Question: During IP-CAN session termination, what action should a PCEF take if it knows the PCRF has restarted since the IP-CAN session establishment?
Option 1: Send a CC-Request with CC-Request-Type AVP set to "TERMINATION_REQUEST" along with available access network information.
Option 2: Initiate a new Diameter Credit Control session before sending any termination requests.
Option 3: Not send a CC-Request to inform the PCRF, as PCC contexts and Diameter sessions are lost upon PCRF restart.
Option 4: Send a CC-Answer directly without receiving a CC-Request to acknowledge the session termination.
Explanation: When a PCRF restarts, it loses PCC contexts and Diameter sessions. Given this, informing the PCRF about an IP-CAN session termination after its restart is unnecessary, as the context for that session is already lost. Thus, the PCEF should not send a CC-Request in such cases, aligning with efficient resource management and acknowledging the loss of session context due to the PCRF's restart.