present application provide a communication system, including: a first network device and a second network device; the first network device is a network device provided by the fourth aspect or any one of the possible implementation manners of the fourth aspect of the embodiments of the present application, and the second network device is a network device provided by the fifth aspect or any one of the possible implementation manners of the fifth aspect of the embodiments of the present application.

The advantages of the sixth aspect can be seen in the advantages of the first aspect and the second aspect, and are not described here.

In a seventh aspect, embodiments of the present application provide a network device, including: a processor, when the processor invokes a computer program in memory, the method of the first aspect or any implementation of the first aspect is performed.

The advantages of the seventh aspect may be seen by the advantages of the first aspect and are not described in detail herein.

In an eighth aspect, embodiments of the present application provide a network device, including: a processor, when the processor invokes a computer program in memory, the method as described above in the second aspect or any implementation of the second aspect is performed.

The advantages of the eighth aspect may be seen by the advantages of the second aspect and are not described in detail herein.

In a ninth aspect, an embodiment of the present application provides a chip, where the chip includes at least one processor, a memory, and an interface circuit, where the memory, the transceiver, and the at least one processor are interconnected by a line, and where the at least one memory stores instructions; the instructions, when executed by the processor, implement the first aspect or any implementation of the first aspect.

The advantages of the ninth aspect may be seen in the advantages of the first aspect and are not described in detail herein.

In a tenth aspect, embodiments of the present application provide a chip, where the chip includes at least one processor, a memory, and an interface circuit, where the memory, the transceiver, and the at least one processor are interconnected by a line, and where the at least one memory stores instructions; the instructions, when executed by the processor, implement the second aspect or any implementation of the second aspect.

The advantages of the tenth aspect may be seen in the advantages of the second aspect and are not described in detail herein.

In an eleventh aspect, embodiments of the present application provide a computer-readable storage medium having instructions stored therein, which when run on a computer or a processor, implement a method provided by the first aspect or any implementation manner of the first aspect of the embodiments of the present application.

The advantages of the eleventh aspect may be seen in the advantages of the first aspect and are not described in detail herein.

In a twelfth aspect, embodiments of the present application provide a computer-readable storage medium having instructions stored therein, which when run on a computer or processor, implement a method provided by the second aspect or any implementation manner of the second aspect.

The advantages of the twelfth aspect may be found in the advantages of the second aspect and are not described in detail herein.

In a thirteenth aspect, embodiments of the present application provide a computer program product which, when run on a network device, implements the method provided by the first aspect or any implementation manner of the first aspect.

The advantages of the thirteenth aspect may be seen in the advantages of the first aspect and are not described in detail herein.

In a fourteenth aspect, embodiments of the present application provide a computer program product which, when run on a network device, implements the method provided by the second aspect or any implementation of the second aspect.

The advantages of the fourteenth aspect may be found in the advantages of the second aspect and are not described in detail herein.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below.

Fig. 1 is a schematic diagram of a network architecture according to an embodiment of the present application;

fig. 2 is a flow chart of a discovery method of an application server according to an embodiment of the present application;

fig. 3 is a flowchart of another discovery method of an application server according to an embodiment of the present application;

fig. 4 is a flowchart of another discovery method of an application server according to an embodiment of the present application;

fig. 5 is a schematic structural diagram of a network device according to an embodiment of the present application;

fig. 6 is a schematic structural diagram of another network device according to an embodiment of the present application;

Fig. 7 is a schematic structural diagram of a communication system according to an embodiment of the present application;

fig. 8 is a schematic structural diagram of still another network device according to an embodiment of the present application.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present application more apparent, the present application will be described in further detail with reference to the accompanying drawings.

The terms first and second and the like in the description, in the claims and in the drawings, are used for distinguishing between different objects and not for describing a particular sequential order. Furthermore, the terms "comprise" and "have," as well as any variations thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those listed steps or elements but may include other steps or elements not listed or inherent to such process, method, article, or apparatus.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.

In the present application, "at least one (item)" means one or more, "a plurality" means two or more, and "at least two (items)" means two or three or more, and/or "for describing an association relationship of an association object, three kinds of relationships may exist, for example," a and/or B "may represent: only a, only B and both a and B are present, wherein a, B may be singular or plural. The character "/" generally indicates that the context-dependent object is an "or" relationship. "at least one of" or the like means any combination of these items, including any combination of single item(s) or plural items(s). For example, at least one (one) of a, b or c may represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", wherein a, b, c may be single or plural.

Embodiments of the present application are described below with reference to the accompanying drawings.

First, a network architecture according to an embodiment of the present application will be described.

The discovery method of the application processor provided by the application processor can be applied to various communication systems, such as an internet of things (internet of things, ioT) system, a narrowband internet of things (narrow band internet of things, NB-IoT) system, a long term evolution (long term evolution, LTE) system, a fifth generation (5 th-generation, 5G) communication system, a hybrid architecture of LTE and 5G, a new wireless (NR) system of 5G, a new communication system in future communication development, and the like.

Referring to fig. 1, fig. 1 is a schematic diagram of a network architecture provided in an embodiment of the present application, and each part involved in fig. 1 is as follows:

the terminal device 110, also referred to as a User Equipment (UE), a terminal, etc. The terminal device is a device having a wireless transceiving function, and can communicate with one or more Core Networks (CNs) via AN access network device in a (radio) access network (R) AN) 120. Can be deployed on land, including indoors or outdoors, hand-held, wearable, or vehicle-mounted; the device can also be deployed on the water surface, such as a ship, etc.; but may also be deployed in the air, for example on an aircraft, balloon or satellite, etc. The terminal device may be a mobile phone, a tablet (Pad), a computer with a wireless transceiving function, a Virtual Reality (VR) terminal device, an augmented reality (augmented reality, AR) terminal device, a wireless terminal in industrial control (industrial control), a wireless terminal in unmanned driving (self driving), a wireless terminal in remote medical (remote medium), a wireless terminal in smart grid (smart grid), a wireless terminal in transportation security (transportation safety), a wireless terminal in smart city (smart city), a wireless terminal in smart home (smart home), or the like.

A (radio) access network (R) AN 120 for providing AN access function for authorized terminal devices in a specific area, and capable of using transmission tunnels of different qualities according to the level of the terminal devices, the demand of services, and the like. For example, the (R) AN may manage radio resources, provide access services for the terminal device, and further complete forwarding of control information and/or data information between the terminal device and a Core Network (CN).

The access network device in the embodiment of the present application is a device that provides a wireless communication function for a terminal device, and may also be referred to as a network device. The access network device may include: a next generation base station node (next generation node basestation, gNB) in a 5G system, an evolved node B (eNB) in long term evolution (long term evolution, LTE), a radio network controller (radio network controller, RNC), a Node B (NB), a base station controller (base station controller, BSC), a base transceiver station (base transceiver station, BTS), a home base station (e.g., home evolved nodeB, or home node B, HNB), a baseband unit (BBU), a transmission point (transmitting and receiving point, TRP) (or referred to as a transmission reception point), a transmission point (transmitting point, TP), a small base station device (pico), a mobile switching center, or a network device in a future network, and the like. It will be appreciated that the specific type of access network device in embodiments of the present application is not limited. In systems with different radio access technologies, the names of devices with access network device functions may vary.

