> Hi, > > I'd like to clarify some facts concerning INVITE transactions which contain > an early media response e.g. > > INV--> > <--183 > <--200 > ACK--> > > Is it permissable/possible for the 200 OK to negotiate different SDP than > the SDP negotiated in the 183?
No, according to RFC3261 and 3264. The same SDP should be included in the 183 and the 200. You need another set of offer and answer to modify session, usually with a re-INVITE or an UPDATE. To consider the issue, the RFC3959 (early disposition) and the RFC3960 (early media) would be helpful. Regards, Jun Koshiko > > That is, is:- > > INVITE > ... > m=audio 6980 RTP/AVP 18 8 4 0 > > > 183 > ... > m=audio 4780 RTP/AVP 18 8 > > > 200 > ... > m=audio 4790 RTP/AVP 4 0 > > > ACK > > a valid exchange? > > Thanks for your time, > > Matthew Gardiner > Software Engineer > Aculab > Tel: +44 (0) 1908 273 911 > Fax: +44 (0) 1908 273 801 > Email: mailto:[EMAIL PROTECTED] > Website: <http://www.aculab.com> > > _______________________________________________ > Sip-implementors mailing list > [email protected] > http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors --------------------------------------------------------- Jun KOSHIKO Next Generation Strategy Research and Development Center NTT-east Corporation Telephone +81 3 5359 5104 Facsimile +81 3 5359 4768 E-mail: [EMAIL PROTECTED] 19-2 Nishi-shinjuku 3-chome Shinjuku-ku Tokyo 163-8019 Japan --------------------------------------------------------- _______________________________________________ Sip-implementors mailing list [email protected] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
