Communication method, device and computer-readable storage medium

Abstract

Embodiments of the present application disclose a communication method, apparatus, and computer-readable storage medium, comprising: receiving first request information from a terminal device, the first request information including first application identification information; determining second information based on the first application identification information and first information obtained from a session management function network element, the second information being a DNS extension mechanism client subnet option or address information of a local DNS resolver; and sending DNS request information to a centralized DNS server or a local DNS resolver based on the second information, the DNS request information including the first application identification information, the DNS request information being used to obtain the address information of the application server. Embodiments of the present application eliminate the need to obtain the second information from the session management function network element each time a request information including application identification information is received from a terminal device, thereby reducing exchange information and thus conserving transmission resources.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of communication technologies, and in particular, to a communication method, apparatus, and computer-readable storage medium. Background Art

[0002] Edge computing (EC) can achieve local processing of distributed business traffic by moving user plane function (UPF) network elements and business processing capabilities down to the edge of the network. Multiple edge application servers (EAS) deployed at the edge of the network may provide services for the same business. The content of this service provided by these EAS is the same, but they may have different Internet protocol (IP) addresses. When a terminal device needs to access the service, it is required to access the available EAS closest to the terminal device. Therefore, when the terminal device has a business demand, if it needs to determine the address information of the EAS, it is necessary to obtain information about the current location of the associated terminal device from the session management function (SMF) network element. Since different SMF network elements need to serve a large number of terminal devices, and each terminal device has different business needs, there is a lot of communication with the SMF network element, and the amount of information that needs to be transmitted is large, resulting in a waste of communication resources. Summary of the Invention

[0003] Embodiments of the present application disclose a communication method, apparatus, and computer-readable storage medium for saving transmission resources.

[0004] A first aspect discloses a communication method, which can be applied to a first entity or a module (e.g., a chip) in the first entity. The first entity is used as an example for illustration below. The communication method may include: receiving first request information from a terminal device, the first request information including first application identification information; determining second information based on the first application identification information and first information obtained from a session network function network element, the second information being address information of a client subnet option DNS extended mechanisms (EDNS) client subnet option (ECS option) or a local domain name system (DNS) resolver; and sending DNS request information to a centralized DNS server or a local DNS resolver based on the second information, the DNS request information including the first application identification information, the DNS request information being used to obtain the address information of the application server.

[0005] In an embodiment of the present application, after the first entity receives request information including application identification information from a terminal device, it can determine the second information based on the first application identification information and the first information obtained from the session network function network element, and send DNS request information to the centralized DNS server or to the local DNS resolver based on the second information. If the first entity has already obtained the first information from the session management function network element before receiving the request information, it is not necessary to obtain the second information from the session management function network element after receiving the request information. Therefore, it is not necessary to obtain the second information from the session management function network element each time after receiving the request information including application identification information from the terminal device, which can reduce the number of communications between the first entity and the session management function network element, thereby saving transmission resources. In addition, after receiving the request information from the terminal device, the first entity can reduce the processing delay of the DNS request information while avoiding interaction with the session network function network element.

[0006] As a possible implementation manner, the communication method may further include: receiving first information from a session management function network element, where the first information includes first application identification information and second information corresponding to the first application identification information.

[0007] In this embodiment of the present application, the first information may be proactively sent by the session management function network element to the first entity. Therefore, the first entity may not send a request to the session management function network element to obtain the first information, which can further reduce the number of communications between the first entity and the session network function network element, thereby saving transmission resources. In addition, the first information includes at least first application identification information and second information corresponding to the first application identification information, so that the second information can be determined based on the first information and the first application identification information.

[0008] As a possible implementation method, the communication method may also include: receiving first information from a session management function network element, the first information including first application identification information, a first identifier, and second information corresponding to the first application identification information and the first identifier, the first identifier being at least one data network access identifier (DNAI).

[0009] In an embodiment of the present application, the first information may be proactively sent by the session management function network element to the first entity. Therefore, the first entity may not send a request to the session management function network element to obtain the first information, which can further reduce the number of communications between the first entity and the session network function network element, thereby saving transmission resources. In addition, the first information includes at least first application identification information, at least one data network access identifier, and second information corresponding to the first application identification information and the data network access identifier, so that the second information can be determined based on the first information and the first application identification information.

[0010] As a possible implementation method, the communication method may also include: receiving a second identifier from a session management function network element, the second identifier being a data network access identifier corresponding to the current location of the terminal device; the first entity determining the second information based on the first application identification information and the first information obtained from the session network function network element includes: determining the second information based on the first application identification information, the second identifier and the first information obtained from the session network function network element.

[0011] In an embodiment of the present application, the session network function network element can actively send the data network access identifier corresponding to the current location of the terminal device to the first entity, so that the first entity can determine the second information based on the first application identification information, the data network access identifier corresponding to the current location of the terminal device and the first information.

[0012] As a possible implementation method, before the first entity receives the first information from the session management function network element, the communication method may also include: sending first application identification information and / or first indication information to the session management function network element, the first application identification information is used to obtain the first information, and the first indication information is used to instruct the session management function network element to send the first information.

[0013] In the embodiment of the present application, the first entity may first send information for obtaining the first information to the session management function network element, so that the session network function network element can send the first information to the first entity based on the information. It can be seen that the first information is sent to the first entity by the session management function network element only when the first entity needs it.

[0014] As a possible implementation, the first information may also include a third identifier, the first identifier, and third information corresponding to the first identifier and the third identifier, the third identifier being the application identification information of the application deployed in the data network corresponding to the first identifier, and the third information being the DNS extension mechanism client subnet option or the address information of the local DNS resolver corresponding to the third identifier.

[0015] In an embodiment of the present application, in addition to including the first application identification information, at least one data network access identification, and the second information corresponding to the first application identification information and the data network access identification, the first information may also include a third identification, a first identification, and third information corresponding to the first identification and the third identification, so that when the first entity subsequently receives other request information including application identification information from the terminal device, the number of times the first information is obtained from the session management function network element can be reduced, and the number of communications between the first entity and the session network function network element can be reduced, thereby saving transmission resources. In addition, after receiving the request information from the terminal device, the first entity can reduce the processing delay of the DNS request information while avoiding interaction with the session network function network element.

[0016] As a possible implementation, the first information may also include a third identifier and third information corresponding to the third identifier, where the third identifier is application identification information of an application deployed in the data network corresponding to the first identifier, and the third information is the DNS extension mechanism client subnet option or the address information of the local DNS resolver corresponding to the third identifier.

[0017] In an embodiment of the present application, in addition to the first application identification information and the second information corresponding to the first application identification information, the first information may also include a third identification and the third information corresponding to the third identification. This allows the first entity to reduce the number of times it obtains the first information from the session management function network element when it subsequently receives other request information including the application identification information from the terminal device, thereby reducing the number of communications between the first entity and the session network function network element, thereby saving transmission resources. In addition, after receiving the request information from the terminal device, the first entity can reduce the processing delay of the DNS request information while avoiding interaction with the session network function network element.

[0018] As a possible implementation method, the communication method may also include: receiving a second indication message and a fourth identifier from a session management function network element, the fourth identifier being a data network access identifier of a data network that no longer serves the terminal device, and the first identifier including the fourth identifier; and deleting the information corresponding to the fourth identifier in the first information according to the second indication message.

[0019] In an embodiment of the present application, the first entity can delete part or all of the first information according to the instructions of the session management function network element, which can reduce the stored information, thereby saving storage space, and reduce the time required for the first entity to determine the second information, thereby reducing the processing delay of the DNS request information.

[0020] As a possible implementation manner, the first entity receives the second indication information and the fourth identifier from the session management function network element, including: receiving the second indication information, the fourth identifier and the fifth identifier from the session management function network element, the fifth identifier being the application identification information of the application deployed in the data network corresponding to the fourth identifier; the first entity deletes the information corresponding to the fourth identifier in the first information, including: deleting the information corresponding to the fourth identifier and the fifth identifier in the first information.

[0021] As a possible implementation method, the first entity sends DNS request information to the centralized DNS server or the local DNS resolver based on the second information, including: when the second information is the DNS extension mechanism client subnet option, sending DNS request information to the centralized DNS server, and the DNS request also includes the second information; when the second information is the address information of the local DNS resolver, sending DNS request information to the local DNS resolver.

[0022] A second aspect discloses a communication method, which can be applied to a session management function network element or a module (e.g., a chip) in the session management function network element. The following description takes the session management function network element as an example. The communication method may include: sending first information to a first entity, the first information including first application identification information and second information corresponding to the first application identification information, or first application identification information, a first identifier, and second information corresponding to the first application identification information and the first identifier, the first identifier being at least one data network access identifier, and the second information being a DNS extension mechanism client subnet option or address information of a local DNS resolver, the first information being used by the first entity to determine the second information.

[0023] In an embodiment of the present application, the session management function network element can proactively send first information to the first entity, so that after the first entity receives the request information including application identification information from the terminal device, it can determine the second information based on the first application identification information and the first information, and send the DNS request information to the centralized DNS server or the local DNS resolver based on the second information. This can avoid the first entity from obtaining the second information from the session management function network element each time it receives the request information including application identification information from the terminal device, and can reduce the number of communications between the first entity and the session management function network element, thereby saving transmission resources. In addition, after receiving the request information from the terminal device, the first entity can reduce the processing delay of the DNS request information while avoiding interaction with the session network function network element.

[0024] As a possible implementation method, the communication method may also include: sending a second identifier to the first entity, the second identifier being the data network access identifier corresponding to the current location of the terminal device; the first information used to determine the second information includes: the first information and the second identifier used to determine the second information.

[0025] In an embodiment of the present application, the session management function network element can actively send the data network access identifier corresponding to the current location of the terminal device to the first entity, so that the first entity can determine the second information based on the first application identification information, the data network access identifier corresponding to the current location of the terminal device and the first information.

[0026] As a possible implementation method, the communication method may also include: receiving first application identification information and / or first indication information from the first entity; the session management function network element sending the first information to the first entity includes: sending the first information to the first entity according to the first application identification information and / or the first indication information.

[0027] In the embodiment of the present application, the session management function network element may send the first information to the first entity only after receiving the information for obtaining the first information from the first entity. It can be seen that the first information may be sent to the first entity by the session management function network element according to the needs of the first entity.

[0028] As a possible implementation, the first information may also include a third identifier, the first identifier, and third information corresponding to the first identifier and the third identifier, the third identifier being the application identification information of the application deployed in the data network corresponding to the first identifier, and the third information being the DNS extension mechanism client subnet option or the address information of the local DNS resolver corresponding to the third identifier.

[0029] In an embodiment of the present application, in addition to including the first application identification information, at least one data network access identification, and the second information corresponding to the first application identification information and the data network access identification, the first information may also include a third identification, a first identification, and third information corresponding to the first identification and the third identification, so that when the first entity subsequently receives request information including other application identification information from a terminal device, the number of times the first information is obtained from the session management function network element can be reduced, and the number of communications between the session management function network element and the first entity can be reduced, thereby saving transmission resources. In addition, after receiving the request information from the terminal device, the first entity can reduce the processing delay of the DNS request information while avoiding interaction with the session network function network element.

[0030] As a possible implementation, the first information may also include a third identifier and third information corresponding to the third identifier, where the third identifier is application identification information of an application deployed in the data network corresponding to the first identifier, and the third information is the DNS extension mechanism client subnet option or the address information of the local DNS resolver corresponding to the third identifier.

[0031] In an embodiment of the present application, in addition to the first application identification information and the second information corresponding to the first application identification information, the first information may also include a third identification and the third information corresponding to the third identification. This allows the first entity to reduce the number of times it obtains the first information from the session management function network element when it subsequently receives other request information including the application identification information from the terminal device, thereby reducing the number of communications between the session management function network element and the first entity, thereby saving transmission resources. In addition, after receiving the request information from the terminal device, the first entity can reduce the processing delay of the DNS request information while avoiding interaction with the session network function network element.

[0032] As a possible implementation method, the communication method may also include: sending a second indication message and a fourth identifier to the first entity, the fourth identifier being a data network access identifier of a data network that no longer serves the terminal device, the first identifier including the fourth identifier, and the second indication message being used to delete the information corresponding to the fourth identifier in the first message.

[0033] In an embodiment of the present application, the session management function network element can send instruction information for deleting information to the first entity, so that the first entity can delete part or all of the first information according to the instruction of the session management function network element, which can reduce the information stored by the first entity, thereby saving the storage space of the first entity, and reducing the time required for the first entity to determine the second information, thereby reducing the processing delay of the DNS request information.

[0034] As a possible implementation manner, the session management function network element sends the second indication information and the fourth identifier to the first entity, including: sending the second indication information, the fourth identifier and the fifth identifier to the first entity, the fifth identifier being the application identification information of the application deployed in the data network corresponding to the fourth identifier; the second indication information is used to delete the information corresponding to the fourth identifier in the first information, including: the second indication information is used to delete the information corresponding to the fourth identifier and the fifth identifier in the first information.

[0035] The third aspect discloses a communication method, which can be applied to a first entity or to a module (e.g., a chip) in the first entity. The first entity is used as an example for explanation below. The communication method may include: receiving a first request message from a terminal device, the first request message including first application identification information; determining second information based on the first information obtained from the session management function network element, the second information being the DNS extension mechanism client subnet option or the address information of the local DNS resolver corresponding to the first identification, the first identification being the data network access identification of the data network with the smallest service range or the closest distance to the terminal device in the data network corresponding to the second identification, and the second identification being at least one data network access identification corresponding to the current location of the terminal device; sending a DNS request message to a centralized DNS server or a local DNS resolver based on the second information, the DNS request message including the first application identification information, and the DNS request message being used to obtain the address information of the application server.

[0036] In an embodiment of the present application, after the first entity receives request information including application identification information from a terminal device, it can determine the second information based on the first information obtained from the session network function network element, and send DNS request information to a centralized DNS server or a local DNS resolver based on the second information. If the first entity has already obtained the first information from the session management function network element before receiving the request information, and the first entity can determine the second information based on the first information, it is not necessary to obtain the second information from the session management function network element after receiving the request information. Therefore, it is not necessary to obtain the second information from the session management function network element each time after receiving the request information including application identification information from the terminal device, which can reduce the number of communications between the first entity and the session management function network element, thereby saving transmission resources. In addition, after receiving the request information from the terminal device, the first entity can reduce the processing delay of the DNS request information while avoiding interaction with the session network function network element.