User plane function network elements (user plane function, UPF) network functions 130 for packet routing and forwarding, quality of service (quality of service, qoS) handling of user plane data, and the like.

A Data Network (DN) network function 140 for providing a network for transmitting data.

The access management function (access and mobility management function, AMF) network function 150 is mainly used for mobility management and access management, and may be used for implementing functions other than session management, such as lawful interception and access authorization/authentication, among the functions of the mobility management entity (mobility management entity, MME). It can be understood that the AMF network function is hereinafter abbreviated as AMF. In this embodiment, the AMF network function includes a remote AMF and a relay AMF, where the remote AMF is: an AMF for providing services to the remote UE; the relay AMF is: AMF for providing services to relay UE.

The session management function network element (session management function, SMF) 160 is mainly used for session management, network interconnection protocol (internet protocol, IP) address allocation and management of terminal devices, selection of termination points for manageable user plane functions, policy control and charging function interfaces, downlink data notification, etc. In this application, the session management function network element may also be referred to as a session management network element.

Policy control network function 170, such as a policy control function network element (policy control function, PCF), a unified policy framework for directing network behavior, providing policy rule information for control plane functions (e.g., AMF, SMF network functions, etc.), etc. In this application, the policy control function network element may also be referred to as a policy control network element.

An authentication server function (authentication server function, AUSF) 180 for authentication service, generating a key to enable bidirectional authentication of the terminal device, supporting a unified authentication framework.

The unified data management (unified data management, UDM) network function 190 may be used to handle terminal device identification, access authentication, registration, mobility management, and the like. It is to be understood that hereinafter the UDM network function is simply referred to as UDM.

An application function (application function, AF) 1100 for performing application-affected data routing, access network opening functions, policy control with policy framework interactions, etc.

A network slice selection function (network slice selection function, NSSF) operable to determine network slice instances, select AMF network functions, and the like.

The network storage network functions, such as including network registration functions (network repository function, NRF), may be used to maintain real-time information for all network function services in the network.

It will be appreciated that the network architecture shown in fig. 1 may also include a proximity services function (ProSe function) that may be used to perform management and control of ProSe traffic, and so on.

The mobility management network function in the embodiment of the present application may be the AMF network function 150 shown in fig. 1, or may be another network function with the AMF network function 150 in the future communication system. Alternatively, the mobility management network function in the present application may also be a mobility management entity (mobility management entity, MME) in long term evolution (long term evolution, LTE), etc.

For convenience of description, the AMF network function 150 is abbreviated as AMF, and the terminal device 110 is referred to as UE, that is, the AMF described later in the embodiment of the present application may be replaced by a mobility management network function or a core network device, and the UE may be replaced by a terminal device.

The network architecture (for example, 5G network architecture) shown in fig. 1 adopts a service-based architecture, and a traditional network element function (or network function) is split into a plurality of self-contained, self-managed and reusable network function service modules based on network function virtualization (network function virtualization, NFV) technology, and customized network function reconstruction can be realized by flexibly defining a service module set, and a service flow is formed by a unified service call interface. The network architecture diagram shown in fig. 1 may be understood as a service-based 5G network architecture diagram in a non-roaming scenario. For roaming scenarios, the embodiments of the present application apply equally.

It will be appreciated that the terms described above may have different names in different fields or different standards, and thus the names shown above should not be construed as limiting the embodiments of the present application. The network functions or functions described above may be either network elements in a hardware device, software functions running on dedicated hardware, or virtualized functions instantiated on a platform (e.g., a cloud platform).

The following describes in detail the discovery method of the application server provided in the embodiment of the present application.

Referring to fig. 2, fig. 2 is a flowchart of a discovery method of an application server according to an embodiment of the present application. The method may be applied to the network architecture shown in fig. 1. As shown in fig. 3, the method includes:

s201: the first network device receives first information sent by the second network device.

Specifically, the second network device is a DNS AF. The first network device is an SMF or PCF.

Specifically, before S201, the UE may transmit DNS Request information (DNS Request) to the DNS AF. The request information may carry a fully qualified domain name (fully qualified domain name, FQDN) for the application. The DNS AF may check, based on the FQDN, whether the application exists in a service layer agreement (service layer agreement, SLA), i.e. a business agreement between the application and the operator. If so, the DNS AF sends a preferred access location information request for the application to the SMF. In the embodiment of the present application, the request may be referred to as first information. The first information may include an application identification (application identity, APP ID). The first information may further include an IP address of the UE, which may be an IPv4 address or an IPv6 address.

S202: the first network device determines at least one first access location based at least on the first information.

Specifically, the first access location is a candidate access location where the UE accesses the application, that is, the UE may access the DN through a UPF corresponding to the access location, and an application server corresponding to the application is deployed in the DN. When the number of the first access positions is a plurality of, the access position of the UE for accessing the application is one of the plurality of first access positions. In particular implementations, the SMF may select the UPF as a PDU session anchor (PDU session anchor, PSA) for the PDU session established by the UE. In summary, the access location may be used to determine a UPF for the UE to access the application. It is known that the first access location is the location of the user plane through which the UE accesses the application, not the location of the UE itself. Wherein the location of the user plane may be represented by subnet information and/or a data network access identity (data network access identifier, DNAI).

Optionally, the first network device is an SMF. The SMF may determine the at least one first access location based on at least one of: and applying corresponding data guiding control information, current position information of the UE, operator strategies, load conditions of the current network and the like.

The application-specific data-oriented control information defines location information (data network access identifier (data network access identifier, DNAI)) corresponding to the DN of the deployment application server, a time (time validity condition) corresponding to access to the application server, location information (time validity condition) of the UE, and the like. Thus, if there is data-oriented control information to which the application corresponds, the SMF may determine an applicable DNAI according to the current time and the current location of the UE, etc. The SMF may also determine the applicable DNAI based on the operator's policy (e.g., the operator has configured a data-oriented application for this application) and the current network load situation.

Wherein the application corresponding data-directed control information may be provided by the UDR. Specifically, the method can directly interact with the UDR to obtain data guiding control information corresponding to the application stored in the UDR. Or the SMF interacts with the PCF to acquire the data guiding control information corresponding to the application acquired by the PCF from the UDR.

Optionally, the first network device is a PCF. The PCF may send a message to the SMF requesting the UE to access the access location of the application, and the SMF may determine the at least one first access location based on at least one of: and applying corresponding data guiding control information, current position information of the UE, operator strategies, load conditions of the current network and the like. The SMF sends the identification information of the at least one first access position to the PCF. Wherein, the application corresponding data guiding control information can be provided by PCF. Specifically, the SMF interacts with the PCF to obtain data-oriented control information corresponding to the application obtained by the PCF from the UDR.

S203: the first network device transmits identification information of at least one first access location to the second network device.

In particular, the identification information of the first access location may be subnet information and/or a data network access identification (data network access identifier, DNAI). For an IPv4 network, the subnet information is the NAT public network IP address range corresponding to the candidate UPF. For an IPv6 network, the subnet information is the range of IPv6 addresses or prefixes corresponding to candidate UPFs.

