Communication method and apparatus, and computer-readable storage medium

A communication apparatus, comprising:

• a memory storing instructions;
• and
• a processor connected to the memory, wherein the processor is configured to execute the instructions to perform operations for:
• receiving first request information from a terminal device, wherein the first request information includes first application identification information;
• determining second information based on first information from a session management function network element, wherein the second information includes extended mechanisms for domain name system (DNS) client subnet option corresponding to a first identifier, wherein the first identifier is a data network access identifier of a data network, in data networks corresponding to a second identifier, closest to the terminal device, and the second identifier includes at least one data network access identifier corresponding to a current location of the terminal device;
• and
• sending DNS request information to a central DNS server based on the second information, wherein the DNS request information includes the first application identification information, and the DNS request information is useable to obtain address information of an application server,
• wherein the processor is further configured to execute the instructions to perform operations for:
• receiving second indication information and a fourth identifier from the session management function network element, wherein
• the fourth identifier is a data network access identifier of, among the data networks corresponding to the second identifier, a data network that no longer serves the terminal device, and
• the first identifier includes the fourth identifier;
• and
• deleting, based on the second indication information, information corresponding to the fourth identifier from the first information.

A system, comprising:

• a first entity comprising a first processor;
• and
• a session management function network element comprising a second processor, wherein
• the first processor is configured to execute instructions to perform operations for:
• receiving first request information from a terminal device, wherein the first request information includes first application identification information;
• determining second information based on first information from the session management function network element, wherein the second information includes extended mechanisms for domain name system (DNS) client subnet option corresponding to a first identifier, wherein the first identifier is a data network access identifier of a data network, in data networks corresponding to a second identifier, closest to the terminal device, and the second identifier includes at least one data network access identifier corresponding to a current location of the terminal device;
• and
• sending DNS request information to a central DNS server based on the second information, wherein the DNS request information includes the first application identification information, and the DNS request information is useable to obtain address information of an application server;
• and
• the second processor is configured to execute instructions to perform operations for:
• sending the first information to the first entity,
• wherein
• the second processor is configured to execute instructions to perform operations for:
• sending second indication information to the first entity, in response to sensing that the first identifier which is the data network access identifier of the data network closest to the terminal device changes, wherein the second indication information indicates to delete the first information;
• and
• the first processor is configured to execute instructions to perform operations for:
• receiving the second indication information from the session management function network element;
• and
• deleting the first information based on the second indication information.