On Thu, 2008-12-18 at 19:09 -0500, Hadriel Kaplan wrote: > The SIP URI is not the only one with this problem - RFC 3860 (im-URI), > RFC 3859 (pres-URI), RFC 3508 (h323-URI), and who knows what else > violate that rule. > > Seems to me any "fixing" should be done to RFC 3986, probably as an > errata.
Let's get a grip on the origin of the problem. The generic URI grammar was stimulated by HTTP URIs. They assume that *if* the URI contains the designation of a host, it will be flagged by the initial "//" -- and the syntax allows "all the standard syntaxes for hosts" in that location. Now if SIP URIs we constructed on that format, we'd have "sip://[email protected]". But I don't expect that to change any time soon. So let's ask, why are SIP URIs written as they are? Clearly, it's because they're based on e-mail addresses, or rather, the "mailto:"; URI scheme: "mailto:[email protected] --> sip:[email protected]". Hmmm, doesn't that mean that mailto: URIs have the same problem? And, as Hadriel notes, *all* the URIs based on the mailto: URI? What have the "mailto" people done about this? That doesn't take long to look up: Page 2 of RFC 2368 says: mailtoURL = "mailto:"; [ to ] [ headers ] to = #mailbox headers = "?" header *( "&" header ) header = hname "=" hvalue hname = *urlc hvalue = *urlc "#mailbox" is as specified in RFC 822 [RFC822]. This means that it consists of zero or more comma-separated mail addresses, possibly including "phrase" and "comment" components. Note that all URL reserved characters in "to" must be encoded: in particular, parentheses, commas, and the percent sign ("%"), which commonly occur in the "mailbox" syntax. So if you want an IPv6 address in your mailto: URI, you're going to have to write the [...] as %5b...%5d. As far as I can tell, the only reason that this rule does not extend (uniformly!) to SIP URIs is that RFC 3261 explicitly forbids it. Perhaps we could allow %-escapes in host-parts as part of the IPv6 upgrades to our software... 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