[0037] As a possible implementation manner, the communication method may further include: receiving first information from a session management function network element, where the first information may include second information.

[0038] In this embodiment of the present application, the first information may be proactively sent by the session management function element to the first entity. Therefore, the first entity may not send a request to the session management function element to obtain the first information, which can further reduce the number of communications between the first entity and the session network function element, thereby saving transmission resources. In addition, the first information includes at least the second information, so that the second information can be determined based on the first information.

[0039] As a possible implementation manner, the communication method may further include: receiving first information from a session management function network element, where the first information may include first application identification information and second information corresponding to the first application identification information.

[0040] In this embodiment of the present application, the first information may be proactively sent by the session management function network element to the first entity. Therefore, the first entity does not need to send a request to the session management function network element to obtain the first information, which can further reduce the number of communications between the first entity and the session network function network element, thereby saving transmission resources. In addition, the first information includes at least first application identification information and second information corresponding to the first application identification information, so that the second information can be determined based on the first information.

[0041] As a possible implementation method, the first information may also include a third identifier and third information corresponding to the third identifier, where the third identifier is application identification information of an application deployed in the data network corresponding to the second identifier, and the third information is the DNS extension mechanism client subnet option or the address information of the local DNS resolver corresponding to the third identifier.

[0042] In an embodiment of the present application, in addition to including the first application identification information and the second information corresponding to the first application identification information, the first information may also include a third identification and third information corresponding to the third identification. This allows the first entity to reduce the number of times it obtains the first information from the session management function network element when it subsequently receives other request information including the application identification information from the terminal device, thereby reducing the number of communications between the first entity and the session network function network element, thereby saving transmission resources. In addition, after receiving the request information from the terminal device, the first entity can reduce the processing delay of the DNS request information while avoiding interaction with the session network function network element.

[0043] As a possible implementation method, the communication method may also include: sending first application identification information and / or first indication information to the session management function network element, the first application identification information is used to obtain the first information, and the first indication information is used to instruct the session management function network element to send the first information.

[0044] In the embodiment of the present application, the first entity may first send information for obtaining the first information to the session management function network element, so that the session network function network element can send the first information to the first entity based on the information. It can be seen that the first information is sent to the first entity by the session management function network element only when the first entity needs it.

[0045] As a possible implementation manner, the communication method may further include: receiving second indication information from a session management function network element, where the second indication information is used to instruct deletion of the first information; and deleting the first information according to the second indication information.

[0046] In the embodiment of the present application, the first entity may delete the first information according to the instruction of the session management function network element, thereby reducing the stored information and saving storage space.

[0047] As a possible implementation method, the first entity sends DNS request information to the centralized DNS server or the local DNS resolver based on the second information, including: when the second information is the DNS extension mechanism client subnet option, sending DNS request information to the centralized DNS server, and the DNS request may also include the second information; when the second information is the address information of the local DNS resolver, sending DNS request information to the local DNS resolver.

[0048] A fourth aspect discloses a communication method, which can be applied to a session management function network element, or to a module (e.g., a chip) in the session management function network element. The following description will be made using the session management function network element as an example. The communication method may include: sending first information to a first entity, where the first information may include second information, or first application identification information and second information corresponding to the first application identification information, the second information being the DNS extension mechanism client subnet option or the address information of the local DNS resolver corresponding to the first identification, the first identification being the data network access identification of the data network with the smallest service range or the closest distance to the terminal device in the data network corresponding to the second identification, the second identification being at least one data network access identification corresponding to the current location of the terminal device, and the first information being used to determine the second information.

[0049] In an embodiment of the present application, the session management function network element can proactively send first information to the first entity, so that after the first entity receives request information including application identification information from the terminal device, it can determine second information based on the first information, and send DNS request information to the centralized DNS server or to the local DNS resolver based on the second information. This can avoid the first entity from obtaining the second information from the session management function network element each time it receives request information including application identification information from the terminal device, and can reduce the number of communications between the first entity and the session management function network element, thereby saving transmission resources. In addition, after receiving the request information from the terminal device, the first entity can reduce the processing delay of the DNS request information while avoiding interaction with the session network function network element.

[0050] As a possible implementation method, the first information may also include a third identifier and third information corresponding to the third identifier, where the third identifier is application identification information of an application deployed in the data network corresponding to the second identifier, and the third information is the DNS extension mechanism client subnet option or the address information of the local DNS resolver corresponding to the third identifier.

[0051] In an embodiment of the present application, in addition to including the first application identification information and the second information corresponding to the first application identification information, the first information may also include a third identification and third information corresponding to the third identification, so that when the first entity subsequently receives a request message including other application identification information from a terminal device, the number of times the first information is obtained from the session management function network element can be reduced, and the number of communications between the session management function network element and the first entity can be reduced, thereby saving transmission resources. In addition, after receiving the request message from the terminal device, the first entity can reduce the processing delay of the DNS request information while avoiding interaction with the session network function network element.

[0052] As a possible implementation method, the communication method may also include: receiving first application identification information and / or first indication information from the first entity; the session management function network element sends first information to the first entity; and sending first information to the first entity based on the first application identification information and / or first indication information.

[0053] In the embodiment of the present application, the session management function network element may send the first information to the first entity only after receiving the information for obtaining the first information from the first entity. It can be seen that the first information may be sent to the first entity by the session management function network element according to the needs of the first entity.

[0054] As a possible implementation manner, the communication method may further include: sending second indication information to the first entity, where the second indication information is used to instruct deletion of the first information.

[0055] In an embodiment of the present application, the session management function network element can send an instruction message for deleting the first information to the first entity, so that the first entity can delete the first information according to the instruction of the session management function network element, which can reduce the information stored by the first entity and thus save the storage space of the first entity.

[0056] The fifth aspect discloses a communication device, which can be a first entity or a module (for example, a chip) in the first entity. The device may include: a receiving unit for receiving first request information from a terminal device, wherein the first request information includes first application identification information; a determining unit for determining second information based on the first application identification information and the first information obtained from the session network function network element, wherein the second information is a DNS extension mechanism client subnet option or address information of a local DNS resolver; a sending unit for sending DNS request information to a centralized DNS server or a local DNS resolver based on the second information, wherein the DNS request information includes the first application identification information, and the DNS request information is used to obtain the address information of the application server.

[0057] As a possible implementation manner, the receiving unit is further configured to receive the first information from the session management function network element, where the first information includes the first application identification information and second information corresponding to the first application identification information.

[0058] As a possible implementation manner, the receiving unit is also used to receive the first information from the session management function network element, the first information including the first application identification information, the first identifier, and the second information corresponding to the first application identification information and the first identifier, the first identifier being at least one data network access identifier.

[0059] As a possible implementation method, the receiving unit is also used to receive a second identifier from the session management function network element, where the second identifier is a data network access identifier corresponding to the current location of the terminal device; the determination unit is specifically used to determine the second information based on the first application identification information, the second identifier and the first information obtained from the session network function network element.

[0060] As a possible implementation manner, the sending unit is also used to send the first application identification information and / or first indication information to the session management function network element before the receiving unit receives the first information from the session management function network element, the first application identification information is used to obtain the first information, and the first indication information is used to instruct the session management function network element to send the first information.

[0061] As a possible implementation, the first information also includes a third identifier, a first identifier, and third information corresponding to the first identifier and the third identifier, the third identifier being application identification information of an application deployed in the data network corresponding to the first identifier, and the third information being the DNS extension mechanism client subnet option or the address information of the local DNS resolver corresponding to the third identifier.

[0062] As a possible implementation, the first information also includes a third identifier and third information corresponding to the third identifier, wherein the third identifier is application identification information of an application deployed in the data network corresponding to the first identifier, and the third information is the DNS extension mechanism client subnet option or the address information of the local DNS resolver corresponding to the third identifier.

[0063] As a possible implementation manner, the receiving unit is also used to receive a second indication information and a fourth identifier from the session management function network element, where the fourth identifier is a data network access identifier of a data network that no longer serves the terminal device, and the first identifier includes the fourth identifier; the device also includes: a deleting unit, used to delete the information corresponding to the fourth identifier in the first information according to the second indication information.

[0064] As a possible implementation manner, the receiving unit receives the second indication information and the fourth identifier from the session management function network element, including: receiving the second indication information, the fourth identifier and the fifth identifier from the session management function network element, the fifth identifier being the application identification information of the application deployed in the data network corresponding to the fourth identifier; the deleting unit is specifically used to delete the information corresponding to the fourth identifier and the fifth identifier in the first information.

[0065] As a possible implementation manner, the sending unit sends DNS request information to a centralized DNS server or a local DNS resolver according to the second information, including: when the second information is the DNS extension mechanism client subnet option, sending DNS request information to the centralized DNS server, and the DNS request also includes the second information; when the second information is the address information of the local DNS resolver, sending DNS request information to the local DNS resolver.

[0066] The sixth aspect discloses a communication device, which can be a session management function network element or a module (for example, a chip) in the session management function network element. The device may include: a sending unit for sending first information to a first entity, the first information including first application identification information and second information corresponding to the first application identification information, or first application identification information, a first identification and second information corresponding to the first application identification information and the first identification, the first identification is at least one data network access identification, the second information is a DNS extension mechanism client subnet option or address information of a local DNS resolver, and the first information is used by the first entity to determine the second information.

[0067] As a possible implementation method, the sending unit is also used to send a second identifier to the first entity, where the second identifier is a data network access identifier corresponding to the current location of the terminal device; the first information is used to determine the second information, including: the first information and the second identifier are used to determine the second information.

[0068] As a possible implementation, the device further includes: a receiving unit for receiving the first application identification information and / or first indication information from the first entity; the sending unit sending the first information to the first entity includes: sending the first information to the first entity according to the first application identification information and / or the first indication information.

[0069] As a possible implementation, the first information also includes a third identifier, a first identifier, and third information corresponding to the first identifier and the third identifier, the third identifier being application identification information of an application deployed in the data network corresponding to the first identifier, and the third information being the DNS extension mechanism client subnet option or the address information of the local DNS resolver corresponding to the third identifier.

[0070] As a possible implementation, the first information also includes a third identifier and third information corresponding to the third identifier, wherein the third identifier is application identification information of an application deployed in the data network corresponding to the first identifier, and the third information is the DNS extension mechanism client subnet option or the address information of the local DNS resolver corresponding to the third identifier.

[0071] As a possible implementation, the sending unit is also used to send a second indication message and a fourth identifier to the first entity, where the fourth identifier is a data network access identifier of a data network that no longer serves the terminal device, the first identifier includes the fourth identifier, and the second indication message is used to delete the information corresponding to the fourth identifier in the first information.

[0072] As a possible implementation manner, the sending unit sending the second indication information and the fourth identifier to the first entity includes: sending the second indication information, the fourth identifier and the fifth identifier to the first entity, the fifth identifier being the application identification information of the application deployed in the data network corresponding to the fourth identifier; the second indication information being used to delete the information corresponding to the fourth identifier in the first information includes: the second indication information being used to delete the information corresponding to the fourth identifier and the fifth identifier in the first information.

[0073] The seventh aspect discloses a communication device, which can be a first entity or a module (for example, a chip) in the first entity. The device may include: a receiving unit, used to receive a first request information from a terminal device, the first request information including first application identification information; a determining unit, used to determine second information based on the first information obtained from the session management function network element, the second information being the DNS extension mechanism client subnet option corresponding to the first identifier or the address information of the local DNS resolver, the first identifier being the data network access identifier of the data network with the smallest service range or the closest distance to the terminal device in the data network corresponding to the second identifier, and the second identifier being at least one data network access identifier corresponding to the current location of the terminal device; a sending unit, used to send DNS request information to a centralized DNS server or a local DNS resolver based on the second information, the DNS request information including the first application identification information, and the DNS request information being used to obtain the address information of the application server.

[0074] As a possible implementation manner, the receiving unit is further configured to receive the first information from the session management function network element, where the first information includes the second information.

[0075] As a possible implementation manner, the receiving unit is further configured to receive the first information from the session management function network element, where the first information includes the first application identification information and second information corresponding to the first application identification information.

[0076] As a possible implementation, the first information also includes a third identifier and third information corresponding to the third identifier, wherein the third identifier is application identification information of an application deployed in the data network corresponding to the second identifier, and the third information is the DNS extension mechanism client subnet option or the address information of the local DNS resolver corresponding to the third identifier.

[0077] As a possible implementation manner, the sending unit is also used to send the first application identification information and / or first indication information to the session management function network element, the first application identification information is used to obtain the first information, and the first indication information is used to instruct the session management function network element to send the first information.

[0078] As a possible implementation manner, the receiving unit is further used to receive second indication information from the session management function network element, and the second indication information is used to indicate deletion of the first information; the device also includes: a deleting unit, used to delete the first information according to the second indication information.

[0079] As a possible implementation manner, the sending unit sends DNS request information to a centralized DNS server or a local DNS resolver according to the second information, including: when the second information is the DNS extension mechanism client subnet option, sending DNS request information to the centralized DNS server, and the DNS request also includes the second information; when the second information is the address information of the local DNS resolver, sending DNS request information to the local DNS resolver.

[0080] The eighth aspect discloses a communication device, which can be a session management function network element or a module (for example, a chip) in the session management function network element. The device may include: a sending unit, for sending first information to a first entity, the first information including second information, or first application identification information and second information corresponding to the first application identification information, the second information is the DNS extension mechanism client subnet option corresponding to the first identification or the address information of the local DNS resolver, the first identification is the data network access identification of the data network with the smallest service range or the closest distance to the terminal device in the data network corresponding to the second identification, the second identification is at least one data network access identification corresponding to the current location of the terminal device, and the first information is used to determine the second information.

[0081] As a possible implementation, the first information also includes a third identifier and third information corresponding to the third identifier, wherein the third identifier is application identification information of an application deployed in the data network corresponding to the second identifier, and the third information is the DNS extension mechanism client subnet option or the address information of the local DNS resolver corresponding to the third identifier.

[0082] As a possible implementation, the device also includes: a receiving unit, used to receive the first application identification information and / or first indication information from the first entity; the sending unit, specifically used to send the first information to the first entity based on the first application identification information and / or the first indication information.

[0083] As a possible implementation manner, the sending unit is further configured to send second indication information to the first entity, where the second indication information is used to instruct deletion of the first information.

