Connection resume method and apparatus

A communications apparatus comprising:

• a transceiver;
• at least one processor;
• and
• one or more memories coupled to the at least one processor storing programming instructions for execution by the at least one processor to cause the communications apparatus to:
• send a first message that carries first indication information to a first network device, wherein the first indication information is used to indicate to calculate a resume message authentication code (MAC) value based on a first parameter set, and the first parameter set comprises a resume cause value and a radio resource control (RRC) resume request message, wherein the first message includes an access stratum (AS) security mode complete message;
• and
• receive a second message from the first network device, wherein
• when the second message carries second indication information, send an RRC resume request message that carries the resume MAC value to a second network device, wherein the second indication information is used to indicate to verify the resume MAC value based on the first parameter set.

A communications apparatus comprising:

• a transceiver;
• at least one processor;
• and
• one or more memories coupled to the at least one processor storing programming instructions for execution by the at least one processor to cause the communications apparatus to:
• receive a first message that is from a terminal device and that carries first indication information, wherein the first indication information is used to indicate to calculate a resume message authentication code (MAC) value based on a first parameter set, and the first parameter set comprises a resume cause value and a radio resource control (RRC) resume request message, wherein the first message includes an access stratum (AS) security mode complete message;
• and
• send a second message that carries second indication information to the terminal device, wherein the second indication information is used to indicate to verify the resume MAC value based on the first parameter set.