Further, the first network device may further determine priority information corresponding to each of the at least one first access location, and send the priority information to the DNS AF. The priority information of each first access location may be determined according to various factors such as the route path optimization degree, the operator policy, the network load, and the like. For example, the shorter the routing path, the higher the priority corresponding to the first access location.

S204: the second network device determines an address of a server of the application based on the identification information of the at least one first access location.

Specifically, the DNS AF determines the address of the server of the application can be divided into two scenarios, and the manner of determination in different scenarios is different. The following description can be seen in particular:

Scene one: network use local DNS server

In this scenario, the DNS AF may select, according to the local configuration and the first access location corresponding to the identification information of each first access location, one access location from the at least one first access location, and further select a local DNS server corresponding to the access location. The DNS AF may send a DNS request (request) message to the local DNS server, which may carry the APP FQDN. The local DNS server may determine the address of the first application server and return the address of the first application server to the second network device DNS AF. The address of the first application server is the address of the application server to which the UE is finally connected.

Specifically, the DNS AF selects a first access location according to the local configuration, and determines a corresponding local DNS server. And the DNS AF sends DNS request information to the local DNS server, and if the local DNS server returns a successful response, the DNS AF determines that the server address carried in the response message is a first application server address, and the first access position is a second access position.

And the local DNS server returns a failure response, and the DNS AF selects a first access position to query. In the embodiment of the present application, the DNS request information described above may be referred to as fourth information. In this embodiment of the present application, the access location finally selected by the DNS AF may be referred to as a second access location. The local DNS server is referred to as a second DNS server.

It can be seen that if the first network sets the identification information of the determined first access location to be DNAI, the DNS AF further needs to determine subnet information according to DNAI.

Further, the DNS AF may select an access location from the at least one first access location according to the local configuration and priority information of the at least one first access location, and further select a local DNS server corresponding to the access location.

Specifically, the DNS AF determines a corresponding local DNS server according to a first access location with the highest priority, and sends DNS request information to the local DNS server, if the local DNS server returns a successful response, the DNS AF determines that the server address carried in the response message is a first application server address, and the first access location is the second access location. If the local DNS server returns a failure response, the DNS AF selects a first access position with a second highest priority for inquiring according to the priority information.

Scene II: network usage centralized DNS server

In this scenario, the DNS AF may send a DNS request (request) message to the centralized DNS server, where the message may carry the identification information of the at least one first access location. The method can be carried by enhancing DNS client subnet (EDNS client subnet, ECS) options, and if the identification information of the access location is subnet information, each ECS option can include the subnet information returned in S203. If the identification information of the access location is DNAI, the dnaf needs to determine subnet information according to DNAI. In the embodiment of the present application, the DNS request information described above may be referred to as third information. In the embodiment of the present application, the centralized DNS server may be referred to as a first DNS server.

Optionally, if the first network device may further determine priority information corresponding to each of the at least one first access location and send the priority information to the DNS AF, the second information sent by the DNS AF to the centralized DNS server may also carry the priority information corresponding to each of the at least one first access location. In this embodiment of the present application, the priority information sent by the first network to the DNS AF may be referred to as first priority information, and the priority information sent by the DNS AF to the centralized DNS server may be referred to as second priority information.

After the centralized DNS server receives the DNS request information, a part of candidate application servers may be selected according to the configuration and the second priority information, and the addresses of the candidate application servers may be returned to the DNS AF, where the DNS AF determines the address of the first application server according to the first priority information. The DNS AF selects an application server address with the highest priority from the returned addresses of the candidate application servers as a first application server address, so that a first access position corresponding to the server address is a second access position.

Alternatively, instead of making a preliminary selection, the centralized DNS server may directly determine the address of the application server corresponding to the at least one first access location.

After the DNS AF determines the address of the first application server, the DNS AF may send data steering control execution (traffic steering control performing) request information to the first network device. When the first network device is a PCF, the PCF may further send the request information to the SMF. The request information may be used to select a user plane network element for the UE to access the application.

Optionally, when the candidate first access location is unique, the SMF may directly select, for the UE, a user plane network element for accessing the application according to the identification information of the candidate location determined by the SMF.

Optionally, when the candidate first access location is not unique, the request information may further carry identification information of a second access location, and the SMF selects, for the UE, a user plane network element for accessing the application according to the identification information of the second access location. Wherein the second access location is an access location that is ultimately selected from a plurality of candidate first access locations. The SMF selects the corresponding UPF of the identification information (DNAI or subnet information) of the finally selected second access position as the PSA for the PDU session established by the UE according to the request information. If the subnet information is IPv6 subnet information, the SMF distributes a corresponding IPv6 address prefix for the UE.

In addition, the DNS AF may further send a DNS response message to the UE, where the response message carries an address of the first application server. The UE may establish a connection with the first application server via the selected PSA to communicate with the first application server.

By implementing the embodiment of the application, as the SMF is configured with the topological structure of the whole network, the SMF determines the candidate access position, the current condition of the network can be better considered, the configuration of the DNS AF is simplified, the situation that the DNS selected server is unavailable can be avoided, the success rate of accessing the application server by the UE is improved, and the network delay is reduced.

Not limited to the UE sending DNS request to the DNS AF, in a specific implementation, the embodiments of the present application also support DNS over HTTPS, and the UE sending request information of DNS over HTTS to the DNS AF. The embodiments of the present application are not limited in this regard.

The first network device involved in the embodiment of the present application may be an SMF or a PCF. In order to understand the discovery method of the application server provided in the embodiment of the present application in more detail, the detailed discovery method of the application server when the first network device is an SMF or PCF is described below.

Referring to fig. 3, fig. 3 is a flowchart of a discovery method of an application server provided in an embodiment of the present application when a first network device is an SMF. As shown in fig. 3, the method includes:

S301: the UE establishes a PDU session.

Specifically, the UE establishes a PDU session, the network selects a PSA, and assigns an IP address to the UE.

Alternatively, the SMF may acquire data steering control information corresponding to the application (traffic steering control data). The data steering control information may specifically include information for identifying the data, a user plane access identity representing an access DN, and a data steering policy corresponding to the DN configured on the UPF. The information for identifying the data may be, for example, a triplet of application data, an APP ID, or the like. The user plane access identity representing the access DN may be DNAI. The data steering policy corresponding to the configuration on the UPF may be a data routing document identification (traffic steering profile ID).

Optionally, the data-oriented control information may further include a space availability condition and a time availability condition. Wherein the space availability condition may be used to represent a UE location of the application data steering information (traffic steering information). A time validity condition, which is typically a time interval, may be used to represent the time of the application traffic steering information.

S302: the UE sends DNS request information to the DNS AF.

Specifically, after the UE establishes a PDU session, an application wants to establish a connection with a border application server, and the UE may send Request information (DNS Request) to the DNS AF, where the Request information may carry the FQDN of the application, and is used to Request an address of the server of the application. In the embodiment of the present application, the request information may be referred to as fifth information.

S303: the DNS AF sends first information to the SMF.

Specifically, the DNS AF may check whether the application has an SLA based on the FQDN. If so, the DNS AF sends a preferred access location information request for the application to the SMF. In the embodiment of the present application, the request may be referred to as first information. The first information may include an APP ID. The first information may further include an IP address of the UE, which may be an IPv4 address or an IPv6 address.

