> -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Paul > Kyzivat > [snip] > IMO that is a value of distinguishing tel from sip/user=phone. With sip, > the supplier of the URI determines the routing. With tel, the originator > of the call determines the routing.
You're implying the supplier or originator of the URI cares, or has a way to let its user determine this. Afaik, there is no button on phones for "let people call me only through sip" vs. "let people call me however they can". Most vendors assume people want the latter, I suspect. But since most or at least many devices use sip: all the time period, and most proxy/etc. vendors want calls to work because their customers do, they will route it whichever way they can to do so. A second problem is the desired behavior of using the From for later requests. Since UA's register a sip URI typically, and they use this for the From of their requests, the far-end UAS will get that From. Since the UAS would then use this URI for its address book to generate new requests later, by your earlier emails this implies that UAS only wants the request to purely stay sip. That would be ok if the original request stayed sip the entire path to the UAS, and the reverse path sometime later could also stay sip. There are actually cases where that's not going to be true, but let's assume it is for now. So imagine if the original request had a sip From but a tel req-uri. For some reason this request gets routed through the PSTN, back over SIP to the final dest UAS. If the PSTN-SIP gateway uses a tel From we're ok, but if it uses a sip From then per the desired behavior the UAS would use this sip URL in later requests and not be able to use the PSTN or whatever to get it back. That, to me, is why this desired behavior is so brittle. There are just so many times/ways a sip URL in the From or req-uri is used when it ostensibly shouldn't, that operators have little choice but to ignore it to make calls work. I think this may be fixable eventually, but I'm not quite sure how to do that and keep all the semantics you're looking for, without having calls fail in the transition period - which is a non-starter. > It is the desire to ignore the domain name in the sip URI that leads to > your need to have this special, unenforceable, policy on responsibility. > (Well, its enforceable in a legal sense with peering agreements, but > that builds a closed garden.) People don't "desire" to ignore the domain name, they "desire" to make calls work. If all UA's sent using tel URLs when they should per your definition, we probably wouldn't be having this conversation. :) -hadriel _______________________________________________ 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
