>> Greetings, >> I am wondering if the below scenario is valid or not. >> >> <-- 183 (with SDP) then, >> <-- 180 (without SDP) > > Yes it's. > However it depends in UAC behaviour on how to render it to the human > (it could choose to render the early-media comming from the same 183, > or it could choose to render internal ringing due to the 180).
I would suggest stopping the playback of audio when you receive the 180 with SDP and revert to the ringing tone. Users does not like silence and sending an 180 would suggest that there's no more early media to me. [Vivek] - With some ITSP's, 183 Session Progress is sent (with SDP) to play the music (something like, please wait while your call is on wait) when actual called party is busy. However, 180 Ringing is sent as soon as call has been placed to called party and called party is ringing. ITSP does not disconnect the media after sending 180 Ringing instead start playing Ring Back Tone (RBT) to caller. Hence, in either manner while caller disconnects the media or not on receipt of 180 Ringing (without SDP), RBT will be played to caller either locally (if caller honors 180 Ringing) or by remote server (if caller does not honors 180 Ringing). I believe in having a check in application to check whether any RTP stream is still there or not after receiving 180 Ringing (without SDP). If no RTP is coming, then only 180 Ringing should be honored to play RBT locally else RTP from ITSP should be played. /O _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors Email Scanned for Virus & Dangerous Content by : www.CleanMailGateway.com _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
