Link re-establishment method, apparatus, and system

A communication method applied to a communication system comprising a control plane (CP) functional entity and a target radio access node (RAN), the method comprising:

• receiving, by the target radio access node (RAN), a re-establishment request message from user equipment (UE);
• sending, by the target RAN, a first message to the control plane (CP) functional entity based on the re-establishment request message, wherein the re-establishment request message comprises a second message authentication code (MAC) generation parameter and an MAC of the UE, the first message comprises the second MAC generation parameter and the MAC;
• receiving, by the CP functional entity, the first message from the target RAN;
• verifying, by the CP functional entity, the MAC based on the first message;
• when verification of the MAC succeeds, sending, by the CP functional entity, a context of the UE to the target RAN;
• receiving, by the target RAN, the context of the UE;
• and
• sending, by the target RAN, a re-establishment response message to the UE.

A communication apparatus comprising:

• at least one processor and a memory;
• wherein
• the memory, configured to store a program;
• and
• the at least one processor, configured to execute the program stored in the memory to enable the communication apparatus to implement the following operations:
• receiving a first message from a target radio access node (RAN), wherein the first message comprises a second message authentication code (MAC) generation parameter and an MAC of user equipment (UE);
• verifying the MAC based on the first message;
• and
• when verification of the MAC succeeds, sending a context of the UE to the target RAN.