[0084] A ninth aspect discloses a communication device, which may be a first entity or a module (e.g., a chip) within the first entity. The communication device may include a processor, a memory, an input interface, and an output interface, the input interface being used to receive information from another communication device outside the communication device, and the output interface being used to output information to another communication device outside the communication device. When the processor executes a computer program stored in the memory, the processor performs the communication method disclosed in the first aspect or any embodiment of the first aspect.

[0085] In a tenth aspect, a communication device is disclosed, which may be a session network function element or a module (e.g., a chip) within a session network function element. The communication device may include a processor, a memory, an input interface, and an output interface. The input interface is configured to receive information from a communication device other than the communication device, and the output interface is configured to output information to the communication device other than the communication device. When the processor executes a computer program stored in the memory, the processor performs the communication method disclosed in the second aspect or any embodiment of the second aspect.

[0086] In an eleventh aspect, a communication device is disclosed, which may be a first entity or a module (e.g., a chip) within the first entity. The communication device may include a processor, a memory, an input interface, and an output interface, the input interface being configured to receive information from another communication device other than the communication device, and the output interface being configured to output information to another communication device other than the communication device. When the processor executes a computer program stored in the memory, the processor executes the communication method disclosed in the third aspect or any embodiment of the third aspect.

[0087] A twelfth aspect discloses a communication device, which may be a session network function element or a module (e.g., a chip) within the session network function element. The communication device may include a processor, a memory, an input interface, and an output interface. The input interface is configured to receive information from a communication device other than the communication device, and the output interface is configured to output information to the communication device other than the communication device. When the processor executes a computer program stored in the memory, the processor performs the communication method disclosed in the fourth aspect or any embodiment of the fourth aspect.

[0088] A thirteenth aspect discloses a communication system, which includes the communication device of the ninth aspect and the communication device of the tenth aspect.

[0089] A fourteenth aspect discloses a communication system, which includes the communication device of the eleventh aspect and the communication device of the twelfth aspect.

[0090] The fifteenth aspect discloses a computer-readable storage medium having a computer program or computer instructions stored thereon. When the computer program or computer instructions are executed, the communication method disclosed in the above aspects is implemented.

[0091] A sixteenth aspect discloses a chip, comprising a processor for executing a program stored in a memory, wherein when the program is executed, the chip executes the above method.

[0092] As a possible implementation, the memory is located outside the chip.

[0093] A seventeenth aspect discloses a computer program product, which includes a computer program code. When the computer program code is executed, the above-mentioned communication method is executed. BRIEF DESCRIPTION OF THE DRAWINGS

[0094] Figure 1 This is a schematic diagram of a 5G network architecture disclosed in an embodiment of the present application;

[0095] Figure 2 This is a schematic diagram of a network architecture disclosed in an embodiment of the present application;

[0096] Figure 3 This is another network architecture diagram disclosed in an embodiment of the present application;

[0097] Figure 4 This is a schematic diagram of a local service discovery disclosed in an embodiment of the present application;

[0098] Figure 5 This is a flow chart of a communication method disclosed in an embodiment of the present application;

[0099] Figure 6 This is a schematic diagram of DNAI deployment disclosed in an embodiment of the present application;

[0100] Figure 7 This is a flow chart of another communication method disclosed in an embodiment of the present application;

[0101] Figure 8 This is a flow chart of another communication method disclosed in an embodiment of the present application;

[0102] Figure 9 This is a flow chart of another communication method disclosed in an embodiment of the present application;

[0103] Figure 10 This is a flow chart of another communication method disclosed in an embodiment of the present application;

[0104] Figure 11 This is a flow chart of another communication method disclosed in an embodiment of the present application;

[0105] Figure 12 This is a schematic structural diagram of a communication device disclosed in an embodiment of the present application;

[0106] Figure 13 is a structural diagram of another communication device disclosed in an embodiment of the present application;

[0107] Figure 14 This is a structural diagram of another communication device disclosed in an embodiment of the present application;

[0108] Figure 15 This is a structural diagram of another communication device disclosed in an embodiment of the present application;

[0109] Figure 16 This is a structural diagram of another communication device disclosed in an embodiment of the present application;

[0110] Figure 17 This is a structural diagram of another communication device disclosed in an embodiment of the present application. DETAILED DESCRIPTION

[0111] The embodiments of the present application disclose a communication method, apparatus, and computer-readable storage medium for saving communication resources, which are described in detail below.

[0112] In order to better understand the communication method, device, and computer-readable storage medium disclosed in the embodiments of the present application, the network architecture used in the embodiments of the present application is described below. Figure 1 , Figure 1 This is a schematic diagram of a 5G network architecture disclosed in the embodiment of this application. Figure 1As shown, the 5G network architecture may include user equipment (UE), (radio) access network (R)AN) equipment, user plane function (UPF) network element, data network (DN), access and mobility management function (AMF) network element, session management function (SMF) network element, policy control function (PCF) network element, application function (AF) network element, unified data management (UDM) network element, authentication server function (AUSF) network element and network slice selection function (NSSF) network element. Different network elements or devices can communicate through interfaces, Figure 1 The interface name shown is only an example and is not specifically limited in the embodiments of the present application.

[0113] UE, which may also be called terminal equipment, mobile station (MS), mobile terminal (MT), etc., is a device that provides voice and / or data connectivity to users. The terminal device may be a handheld terminal, a laptop computer, a subscriber unit, a cellular phone, a smart phone, a wireless data card, a personal digital assistant (PDA) computer, a tablet computer, a wireless modem, a handheld device, a laptop computer, a cordless phone or a wireless local loop (WLL) station, a machine type communication (MTC) terminal, a wearable device (such as a smart watch, a smart bracelet, a pedometer, etc.), an in-vehicle device (such as a car, a bicycle, an electric car, an airplane, a ship, a train, a high-speed rail, etc.), a virtual reality (VR) device, an augmented reality (AR) device, a wireless terminal in industrial control, a smart home device (such as a refrigerator, a television, an air conditioner, an electric meter, etc.), an intelligent robot, a workshop device, a wireless terminal in self-driving, a wireless terminal in remote medical surgery, a smart grid, etc. The invention relates to wireless terminals in a network, a wireless terminal in a transportation safety grid, a wireless terminal in a smart city, a wireless terminal in a smart home, flying equipment (for example, smart robots, hot air balloons, drones, airplanes), or other devices that can access the network. Figure 1 The terminal device is shown as UE, which is only an example and does not limit the terminal device. The UE can access the DN by establishing a session between the UE-(R)AN device-UPF-DN, that is, a protocol data unit (PDU) session.

[0114] (R)AN equipment provides wireless access for UEs and is primarily responsible for air interface-side functions such as wireless resource management, quality of service (QoS) flow management, data compression, and encryption. (R)AN equipment can include various base stations, such as macro base stations, micro base stations (also known as small stations), relay stations, and access points. (R)AN equipment can also include wireless fidelity (WiFi) access points (APs). (R)AN equipment can also include worldwide interoperability for microwave access (WiMax) base stations (BSs).

[0115] The UPF network element is primarily responsible for user message processing, such as forwarding and billing. It can receive user messages from the DN and transmit them to the UE via RAN equipment. It can also receive user messages from the UE via RAN equipment and forward them to the DN. The transmission resources and scheduling functions that the UPF network element provides to the UE are managed and controlled by the SMF network element.

[0116] A DN can be the internet, an IP Multimedia Service (IMS) network, or a local area network (e.g., a multi-access edge computing (MEC) network). The DN is the destination for a UE's PDU session access. The DN includes or deploys an application server, which can communicate with the UE and provide services to the UE.

[0117] The AMF network element can access the UE's non-access stratum (NAS) signaling (including session management (SM) signaling) through the N1 interface and the RAN signaling through the N2 interface to complete the UE registration process and forwarding of SM signaling and mobility management.

[0118] The SMF network element is primarily responsible for session management in mobile networks, such as session establishment, modification, release, and update. Specific functions include allocating IP addresses to users and selecting UPF network elements that provide packet forwarding functions.

[0119] The PCF network element can be responsible for terminal device policy management, including both mobility-related policies and PDU session-related policies, such as QoS policies and billing policies.

[0120] The AF network element mainly supports interaction with the 3rd Generation Partnership Project (3GPP) core network to provide services, affecting service flow routing, access network capability exposure, policy control, etc.

[0121] The UDM network element is responsible for user key management, user identity processing, access authorization of subscription data, UE network function entity management, session and service continuity management, short message push, lawful interception, contract management, short message management, and is used to control user data, such as contract information management.

[0122] The AUSF network element may be responsible for authenticating and authorizing UE access.

[0123] The above network elements in the core network can also be called functional entities, which can be network elements implemented on dedicated hardware, software instances running on dedicated hardware, or instances of virtualized functions on an appropriate platform. For example, the above virtualization platform can be a cloud platform.

[0124] It should be noted that Figure 1 The system architecture shown is not limited to including only the network elements shown in the figure, but may also include other devices not shown in the figure, which will not be listed one by one in this application.

[0125] It should be noted that the embodiment of the present application does not limit the distribution form of each network element in the core network. Figure 1 The distribution form shown is only exemplary and is not limited in this application.

[0126] It should be understood that the names of all network elements in this application are only examples. In future communications, such as 6G, they may also be called other names, or in future communications, such as 6G, the network elements involved in this application may also be replaced by other entities or devices with the same functions, etc., and this application does not limit this. A unified explanation is given here and no further details will be given later.

[0127] It should be noted that Figure 1 The 5G network architecture shown does not constitute a limitation on the 5G network. Optionally, the method of the embodiment of the present application is also applicable to various future communication systems, such as 6G or other communication networks.

[0128] Figure 1 The 5G network architecture shown has only one UPF network element. Based on the above basic network architecture, 5G can also support the insertion of multiple session anchor UPF network elements on the user plane path (i.e., data path) of a PDU session to support the connection to the local DN, so that the UE can access the application server in the local DN nearby. Figure 2 , Figure 2 This is a network architecture diagram disclosed in the embodiment of this application. Figure 2 As shown, multiple UPF network elements are introduced into the network architecture of the communication system. These multiple UPF network elements can be respectively an uplink classifier (ULCL) / branching point (BP), a UPF PDU session anchor (PSA) 1 and a UPF PSA2. Among them, ULCL / BP can distribute the uplink data packet from the UE to PSA1 or PSA2 according to the distribution rules, and can also send the downlink data packet from PSA1 or PSA2 to the UE. There is an N6 interface between PSA1 and the DN. For example, the DN can be a DN located in a central data center (data central, DC). There is an N6 interface between PSA2 and the local DN. For example, the local DN can be located in a local DC or MEC node. Among them, the local DN can also be understood as a DN that deploys the application server in an edge hosting environment (EHE) closer to the UE, which can also be called EAS. When the UE has service requirements, the SMF network element can be inserted into the UPF network element corresponding to the local DN (i.e., local (L)-PSA) so that the UE can access the application server in the local DN nearby. For example, Figure 2 The PAS2 in is an L-PSA. It should be noted that Figure 2 The number of UPF network elements is only an example, and may include more or fewer UPFs, which is not limited in this application.

[0129] It should be noted that Figure 2 Only one L-PSA is shown in the figure, but it should be understood that multiple L-PSAs and multiple ULCL / BPs may also be included, and this application does not limit this. Figure 3 , Figure 3 This is another network architecture diagram disclosed in the embodiment of this application. Figure 3 As shown, the network architecture can have multiple L-PSAs, for example Figure 3 L-PSA1 and L-PSA2 in Figure 1. In this network architecture, the ULCL / BP can connect to multiple L-PSAs. In this example, the ULCL / BP can be co-located with L-PSA1 to connect to MEC1; L-PSA2 can connect to MEC2, and the PSA can connect to the central DC. It should be understood that the ULCL / BP and L-PSA1 can also be two independent network elements or devices.

[0130] In order to better understand the embodiments of the present application, the application scenarios of the embodiments of the present application are described below. In the traditional mobile network architecture and deployment of the fourth generation mobile communication technology (4G) and before, the user plane equipment basically complies with the tree topology deployment. Uplink user messages pass through the base station and the backhaul network, and finally access the data network through the centrally deployed anchor gateway. These anchor gateways are generally deployed at a higher position in the data network, such as a regional center room. This topology is relatively simple, which facilitates operators to perform centralized business management and message processing at the anchor gateway.

[0131] With the explosive growth of mobile service traffic, this deployment model is increasingly unable to support this rapidly increasing mobile service traffic model. On the one hand, in a network with centralized anchor gateway deployment, the increasing traffic ultimately concentrates at the gateways and core equipment rooms, placing increasingly stringent requirements on backhaul network bandwidth, equipment room throughput, and gateway specifications. On the other hand, the long-distance backhaul network and complex transmission environment from base stations to anchor gateways result in significant latency and jitter in user message transmission.

[0132] To address these issues, the industry has proposed EC. EC enables local processing of distributed service traffic by moving UPF network elements and service processing capabilities to the network edge, avoiding excessive traffic concentration and significantly reducing the specifications required for core equipment rooms and centralized gateways. It also shortens backhaul network distances, reducing user message latency and jitter, and enabling the deployment of ultra-low-latency services.

[0133] In EC deployment scenarios, EASs corresponding to certain services may be distributed across multiple network edges. These EASs provide the same services and content, but have different IP addresses. When a UE needs to access a service, EC scenarios require it to access the closest available EAS. Therefore, the UE needs to obtain the IP address of the appropriate EAS.

[0134] See also Figure 4 , Figure 4 This is a schematic diagram of a local service discovery disclosed in an embodiment of this application. Figure 4As shown, the UE can send a first request message to the first entity, and the first request message can carry or include application identification information. After receiving the first request message from the UE, the first entity can send a second request message to the SMF network element, and the second request message includes the application identification information. After receiving the second request message from the first entity, the SMF network element can send information related to the current location of the UE to the first entity, such as the DNS extended mechanisms for DNS (EDNS) client subnet option (ECS option), the address information of the local DNS resolver, etc. After the first entity receives the above information from the SMF network element, when the above information is the ECS option, it can send a first DNS request message to the centralized DNS server, and the first DNS request message includes the above application identification information and the above information. After receiving the first DNS request message from the first prompt, the centralized DNS server can determine the application identification information and the address information of the application server corresponding to the above information, and send the address information of the application server to the UE through the first entity. When the above information is the address information of the local DNS resolver, the first entity may send a second request message to the local DNS resolver, and the second request message includes the above application identification information. After the local DNS resolver receives the second request message from the first entity, when the application identification information and the address information of the application server corresponding to the above information can be determined, the address information of the application server can be sent to the UE; when the application identification information and the address information of the application server corresponding to the above information cannot be determined, a third request message may be sent to the centralized DNS server or the local DNS server. The second request information and the third request information may be DNS request information, or other request information, which is not limited here. The ECS option may be the address information of the local UPF network element, or the address information of the MEC platform subnet corresponding to the current location of the terminal device, or the address information of the network segment where the terminal device is located, or information about the location of other associated terminal devices. The address information may be an IP address, or other information that can uniquely identify the address.

