Hi, according to RFC 3261 - 16.10 CANCEL Processing (Proxy) If a response context is not found, the element does not have any knowledge of the request to apply the CANCEL to. It MUST statelessly forward the CANCEL request (it may have statelessly forwarded the associated request previously).
In my case I do know that my proxy doesn't behave as a stateless proxy so I see no reason to forward a CANCEL if it doesn't match a server transaction. And I do know that such forwarded CANCEL will not success. I've also told that such requeriment (statelessly forwarding a CANCEL if not transaction is matched) would never work in some scenarios as IMS. Basically, if I do know that my proxy always behaves statefully there is no use case in forwarding a CANCEL not matching a server transaction. IMHO such "MUST" in 16.10 should be relaxed and local policies allowed. BTW, could an always-stateful proxy reply 481 upon receipt of a CANCEL not matching a server transaction? or should it ignore it? (this is not contemplated in RFC 3261 as it mandates statelessly forwarding of the CANCEL, but I hope such requeriment should be removed/relaxed in a future revision of SIP protocol). Thanks a lot. -- Iñaki Baz Castillo <[email protected]> _______________________________________________ Sip mailing list https://www.ietf.org/mailman/listinfo/sip This list is essentially closed and only used for finishing old business. Use [email protected] for questions on how to develop a SIP implementation. Use [email protected] for new developments on the application of sip. Use [email protected] for issues related to maintenance of the core SIP specifications.
