----- Original Message ----- From: "Del Stevens" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Monday, April 02, 2007 7:31 PM Subject: [Sip-implementors] CANCEL with/without 1xx To tag
>I have not seen anywhere confirmation one way or another on this topic. > > > F1 A ----- INVITE -------> B > F2 A <----- 183 ------------ B > F3 A ----- CANCEL ----> B > > F1 contains From tag. > F2 contains From tag and To tag > > The question is: Is the F3 CANCEL required to send both From and To tags? > > RFC 3261 Section 9.1 states... > > The following procedures are used to construct a CANCEL request. The > Request-URI, Call-ID, To, the numeric part of CSeq, and From header > fields in the CANCEL request MUST be identical to those in the > request being cancelled, including tags. Hello Del, CANCEL is identical to the request being CANCEL'led (as mentioned above, i.e the INVITE), so there wouldn't be a To Tag, and only a From Tag (for fresh INVITE's). So, the CANCEL in F3 will have a From Tag, and no To tag. Best regards, Simith > _______________________________________________ > 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
