> 1) Can CRBT be played without Reliable provisional Response? If yes then > whether the SDP is required in that unreliable provisional response?
Yes; it can be played. The preview SDP is not required (unless contains something required before rendering media); however you have a higher likelihood of it being rendered. > 2) Also since Paul already replied that as per RFC 6337 there should not > be > any new offer in 200OK of INVITE [as per my call flow in first mail] . So > my > question is after CRBT how will be caller A informed the change on Media.. > Please refer my below example. > A has sent INVITE to B for a Video call. Then in CRBT is some > song/music > being played to A instead of ringing... After the establishment of call > the > Video chat should start. So How SDP negotiation will happen? Since 100rel not used, the offer/answer model basically leaves you two options (excluding commonly used offer/answer violations) if the called party needs to supply an updated SDP. 1) Send re-INVITE after receiving ACK. 2) Simulate a forking proxy interaction. For instance, send a new To tag within the 200 response. > I will be really grateful if you clarify my query by two example of SDP > flow. > One without using any reliable provisional response and another using > Reliable provisional response If 100rel is used and UPDATE is supported by both parties, the called party has an additional option. 3) Send UPDATE and receive final response before sending INVITE final response. _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
