From: George AK <[EMAIL PROTECTED]> Is it a must to have offer-answer (SDP based) in an INVITE session? Can I have a INVITE-200-ACK with out an SDP Offer-Answer?
RFC 3261 explicitly allows that there might be other ways to describe an offer or answer than SDP, and so that media-type may be used in the body of an INVITE, etc. But there are no standard types other than SDP. Given the semantics of INVITE, it cannot do anything useful unless it contains (or requests) something that is semantically an offer of a session of some sort. So the summary is "An INVITE dialog usage must involve an offer and answer. The offer/answer do not need to be SDP, but there is no standardized media-type for doing so other than SDP." Dale _______________________________________________ Sip-implementors mailing list Sip-implementors@cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