[0135] In the above method, each time a UE sends a request message, the first entity needs to perform two signaling exchanges with the SMF network element. Both the first entity and the SMF network element serve a large number of UEs, and each UE generates a large number of request messages. This results in excessive signaling exchanges between the first entity and the SMF network element, resulting in a large amount of signaling overhead and resource constraints. In addition, the need for two signaling exchanges between the first entity and the SMF network element increases the delay for the UE to obtain the address information of the application server.

[0136] It should be understood that the above-mentioned first entity may be an independent device or network element, or may be a function or model deployed on other devices or network elements.

[0137] Based on the above network architecture, please refer to Figure 5 , Figure 5 This is a flow chart of a communication method disclosed in an embodiment of the present application. Figure 5 As shown, the communication method may include the following steps.

[0138] 501. A terminal device sends first request information including first application identification information to a first entity.

[0139] Accordingly, the first entity may receive first request information including first application identification information from the terminal device.

[0140] When the terminal device has a business demand, the terminal device can send a first request message to the first entity. The terminal device can send the first request message to the first entity through ULCL / BP and PSA, or send the first request message to the first entity through other devices or network elements, which are not limited here. The first request message can be DNS request information, or a DNS query (query) message, or other request information, which are not limited here. The application identification information is information used to identify the application, which can be a fully qualified domain name (FQDN), an application identity (AppID), a business identifier, or other information that can uniquely identify the application.

[0141] In one case, the first request information may not include the identifier of the terminal device, but the SMF network element can determine which terminal device sends the first request information through the PDU session that transmits the first request information.

[0142] In another case, the first request information may further include an identifier of the terminal device. The first entity may determine which terminal device sent the first request information based on the identifier of the terminal device.

[0143] 502. The first entity determines the second information based on the first application identification information and the first information obtained from the SMF network element.

[0144] After the first entity receives the first request information from the terminal device, it can determine the second information based on the first application identification information and the first information obtained from the SMF network element. The first entity can first search or match the first information including the first application identification information from the first information obtained from the SMF network element, and then obtain the second information corresponding to the first application identification information from the searched or matched first information. The second information can be information about the current location of the associated terminal device, that is, information associated with the current location of the terminal device. The second information can be an ECS option, or it can be the address information of the local DNS resolver, or it can be information about the location of other associated terminal devices.

[0145] In one implementation, the first information may include first application identification information and second information corresponding to the first application identification information. Furthermore, the first information may also include a third identification and third information corresponding to the third identification, where the third identification is application identification information of an application deployed in the data network corresponding to the first identification, and the third information is address information of the ECS option or local DNS resolver corresponding to the third identification.

[0146] The first information can be understood to include two parts: application identification information and fourth information. The fourth information is information about the current location of the associated terminal device, including the second information, and may also include the third information. The application identification information included in the first information and the fourth information can be in a one-to-one correspondence, that is, one application identification information only corresponds to one fourth information, and accordingly, one fourth information only corresponds to one application identification information. The application identification information included in the first information and the fourth information can also be in a many-to-one relationship, that is, one application identification information can correspond to one fourth information, and multiple application identification information can also correspond to one fourth information. The relationship between the application identification information and the fourth information can be expressed as a correspondence between the application identification information and the fourth information, and can be stored in a data table, key-value pair, context or other form, and there is no limitation on the storage form. For example, the correspondence between the application identification information and the fourth information can be as shown in Table 1 or Table 2:

[0147] Application identification information The Fourth Message Application 1 Information 1 Application 2 Information 2 … … Application K Information K

[0148] Table 1

[0149] Application identification information The Fourth Message Application 1 Information 1 Application 2 Information 1 … … Application K Information M

[0150] Table 2

[0151] K and M are integers greater than or equal to 1. In the above table, Application 1 to Application K are application identifiers, and Information 1 to Information K are information about the current location of the associated terminal device corresponding to the application identifier.

[0152] Furthermore, the first information may also include a data network access identifier (DNAI) corresponding to the first application identification information and the second information. The first information may also include a DNAI corresponding to the third identifier and the third information. DNAI is an identifier of a user plane access to one or more DN(s) where applications are deployed, connected to the data network where the application is deployed. DNAI can be an identifier of an access point for edge computing, or an identifier of an access (or location) of a server deployed at the edge of the network. When the first information includes DNAI, it can be understood that the first information can uniquely determine the information of the current location of an associated terminal device by an application identification information and a DNAI.

[0153] In another implementation, the first information may include first application identification information, a first identifier, and second information corresponding to the first application identification information and the first identifier, where the first identifier is at least one DNAI. The first information may also include a third identifier, the first identifier, and third information corresponding to the first identifier and the third identifier.

[0154] A DNAI and an application identification information included in the first information can uniquely identify a fourth information. The relationship between the DNAI, the application identification information, and the fourth information can be expressed as a corresponding relationship between the DNAI, the application identification information, and the fourth information. The storage can be in a data table, a key-value pair, a context, or other form, and the storage form is not limited. For example, the corresponding relationship between the DNAI, the application identification information, and the fourth information can be as shown in Table 3:

[0155] DNAI Application identification information The Fourth Message DNAI 1 Application 1 Information 1 DNAI 2 Application 2 Information 2 … … … DNAI K Application K Information K

[0156] Table 3

[0157] Information 1-Information K in Table 3 corresponds to K different information. The applications corresponding to Application 1-Application K can have the same application, and DNAI 1-DNAIK can also have the same one, but DNAI+application identification information cannot have the same one.

[0158] It can be seen that the first information can not only include the information currently required to determine the second information, but also include the information currently not required to determine the second information. This information may be used after the first entity receives other request information including application identification information, thereby reducing the interaction between the first entity and the SMF network element, thereby saving transmission resources.

[0159] The SMF network element may send the first information to the first entity. The SMF network element may proactively send the first information to the first entity. For example, when the SMF network element detects that the terminal device has established a PDU session, or when the DNAI corresponding to the current location of the terminal device has changed, the SMF network element may send the first information to the first entity. The SMF network element may also send the first information to the first entity after receiving information for obtaining the first information from the first entity.

[0160] Accordingly, the first entity can receive the first information from the SMF network element. The first information can be received by the first entity before or at the same time as receiving the first request information, or can be received by the first entity after receiving the first request information. When the first information is received by the first entity before receiving the first request information, the first information can be actively sent to the first entity by the SMF, or can be obtained from the SMF network element after the first entity has previously received other request information including application identification information. Therefore, after the first entity receives the first request information, it does not need to obtain the first information from the SMF network element, which can reduce the interaction between the first entity and the SMF network element, thereby saving transmission resources.

[0161] After the first entity receives the first request information from the terminal device, it can first determine whether there is the first information that can determine the second information. When it is determined that there is the first information that can determine the second information, the second information can be determined based on the first information and the first application identification information. When it is determined that there is no first information that can determine the second information, the first application identification information and / or the first indication information can be sent to the SMF network element first. After the SMF network element receives the first application identification information and / or the first indication information from the first entity, it can send the first information to the first entity based on the first application identification information and / or the first indication information. In addition, the SMF network element can also send the second information to the first entity together with the first information. When the SMF network element does not send the second information to the first entity, after the first entity receives the first information from the SMF network element, it can determine the second information based on the first application identification information and the first information.

[0162] When the first entity sends the first indication information to the SMF network element, the SMF network element can determine the first information based on the current location of the terminal device, that is, it can determine the first information based on the DNAI corresponding to the current location of the terminal device, that is, it can determine the first information based on the DNAI including the current location of the terminal device in the corresponding area in the DNAI. When the first entity sends the first application identification information to the SMF network element, the SMF network element can determine the first information based on the first application identification information, or it can determine the first information based on the first application identification information and the current location of the terminal device. When the first entity sends the first application identification information and the first indication information to the SMF network element, the SMF network element can determine the first information based on the first application identification information and the current location of the terminal device.

[0163] In addition, the SMF network element can also consider the service contract information of the terminal device, and can determine the first information based on the edge service signed by the terminal device in the service contract information, that is, determine the first information based on the application identification information and the first application identification information in the service contract information of the terminal device.

[0164] When the first entity sends the first application identification information to the SMF network element, the first information may include the first application identification information. In addition, the first information may also include other application identification information in addition to the first application identification information, the DNAI of the data network where the application corresponding to the application identification information is deployed, and the ECS option or local DNS resolver address corresponding to the application identification information and DNAI. The application identification information may include one or more of the following:

[0165] a) application identification information of some or all applications deployed in a first data network, where the first data network is a data network corresponding to the current location of the terminal device and on which the application corresponding to the first application identification information is deployed;

[0166] b) application identification information of an application deployed in the first data network but not in the second data network, where the second data network is a set of data networks corresponding to the current location of the terminal device and whose service range is included in the first data network;

[0167] c) application identification information of some or all applications deployed in the second data network;

[0168] d) Application identification information of some or all applications deployed in a third data network but not deployed in the first data network and the second data network, where the third data network is a collection of data networks whose service scope includes the first data network.

[0169] For an example, see Figure 6 , Figure 6This is a schematic diagram of DNAI deployment disclosed in the embodiment of this application. Figure 6 As shown, the service scope of DNAI3 is larger than the service scope of DNAI1 and the service scope of DNAI2. The service scope of DNAI3 includes the service scope of DNAI1 and the service scope of DNAI2, but there is no overlap between the service scope of DNAI1 and the service scope of DNAI2. The following is an example in which the application identification information is FQDN and the information of the current location of the associated terminal device is ECS option. DNAI1 is deployed with services S1 and S3. Service S1 corresponds to FQDN1 and ECS option1, and service 3 corresponds to FQDN3 and ECS option3. DNAI2 is deployed with service S2. Service S2 corresponds to FQDN2 and ECS option2. DNAI3 is deployed with services S3, S4 and S5. Service S3 corresponds to FQDN3 and ECS option3', service S4 corresponds to FQDN4 and ECS option4, and service S5 corresponds to FQDN5 and ECS option5. When the terminal device is currently within the service range of DNAI1 and DNAI3, after the SMF network element receives the request information containing FQDN4 from the first entity, the SMF network element may send FQDN4 and ECS option4 corresponding to FQDN4 (or FQDN4, DNAI3 and ECSoption4 corresponding to FQDN4 and DNAI3) to the first entity. In addition, the SMF network element may also send one or more of the following information to the first entity.

[0170] a) FQDN3 and ECS option 3' corresponding to FQDN3 (or FQDN3, DNAI3, and ECS option 3' corresponding to FQDN3 and DNAI3), FQDN5 and ECS option 5 corresponding to FQDN5 (or FQDN5, DNAI3, and ECS option 5 corresponding to FQDN5 and DNAI3);

[0171] b) FQDN5 and ECS option 5 corresponding to FQDN5 (or FQDN5, DNAI3, and ECS option 5 corresponding to FQDN5 and DNAI3);

[0172] c) FQDN1 and ECS option 1 corresponding to FQDN1 (or FQDN1, DNAI1, and ECS option 1 corresponding to FQDN1 and DNAI1), FQDN3 and ECS option 3 corresponding to FQDN3 (or FQDN3, DNAI1, and ECS option 3 corresponding to FQDN3 and DNAI1);

[0173] d) Due to Figure 6 There is no data network with a larger service range than the data network corresponding to DNAI3, so the corresponding information cannot be determined according to the above d). The service range of a data network can be the set of locations of all terminal devices that can access the data network.

[0174] When the terminal device is currently within the service range of DNAI1 and DNAI3, after the SMF network element receives the request information including FQDN1 from the first entity, the SMF network element may send FQDN1 and ECSoption1 corresponding to FQDN1 (or FQDN1, DNAI1 and ECS option1 corresponding to FQDN1 and DNAI1) to the first entity. In addition, the SMF network element may also send one or more of the following information to the first entity.

[0175] a) FQDN3 and ECS option 3 corresponding to FQDN3 (or FQDN3, DNAI1, and ECS option 3 corresponding to FQDN3 and DNAI1);

[0176] b) FQDN3 and ECS option 3 corresponding to FQDN3 (or FQDN3, DNAI1, and ECS option 3 corresponding to FQDN3 and DNAI1);

[0177] c) Due to Figure 6 There is no data network with a smaller service range than the data network corresponding to DNAI1, so the corresponding information cannot be determined according to the above c);

[0178] d) FQDN4 and ECS option 4 corresponding to FQDN4 (or FQDN4, DNAI3, and ECS option 4 corresponding to FQDN4 and DNAI3), FQDN5 and ECS option 5 corresponding to FQDN5 (or FQDN5, DNAI3, and ECS option 5 corresponding to FQDN5 and DNAI3).

[0179] The SMF network element can configure or obtain the area corresponding to DNAI, that is, the service scope of DNAI. The service scope of DNAI can be a specific location set. For example, a set of one or more tracking areas (TA) 1, TA2, ..., RAN_1, RAN_2 or cells (Cell)_1, Cell_2, etc. The service scope of DNAI can also be a set of geographic location information, such as longitude and latitude or administrative areas. The service scope of DNAI can also be a set of service scopes of one or more UPF network elements corresponding to DNAI. Among them, these one or more UPF network elements can serve the data network. The service scope of UPF network elements can be a specific location set or a set of geographic location information. The service scope of DNAI can also be identified by the service scope of the application server (AS) and / or enabler server (ES) deployed in the data network, wherein the expression of the service scope of AS or ES is the same as described above and will not be repeated. The service scope of DNAI can also be a set of locations of terminal devices accessing the data network corresponding to the DNAI.

[0180] When a PDU session is established, or the DNAI corresponding to the terminal device changes, the SMF network element can send a second identifier to the first entity. The second identifier is the DNAI corresponding to the current location of the terminal device. The first entity can determine the second information based on the first application identification information, the second identifier and the first information. The first entity can first search or match the first information including the first application identification information from the first information obtained from the SMF network element, and then obtain the second information corresponding to the first application identification information and the second identifier from the searched or matched first information.