S304: the SMF obtains data-oriented control information corresponding to the application from the UDR.

Specifically, the SMF may determine the UE according to the IP address of the UE. If the SMF does not obtain the data-oriented control information corresponding to the application in S301, the SMF may interact with the UDR to obtain the data-oriented control information corresponding to the application stored in the UDR. Or the SMF may interact with the PCF to obtain data-oriented control information corresponding to the application obtained by the PCF from the UDR.

S305: the SMF determines at least one first access location based at least on the first information.

Specifically, the SMF may determine at least one first access location according to at least one of: and applying corresponding data guiding control information, current position information of the UE, operator strategies, load conditions of the current network and the like.

If there is data-oriented control information to which the application corresponds, the SMF may determine an applicable DNAI according to the current time and the current location of the UE, etc. The SMF may also determine the applicable DNAI based on the operator's policy (e.g., the operator has configured a data-oriented application for this application) and the current network load situation.

The first access location is a candidate access location where the UE accesses the application, that is, the UE may access the DN through a UPF corresponding to the access location, and an application server corresponding to the application is deployed in the DN. When the number of the first access positions is a plurality of, the access position of the UE access application is one of the plurality of first access positions. In particular implementations, the SMF may select the UPF as a PDU session anchor (PDU Session Anchor, PSA) for the PDU session established by the UE. In summary, the access location may be used to determine a UPF for the UE to access the application.

In particular, the identification information of the first access location may be a subnet address and/or DNAI. For an IPv4 network, the subnet information is the NAT public network IP address range corresponding to the candidate UPF. For an IPv6 network, the subnet information is the range of IPv6 addresses or prefixes corresponding to candidate UPFs.

S306: the SMF sends identification information of at least one first access location to the DNS AF.

Specifically, after the SMF sends the identification information of at least one first access location to the DNS AF, the DNS AF may determine an address of a server of the application according to the identification information of the at least one first access location. The identification information of the first access location may be subnet information and/or DNAI.

Further, the SMF may further determine priority information corresponding to each of the at least one first access location, and send the priority information to the DNS AF. The priority information of each first access location may be determined according to various factors such as the route path optimization degree, the operator policy, the network load, and the like. For example, the shorter the routing path, the higher the priority corresponding to the first access location.

The DNS AF determines the address of the server of the application can be divided into two scenarios, with the manner of determination being different in different scenarios. The following description can be seen in particular:

scene one: network using local DNS server (S307-S309)

S307: the DNS AF sends fourth information to the local DNS server.

Specifically, the DNS AF may select, according to the local configuration, an access location from the at least one first access location, and further select a local DNS server corresponding to the access location. The DNS AF may send a DNS request (request) message to the local DNS server, which may carry the APP FQDN. In the embodiment of the present application, the DNS request information described above may be referred to as fourth information. In this embodiment of the present application, the access location finally selected by the DNS AF may be referred to as a second access location. The local DNS server is referred to as a second DNS server.

It is known that if the identification information of the access location sent by the SMF in S306 is DNAI, the DNS AF needs to determine the subnet information according to the DNAI.

Specifically, the DNS AF selects a first access location according to the local configuration, and determines a corresponding local DNS server. And the DNS AF sends DNS request information to the local DNS server, and if the local DNS server returns a successful response, the DNS AF determines that the server address carried in the response message is a first application server address, and the first access position is a second access position. And the local DNS server returns a failure response, and the DNS AF selects a first access position to query.

S308: the local DNS server determines an address of the first application server.

Specifically, the local DNS server determines an address of a first application server, where the address of the first application server is the address of the application server that the UE finally accesses.

S309: the local DNS server sends the address of the first application server to the DNS AF.

Specifically, the local DNS server may return a response message to the DNS AF, where the response message may carry an address of the first application server.

Scene II: network using centralized DNS server (S310-S313)

S310: the DNS AF sends third information to the centralized DNS server.

Specifically, the DNS AF may send a DNS request (request) message to the centralized DNS server, where the message may carry the identification information of the at least one first access location. The ECS options may specifically be carried, and if the identification information of the access location is subnet information, each ECS option may include the subnet information returned in S306. If the identification information of the access location is DNAI, the DNS AF needs to determine subnet information according to DNAI. In the embodiment of the present application, the DNS request information described above may be referred to as third information. In the embodiment of the present application, the centralized DNS server may be referred to as a first DNS server.

Optionally, if the SMF may further determine the priority information corresponding to each of the at least one first access location and send the priority information to the DNS AF, the third information sent by the DNS AF to the centralized DNS server may also carry the priority information corresponding to each of the at least one first access location. In this embodiment of the present application, priority information sent by the SMF to the DNS AF may be referred to as first priority information, and priority information sent by the DNS AF to the centralized DNS server may be referred to as second priority information.

S311: the centralized DNS server initially selects at least one application server.

Alternatively, the centralized DNS server may select a part of the candidate application servers according to the configuration and the second priority information described above.

The DNS AF selects an application server address with the highest priority from the returned addresses of the candidate application servers as a first application server address, so that a first access position corresponding to the server address is a second access position.

S312: the centralized DNS server sends the address of the at least one application server to the DNS AF.

Specifically, the centralized DNS server may send the determined address of the at least one candidate application server to the DNS AF, so that the DNS AF further selects an application server, from the candidate application servers, to which the UE finally accesses.

Alternatively, the identification information of the access location sent by the SMF to the DNS AF may be different from the identification information of the access location sent by the DNS AF to the centralized DNS server or the local DNS server. In the embodiment of the present application, the identification information of the access location sent by the SMF to the DNS AF may be referred to as first identification information, and the identification information of the access location sent by the DNS AF to the centralized DNS server or the local DNS server may be referred to as second identification information. The DNS AF may map the first identification information to the second identification information.

In particular, the first identification information may be first DNAI and/or first subnet information. The second identification information may be second DNAI and/or second subnet information. The second DNAI may be determined according to the first DNAI and the second subnet information may be determined according to the first DNAI or the first subnet information. That is, when the first identification information is DNAI, the DNS AF may map DNAI to subnet information.

S313: the DNS AF determines an address of the first server from the addresses of the at least one application server.

Specifically, the DNS AF may be determined according to priority information of the first access location corresponding to the address of the candidate application server.

S314: the DNS AF sends request information to the SMF.

Specifically, the DNS AF sends data steering control enforcement (traffic steering control performing) request information to the SMF, which request information can be used to select a user plane network element for the UE to access the application.

Optionally, when the candidate first access location is not unique, the request information may further carry identification information of a second access location, and the SMF selects, for the UE, a user plane network element for accessing the application according to the identification information of the second access location. Wherein the second access location is an access location that is ultimately selected from a plurality of candidate first access locations.

S315: SMF is inserted into PSA.

Specifically, the SMF selects, as the PSA, a UPF corresponding to identification information (DNAI or subnet information) of the finally selected second access location for the PDU session established by the UE according to the above request information. If the subnet information is IPv6 subnet information, the SMF distributes a corresponding IPv6 address prefix for the UE.

S316: the DNS AF sends the address of the first application server to the UE.

Specifically, the DNS AF may send a DNS response message to the UE, where the response message carries the address of the first application server. The UE may establish a connection with the first application server via the selected PSA to communicate with the first application server.

