On Tue, Sep 2, 2008 at 2:18 PM, Robert Joly <[EMAIL PROTECTED]> wrote: >> Hello! >> >> Consider an inbound call starting at an ITSP that is trying >> to establish a call with extension 202. >> Consider another phone (lets say extension 206) that attempts >> to do a call pickup while phone 202 is Ringing. >> 206 sends sipxbridge an INVITE with SDP OFFER and a Replaces header. >> [ Note at this point that the ITSP is currently trying to >> establish a call with 202 so the SDP answer has not gone back >> from 202. ] >> >> sipxbridge, sends back an SDP offer to 206 in the OK using >> the SDP offer from the ITSP. > > As far as 206 is concerned, the SDP carried in the 200 OK it receives > *is* the SDP answer which completes the Offer/Answer cycle and explains > why the Ack from 206 does not carry an SDP body.
I thought the offer answer model allowed for a "counter offer" to be presented in the OK. I have never seen this happen but I thought it was possible. Bad assumption on my part. The obvious problem > here is that the SDP offer generated by the ITSP is being provided as an > SDP answer to 206's SDP offer when the two SDPs do not, in reality, have > that offer/answer relationship which will lead to media negotiation > problems in many cases. > > Thinking out loud here but if the ITSP does not support INVITE with > replaces then perhaps your best bet is to craft an SDP answer based on > your knowledge of the offers from the ITSP and 206 and provide it to > both 206 and the ITSP in the 200 Oks you send them. In this case, I assume one can just pick a codec common to both of them and send forth replies to either side. I think I am forced to follow this option. Thanks Ranga > >> >> I would expect at this point that 206 would answer with an >> SDP ANSWER in the ACK but it responds to sipxbridge with ACK >> with no SDP. >> >> >> Is this a bug in the phone or is my understanding flawed? >> Traces can be posted if needed. >> >> >> >> Thanks in advance >> >> Ranga >> >> >> -- >> M. Ranganathan >> _______________________________________________ >> sipx-dev mailing list >> [email protected] >> List Archive: http://list.sipfoundry.org/archive/sipx-dev >> Unsubscribe: http://list.sipfoundry.org/mailman/listinfo/sipx-dev >> > -- M. Ranganathan _______________________________________________ sipx-dev mailing list [email protected] List Archive: http://list.sipfoundry.org/archive/sipx-dev Unsubscribe: http://list.sipfoundry.org/mailman/listinfo/sipx-dev
