Hi Franz, I think only one answer can answer your both questions, that is UAC can decide whether accept your new offer(SDP-3)
So, 1)Will UACs follow the change of SDP during session setup? if UAC want to accept your SDP-3, it will follow the change of SDP, otherwise it will not. 2)Will SDP-4 be identical to SDP-1 if UAC don't accept your SDP-3, SDP-4 may be indentical to SDP-1 On 1/25/07, Franz Edler <[EMAIL PROTECTED]> wrote: > > Hi, > > I would like to use two offer/answer cycles during session setup (without > using UPDATE) and ask for feedback if the following sequence will work. > > This is the sequence seen from UAC perspective. > > UAC Proxy > --- INVITE SDP-1 ------------------> > <-- 183 Session Progress SDP-2 ----- > > <-- 200 OK SDP-3 -------------------- > --- ACK SDP-4 ----------------------> > > The point is that 200 OK carries a new SDP (SDP-3, the actual SDP of the > Session Partner), while 183 carries the SDP-2 of an announcement. > > SDP-1 / SDP-2 is the first offer/answer > SDP-3 / SDP-4 is the second offer/answer (expectation SDP-4 = SDP-1). > > >From my interpretation of RFC3264 the sequence could work. The Caller > gets a > special announcement before cut through. > > My doubts & questions are now: > - Will UACs follow the change of SDP during session setup? > - Will SDP-4 be identical to SDP-1? > > Who knows how UAs might behave? > > Cheers > Franz > > _______________________________________________ > 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