[0181] In one case, the interaction between the first entity and the SMF network element can determine which terminal device the information transmitted is from through a PDU session. In another case, the information for the terminal device transmitted between the first entity and the SMF network element may include an identifier of the terminal device, so that it can be determined which terminal device the information transmitted is from based on the identifier of the terminal device.

[0182] 503. The first entity sends DNS request information to the centralized DNS server or the local DNS resolver according to the second information.

[0183] Accordingly, the centralized DNS server or the local DNS resolver receives DNS request information from the first entity. The DNS request information is used to obtain address information of the application server, that is, the address information of the application server where the application corresponding to the first application identification information is deployed.

[0184] After the first entity determines the second information based on the first application identification information and the first information obtained from the SMF network element, when the second information is an ECS option, the first entity may send DNS request information to the centralized DNS server, and the DNS request may further include the second information. In the case where the first request information is DNS request information, the DNS request information sent by the first entity to the centralized DNS server includes the second information in addition to the first application identification information, as compared to the first request information.

[0185] When the second information is the address information of the local DNS resolver, the first entity may send DNS request information to the local DNS resolver. In the case where the first request information is the DNS request information, the DNS request information sent by the first entity to the local DNS resolver is the same as the first request information.

[0186] The detailed description of the centralized DNS server and local DNS resolver can be found in Figure 4 The corresponding description.

[0187] After the SMF network element sends the first information to the first entity, when the SMF network element senses that the DNAI corresponding to the terminal device has changed, it can send the second indication information and the fourth identifier to the first entity. Accordingly, the first entity can receive the second indication information and the fourth identifier from the SMF network element, and then delete the information corresponding to the fourth identifier in the first information according to the second indication information. The fourth identifier is the DNAI of the data network that no longer serves the terminal device, and the first identifier can include the fourth identifier. For example, when the fourth identifier is DNAI 1 in Table 3, the first entity can delete DNAI 1 in the first information, the application identification information corresponding to DNAI 1, and the fourth information.

[0188] The SMF network element may send second indication information, a fourth identifier, and a fifth identifier to the first entity, where the fifth identifier is application identification information of an application deployed in the data network corresponding to the fourth identifier. The first entity may delete the information corresponding to the fourth identifier and the fifth identifier in the first information based on the second indication information. For example, when the fourth identifier is DNAI 1 in Table 3 and the fifth identifier is Application 1 in Table 3, the first entity deletes information 1 corresponding to DNAI 1 and Application 1.

[0189] Based on the above network architecture, please refer to Figure 7 , Figure 7 This is a flow chart of another communication method disclosed in the embodiment of this application. Figure 7 As shown, the communication method may include the following steps.

[0190] 701. The terminal device establishes a PDU session.

[0191] 702. The SMF network element sends a second identifier to the first entity.

[0192] Correspondingly, the first entity receives the second identifier from the SMF network element.

[0193] When a PDU session associated with a terminal device is established, or when a change in the DNAI corresponding to the terminal device is detected, the SMF network element may send a second identifier to the first entity. The change in the DNAI corresponding to the terminal device may be a change in all or part of the DNAI corresponding to the terminal device.

[0194] In one case, when the MEC deployment situation changes, the AF network element can send a notification to the SMF network element. After receiving the notification from the AF network element, the SMF network element can perceive the current deployment situation of the MEC based on the notification. In another case, the SMF network element can perceive the current location of the terminal device through the AMF network element and / or the location management function (LMF) network element, and then determine the DNAI corresponding to the current location of the terminal device, that is, the DNAI of the corresponding area including the current location of the terminal device. The location of the terminal device can be identified by TA, cell ID, etc.

[0195] The SMF network element can send the second identifier to the first entity through signaling, messages, etc. For example, when the first entity is a UPF network element or is deployed on a UPF network element, the SMF network element can send the second identifier to the first entity through N4 Session Modification signaling. When the first entity is an independent network element or device, the SMF network element can send the second identifier to the first entity through Nsmf_EventExposure_Notify signaling. The above is only an exemplary description of the SMF network element sending the second identifier to the first entity through signaling, messages, etc., and does not constitute a limitation thereto.

[0196] 703. The terminal device sends first request information including first application identification information to the first entity.

[0197] Correspondingly, the first entity receives first request information from the terminal device.

[0198] 704. The first entity determines second information according to the first application identification information, the second identification, and the first information.

[0199] After receiving the first request information from the terminal device, the first entity can determine the second information based on the first application identification information, the second identification information, and the first information. If the first entity fails to determine the second information, that is, the first information does not exist in the first entity or the existing first information does not include the information required to determine the second information, steps 705 and 706 can be performed first. If the second information can be directly received through step 706, the first entity can skip step 704. If the second information cannot be received through step 706, the first entity needs to perform step 704 again and then perform step 707.

[0200] 705. The first entity sends first application identification information and / or first indication information to the SMF network element.

[0201] Correspondingly, the SMF network element receives the first application identification information and / or the first indication information from the first entity.

[0202] When the first entity sends the first application identification information and the first indication information to the SMF network element, the first application identification information and the first indication information can be sent through the same signaling, message, etc. For example, when the first entity is a UPF network element or is deployed on a UPF network element, the first entity can send the first application identification information and the first indication information to the SMF network element through an N4 report message. When the first entity is an independent network element or device, the first entity can send the first application identification information and the first indication information to the SMF network element through Nsmf_EventExposure_AppRelocationInfo, or it can first send an AF request (AFrequest) to the PCF network element, and then the PCF network element can send an Npcf_SMPolicyControl_Updata Request to the SMF network element. The AF request and the Npcf_SMPolicyControl_Updata Request include the first application identification information and the first indication information. When the first entity sends information to the SMF network element, it can communicate with the SMF network element directly, or it can communicate with the SMF network element through other network elements or devices such as NEF network elements and PCF network elements. The above is only an exemplary description of the first entity sending the first application identification information and the first indication information to the SMF network element through signaling, messages, etc., and does not constitute a limitation thereto.

[0203] 706. The SMF network element sends the first information to the first entity according to the first application identification information and / or the first indication information.

[0204] Accordingly, the first entity receives the first information from the SMF network element.

[0205] The SMF network element may send the first information to the first entity through signaling, messages, etc. For example, when the N4 report message is used in step 704, the SMF network element may send the first information to the first entity through the N4 report Ack message; when the Nsmf_EventExposure_AppRelocationInfo is used in step 704 or forwarded via the PCF network element, the SMF network element may send the first information to the first entity through the Nsmf_EventExposure_Notify. The above is merely an exemplary description of the SMF network element sending the first information to the first entity through signaling, messages, etc., and does not constitute a limitation thereto.

[0206] It should be understood that the first information sent in step 705 is applicable to all terminal devices that can be served by the first entity.

[0207] 707. The first entity sends DNS request information to the centralized DNS server or the local DNS resolver according to the second information.

[0208] Accordingly, the centralized DNS server or the local DNS resolver receives the DNS request information from the first entity.

[0209] After the first entity sends the DNS request information to the centralized DNS server or the local DNS resolver according to the second information, the remaining EAS discovery process may continue to be executed.

[0210] The first entity may delete part or all of the first information at any time or upon being triggered by any specific condition, in accordance with certain conditions or rules. For example, the deletion may be periodic, or when the remaining storage space is less than a first threshold, or when the storage time of the information is greater than or equal to a second threshold.

[0211] The detailed description of steps 701 to 707 can be referred to the above related description and will not be repeated here.

[0212] Based on the above network architecture, please refer to Figure 8 , Figure 8 This is a flow chart of another communication method disclosed in the embodiment of this application. Figure 8 As shown, the communication method may include the following steps.

[0213] 801. The terminal device establishes a PDU session.

[0214] 802. The terminal device sends first request information including first application identification information to the first entity.

[0215] Correspondingly, the first entity receives first request information from the terminal device.

[0216] 803. The first entity determines second information according to the first application identification information and the first information.

[0217] After receiving the first request information from the terminal device, the first entity can determine the second information based on the first application identification information and the first information. If the first entity fails to determine the second information, that is, if the first information does not exist in the first entity or the existing first information does not include the information required to determine the second information, steps 804 and 805 can be performed first. If the second information can be directly received through step 805, the first entity does not need to perform step 803. If the second information cannot be received through step 805, the first entity needs to perform step 803 again.

[0218] 804. The first entity sends first application identification information and / or first indication information to the SMF network element.

[0219] Correspondingly, the SMF network element receives the first application identification information and / or the first indication information from the first entity.

[0220] 805. The SMF network element sends the first information to the first entity according to the first application identification information and / or the first indication information.

[0221] Accordingly, the first entity receives the first information from the SMF network element.

[0222] The first information sent in step 805 can only be used as a basis for determining the second information when receiving a request message including application identification information from the terminal device. It cannot be used as a basis for determining the second information when receiving a request message including application identification information from other terminal devices. That is, the first information can only serve the corresponding terminal device and cannot serve other terminal devices. Therefore, after receiving the first information, the first entity can establish a relationship between the first information and the terminal device.

[0223] 806. The first entity sends DNS request information to the centralized DNS server or the local DNS resolver according to the second information.

[0224] Accordingly, the centralized DNS server or the local DNS resolver receives the DNS request information from the first entity.

[0225] 807. The SMF network element sends the second indication information and the fourth identifier to the first entity.

[0226] Correspondingly, the first entity receives the second indication information and the fourth identifier from the SMF network element.

[0227] When the SMF network element senses that the DNAI corresponding to the terminal device has changed, the SMF network element can send the second indication information and the fourth identifier to the first entity, or it can send the second indication information, the fourth identifier and the fifth identifier to the first entity.

[0228] It should be understood that due to different deployment situations of the MEC platform, when the terminal device is in the same location, the corresponding DNAI may be different for different services. When the location of the terminal device does not change, but the service changes, if only part of the service changes, the SMF network element can send the second indication information, the fourth identifier and the fifth identifier to the first entity; if all services change, the SMF network element can send the second indication information and the fourth identifier to the first entity. Different services correspond to different application identification information.

[0229] 808. The first entity deletes the information corresponding to the fourth identifier in the first information according to the second instruction information.

[0230] The first entity may delete the information corresponding to the fourth identifier in the first information according to the second indication information, or may delete the information corresponding to the fourth identifier and the fifth identifier in the first information according to the second indication information.

[0231] For example, if the terminal device is in Figure 6 Within the service range of DNAI1, when the terminal device moves from the service range of DNAI1 to the service range of DNAI2, since the terminal device is still within the service range of DNAI3, the fourth identifier is DNAI1, and the first entity can delete the DNAI1, the FQDN corresponding to DNAI1, and the ECS option corresponding to DNAI1 in the first information corresponding to the above-mentioned terminal device, such as FQDN1 and the ECS option1 corresponding to FQDN1 (or FQDN1, DNAI1, and the ECS option1 corresponding to FQDN1 and DNAI1), FQDN3 and the ECS option3 corresponding to FQDN3 (or FQDN3, DNAI1, and the ECS option3 corresponding to FQDN3 and DNAI1).

[0232] The detailed description of steps 801 to 808 can refer to the above related description and will not be repeated here.

[0233] Based on the above network architecture, please refer to Figure 9 , Figure 9 This is a flow chart of another communication method disclosed in the embodiment of this application. Figure 9 As shown, the communication method may include the following steps.

[0234] 901. A terminal device sends first request information including first application identification information to a first entity.

[0235] Correspondingly, the first entity receives first request information including first application identification information from the terminal device.

[0236] Here, step 901 is the same as step 501 , and a detailed description may refer to step 501 .

[0237] 902. The first entity determines the second information based on the first information obtained from the SMF network element.

[0238] After the first entity receives the first request information from the terminal device, it can determine the second information based on the first information obtained from the SMF network element. The second information is the ECS option corresponding to the first identifier or the address information of the local DNS resolver, the first identifier is the DNAI of the data network with the smallest service range in the data network corresponding to the second identifier, the data network with the closest distance to the above-mentioned terminal device, or the data network that can reflect the most accurate location of the above-mentioned terminal device, and the second identifier is at least one DNAI corresponding to the current location of the above-mentioned terminal device. The first identifier can be the DNAI of the data network with the smallest service range in the data network corresponding to the second identifier, or the DNAI of the data network with the closest distance to the above-mentioned terminal device, or the DNAI of the data network that can reflect the most accurate location of the above-mentioned terminal device.

[0239] In one implementation, the first information may include the second information. It can be seen that the first information may only include the address information of the ECSoption or the local domain name system DNS resolver.

[0240] In another implementation, the first information may include first application identification information and second information corresponding to the first application identification information. The first information may also include a third identification and third information corresponding to the third identification, where the third identification is application identification information of an application deployed in the data network corresponding to the second identification, and the third information is address information of an ECS option or a local DNS resolver corresponding to the third identification.

[0241] When it is assumed that the second information is only related to the first identifier, the first information only includes the ECS option or the address information of the local domain name system DNS resolver. When there is no such assumption, the first information may include the application identifier information and the ECS option or the address information of the local DNS resolver corresponding to the application identifier information.

[0242] It should be understood that the first information can only be used by the above-mentioned terminal device as a basis for determining the second information, and cannot be used by other terminal devices.

[0243] For other detailed descriptions of step 902 , please refer to the relevant descriptions in step 502 .

[0244] 903. The first entity sends DNS request information to the centralized DNS server or the local DNS resolver.

[0245] Among them, step 903 is the same as step 503, and the detailed description can refer to step 503.

[0246] After the SMF network element sends the first information to the first entity, when it senses that the first identifier corresponding to the current location of the terminal device has changed, it can send a second indication information to the first entity. Accordingly, the first entity can receive the second indication information from the SMF network element and then delete the first information according to the second indication information, that is, delete the first information corresponding to the terminal device.

[0247] Based on the above network architecture, please refer to Figure 10 , Figure 10 This is a flow chart of another communication method disclosed in the embodiment of this application. Figure 10 As shown, the communication method may include the following steps.

[0248] 1001. The terminal device establishes a PDU session.

[0249] 1002. The SMF network element sends first information to the first entity.

