Yes, in this case, a transaction stateful proxy should send a CANCEL to Bob when the 1xx is received. Yes, you do need to save "state", but that can be as simple as a flag in the client transaction that indicates a CANCEL should be sent when a 1xx arrives.
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Iñaki Baz Castillo Sent: Thursday, June 09, 2011 7:15 PM To: Bob Penfield Cc: [email protected] Subject: Re: [Sip-implementors] About CANCEL in a proxy (no changes to server/client transaction) 2011/6/10 Iñaki Baz Castillo <[email protected]>: > - Alice calls Bob through a proxy. > - Proxy sends the INVITE to Bob and replies 100 to Alice. > - Proxy gets no provisional response fmo Bob. > - Alice sends CANCEL after a while. > - Proxy replies 200 for CANCEL. > - Proxy doesn't send CANCEL to Bob as there is not 1xx response. > - Some seconds later Bob replies 1xx. > - Should then the proxy send a CANCEL to Bob? If so, the proxy must keep some "state" for the CANCEL. This is, the proxy receives the CANCEL, generates a CANCEL for each pending branch (which has already replies a 1xx) and "stores" a state somewhere, so when pending branches reply their first 1xx, the proxy automatically sends the CANCEL to them. Am I right? Thanks a lot. -- Iñaki Baz Castillo <[email protected]> _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
