> Do you find some advantage to it over simply using early media > with a different to-tag? It allows the early media session and answered media session to be negotiated prior to INVITE 2xx. The main benefit is to reduce clipping upon INVITE 2xx if forking has occurred and all UAS actually support early-session. More specifically, UAS may assume only answered media will be sent to the port for answer; thus it could quickly start rendering answered media prior to receiving INVITE 2xx. UAC can allocate other ports for early media; or it can refuse or hold early media without it subsequently delaying answered media (by requiring another offer/answer exchange). Works good in theory if all user-agents support it. I have no idea how well it works in the real world. :) _______________________________________________ Sipping mailing list https://www.ietf.org/mailman/listinfo/sipping This list is for NEW development of the application of SIP Use sip-implementors@xxxxxxxxxxxxxxx for questions on current sip Use sip@xxxxxxxx for new developments of core SIP