[0250] In one implementation, the first information may include the second information. In another implementation, the first information may include first application identification information and second information corresponding to the first application identification information. The first information may also include a third identification and third information corresponding to the third identification, where the third identification is application identification information of an application deployed in the data network corresponding to the second identification, and the third information is address information of an ECS option or a local DNS resolver corresponding to the third identification. For a detailed description of the first information, please refer to the relevant description in step 902.

[0251] Among them, step 1002 is similar to step 702, and a detailed description can refer to step 702. The difference is that in step 702, the DNAI corresponding to the terminal device is sensed to change and sent, while in step 1002, the first identifier corresponding to the current location of the terminal device is sensed to change and sent.

[0252] For example, when the terminal device is Figure 6When the service range of DNAI1 in the data network moves to the service range of DNAI2, and DNAI2 is the DNAI of the data network with the smallest service range among the DNAIs corresponding to the terminal device, the closest distance to the terminal device, or the data network that can reflect the most accurate location of the above-mentioned terminal device, the SMF network element can send ECS option2 (or FQDN2 and ECS option2 corresponding to FQDN2) to the first entity. When the SMF network element sends FQDN2 and ECS option2 corresponding to FQDN2 to the first entity, the SMF network element can also send FQDN3 and ECS option3' corresponding to FQDN3, FQDN4 and ECS option4 corresponding to FQDN4, and FQDN3 and ECS option5 corresponding to FQDN3 to the first entity.

[0253] It should be understood that when the above assumptions are met and the second information corresponding to DNAI1 and DNAI2 is the same, when the SMF network element perceives that the first identifier corresponding to the current location of the terminal device changes from DNAI1 to DNAI2, since the first information existing in the first entity is the same as the first information to be sent, the SMF network element may not repeatedly send the first information to the first entity, which can reduce the transmission of unnecessary information and thus save transmission resources.

[0254] It should be understood that when the above assumptions are not met, and the applications deployed in the data networks corresponding to DNAI1 and DNAI2 are the same, and the second information corresponding to each application is also the same, when the SMF network element perceives that the first identifier corresponding to the current location of the terminal device changes from DNAI1 to DNAI2, since the first information existing in the first entity is the same as the first information to be sent, the SMF network element may not repeatedly send the first information to the first entity, which can reduce the transmission of unnecessary information and thus save transmission resources.

[0255] In addition, the service contract information of the terminal device may also be considered. The first information may be determined based on the edge service contracted by the terminal device in the service contract information, that is, the first information may be determined based on the application identification information in the service contract information of the terminal device.

[0256] It should be understood that the first information can only be used by the above-mentioned terminal device as a basis for determining the second information, and cannot be used by other terminal devices.

[0257] 1003. The terminal device sends first request information including first application identification information to the first entity.

[0258] Correspondingly, the first entity receives first request information from the terminal device.

[0259] 1004. The first entity determines second information according to the first application identification information and the first information.

[0260] After the first entity receives the first request information from the terminal device, it can determine the second information based on the most recent first information and the first application identification information in the first information of the terminal device received from the SMF network element. The second information is the ECS option corresponding to the first identifier or the address information of the local DNS resolver. The first identifier is the DNAI of the data network with the smallest service range and the closest distance to the above-mentioned terminal device in the data network corresponding to the second identifier, which can reflect the most accurate location of the above-mentioned terminal device. The second identifier is at least one DNAI corresponding to the current location of the above-mentioned terminal device.

[0261] 1005. The first entity sends DNS request information to the centralized DNS server or the local DNS resolver according to the second information.

[0262] Accordingly, the centralized DNS server or the local DNS resolver receives the DNS request information from the first entity.

[0263] Step 1005 is similar to step 707 , and a detailed description may refer to step 707 .

[0264] For detailed description of steps 1001 to 1005 , please refer to the above related description and will not be repeated here.

[0265] Based on the above network architecture, please refer to Figure 11 , Figure 11 This is a flow chart of another communication method disclosed in the embodiment of this application. Figure 11 As shown, the communication method may include the following steps.

[0266] 1101. The terminal device establishes a PDU session.

[0267] 1102. The terminal device sends first request information including first application identification information to the first entity.

[0268] Correspondingly, the first entity receives first request information from the terminal device.

[0269] 1103. The first entity determines second information based on the first application identification information and the first information.

[0270] The second information is the ECS option or address information of the local DNS resolver corresponding to the first identifier. The first identifier is the DNAI of the data network corresponding to the second identifier, which has the smallest service range, or is closest to the above-mentioned terminal device, or can reflect the most accurate location of the above-mentioned terminal device. The second identifier is at least one DNAI corresponding to the current location of the above-mentioned terminal device.

[0271] After receiving the first request information from the terminal device, the first entity can determine the second information based on the first application identification information and the first information. If the first entity fails to determine the second information, that is, if the first information does not exist in the first entity or the existing first information does not include the information required to determine the second information, steps 1104 and 1105 can be performed first. If the second information can be directly received through step 1105, the first entity does not need to perform step 1103. If the second information cannot be received through step 1105, the first entity needs to perform step 1103 again.

[0272] 1104. The first entity sends first application identification information and / or first indication information to the SMF network element.

[0273] Correspondingly, the SMF network element receives the first application identification information and / or the first indication information from the first entity.

[0274] 1105. The SMF network element sends the first information to the first entity according to the first application identification information and / or the first indication information.

[0275] Accordingly, the first entity receives the first information from the SMF network element.

[0276] The first information sent in step 1105 is only useful for the terminal device, and is useless for other terminal devices. Therefore, after receiving the first information, the first entity can establish a relationship between the first information and the terminal device.

[0277] In one implementation, the first information may include the second information. In another implementation, the first information may include first application identification information and second information corresponding to the first application identification information. The first information may also include a third identification and third information corresponding to the third identification, where the third identification is application identification information of an application deployed in the data network corresponding to the second identification, and the third information is address information of the ECS option or local DNS resolver corresponding to the third identification.

[0278] 1106. The first entity sends DNS request information to the centralized DNS server or the local DNS resolver according to the second information.

[0279] Accordingly, the centralized DNS server or the local DNS resolver receives the DNS request information from the first entity.

[0280] 1107. The SMF network element sends second indication information to the first entity.

[0281] Correspondingly, the first entity receives second indication information from the SMF network element.

[0282] When the SMF network element senses that the first identifier corresponding to the terminal device has changed, the SMF network element can send a second indication message to the first entity.

[0283] 1108. The first entity deletes the first information according to the second instruction information.

[0284] The first entity may delete the first information according to the second indication information, that is, delete the first information corresponding to the terminal device.

[0285] The detailed description of steps 1101 to 1108 can be referred to the above related description and will not be repeated here.

[0286] It should be understood that the functions performed by the terminal device in the above communication method can also be performed by a module (for example, a chip) in the terminal device, the functions performed by the first entity can also be performed by a module (for example, a chip) in the first entity, the functions performed by the SMF network element can also be performed by a module (for example, a chip) in the SMF network element, the functions performed by the DNS server can also be performed by a module (for example, a chip) in the DNS server, and the functions performed by the DNS resolver can also be performed by a module (for example, a chip) in the DNS resolver.

[0287] It should be understood that the SMF network element in the above communication method can be replaced by other mobile network control plane network elements or devices.

[0288] It should be understood that the relevant information in the above different embodiments can be referenced to each other.

[0289] Based on the above network architecture, please refer to Figure 12 , Figure 12 This is a schematic diagram of the structure of a communication device disclosed in an embodiment of the present application. Figure 12 As shown, the communication device may include:

[0290] The receiving unit 1201 is configured to receive first request information from a terminal device, where the first request information includes first application identification information;

[0291] A determining unit 1202 is configured to determine second information based on the first application identification information and the first information obtained from the session network function network element, where the second information is address information of the ECS option or the local DNS resolver;

[0292] The sending unit 1203 is configured to send DNS request information to the centralized DNS server or the local DNS resolver according to the second information, where the DNS request information includes the first application identification information, and the DNS request information is used to obtain address information of the application server.

[0293] In one embodiment, the receiving unit 1201 is further configured to receive first information from a session management function network element, where the first information includes first application identification information and second information corresponding to the first application identification information.

[0294] In one embodiment, the receiving unit 1201 is further used to receive first information from a session management function network element, where the first information includes first application identification information, a first identification, and second information corresponding to the first application identification information and the first identification, and the first identification is at least one data network access identification.

[0295] In one embodiment, the receiving unit 1201 is further configured to receive a second identifier from a session management function network element, where the second identifier is a data network access identifier corresponding to the current location of the terminal device;

[0296] The determining unit 1202 is specifically configured to determine the second information according to the first application identification information, the second identification, and the first information obtained from the session network function network element.

[0297] In one embodiment, the sending unit 1203 is also used to send first application identification information and / or first indication information to the session management function network element before the receiving unit receives the first information from the session management function network element, the first application identification information is used to obtain the first information, and the first indication information is used to instruct the session management function network element to send the first information.

[0298] In one embodiment, the first information also includes a third identifier, the first identifier, and third information corresponding to the first identifier and the third identifier, the third identifier is the application identification information of the application deployed in the data network corresponding to the first identifier, and the third information is the address information of the ECS option or local DNS resolver corresponding to the third identifier.

[0299] In one embodiment, the first information also includes a third identifier and third information corresponding to the third identifier, the third identifier is the application identification information of the application deployed in the data network corresponding to the first identifier, and the third information is the address information of the ECS option or local DNS resolver corresponding to the third identifier.

[0300] In one embodiment, the receiving unit 1201 is further configured to receive second indication information and a fourth identifier from a session management function network element, where the fourth identifier is a data network access identifier of a data network that no longer serves the terminal device, and the first identifier includes the fourth identifier;

[0301] The communication device may further include:

[0302] The deleting unit 1204 is configured to delete the information corresponding to the fourth identifier in the first information according to the second indication information.

[0303] In one embodiment, the receiving unit 1201 receives the second indication information and the fourth identifier from the session management function network element, including:

[0304] receiving second indication information, a fourth identifier, and a fifth identifier from a session management function network element, where the fifth identifier is application identification information of an application deployed in a data network corresponding to the fourth identifier;

[0305] The deleting unit 1204 is specifically configured to delete the information corresponding to the fourth identifier and the fifth identifier in the first information.

[0306] In one embodiment, the sending unit 1203 sends the DNS request information to the centralized DNS server or the local DNS resolver according to the second information, including:

[0307] When the second information is an ECS option, a DNS request message is sent to the centralized DNS server, where the DNS request also includes the second information;

[0308] When the second information is the address information of the local DNS resolver, the DNS request information is sent to the local DNS resolver.

[0309] For a more detailed description of the receiving unit 1201, the determining unit 1202, the sending unit 1203 and the deleting unit 1204, please refer to the above Figure 5 、 Figure 7 and Figure 8 The relevant description of the first entity in the method embodiment shown is directly obtained and will not be repeated here.

[0310] Based on the above network architecture, please refer to Figure 13 , Figure 13 This is a schematic diagram of the structure of another communication device disclosed in the embodiment of this application. Figure 13 As shown, the communication device may include:

[0311] Sending unit 1301 is used to send first information to a first entity, where the first information includes first application identification information and second information corresponding to the first application identification information, or first application identification information, a first identifier, and second information corresponding to the first application identification information and the first identifier, the first identifier is at least one data network access identifier, and the second information is address information of an ECS option or a local DNS resolver. The first information is used by the first entity to determine the second information.

[0312] In one embodiment, the sending unit 1301 is further configured to send a second identifier to the first entity, where the second identifier is a data network access identifier corresponding to the current location of the terminal device;

[0313] The first information used to determine the second information includes:

[0314] The first information and the second identifier are used to determine the second information.

[0315] In one embodiment, the communication device may further include:

[0316] The receiving unit 1302 is configured to receive first application identification information and / or first indication information from a first entity;

[0317] The sending unit 1301 sending the first information to the first entity includes:

[0318] The first information is sent to the first entity according to the first application identification information and / or the first indication information.

[0319] In one embodiment, the first information also includes a third identifier, the first identifier, and third information corresponding to the first identifier and the third identifier, the third identifier is the application identification information of the application deployed in the data network corresponding to the first identifier, and the third information is the address information of the ECS option or local DNS resolver corresponding to the third identifier.

[0320] In one embodiment, the first information also includes a third identifier and third information corresponding to the third identifier, the third identifier is the application identification information of the application deployed in the data network corresponding to the first identifier, and the third information is the client subnet option or the address information of the local DNS resolver corresponding to the third identifier.

[0321] In one embodiment, the sending unit 1301 is also used to send a second indication message and a fourth identifier to the first entity, where the fourth identifier is a data network access identifier of a data network that no longer serves the terminal device, the first identifier includes the fourth identifier, and the second indication message is used to delete the information corresponding to the fourth identifier in the first information.

[0322] In one embodiment, the sending unit 1301 sending the second indication information and the fourth identifier to the first entity includes:

[0323] Sending the second indication information, the fourth identifier, and the fifth identifier to the first entity, where the fifth identifier is application identification information of the application deployed in the data network corresponding to the fourth identifier;

[0324] The second instruction information is used to delete the information corresponding to the fourth identifier in the first information, including:

[0325] The second indication information is used to delete the information corresponding to the fourth identifier and the fifth identifier in the first information.

[0326] For a more detailed description of the sending unit 1301 and the receiving unit 1302, please refer to the above Figure 5 、 Figure 7 and Figure 8 The relevant description of the SMF network element in the method embodiment shown is directly obtained and will not be repeated here.

[0327] Based on the above network architecture, please refer to Figure 14 , Figure 14 This is a structural diagram of another communication device disclosed in the embodiment of this application. Figure 14 As shown, the communication device may include:

[0328] The receiving unit 1401 is configured to receive first request information from a terminal device, where the first request information includes first application identification information;

[0329] a determining unit 1402, configured to determine second information based on first information obtained from a session management function network element, where the second information is the ECS option or address information of the local DNS resolver corresponding to the first identifier, the first identifier is a data network access identifier of a data network with the smallest service range or the closest distance to the terminal device among the data networks corresponding to the second identifier, and the second identifier is at least one data network access identifier corresponding to a current location of the terminal device;

[0330] The sending unit 1403 is configured to send DNS request information to the centralized DNS server or the local DNS resolver according to the second information, where the DNS request information includes the first application identification information and is used to obtain address information of the application server.

[0331] In one embodiment, the receiving unit 1401 is further configured to receive first information from a session management function network element, where the first information includes the second information.

