> That is the point of the draft. All of the uses of INFO > today have alternatives that do not have the same problems. > > In fact, I am really thinking the draft should point out the > use of INFO for SIP-T is also incorrect. SIP-T should use a > control channel, not the "SIP" > channel, for transporting proprietary signaling. The only > thing SIP-T does is re-create TCP over SIP. Not a very > useful use of SIP.
I don't think that's a fair assessment of SIP-T, since you seem to be ignoring the fact that SIP-T also (primarily) uses other methods than INFO. The encapsulation of 'proprietary' signaling is done to convey information that cannot currently be conveyed in pure SIP. But other than that, within the VoIP domain the regular SIP dialog model is used to establish and tear down sessions. SIP headers take precedence over the contents of the ISUP/Q.931 message, so the 'tunneled' message is only used to fill in some blanks at the receiving end. For the most part proxies and even user agents can safely ignore the message body and still participate in the SIP dialog. Some ISUP/Q.931 messages arrive at a stage in the session where SIP doesn't define any interaction between UAs, so currently INFO is used as a tunnel. If you believe it should be replaced by something less ambiguous, that won't be abused outside the scope of SIP-T the same way INFO is today, I guess that's fair enough. But saying that SIP-T should use TCP tunnels instead seems a bit harsh. Bram _______________________________________________ Sip mailing list https://www1.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
