> -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of [EMAIL PROTECTED] > Sent: Tuesday, April 08, 2008 7:31 PM > To: [email protected] > Subject: Re: [Sip] E.164 - who owns it > > From: "Dan Wing" <[EMAIL PROTECTED]> > > If those URIs included ";user=phone", there is a transitive > relationship between the SIP URI and the TEL URI. Without > ";user=phone", I agree that no meaning is supposed to be applied > to the user-part (the part to the left of the "@"). > > True. In that case, we have SIP URIs which are essentially aliases > for tel URIs. But in that case, any signing should be of the > fundamental tel URI, which then obviates the problem with an SBC that > translates one alias-URI into another.
But the only mechanism we have to sign, RFC4474, does not provide a way to sign a tel URI. > In SIP, you accomplish something similar to the TCP SYN cookie by > sending a SIP request towards the E.164, asking them to sign the > request and return it to you. Details are in > draft-wing-sip-e164-rrc-01.txt and comments are welcome. > > It seems like this mechanism is at most as certain as the E.164 > mapping that it uses for the "reverse direction". I gather from the > Enum people there is some trouble with that. I don't understand your statement; draft-wing-sip-e164-rrc-01.txt does not use ENUM, rather it uses the same routing that the SIP network (of proxies, B2BUAs, and SBCs) uses. > It seems to me that in practice, people don't validate requestors by > checking their apparent IP address, but rather by whether they can > present certificates. But that is probably an issue that has been > hashed over before... draft-wing-sip-e164-rrc-01.txt does not have people perform the reverse routability check. The reverse routability check happens without the users noticing, as part of validating that an E.164 request that just arrived would have a new request (towards that same E.164) routing in the same direction. -d _______________________________________________ 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