[0332] In one embodiment, the receiving unit 1401 is further configured to receive first information from a session management function network element, where the first information includes first application identification information and second information corresponding to the first application identification information.

[0333] In one embodiment, the first information also includes a third identifier and third information corresponding to the third identifier, the third identifier is the application identification information of the application deployed in the data network corresponding to the second identifier, and the third information is the address information of the ECS option or local DNS resolver corresponding to the third identifier.

[0334] In one embodiment, the sending unit 1403 is further used to send first application identification information and / or first indication information to the session management function network element, the first application identification information is used to obtain the first information, and the first indication information is used to instruct the session management function network element to send the first information.

[0335] In one embodiment, the receiving unit 1401 is further configured to receive second indication information from a session management function network element, where the second indication information is used to instruct deletion of the first information;

[0336] The communication device may further include:

[0337] The deleting unit 1404 is configured to delete the first information according to the second instruction information.

[0338] In one embodiment, the sending unit 1403 sends the DNS request information to the centralized DNS server or the local DNS resolver according to the second information, including:

[0339] When the second information is an ECS option, a DNS request message is sent to the centralized DNS server, where the DNS request also includes the second information;

[0340] When the second information is the address information of the local DNS resolver, the DNS request information is sent to the local DNS resolver.

[0341] For a more detailed description of the receiving unit 1401, the determining unit 1402, the sending unit 1403 and the deleting unit 1404, please refer to the above Figures 9-11 The relevant description of the first entity in the method embodiment shown is directly obtained and will not be repeated here.

[0342] Based on the above network architecture, please refer to Figure 15 , Figure 15 This is a structural diagram of another communication device disclosed in the embodiment of this application. Figure 15 As shown, the communication device may include:

[0343] Sending unit 1501 is used to send first information to a first entity, where the first information includes second information, or first application identification information and second information corresponding to the first application identification information, the second information is the address information of the ECSoption or local DNS resolver corresponding to the first identification, the first identification is the data network access identification of the data network with the smallest service range or the closest distance to the terminal device in the data network corresponding to the second identification, and the second identification is at least one data network access identification corresponding to the current location of the terminal device. The first information is used to determine the second information.

[0344] In one embodiment, the first information also includes a third identifier and third information corresponding to the third identifier, the third identifier is the application identification information of the application deployed in the data network corresponding to the second identifier, and the third information is the address information of the ECS option or local DNS resolver corresponding to the third identifier.

[0345] In one embodiment, the communication device may further include:

[0346] The receiving unit 1502 is configured to receive first application identification information and / or first indication information from a first entity;

[0347] The sending unit 1501 is specifically configured to send first information to the first entity according to the first application identification information and / or the first indication information.

[0348] In one embodiment, the sending unit 1501 is further configured to send second indication information to the first entity, where the second indication information is used to instruct deletion of the first information.

[0349] For a more detailed description of the sending unit 1501 and the receiving unit 1502, please refer to the above Figures 9-11 The relevant description of the SMF network element in the method embodiment shown is directly obtained and will not be repeated here.

[0350] Based on the above network architecture, please refer to Figure 16 , Figure 16 This is a structural diagram of another communication device disclosed in the embodiment of this application. Figure 16 As shown, the communication device may include a processor 1601, a memory 1602, an input interface 1603, an output interface 1604, and a bus 1605. The memory 1602 may be independent or connected to the processor 1601 via the bus 1605. The memory 1602 may also be integrated with the processor 1601. The bus 1605 is used to connect these components.

[0351] In one embodiment, the communication device may be a first entity or a module (e.g., a chip) within the first entity. When the computer program instructions stored in the memory 1602 are executed, the processor 1601 is used to control the receiving unit 1201 and the sending unit 1203 to perform the operations performed in the above embodiments. The processor 1601 is also used to perform the operations performed by the determining unit 1202 and the deleting unit 1204 in the above embodiments. The input interface 1603 is used to perform the operations performed by the receiving unit 1201 in the above embodiments, and the output interface 1604 is used to perform the operations performed by the sending unit 1203 in the above embodiments. The above-mentioned first entity or the module within the first entity may also be used to perform the above-mentioned Figure 5 、 Figure 7 and Figure 8 The various methods performed by the first entity in the method embodiment are not described in detail.

[0352] In one embodiment, the communication device may be an SMF network element or a module (e.g., a chip) within the SMF network element. When the computer program instructions stored in the memory 1602 are executed, the processor 1601 is used to control the sending unit 1301 and the receiving unit 1302 to perform the operations performed in the above embodiment, the input interface 1603 is used to perform the operations performed by the receiving unit 1302 in the above embodiment, and the output interface 1604 is used to perform the operations performed by the sending unit 1301 in the above embodiment. The above-mentioned SMF network element or the module within the SMF network element may also be used to perform the above-mentioned Figure 5 、 Figure 7 and Figure 8 The various methods executed by the SMF network element in the method embodiment are not described in detail.

[0353] In one embodiment, the communication device may be a first entity or a module (e.g., a chip) within the first entity. When the computer program instructions stored in the memory 1602 are executed, the processor 1601 is used to control the receiving unit 1401 and the sending unit 1403 to perform the operations performed in the above-mentioned embodiment. The processor 1601 is also used to perform the operations performed by the determining unit 1402 and the deleting unit 1404 in the above-mentioned embodiment. The input interface 1603 is used to perform the operations performed by the receiving unit 1401 in the above-mentioned embodiment, and the output interface 1604 is used to perform the operations performed by the sending unit 1403 in the above-mentioned embodiment. The above-mentioned first entity or the module within the first entity may also be used to perform the above-mentioned Figures 9-11 The various methods performed by the first entity in the method embodiment are not described in detail.

[0354] In one embodiment, the communication device may be an SMF network element or a module (e.g., a chip) within the SMF network element. When the computer program instructions stored in the memory 1602 are executed, the processor 1601 is used to control the sending unit 1501 and the receiving unit 1502 to perform the operations performed in the above embodiment, the input interface 1603 is used to perform the operations performed by the receiving unit 1502 in the above embodiment, and the output interface 1604 is used to perform the operations performed by the sending unit 1501 in the above embodiment. The above SMF network element or the module within the SMF network element may also be used to perform the above Figures 9-11 The various methods executed by the SMF network element in the method embodiment are not described in detail.

[0355] Based on the above network architecture, please refer to Figure 17 , Figure 17 This is a structural diagram of another communication device disclosed in the embodiment of this application. Figure 17 As shown, the communication device may include an input interface 1701, a logic circuit 1702 and an output interface 1703. The input interface 1701 and the output interface 1703 are connected through the logic circuit 1702. The input interface 1701 is used to receive information from other communication devices, and the output interface 1703 is used to output, schedule or send information to other communication devices. The logic circuit 1702 is used to perform operations other than the operations of the input interface 1701 and the output interface 1703, such as implementing the functions implemented by the processor 1601 in the above embodiment. The communication device can be a network device or a module of a network device, a first terminal device or a module of a first terminal device, or a second terminal device or a module of a second terminal device. A more detailed description of the input interface 1701, the logic circuit 1702 and the output interface 1703 can be directly obtained by referring to the relevant description of the first entity and the SMF network element in the above method embodiment, and will not be repeated here.

[0356] An embodiment of the present application further discloses a computer-readable storage medium having instructions stored thereon, which, when executed, execute the method in the above method embodiment.

[0357] The embodiments of the present application further disclose a computer program product comprising instructions, which, when executed, perform the method in the above method embodiments.

[0358] The embodiment of the present application also discloses a communication system, which includes a network device, a first terminal device and a second terminal device. For detailed description, please refer to Figure 5 、 Figure 7-11 The communication method shown.

[0359] The specific implementation methods described above further illustrate the purpose, technical solutions and beneficial effects of this application. It should be understood that the above description is only the specific implementation methods of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent replacements, improvements, etc. made on the basis of the technical solutions of this application should be included in the scope of protection of this application.

Claims

1. A communication method, characterized in that: include: Receiving first request information from a terminal device, where the first request information includes first application identification information; determining second information based on the first application identification information and first information obtained from a session management function network element, where the second information is a DNS extension mechanism client subnet option or address information of a local domain name system DNS resolver; the first information includes the first application identification information, a first identifier, and second information corresponding to the first application identification information and the first identifier, where the first identifier is at least one data network access identifier; Sending DNS request information to a centralized DNS server or a local DNS resolver according to the second information, wherein the DNS request information includes the first application identification information, and the DNS request information is used to obtain address information of the application server; receiving second indication information and a fourth identifier from the session management function network element, where the fourth identifier is a data network access identifier of a data network that no longer serves the terminal device, and the first identifier includes the fourth identifier; According to the second indication information, the information corresponding to the fourth identifier in the first information is deleted.

2. The method according to claim 1, characterized in that The method further comprises: The first information is received from the session management function network element, where the first information includes the first application identification information and second information corresponding to the first application identification information.

3. The method according to claim 1, characterized in that The method further comprises: Receive the first information from the session management function network element, where the first information includes the first application identification information, a first identifier, and second information corresponding to the first application identification information and the first identifier, where the first identifier is at least one data network access identifier.

4. The method according to any one of claims 1 to 3, characterized in that The method further comprises: receiving a second identifier from the session management function network element, where the second identifier is a data network access identifier corresponding to the current location of the terminal device; The determining the second information according to the first application identification information and the first information obtained from the session management function network element includes: The second information is determined according to the first application identification information, the second identification, and the first information obtained from the session management function network element.

5. The method according to any one of claims 2 to 3, characterized in that: Before receiving the first information from the session management function network element, the method further includes: The first application identification information and / or first indication information is sent to the session management function network element, where the first application identification information is used to obtain the first information, and the first indication information is used to instruct the session management function network element to send the first information.

6. The method according to claim 3, characterized in that The first information also includes a third identifier, a first identifier, and third information corresponding to the first identifier and the third identifier, wherein the third identifier is application identification information of an application deployed in the data network corresponding to the first identifier, and the third information is the DNS extension mechanism client subnet option or the address information of the local DNS resolver corresponding to the third identifier.

7. The method according to claim 2, characterized in that The first information also includes a third identifier and third information corresponding to the third identifier, wherein the third identifier is application identification information of an application deployed in the data network corresponding to the first identifier, and the third information is the DNS extension mechanism client subnet option or the address information of the local DNS resolver corresponding to the third identifier.

8. The method according to any one of claims 1 to 3, characterized in that The receiving the second indication information and the fourth identifier from the session management function network element includes: receiving second indication information, a fourth identifier, and a fifth identifier from the session management function network element, wherein the fifth identifier is application identification information of an application deployed in the data network corresponding to the fourth identifier; Deleting the information corresponding to the fourth identifier in the first information includes: Delete information corresponding to the fourth identifier and the fifth identifier in the first information.

9. The method according to any one of claims 1 to 3, characterized in that The sending of DNS request information to the centralized DNS server or the local DNS resolver according to the second information includes: When the second information is the DNS extension mechanism client subnet option, sending a DNS request message to a centralized DNS server, wherein the DNS request further includes the second information; When the second information is the address information of the local DNS resolver, DNS request information is sent to the local DNS resolver.

10. A communication method, characterized in that: include: Sending first information to a first entity, the first information including first application identification information and second information corresponding to the first application identification information, or the first application identification information, a first identifier, and second information corresponding to the first application identification information and the first identifier, the first identifier being at least one data network access identifier, and the second information being a DNS extension mechanism client subnet option or address information of a local domain name system (DNS) resolver, the first information being used by the first entity to determine the second information; Send a second indication message and a fourth identifier to the first entity, where the fourth identifier is a data network access identifier of a data network that no longer serves the terminal device, the first identifier includes the fourth identifier, and the second indication message is used to delete the information corresponding to the fourth identifier in the first message.

11. The method according to claim 10, characterized in that The method further comprises: Sending a second identifier to the first entity, where the second identifier is a data network access identifier corresponding to the current location of the terminal device; The first information used to determine the second information includes: The first information and the second identifier are used to determine the second information.

12. The method according to claim 10 or 11, characterized in that The method further comprises: receiving the first application identification information and / or first indication information from the first entity; The sending the first information to the first entity includes: Send first information to the first entity according to the first application identification information and / or the first indication information.

13. The method according to any one of claims 10-11, characterized in that The first information also includes a third identifier, a first identifier, and third information corresponding to the first identifier and the third identifier, wherein the third identifier is application identification information of an application deployed in the data network corresponding to the first identifier, and the third information is the DNS extension mechanism client subnet option or the address information of the local DNS resolver corresponding to the third identifier.

14. The method according to any one of claims 10-11, characterized in that The first information also includes a third identifier and third information corresponding to the third identifier, wherein the third identifier is application identification information of an application deployed in the data network corresponding to the first identifier, and the third information is the DNS extension mechanism client subnet option or the address information of the local DNS resolver corresponding to the third identifier.

15. The method according to any one of claims 10-11, characterized in that The sending the second indication information and the fourth identifier to the first entity includes: Sending second indication information, a fourth identifier, and a fifth identifier to the first entity, where the fifth identifier is application identification information of an application deployed in the data network corresponding to the fourth identifier; The second indication information for deleting the information corresponding to the fourth identifier in the first information includes: The second indication information is used to delete information corresponding to the fourth identifier and the fifth identifier in the first information.

16. A communication method, characterized in that: include: Receiving first request information from a terminal device, where the first request information includes first application identification information; determining second information based on first information obtained from a session management function network element, the second information being a DNS extension mechanism client subnet option or address information of a local domain name system DNS resolver corresponding to the first identifier, the first identifier being a data network access identifier of a data network with the smallest service range or the closest distance to the terminal device in the data network corresponding to the second identifier, and the second identifier being at least one data network access identifier corresponding to a current location of the terminal device; Sending DNS request information to a centralized DNS server or a local DNS resolver according to the second information, wherein the DNS request information includes the first application identification information, and the DNS request information is used to obtain address information of the application server; receiving second indication information from the session management function network element, where the second indication information is used to instruct deletion of the first information; The first information is deleted according to the second instruction information.

17. The method according to claim 16, characterized in that The method further comprises: The first information is received from the session management function network element, where the first information includes the second information.

18. The method according to claim 16, characterized in that The method further comprises: The first information is received from the session management function network element, where the first information includes the first application identification information and second information corresponding to the first application identification information.

