The scenario that you describe in your first question is invalid. According to RFC 3312, Section 11, the precondition tag *must* be present in the Require header if the offer contains a mandatory precondition. If the UAS doesn't support the precondition extension, it will respond with a 420 Bad Extension and specify the precondition option tag in the Unsupported header.
If the offerer includes the precondition tag in the Supported header, then the qos lines in the SDP must be optional. If the UAS doesn't support preconditions, it will silently ignore the precondition tag and the qos lines in the SDP. -- Gary Cote www.awardsolutions.com _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
