On Wed, 2008-12-10 at 16:39 +0530, [EMAIL PROTECTED] wrote: > Is it correct to have “user=phone” added only in ACK’s To header while > it is missing in initial INVITE, even though both the messages use > Tel-URI.
The matter is not well-settled by the standards. RFC 3261 requires the UAs to not change the To/From URIs in requests they generate, but it also requires that UAs not look at the To/From URIs that they receive, only the tags (except in certain special circumstances). Some proposed changes and uses of SIP require the To/From URIs to be changed. So the current best practice is (1) Never depend on the To/From URIs in incoming messages to be the same as in the initial INVITE, only pay attention to the tags, and (2) Only change the To/From URIs in specific situations where you absolutely must do so. In this case, there is no reason why the ACK To/From URIs differ from the INVITE values (indeed, it's hard to think of any reason it could be), so "user=phone" should not be added. 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
