From: Salvatore Loreto <[EMAIL PROTECTED]> the context-id solves this use case
in the draft: http://tools.ietf.org/id/draft-loreto-sipping-context-id-requirements-00.txt I have described how the context-id can solve the problem to "correlate the INVITE, SUBSCRIBE request and recall INVITE in SIP Call completion scenario" We've discussed context-id in the design committee, and we've also discussed having the SUBSCRIBE provide the Call-Id (or from-tag) of the INVITE, which for our purposes is very similar to context-id. Unfortunately, neither proposal works well in the "call completion" context, for several reasons: The vast majority of INVITEs will never be subject to call-completion, and there is no way to predict in advance which ones will. Thus, for efficiency's sake, providers don't want to attach to each INVITE an additional context-id. One would hope to avoid the first problem by using the Call-Id or from-tag of the INVITE as its context-id, but in practice, many calls pass through SBCs which modify both of those. In addition, for truly wide-scale use, we would have to get the operators of SBCs to configure them to propagate the context-id, which cannot be done immediately. Dale _______________________________________________ Sip mailing list https://www.ietf.org/mailman/listinfo/sip This list is for NEW development of the core SIP Protocol Use [EMAIL PROTECTED] for questions on current sip Use [EMAIL PROTECTED] for new developments on the application of sip