Referring to fig. 4, fig. 4 is a flowchart of a discovery method of an application server provided in the embodiment of the present application when a first network device is a PCF. As shown in fig. 4, the method includes:

s401: the UE establishes a PDU session.

Optionally, the PCF may obtain application-corresponding data-directed control information (traffic steering control data). The data steering control information may specifically include information for identifying the data, a user plane access identity representing an access DN, and a data steering policy corresponding to the DN configured on the UPF. The information for identifying the data may be, for example, a triplet of application data, an APP ID, or the like. The user plane access identity representing the access DN may be DNAI. The data steering policy corresponding to the configuration on the UPF may be a data routing document identification (traffic steering profile ID).

Optionally, the data-oriented control information may further include a space availability condition and a time availability condition. Wherein the space availability condition may be used to represent a UE location of the application data steering information (traffic steering information). A time validity condition, which is typically a time interval, may be used to represent the time of the application LAN traffic steering information.

S402: the UE sends DNS request information to the DNS AF.

Specifically, S402 corresponds to S302, and is not described here.

S403: the DNS AF sends first information to the PCF.

In particular, the DNS AF may check, based on the FQDN, whether the application has a traffic layer agreement (service layer agreement, SLA). If so, the DNS AF sends a request for preferred access location information of the application to the PCF. In the embodiment of the present application, the request may be referred to as first information. The first information may include an APP ID. The first information may further include an IP address of the UE, which may be an IPv4 address or an IPv6 address.

S404: the PCF sends the second information to the SMF.

Specifically, if the PCF itself cannot determine the candidate access location information, the PCF may send the second information to the SMF. The second information may be used to request the UE to access an access location of the application, where the second information may carry a data steering control policy (traffic steering control policy), where the policy may include information such as an APP ID, DNAI list, etc.

In one possible embodiment, the PCF itself may determine candidate access location information. If the PCF fails to obtain the data-oriented control information corresponding to the application in S401, the PCF may interact with the UDR to obtain the data-oriented control information corresponding to the application stored in the UDR. The PCF may specify a data steering control policy based on the steering control information, where the policy may include information such as APP ID, DNAI list, etc.

In the embodiment of the present application, the PCF itself cannot determine candidate access location information is taken as an example for explanation.

S405: the SMF obtains data-oriented control information corresponding to the application from the PCF.

Specifically, if the SMF cannot obtain the data-oriented control information corresponding to the application, the SMF may interact with the PCF to obtain the data-oriented control information corresponding to the application. Further, the PCF may interact with the UDR to obtain data-oriented control information corresponding to the application stored in the UDR.

S406: the SMF determines at least one first access location based at least on the first information.

Specifically, S406 corresponds to S305, and is not described here.

S407: the SMF sends identification information of at least one first access location to the PCF.

Specifically, the SMF may send a response message to the PCF, where the response message may carry the identification information of the at least one first access location. The identification information may be subnet information and/or DNAI. The subnet information may be IPv4 subnet information or IPv6 subnet information.

S408: the PCF sends the identification information of the at least one first access location to the DNS AF.

Specifically, the PCF may send a response message to the DNS AF, where the response message may carry the identification information of the at least one first access location.

Similar to the previous embodiment, in the embodiment of the present application, the address of the server of the DNS AF determination application may also be divided into two scenarios, and the determination manners in the different scenarios are different. The following description can be seen in particular:

scene one: network using local DNS server (S409-S411)

S409: the DNS AF sends fourth information to the local DNS server.

Specifically, S409 corresponds to S307, and is not described here.

S410: the local DNS server determines an address of the first application server.

Specifically, S4010 corresponds to S308, and is not described here.

S411: the local DNS server sends the address of the first application server to the DNS AF.

Specifically, S411 corresponds to S309, and is not described here.

Scene II: network usage centralized DNS server (S412-S415)

S412: the DNS AF sends third information to the centralized DNS server.

Specifically, S412 corresponds to S310, and is not described here.

S413: the centralized DNS server initially selects at least one application server.

Specifically, S413 corresponds to S311, and is not described here.

S414: the centralized DNS server sends the address of the at least one application server to the DNS AF.

Specifically, S414 corresponds to S312, and is not described here.

S415: the DNS AF determines an address of the first server from the addresses of the at least one application server.

Specifically, S415 coincides with S313, and is not described here.

S416: the DNS AF sends the request information to the PCF.

Specifically, the DNS AF sends a data steering control enforcement (traffic steering control performing) request information to the PCF, which request information may be used to select a user plane network element for the UE to access the application, which request information may carry the APP ID. When the candidate first access location is not unique, the request information may also carry identification information of the second access location, such as DNAI and/or subnet information.

S417: the PCF sends the request information to the SMF.

Specifically, the PCF sends a data steering control execution (traffic steering control performing) request message to the SMF, which request message may be used to select a user plane element for the UE to access the application, which request message may carry the APP ID.

Optionally, when the candidate first access location is not unique, the request information may further carry identification information of a second access location, and the PCF selects, for the UE, a user plane network element for accessing the application according to the identification information of the second access location. Wherein the second access location is an access location that is ultimately selected from a plurality of candidate first access locations.

S418: SMF is inserted into PSA.

Specifically, S418 is consistent with S315, and is not described here.

S419: the DNS AF sends the address of the first application server to the UE.

Specifically, S419 corresponds to S316, and is not described here.

The method provided by the embodiment of the present application is described in detail above, and the network device provided by the embodiment of the present application will be described in detail below.

Referring to fig. 5, fig. 5 is a schematic structural diagram of a network device according to an embodiment of the present application. The network device may be configured to perform the steps performed by the first network device in the discovery method of the application server provided in the present application. As shown in fig. 5, the network device 50 may include at least: receiving section 510, determining section 520, and transmitting section 530. Wherein:

A receiving unit 510, configured to receive first information sent by the second network device, where the first information includes an identifier of an application.

A determining unit 520, configured to determine at least one first access location according to at least the first information, where the first access location is a candidate access location for the user equipment to access the application.

A transmitting unit 530, configured to transmit identification information of the at least one first access location to the second network device, where the identification information of the at least one first access location is used for determining an address of a server of the application.

In one possible implementation, the network device 50 is a session management network element.

The receiving unit 510 is further configured to: and receiving request information sent by the second network device, where the request information is used to request the network device 50 to select, for the user equipment, a user plane network element that accesses the application.

In one possible implementation, the determining unit 520 is specifically configured to: and determining the at least one first access position according to at least one of data guiding control information corresponding to the application, current position information of the user equipment, operator strategies and load conditions of the current network.

In one possible implementation, the data-oriented control information corresponding to the application is obtained by the network device 50 from a unified data repository or policy control network element.

In one possible implementation, the network device 50 is a policy control network element.

The determining unit 520 is specifically configured to: sending second information to a session management network element, wherein the second information is used for requesting the user equipment to access the access position of the application; and receiving the identification information of the at least one access position sent by the session management network element.

In a possible implementation, the network device 50 provides the session management network element with data-oriented control information corresponding to the application.

In one possible implementation, the receiving unit 510 is further configured to: and receiving request information of the second network equipment, wherein the request information is used for requesting the session management network element to select a user plane network element for accessing the application for the user equipment.

