Since the proxy forked the call it will cancel B regardless of the presence of SDP in 18x.
A must treat the answer from C as an independent Answer to the offer it made because the to tags are different. A must silently close the transaction it has with regard to B and complete the dialog towards C. Kasturi > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On > Behalf Of Andreas Byström > Sent: Thursday, September 13, 2007 9:48 AM > To: [email protected] > Subject: [Sip-implementors] Early media and forking calls > > Hi everyone, > > I'm working with a case that involves a call from A that a > proxy forks to B and C. I see a potential problem when the > following happens: > * A sends SDP offer > <proxy forks the call to B and C> > * B answers with a 183 including a sdp answer > * C sends 180 with no spd > * C answers the call first, which means C sends a sdp > response in the 200 OK. > > I have tried to find info on this but have failed to do so. > So I was thinking that someone on this forum have already > been facing a scenario like this, or maybe know where I can > find info on how to solve it in a way that dont violate specs > (and also works of course) > > How should A handle this (it already got a sdp answer on the > offer)? Does A or proxy have to start a renegotiation with C? > Should A see in the tag that this is a respone from another > UA then from where it did get the first spd answer (the on in > 183 sent from B) and therefore accept it? > Proxy needs to send a cancel to B when it sees that C is > replying wiht 200 OK. Does the proxy also need to say > something to A to terminate the media session already set up > between A and B? > > Thanks in advance > // Andreas > > _______________________________ > > Andreas Byström > Software Engineer > > Teligent AB > Konsul Jonssons väg 17 > P.O. Box 213 > SE 14923 Nynäshamn > > mail: [EMAIL PROTECTED] > web: www.teligent.se <http://www.teligent.se/> > phone: +46 (0)8 4101 7221 > mobile: +46 (0)733 1172 21 > fax: +46 (0)8 520 193 36 > _______________________________ > > _______________________________________________ > 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