19. The method according to claim 18, characterized in that The first information also includes a third identifier and third information corresponding to the third identifier, wherein the third identifier is application identification information of an application deployed in the data network corresponding to the second identifier, and the third information is the DNS extension mechanism client subnet option or the address information of the local DNS resolver corresponding to the third identifier.

20. The method according to any one of claims 16 to 19, characterized in that: The method further comprises: Sending the first application identification information and / or first indication information to the session management function network element, where the first application identification information is used to obtain the first information, and the first indication information is used to instruct the session management function network element to send the first information; Receive the first information from the session management function network element.

21. The method according to any one of claims 16 to 19, characterized in that: The second information is the DNS extension mechanism client subnet option, and sending DNS request information to the centralized DNS server or the local DNS resolver according to the second information includes: Sending DNS request information to a centralized DNS server, where the DNS request also includes the second information.

22. The method according to any one of claims 16 to 19, characterized in that: The second information is the address information of the local DNS resolver, and the sending of the DNS request information to the centralized DNS server or the local DNS resolver according to the second information includes: Sending DNS request information to the local DNS resolver.

23. A communication method, characterized in that: include: Sending first information to a first entity, where the first information includes second information, or first application identification information and second information corresponding to the first application identification information, the second information being a DNS extension mechanism client subnet option or address information of a local domain name system DNS resolver corresponding to the first identification, the first identification being a data network access identifier of a data network with the smallest service range or closest distance to a terminal device among the data networks corresponding to the second identification, the second identification being at least one data network access identifier corresponding to a current location of the terminal device, and the first information being used to determine the second information; Second indication information is sent to the first entity, where the second indication information is used to instruct deletion of the first information.

24. The method according to claim 23, wherein The first information also includes a third identifier and third information corresponding to the third identifier, wherein the third identifier is application identification information of an application deployed in the data network corresponding to the second identifier, and the third information is the DNS extension mechanism client subnet option or the address information of the local DNS resolver corresponding to the third identifier.

25. The method according to claim 23 or 24, characterized in that The method further comprises: receiving the first application identification information and / or first indication information from the first entity; The sending of the first information to the first entity: Send first information to the first entity according to the first application identification information and / or the first indication information.

26. A communication device, characterized in that: include: A receiving unit, configured to receive first request information from a terminal device, where the first request information includes first application identification information; a determining unit, configured to determine second information based on the first application identification information and first information obtained from a session management function network element, where the second information is a DNS extension mechanism client subnet option or address information of a local domain name system DNS resolver; the first information includes the first application identification information, a first identifier, and second information corresponding to the first application identification information and the first identifier, where the first identifier is at least one data network access identifier; a sending unit, configured to send DNS request information to a centralized DNS server or a local DNS resolver according to the second information, wherein the DNS request information includes the first application identification information, and the DNS request information is used to obtain address information of the application server; The receiving unit is further configured to receive second indication information and a fourth identifier from the session management function network element, where the fourth identifier is a data network access identifier of a data network that no longer serves the terminal device, and the first identifier includes the fourth identifier; A deleting unit is used to delete the information corresponding to the fourth identifier in the first information according to the second indication information.

27. The device according to claim 26, characterized in that The receiving unit is further configured to receive the first information from the session management function network element, where the first information includes the first application identification information and second information corresponding to the first application identification information.

28. The device according to claim 26, characterized in that The receiving unit is further used to receive the first information from the session management function network element, where the first information includes the first application identification information, a first identifier, and second information corresponding to the first application identification information and the first identifier, where the first identifier is at least one data network access identifier.

29. The device according to any one of claims 26 to 28, characterized in that The receiving unit is further configured to receive a second identifier from the session management function network element, where the second identifier is a data network access identifier corresponding to the current location of the terminal device; The determining unit is specifically configured to determine the second information according to the first application identification information, the second identification, and the first information obtained from the session management function network element.

30. The device according to any one of claims 27-28, characterized in that The sending unit is further configured to send the first application identification information and / or first indication information to the session management function network element before the receiving unit receives the first information from the session management function network element, wherein the first application identification information is used to obtain the first information, and the first indication information is used to instruct the session management function network element to send the first information.

31. The device according to claim 28, characterized in that The first information also includes a third identifier, a first identifier, and third information corresponding to the first identifier and the third identifier, wherein the third identifier is application identification information of an application deployed in the data network corresponding to the first identifier, and the third information is the DNS extension mechanism client subnet option or the address information of the local DNS resolver corresponding to the third identifier.

32. The device according to claim 27, wherein The first information also includes a third identifier and third information corresponding to the third identifier, wherein the third identifier is application identification information of an application deployed in the data network corresponding to the first identifier, and the third information is the DNS extension mechanism client subnet option or the address information of the local DNS resolver corresponding to the third identifier.

33. The device according to any one of claims 26 to 28, characterized in that The receiving unit receiving the second indication information and the fourth identifier from the session management function network element includes: receiving second indication information, a fourth identifier, and a fifth identifier from the session management function network element, wherein the fifth identifier is application identification information of an application deployed in the data network corresponding to the fourth identifier; The deleting unit is specifically configured to delete information corresponding to the fourth identifier and the fifth identifier in the first information.

34. The device according to any one of claims 26 to 28, characterized in that The sending unit sending the DNS request information to the centralized DNS server or the local DNS resolver according to the second information includes: When the second information is the DNS extension mechanism client subnet option, sending a DNS request message to a centralized DNS server, wherein the DNS request further includes the second information; When the second information is the address information of the local DNS resolver, DNS request information is sent to the local DNS resolver.

35. A communication device, characterized in that: include: a sending unit, configured to send first information to a first entity, where the first information includes first application identification information and second information corresponding to the first application identification information, or first application identification information, a first identifier, and second information corresponding to the first application identification information and the first identifier, the first identifier being at least one data network access identifier, and the second information being a DNS extension mechanism client subnet option or address information of a local domain name system (DNS) resolver, the first information being used by the first entity to determine the second information; Send a second indication message and a fourth identifier to the first entity, where the fourth identifier is a data network access identifier of a data network that no longer serves the terminal device, the first identifier includes the fourth identifier, and the second indication message is used to delete the information corresponding to the fourth identifier in the first message.

36. The device according to claim 35, characterized in that The sending unit is further configured to send a second identifier to the first entity, where the second identifier is a data network access identifier corresponding to the current location of the terminal device; The first information used to determine the second information includes: The first information and the second identifier are used to determine the second information.

37. The device according to claim 35 or 36, characterized in that The device further comprises: a receiving unit, configured to receive the first application identification information and / or first indication information from the first entity; The sending unit sending the first information to the first entity includes: Send first information to the first entity according to the first application identification information and / or the first indication information.

38. The device according to any one of claims 35-36, characterized in that The first information also includes a third identifier, a first identifier, and third information corresponding to the first identifier and the third identifier, wherein the third identifier is application identification information of an application deployed in the data network corresponding to the first identifier, and the third information is the DNS extension mechanism client subnet option or the address information of the local DNS resolver corresponding to the third identifier.

39. The device according to any one of claims 35-36, characterized in that The first information also includes a third identifier and third information corresponding to the third identifier, wherein the third identifier is application identification information of an application deployed in the data network corresponding to the first identifier, and the third information is the DNS extension mechanism client subnet option or the address information of the local DNS resolver corresponding to the third identifier.

40. The device according to any one of claims 35-36, characterized in that The sending unit sending the second indication information and the fourth identifier to the first entity includes: Sending second indication information, a fourth identifier, and a fifth identifier to the first entity, where the fifth identifier is application identification information of an application deployed in the data network corresponding to the fourth identifier; The second indication information for deleting the information corresponding to the fourth identifier in the first information includes: The second indication information is used to delete information corresponding to the fourth identifier and the fifth identifier in the first information.

41. A communication device, characterized in that include: A receiving unit, configured to receive first request information from a terminal device, where the first request information includes first application identification information; a determining unit, configured to determine second information based on first information obtained from a session management function network element, where the second information is a DNS extension mechanism client subnet option or address information of a local domain name system DNS resolver corresponding to the first identifier, the first identifier is a data network access identifier of a data network with the smallest service range or the closest distance to the terminal device in the data network corresponding to the second identifier, and the second identifier is at least one data network access identifier corresponding to a current location of the terminal device; a sending unit, configured to send DNS request information to a centralized DNS server or a local DNS resolver according to the second information, wherein the DNS request information includes the first application identification information, and the DNS request information is used to obtain address information of the application server; The receiving unit is further configured to receive second indication information from the session management function network element, where the second indication information is used to instruct deletion of the first information; A deleting unit is used to delete the first information according to the second indication information.

42. The device according to claim 41, characterized in that The receiving unit is further configured to receive the first information from the session management function network element, where the first information includes the second information.

43. The device according to claim 41, characterized in that The receiving unit is further configured to receive the first information from the session management function network element, where the first information includes the first application identification information and second information corresponding to the first application identification information.

44. The device according to claim 43, characterized in that The first information also includes a third identifier and third information corresponding to the third identifier, wherein the third identifier is application identification information of an application deployed in the data network corresponding to the second identifier, and the third information is the DNS extension mechanism client subnet option or the address information of the local DNS resolver corresponding to the third identifier.

45. The device according to any one of claims 41 to 44, characterized in that The sending unit is further configured to send the first application identification information and / or first indication information to the session management function network element, where the first application identification information is used to obtain the first information, and the first indication information is used to instruct the session management function network element to send the first information; The receiving unit is further configured to receive the first information from the session management function network element.

46. ​​The device according to any one of claims 41 to 44, characterized in that The second information is the DNS extension mechanism client subnet option, and the sending unit sends the DNS request information to the centralized DNS server or the local DNS resolver according to the second information, including: Sending DNS request information to a centralized DNS server, where the DNS request also includes the second information.

47. The device according to any one of claims 41 to 44, characterized in that The second information is the address information of the local DNS resolver, and the sending unit sending the DNS request information to the centralized DNS server or the local DNS resolver according to the second information includes: Sending DNS request information to the local DNS resolver.

48. A communication device, characterized in that include: a sending unit, configured to send first information to a first entity, where the first information includes second information, or first application identification information and second information corresponding to the first application identification information, the second information being a DNS extension mechanism client subnet option or address information of a local domain name system DNS resolver corresponding to the first identification, the first identification being a data network access identifier of a data network with the smallest service range or closest distance to a terminal device among the data networks corresponding to the second identification, the second identification being at least one data network access identifier corresponding to a current location of the terminal device, and the first information being used to determine the second information; Second indication information is sent to the first entity, where the second indication information is used to instruct deletion of the first information.

49. The device according to claim 48, characterized in that The first information also includes a third identifier and third information corresponding to the third identifier, wherein the third identifier is application identification information of an application deployed in the data network corresponding to the second identifier, and the third information is the DNS extension mechanism client subnet option or the address information of the local DNS resolver corresponding to the third identifier.

50. The device according to claim 48 or 49, characterized in that The device further comprises: a receiving unit, configured to receive the first application identification information and / or first indication information from the first entity; The sending unit is specifically configured to send the first information to the first entity according to the first application identification information and / or the first indication information.

51. A communication device, characterized in that The method comprises a processor, a memory, an input interface and an output interface, wherein the input interface is used to receive information from other communication devices outside the communication device, the output interface is used to output information to other communication devices outside the communication device, and the processor calls the computer program stored in the memory to implement the method according to any one of claims 1 to 9.

52. A communication device, characterized in that It includes a processor, a memory, an input interface and an output interface, the input interface is used to receive information from other communication devices outside the communication device, the output interface is used to output information to other communication devices outside the communication device, and the processor calls the computer program stored in the memory to implement the method according to any one of claims 10 to 15.

53. A communication device, characterized in that It includes a processor, a memory, an input interface and an output interface, the input interface is used to receive information from other communication devices outside the communication device, the output interface is used to output information to other communication devices outside the communication device, and the processor calls the computer program stored in the memory to implement the method described in any one of claims 16-22.

54. A communication device, characterized in that It includes a processor, a memory, an input interface and an output interface, the input interface is used to receive information from other communication devices outside the communication device, the output interface is used to output information to other communication devices outside the communication device, and the processor calls the computer program stored in the memory to implement the method described in any one of claims 23-25.

55. A communication system, characterized in that include: The device as claimed in claim 51 and the device as claimed in claim 52.

56. A communication system, characterized in that include: The device as claimed in claim 53 and the device as claimed in claim 54.

57. The system according to claim 56, wherein: A centralized DNS server is also included for receiving the DNS request information.

58. The system according to claim 56, wherein: A local DNS resolver is also included for receiving the DNS request information.

59. The system according to any one of claims 56-58, characterized in that It also includes a terminal device for sending the first request information to the apparatus as claimed in claim 51.

60. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program or computer instructions, and when the computer program or computer instructions are executed, the method according to any one of claims 1 to 25 is implemented.

61. A chip, characterized in that: The chip comprises a processor for executing a program stored in a memory, and when the program is executed, the chip executes the method according to any one of claims 1 to 25.

62. A communication method, characterized in that: include: The first entity receives first request information from the terminal device, where the first request information includes first application identification information; The first entity sends the first application identification information to a session management function network element; The session management function network element sends first information to the first entity according to the first application identification information; The first entity determines second information based on the first information, where the second information is a DNS extension mechanism client subnet option or address information of a local domain name system DNS resolver corresponding to the first identifier, the first identifier is a data network access identifier of a data network with the smallest service range or the closest distance to the terminal device among the data networks corresponding to the second identifier, and the second identifier is at least one data network access identifier corresponding to a current location of the terminal device; The first entity sends DNS request information to a centralized DNS server or a local DNS resolver according to the second information, where the DNS request information includes the first application identification information and is used to obtain address information of the application server; The first entity receives second indication information from the session management function network element, where the second indication information is used to instruct deletion of the first information; The first entity deletes the first information according to the second indication information.

63. The method according to claim 62, characterized in that The second information is the DNS extension mechanism client subnet option, and sending DNS request information to the centralized DNS server or the local DNS resolver according to the second information includes: sending DNS request information to the centralized DNS server, the DNS request also including the second information; The method further includes: the centralized DNS server receiving the DNS request information.

64. The method according to claim 62, characterized in that The second information is address information of the local DNS resolver, and the sending of the DNS request information to the centralized DNS server or the local DNS resolver according to the second information includes: sending the DNS request information to the local DNS resolver; The method further includes: the local DNS resolver receiving the DNS request information.

65. The method according to any one of claims 62-64, characterized in that The method further comprises: The terminal device sends the first request information.

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