________________________________________ From: [email protected] [[email protected]] On Behalf Of [email protected] [[email protected]]
Is it OK to send unreliable provisional response, while waiting for PRACK for a already sent provisional response?? According to RFC 3262, it has been explicitly mentioned that reliable provisional response should not be sent, while waiting for PRACK for a already sent provisional response. ________________________________________ Officially, a UAS that supports PRACK should not send a non-reliable provisional response (other than the exceptions that have been described) if the INVITE contains "Require: 100rel". See RFC 3262 section 3: The UAS MUST send any non-100 provisional response reliably if the initial request contained a Require header field with the option tag 100rel. If the UAS is unwilling to do so, it MUST reject the initial request with a 420 (Bad Extension) and include an Unsupported header field containing the option tag 100rel. It seems reasonable that the UAC may be depending on reliable delivery of 1xx responses, so it seems unwise for a UAS to violate this restriction. But there is the implication that if the INVITE contains "Supported: 100rel" but not "Required: 100rel" the UAS may have the choice of using 100rel or not for each 1xx response. Dale _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
