Hi All, Stuck on a scenario, want to understand what should be the UAC behavior if it receive "481 Call/Transaction Does Not Exist" for the CANCEL it sent to terminate the transaction.
RFC3261 is not much clear on this part, here is the call flow, UAC UAS ------------------------> INVITE <------------------------ 100 Trying <------------------------ 180 Ringing ------------------------> CANCEL <------------------------ 481 CANCEL As per my understanding, the primary purpose of the CANCEL request is to terminate a pending transaction. The CANCEL request is never sent to terminate a SIP dialog or, a session. The UAC upon receiving the error response to a CANCEL request should destroy the transaction ( e.g. INVITE ) for which it issued the CANCEL request. INVITE transaction should be destroyed on the UAC side? UAC must send the ACK for 481 to clear the transaction/ dialog at UAS side? Cheers, Aman _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