It will be appreciated that for the specific implementation of the network device shown in fig. 5, reference may be made to the steps performed by the first network device shown in fig. 2, 3 and 4, which are not described in detail herein.

The embodiment of the application provides another network device. Referring to fig. 6, fig. 6 is a schematic structural diagram of a network device according to an embodiment of the present application. The network device may be configured to perform the steps performed by the second network device in the discovery method of the application server provided in the present application. As shown in fig. 6, the network device 60 may include at least: a transmitting unit 610, a receiving unit 620, and a determining unit 630. Wherein:

a sending unit 610, configured to send first information to a first network device, where the first information includes an identifier of an application.

A receiving unit 620, configured to receive first identification information of at least one first access location sent by the first network device; the first access location is a candidate access location for the user equipment to access the application.

A determining unit 630, configured to determine an address of the first server of the application according to the first identification information of the at least one first access location.

In one possible implementation, the determining unit 630 is specifically configured to: transmitting third information to the first Domain Name System (DNS), wherein the third information comprises second identification information of at least one first access position, and the second identification information of the at least one first access position is determined according to the first identification information of the at least one first access position; receiving an address of at least one server of the application corresponding to second identification information of the at least one first access position sent by the first DNS server; and determining the address of the first server from the addresses of the at least one server.

In one possible implementation, the receiving unit 620 is further configured to: and receiving first priority information of first identification information of the at least one first access position sent by the network equipment.

The determining unit 630 is specifically configured to: transmitting third information to the first DNS server, wherein the third information comprises second identification information of at least one first access position, and the second identification information of the at least one first access position is determined according to the first identification information of the at least one first access position; receiving at least one server address of the application corresponding to second identification information of the at least one first access position sent by the first DNS server; and determining the address of the first server according to the at least one server address of the application corresponding to the first priority information and the second identification information of the at least one first access position.

In one possible implementation, the determining unit 630 is specifically configured to: determining a second DNS server corresponding to the second access position according to the first identification information of the at least one first access position, and sending fourth information to the second DNS server; the fourth information is used for acquiring the address of the first server; the first identification information of the at least one first access location includes first identification information of the second access location; the second network device receives the address of the first server sent by the second DNS server.

In one possible implementation, the receiving unit 620 is specifically configured to: and receiving priority information corresponding to the first identification information of the at least one first access position sent by the first network equipment.

The determining unit 630 is specifically configured to: and determining the second DNS server corresponding to the second access position according to the priority information corresponding to the first identification information of the at least one first access position, and sending the fourth information to the second DNS server.

In one possible implementation, the receiving unit 620 is further configured to: and receiving fifth information sent by the user equipment, wherein the fifth information is used for requesting the address of the server of the application.

In one possible implementation, the sending unit 610 is further configured to: and sending request information to the first network device, wherein the request information is used for requesting the first network device to select a user plane network element for accessing the application for the user device.

In one possible implementation, the sending unit 610 is further configured to: and sending the address of the first server to the user equipment.

It will be appreciated that for the specific implementation of the network device shown in fig. 6, reference may be made to the steps performed by the second network device shown in fig. 2, 3 and 4, which are not described in detail herein.

Referring to fig. 7, fig. 7 is a schematic structural diagram of a communication system according to an embodiment of the present application. The communication system may be used to perform the methods shown in fig. 2, 3 and 4. As shown in fig. 7, the communication system includes:

the first network device 710 is configured to receive first information of the second network device 720, where the first information includes an identification of an application.

The first network device 710 is further configured to determine at least one first access location according to at least the first information, where the first access location is a candidate access location for the user equipment to access the application.

The first network device 710 is further configured to send the first identification information of the at least one first access location to the second network device 720.

The second network device 720 is configured to determine an address of the first server of the application according to the first identification information of the at least one first access location.

In one possible implementation, the first network device 710 is a session management network element.

The first network device 710 is further configured to receive request information sent by the second network device 720, where the request information is used to request the first network device 710 to select, for the user equipment, a user plane network element that accesses the application.

In one possible implementation, the first network device 710 is specifically configured to: and determining the at least one first access position according to at least one of data guiding control information corresponding to the application, current position information of the user equipment, operator strategies and load conditions of the current network.

In one possible implementation, the data-oriented control information corresponding to the application is obtained by the first network device 710 from a unified data repository or a policy control network element.

In one possible implementation, the first network device 710 is a policy control network element.

The first network device 710 is specifically configured to: sending second information to a session management network element, wherein the second request is used for requesting the user equipment to access the access position of the application; and receiving the identification information of the at least one access position sent by the session management network element.

In one possible implementation, the first network device 710 provides the session management network element with data-oriented control information corresponding to the application.

In one possible implementation, the second network device 720 is specifically configured to: transmitting third information to the first Domain Name System (DNS), wherein the third information comprises second identification information of at least one first access position, and the second identification information of the at least one first access position is determined according to the first identification information of the at least one first access position; receiving an address of at least one server of the application corresponding to second identification information of the at least one first access position sent by the first DNS server; and determining the address of the first server from the addresses of the at least one server.

In a possible implementation manner, the first network device 710 is further configured to send first priority information of the first identification information of the at least one first access location to the second network device 720.

The second network device 720 is specifically configured to: transmitting third information to the first DNS server, wherein the third information comprises second identification information of at least one first access position, and the second identification information of the at least one first access position is determined according to the first identification information of the at least one first access position; receiving at least one server address of the application corresponding to second identification information of the at least one first access position sent by the first DNS server; and determining the address of the first server according to the at least one server address of the application corresponding to the first priority information and the second identification information of the at least one first access position.

In one possible implementation, the second network device 720 is specifically configured to: determining a second DNS server corresponding to the second access position according to the first identification information of the at least one first access position, and sending fourth information to the second DNS server; the fourth information is used for acquiring the address of the first server; the first identification information of the at least one first access location includes first identification information of the second access location; the second network device receives the address of the first server sent by the second DNS server.

In a possible implementation manner, the first network device 710 is further configured to send priority information corresponding to the first identification information of the at least one first access location to the second network device 720.

The second network device 720 is specifically configured to: and determining the second DNS server corresponding to the second access position according to the priority information corresponding to the first identification information of the at least one first access position, and sending the fourth information to the second DNS server.

In a possible implementation manner, the second network device 720 is further configured to receive fifth information sent by the user device, where the fifth information is used to request an address of a server of the application.

In a possible implementation manner, the second network device 720 is further configured to send the address of the first server to the user equipment.

It will be appreciated that for a specific implementation of each network device in the communication system shown in fig. 7, reference may be made to the methods shown in fig. 2, 3 and 4, which are not described in detail herein.

Referring to fig. 8, fig. 8 is a schematic structural diagram of a network device according to an embodiment of the present application.

In one embodiment, the network device may be used as a first network device or a second network device. The specific implementation of the network device may refer to the methods shown in fig. 2, 3 and 4.

