Hi Saurav I believe there is no issue due to rtpmap as its required only for dynamic payloads and not for static payloads . Reason of UE A sending BYE could be mismatch in payload no for telephony event . A is sending 99 but B is sending 101 .So A finds this wrong and send BYE But UE A* should not* send BYE and accept this answer sending telephony events with payload no 101 instead of 99 which is expected by UE B. And UE B needs to send telephony events with payload no 99 towards UE A. Hope this helps
Thanks & Regards Ankur Bansal On Tue, Nov 4, 2014 at 9:12 PM, Sourav Dhar Chaudhuri < sourav_mi...@yahoo.co.in> wrote: > Hi, > I am observing a behavior SDP negotiation. In the Below Example just > After Media Negotiation. A is sending BYE without any media flow . Please > refer the below call flow & my query. > > > A --------------------------- INVITE with SDP -------------------------> > B > > ########## SDP details in Offer ############## > > v=0 > o=- 1414764441 1414764441 IN IP4 172.29.62.182 > s=Basic Session > c=IN IP4 172.29.62.182 > t=0 0 > m=audio 37620 RTP/AVP 18 8 0 99 106 107 > a=rtpmap:99 telephone-event/8000 > a=fmtp:99 0-15 > a=rtpmap:106 PCMU/8000 > a=rtpmap:107 PCMA/8000 > a=ptime:20 > > A <------------------------- 100 Trying > -------------------------------------- B > > A <------------------------ 180 Ringing > (unreliable)------------------------------------- B > > A <------------------------ 200 OK with SDP > ------------------------------ B > > ########## SDP details in Answer ################ > > v=0 > o=0000000000 37448557 1 IN IP4 172.29.62.11 > s=- > c=IN IP4 172.29.62.11 > t=0 0 > m=audio 53378 RTP/AVP 8 101 > a=sendrecv > a=ptime:20 > a=rtpmap:101 telephone-event/8000 > a=fmtp:101 0-15 > > A -------------------------- ACK > -------------------------------------------> B > A -------------------------- BYE > ------------------------------------------> B > > the call is getting disconnected without any media transfer. > > I can see there are six codecs [ 18 8 0 99 106 107 ] with attribute for > only for three [ 99 106 107 ] in SDP offer. Those three [ 99 106 107 ] > only having rtpmap details. > > But in SDP answer two codec [ 8 101 ] with attribute for only [ 101 ]. The > rtpmap is also for only [ 101 ]. > > So is the A is behaving correctly ? Whether there is failure in SDP > negotiation? If yes then why? > > > > > Regards, > Sourav Dhar Chaudhuri > _______________________________________________ > Sip-implementors mailing list > Sip-implementors@lists.cs.columbia.edu > https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors > _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
