How about, if Alice decides to move from an audio call to a audio/video/whiteboard call. I would presume Bob's UA will notify him of such a request (a standard implementation must). Also, Bob's UA could 'alert' Alice's UA of Bob's presentation. For whatever reason Bob pauses (or limitation on Bob's UA), Alice could cancel the re-Invite, and continue with the audio call. Alice may also choose to cancel the video session outright, after sending the re-Invite.
The issuer of request (re-Invite) should have the prerogative to cancel the re-Invite for any case. Sahil > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:sip-implementors- > [EMAIL PROTECTED] On Behalf Of Jeroen van Bemmel > Sent: Friday, May 19, 2006 9:24 AM > To: Sweeney, Andrew (Andrew); [email protected] > Subject: Re: [Sip-implementors] Cancelling a Re-Invite?? > > Andy, > > It is allowed, but since reINVITEs often don't involve user interaction (and > hence typically give a final response quickly, no "ringing.....") it is not > recommended. > You would almost always be too late, it's better to wait for the reINVITE > response > > Regards, > > Jeroen > > ----- Original Message ----- > From: "Sweeney, Andrew (Andrew)" <[EMAIL PROTECTED]> > To: <[email protected]> > Sent: Friday, May 19, 2006 2:15 PM > Subject: [Sip-implementors] Cancelling a Re-Invite?? > > > > > > Is it valid to cancel a re-invite as in the call flow shown below? > > > > I have never seen it. I though Cancels were only sent before a dialog was > > established. > > > > Thanks > > Andy > > > > LOCAL-SIP REMOTE-SIP > > INVITE > > ---------------------> > > 180 > > <--------------------- > > 200 > > <--------------------- > > ACK > > ----------------------> > > (re)INVITE > > <--------------------- > > some error response > > ----------------------> > > CANCEL > > <--------------------- > > 200 > > ---------------------> > > 487 > > ---------------------> > > ACK > > <-------------------- > > BYE > > <-------------------- > > > > _______________________________________________ > > 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 _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
