No. 416 is for "I don't understand your scheme, you can try sip: instead". It is very likely that the endpoint will then try sip:
It makes no sense in the other direction, i.e., when you receive SIP but you only allow for a SIPS resource (it would cause an infinite loop). The interesting thing with 416 is that a proxy or UAS that doesn't support SIPS is that it is likely to use it. If the UAC is "dumb" it would retry it with sip (which would effectively be a downgrade, and therefore would be bad). A proxy or UAS that wants to REJECT a SIPS request and not risk having the UA re-attempting the session by downgrading should therefore use something else. Initially, I tought 403 was the proper mechanism. Juha seems to agree. Dean also seems to like it. Robert, any toughts? I think I remember it was you who preferred 404? > -----Original Message----- > From: Elwell, John [mailto:[EMAIL PROTECTED] > Sent: Sunday, April 29, 2007 06:55 > To: Dean Willis; Audet, Francois (SC100:3055) > Cc: SIP IETF; Hans Persson > Subject: RE: [Sip] Re: draft-ietf-sip-sips-03 > > Isn't this what 416 is for? > > John > > > -----Original Message----- > > From: Dean Willis [mailto:[EMAIL PROTECTED] > > Sent: 28 April 2007 00:14 > > To: Francois Audet > > Cc: SIP IETF; Hans Persson > > Subject: Re: [Sip] Re: draft-ietf-sip-sips-03 > > > > > > On Apr 27, 2007, at 4:03 PM, Francois Audet wrote: > > > > > > > > Basically, I've used 403 (Forbidden) when a UAC tries to register > > > with the wrong scheme in the Contact. > > > > > > And I've used 404 (Not Found) when a UAC sends a non-REGISTER > > > request to a SIP URI when only a SIPS URI exists for that > > resource. > > > I used to have 403 for that, but I received some comments from > > > somebody on the list that 404 (Not Found) would be more > appropriate. > > > > > > I don't feel strongly about this issue. > > > > > > If anybody has any ideas, please go ahead. > > > > > > > Nonchair comment: > > > > If we agree that SIP and SIPS point at the same thing, then > rejecting > > a SIP request with a 404 when there is an "equivalent" registration > > seems wrong. 403 seems better, but what it seems like we need is an > > "Invalid Scheme" response. I'm also tempted by 488 (Not Acceptable > > Here) even though we normally use that for SDP. > > > > Even a 400 (Bad Request) seems better than 404. > > > > -- > > Dean > > > > > > > > _______________________________________________ > > 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 > > > _______________________________________________ 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