As an example, when the determining unit (520 or 630) in the network device shown in fig. 5 or fig. 6 is implemented with a processor, the transmitting unit (530 or 610) and the receiving unit (510 or 620) are implemented with a transceiver, as shown in fig. 8, the network device 80 includes at least one processor 820 for implementing the functions of the first network device or the second network device in the method provided in the embodiment of the present application, and the network device 80 may further include the transceiver 810. The transceiver may be used to communicate with other devices over a transmission medium. Processor 820 utilizes transceiver 810 to transmit and receive data (e.g., to transmit and receive messages, etc.) and is configured to implement the methods described in the method embodiments above.

Optionally, the network device 80 may also include at least one memory 830 for storing program instructions and/or data. Memory 830 is coupled to processor 820. The coupling in the embodiments of the present application is an indirect coupling or communication connection between devices, units, or modules, which may be in electrical, mechanical, or other forms for information interaction between the devices, units, or modules. Processor 820 may operate in conjunction with memory 830. Processor 820 may execute program instructions stored in memory 830.

The specific connection medium between the transceiver 810, the processor 820, and the memory 830 is not limited in the embodiments of the present application. In the embodiment of the present application, the memory 830, the processor 820 and the transceiver 810 are connected through the bus 840 in fig. 8, where the bus is indicated by a thick line in fig. 8, and the connection manner between other components is only schematically illustrated, but not limited thereto. The buses may be classified as address buses, data buses, control buses, etc. For ease of illustration, only one thick line is shown in fig. 8, but not only one bus or one type of bus.

In the embodiments of the present application, the processor may be a general purpose processor, a digital signal processor, an application specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component, and may implement or execute the methods, steps, and logic blocks disclosed in the embodiments of the present application. The general purpose processor may be a microprocessor or any conventional processor or the like. The steps of a method disclosed in connection with the embodiments of the present application may be embodied directly in a hardware processor for execution, or in a combination of hardware and software modules in the processor for execution.

The memory in embodiments of the present application may be either volatile memory or nonvolatile memory, or may include both volatile and nonvolatile memory. The nonvolatile memory may be a read-only memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an electrically Erasable EPROM (EEPROM), or a flash memory. The volatile memory may be random access memory (random access memory, RAM) which acts as an external cache. By way of example, and not limitation, many forms of RAM are available, such as Static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous DRAM (SLDRAM), and direct memory bus RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

According to the method provided by the embodiment of the application, the application further provides a computer program product, which comprises: computer program code for causing a computer to perform the method of the embodiments shown in fig. 2 and/or fig. 3 and/or fig. 4 when the computer program code is run on the computer.

According to the method provided in the embodiments of the present application, there is further provided a computer readable medium storing a program code, which when run on a computer, causes the computer to perform the method in the embodiments shown in fig. 2 and/or fig. 3 and/or fig. 4.

According to the method provided by the embodiments of the present application, there is also provided a computer program that may be used to perform the method of the embodiments shown in fig. 2 and/or fig. 3 and/or fig. 4.

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, the processes or functions described in accordance with embodiments of the present application are produced in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by a wired (e.g., coaxial cable, fiber optic, digital subscriber line (digital subscriber line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. that contains an integration of one or more available media. The usable medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a magnetic tape), an optical medium (e.g., a high-density digital video disc (digital video disc, DVD)), or a semiconductor medium (e.g., a Solid State Disk (SSD)), or the like.

As used in this specification, the terms "component," "module," "system," and the like are intended to refer to a computer-related entity, either hardware, firmware, a combination of hardware and software, or software in execution. For example, a component may be, but is not limited to being, a process running on a processor, an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application running on a computing device and the computing device can be a component. One or more components may reside within a process and/or thread of execution and a component may be localized on one computer and/or distributed between two or more computers. Furthermore, these components can execute from various computer readable media having various data structures stored thereon. The components may communicate by way of local and/or remote processes such as in accordance with a signal having one or more data packets (e.g., data from two components interacting with one another in a local system, distributed system, and/or across a network such as the internet with other systems by way of the signal).

Those of ordinary skill in the art will appreciate that the various illustrative logical blocks (illustrative logical block) and steps (steps) described in connection with the embodiments disclosed herein can be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It will be clear to those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described systems, apparatuses and units may refer to corresponding procedures in the foregoing method embodiments, and are not repeated herein.

The foregoing is merely specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the present application, and the changes and substitutions are intended to be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A discovery method of an application server, comprising:

the method comprises the steps that first network equipment receives first information of second network equipment, wherein the first information comprises an application identifier, and the first information is determined by the second network equipment according to domain name system request information sent by user equipment;

the first network equipment determines at least one first access position according to at least the first information, wherein the first access position is a candidate access position for the user equipment to access the application;

The first network device sends the identification information of the at least one first access position to the second network device, wherein the identification information of the at least one first access position is used for determining the address of the server of the application, and the identification information of the at least one first access position is at least one piece of subnet information.

2. The method of claim 1, wherein the first network device is a session management network element;

after the first network device transmits the identification information of the at least one first access location to the second network device, the method further comprises: the first network device receives request information sent by the second network device, where the request information is used to request the first network device to select a user plane network element for accessing the application for the user device.

3. The method of claim 2, wherein the request information further comprises identification information of a second access location, the second access location being an access location selected by the second network device from the at least one first access location, in the case where the at least one first access location comprises the second access location.

4. A method according to claim 2 or 3, wherein the first network device determining at least one first access location based at least on the first information comprises: the first network device determines the at least one first access position according to at least one of data guiding control information corresponding to the application, current position information of the user device, operator policy and load condition of the current network.

5. The method of claim 4, wherein the application-corresponding data-oriented control information is obtained by the first network device from a unified data store or a policy control network element.

6. The method of claim 1, wherein the first network device is a policy control network element; the first network device determining at least one first access location based at least on the first information, including:

the first network device sends second information to a session management network element, wherein the second information is used for requesting the user device to access an access position of the application;

the first network device receives the identification information of the at least one access position sent by the session management network element.

7. The method of claim 6, wherein the identification information of the at least one first access location is determined by the session management network element based on at least one of data steering control information corresponding to the application, current location information of the user device, operator policy, and load status of a current network.

8. The method of claim 7, wherein the first network device provides data-directed control information corresponding to the application to the session management network element.

9. The method according to any of claims 6-8, wherein after the first network device sends the identification information of the at least one first access location to the second network device, the method further comprises:

the first network device receives request information of the second network device, where the request information is used to request the session management network element to select a user plane network element for the user device to access the application.

10. The method of claim 9, wherein the request information further comprises identification information of a second access location, the second access location being an access location selected by the second network device from the at least one first access location, in the case where the at least one first access location comprises the second access location.

11. The method of claim 1, wherein the at least one piece of subnet information is subnet information corresponding to a user plane network element that the user equipment can employ to access the application.

12. A discovery method of an application server, comprising:

the method comprises the steps that second network equipment sends first information to first network equipment, wherein the first information comprises an application identifier, and the first information is determined by the second network equipment according to domain name system request information sent by user equipment;

the second network equipment receives first identification information of at least one first access position sent by the first network equipment, wherein the first access position is a candidate access position for the user equipment to access the application;

the second network device determines an address of a first server of the application according to first identification information of the at least one first access location, wherein the first identification information of the at least one first access location is at least one first subnet information.

13. The method of claim 12, wherein the second network device determining the address of the first server of the application from the first identification information of the at least one first access location comprises:

The second network device sends third information to a first Domain Name System (DNS), wherein the third information comprises second identification information of at least one first access position, and the second identification information of the at least one first access position is determined according to the first identification information of the at least one first access position;

the second network device receives an address of at least one server of the application corresponding to second identification information of the at least one first access position, which is sent by the first DNS server;

the second network device determines an address of the first server from the addresses of the at least one server.

14. The method of claim 12, wherein the method further comprises: the second network device receives first priority information of first identification information of the at least one first access position sent by the network device;

the second network device determining an address of a first server of the application according to the first identification information of the at least one first access location, including:

the second network device sends third information to the first DNS server, wherein the third information comprises second identification information of at least one first access position, and the second identification information of the at least one first access position is determined according to the first identification information of the at least one first access position;

The second network device receives at least one server address of the application corresponding to second identification information of the at least one first access position, which is sent by the first DNS server;

and the second network equipment determines the address of the first server according to the first priority information and at least one server address of the application corresponding to the second identification information of the at least one first access position.

15. The method of claim 14, wherein the third information further comprises second priority information corresponding to second identification information of the at least one first access location, wherein the second priority information is determined from the first priority information; the address of the at least one first server sent by the first DNS server is determined by the first DNS server according to the second priority information.

16. The method of claim 12, wherein the second network device determining the address of the first server of the application from the first identification information of the at least one first access location comprises:

the second network device determines a second DNS server corresponding to a second access position according to the first identification information of the at least one first access position, and sends fourth information to the second DNS server, wherein the at least one access position comprises the second access position, and the second access position is an access position selected by the second network device from the at least one first access position; the fourth information is used for acquiring the address of the first server; the first identification information of the at least one first access location includes first identification information of the second access location; the second network device receives the address of the first server sent by the second DNS server.

17. The method of claim 16, wherein the method further comprises: the second network equipment receives priority information corresponding to first identification information of at least one first access position sent by the first network equipment;

the second network device determining a second DNS server corresponding to the second access location according to the first identification information of the at least one first access location, and sending fourth information to the second DNS server, including:

the second network device determines the second DNS server corresponding to the second access position according to the priority information corresponding to the first identification information of the at least one first access position, and sends the fourth information to the second DNS server.

18. The method according to any of claims 12-17, wherein after the second network device determines the address of the first server of the application from the first identification information of the at least one first access location, the method further comprises: and the second network equipment sends request information to the first network equipment, wherein the request information is used for requesting the first network equipment to select a user plane network element for accessing the application for the user equipment.

19. The method of claim 18, wherein the request information further comprises first identification information for a second access location, the at least one first access location comprising the second access location, the second access location corresponding to an address of the first server.

20. The method of any one of claims 12-17, further comprising: the second network device sends an address of the first server to the user device.

21. The method of claim 14 or 15, wherein the second identification information of the at least one first access location is at least one second subnet information, wherein the at least one second subnet information is determined from the at least one first subnet information.

22. A discovery method of an application server, comprising:

The first network device sends first identification information of the at least one first access position to the second network device;

the second network device determines an address of a first server of the application according to first identification information of the at least one first access location, wherein the first identification information of the at least one first access location is one or more first subnet information.

23. The method of claim 22, wherein the first network device is a session management network element;

after the second network device determines the address of the first server of the application according to the first identification information of the at least one first access location, the method further comprises: the first network device receives request information sent by the second network device, where the request information is used to request the first network device to select a user plane network element for accessing the application for the user device.

24. The method of claim 23, wherein the request information further comprises identification information of a second access location, the second access location being an access location selected by the second network device from the at least one first access location, in the case the at least one first access location comprises the second access location.

25. The method of claim 23, wherein the first network device determining at least one first access location based at least on the first information comprises: the first network device determines the at least one first access position according to at least one of data guiding control information corresponding to the application, current position information of the user device, operator policy and load condition of the current network.

26. The method of claim 25, wherein the application-corresponding data-oriented control information is obtained by the first network device from a unified data store or a policy control network element.

27. The method of claim 22, wherein the first network device is a policy control network element; the first network device determining at least one first access location based at least on the first information, including:

28. The method of claim 27, wherein the identification information of the at least one first access location is determined by the session management network element based on at least one of data steering control information corresponding to the application, current location information of the user device, operator policy, and load status of a current network.

29. The method of claim 28, wherein the first network device provides data-directed control information corresponding to the application to the session management network element.

30. The method of any of claims 27-29, wherein after the second network device determines the address of the first server of the application from the first identification information of the at least one first access location, the method further comprises: the first network device receives request information of the second network device, where the request information is used to request the session management network element to select a user plane network element for the user device to access the application.

31. The method of claim 30, wherein the request information further comprises identification information of a second access location, the second access location being an access location selected by the second network device from the at least one first access location, in the case the at least one first access location comprises the second access location.

32. The method according to any of claims 22-29, wherein the second network device determining the address of the first server of the application from the first identification information of the at least one first access location comprises:

33. The method of any one of claims 22-29, wherein the method further comprises: the first network device sends first priority information of first identification information of the at least one first access position to the second network device;

34. The method of claim 33, wherein the third information further comprises second priority information corresponding to second identification information of the at least one first access location, wherein the second priority information is determined from the first priority information; the address of the at least one first server sent by the first DNS server is determined by the first DNS server according to the second priority information.

35. The method according to any of claims 22-27, wherein the second network device determining the address of the first server of the application from the first identification information of the at least one first access location comprises:

the second network equipment determines a second DNS server corresponding to a second access position according to the first identification information of the at least one first access position, and sends fourth information to the second DNS server; the fourth information is used for acquiring the address of the first server; the first identification information of the at least one first access location includes first identification information of the second access location, the second access location being an access location selected by the second network device from the at least one first access location;

the second network device receives the address of the first server sent by the second DNS server.

36. The method of claim 35, wherein the method further comprises: the first network device sends priority information corresponding to first identification information of the at least one first access position to the second network device;

37. The method of any one of claims 22-27, wherein the method further comprises: the second network device sends an address of the first server to the user device.

38. The method of claim 22, wherein the at least one first subnet information is subnet information corresponding to a user plane network element that the user device can employ to access the application.

39. The method of any of claims 32-34, wherein the second identification information of the at least one first access location is at least one second subnet information, wherein the at least one second subnet information is determined from the at least one first subnet information.

40. A network device comprising one or more processors to invoke the transceiver to transceive data, a transceiver, and a memory to store computer program code and/or data, the computer program code comprising computer instructions to invoke the one or more processors to cause the network device to perform the method of any of claims 1-11.

41. A network device comprising one or more processors to invoke the transceiver to transceive data, a transceiver, and a memory to store computer program code and/or data, the computer program code comprising computer instructions to invoke the one or more processors to cause the network device to perform the method of any of claims 12-21.

42. A communication system comprising a first network device and a second network device; the first network device is the network device of claim 40 and the second network device is the network device of claim 41.

43. A chip, wherein the chip comprises at least one processor and a memory, the memory and the at least one processor are interconnected through a circuit, and instructions are stored in the at least one memory; when executed by the processor, the instructions implement the method of any of claims 1-21.

44. A computer readable storage medium, characterized in that the computer readable storage medium has stored therein program instructions which, when run on a processor, implement the method of any of claims 1-21.