On 4/13/12 1:36 AM, Keerthi Srinivasan wrote: > Hi Paul, > > Sorry, Here are the sample messages
Keerthi, Ah! Sorry!!! I have just realized that my mail client (thunderbird) was altering your examples in the reply. And I had been commenting on that altered form. :-( So I am included an entirely new response to you: > 1. Unknown URI schema in Request URI > > REGISTER test:example.com SIP/2.0 > To: sip:[email protected] > From: <sip:[email protected]>;tag=3234233 > Call-ID: [email protected] > CSeq: 234902 REGISTER > Max-Forwards: 70 > Via: SIP/2.0/UDP 192.0.2.21:5060;branch=z9hG4bKkdjuw > Contact: <sip:[email protected]> > l: 0 So yes, the request-line and r-uri are *syntactically* correct but with "test" as an unknown URI scheme. The 416 response is designed for this case. > 2. Unknown URI schema in From Header > > REGISTER sip:example.com SIP/2.0 > To: sip:[email protected] > From: <test:[email protected]>;tag=3234233 > Call-ID: [email protected] > CSeq: 234902 REGISTER > Max-Forwards: 70 > Via: SIP/2.0/UDP 192.0.2.21:5060;branch=z9hG4bKkdjuw > Contact: <sip:[email protected]> > l: 0 First, see my comment on the To-URI below. The From-URI is *syntactically* valid. 3261 says that the From header is normally the same as the To-header, except in case of third party registration. So this is an example of third party registration. The registrar is responsible for authorizing the registration. So it is free to decide that this form of third party registration is not authorized. If the registrar doesn't want to allow this then I think 403 is the proper response. (400 doesn't seem right because the message is well formed.) Because the From-URI is syntactically correct, a *proxy* should leave it be and forward the request. > 3. Unknown URL schema in To Header > > REGISTER sip:example.com SIP/2.0 > To: ram:[email protected] > From: <sip:[email protected]>;tag=3234233 > Call-ID: [email protected] > CSeq: 234902 REGISTER > Max-Forwards: 70 > Via: SIP/2.0/UDP 192.0.2.21:5060;branch=z9hG4bKkdjuw > Contact: <sip:[email protected]> > l: 0 3261 says that the To-URI MUST be a SIP or SIPS URI. So the registrar should probably reject this request. There isn't any clear best response for this. Certainly 400 could be used, and 403 or 404 could also be justified. Because the To-URI is syntactically correct, a *proxy* could leave it be and forward the request. Or it could enforce the restriction above. > 4. Unknown URI Schema in Contact Header > > REGISTER sip:example.com SIP/2.0 > To: sip:[email protected] > From: <sip:[email protected]>;tag=3234233 > Call-ID: [email protected] > CSeq: 234902 REGISTER > Max-Forwards: 70 > Via: SIP/2.0/UDP 192.0.2.21:5060;branch=z9hG4bKkdjuw > Contact: <test:[email protected]> > l: 0 The Contact URI is syntactically correct. It is *legal* to register non-sip contact addresses (such as http), though I have not seen any hints of it being done in practice. So a registrar could accept this and include the uri in the list of registered URIs. (That is what would happen according to the steps in section 10.3 of 3261. But the registrar has discretion about what it does. In particular, it can choose to reduce the expiration time for the contact to zero, which has the effect of refusing the contact while accepting the request. The result of doing this would be a 200 response that doesn't include this Contact URI. A proxy doesn't need to process the Contact, so it should forward the request. (Note that "unknown" schemes in registered contacts will present issues when the corresponding AOR (sip:[email protected]) is being translated by the ram.com proxy. The proxy presumably can't forward a request to test:[email protected]. Its choices are: ignore this contact, or return a 3xx response containing it so that an upstream node can have a chance to do something with it.) Thanks, Paul > On Wed, Apr 11, 2012 at 6:57 PM, Paul Kyzivat <[email protected] > <mailto:[email protected]>> wrote: > > On 4/11/12 6:29 AM, Keerthi Srinivasan wrote: > > Dear All, > > > > What could be the Proxy and Registrar behavior for the Unknown > URI schema > > in From, To, Contact and Request URI? > > > > Here is the sample SIP message. > > > > 1. Unknown URI schema in Request URI > > > > REGISTER* test:example.com <http://example.com><sip:example.com > <http://example.com>> *SIP/2.0 > > To: sip:[email protected] <mailto:sip%[email protected]> > > From:<sip:[email protected] > <mailto:sip%[email protected]><http://www.example.com/>>;tag=3234233 > > Call-ID: [email protected] > <mailto:[email protected]> > > CSeq: 234902 REGISTER > > Max-Forwards: 70 > > Via: SIP/2.0/UDP 192.0.2.21:5060;branch=z9hG4bKkdjuw > > Contact:<sip:[email protected] <mailto:sip%[email protected]>> > > l: 0 > > The request URI isn't just an unknown uri scheme - it is syntactically > incorrect. (The "<" and ">" aren't valid.) > > There isn't any good way to proceed with this. So the request ought to > be failed. > > > 2. Unknown URI schema in From Header > > > > REGISTER sip:example.com <http://example.com><sip:example.com > <http://example.com>> SIP/2.0 > > To: sip:[email protected] <mailto:sip%[email protected]> > > From:<*test:[email protected] > <mailto:test%[email protected]><http://www.example.com/>*>;tag=3234233 > > Call-ID: [email protected] > <mailto:[email protected]> > > CSeq: 234902 REGISTER > > Max-Forwards: 70 > > Via: SIP/2.0/UDP 192.0.2.21:5060;branch=z9hG4bKkdjuw > > Contact:<sip:[email protected] <mailto:sip%[email protected]>> > > l: 0 > > The From-URI is syntactically incorrect. An attempt to form a response > to this will generate either a syntactically incorrect one, or else one > that has a From-URI different from the request. There are no good > actions. So I guess you can take your pick: drop the request without > response, respond with a From copied from the request, or respond with a > From that is patched up in some way. I wouldn't expect any good > outcome > regardless of which option you take. The UAC is broken and needs to be > fixed. > > > 3. Unknown URL schema in To Header > > > > REGISTER sip:example.com <http://example.com> SIP/2.0 > > To: *ram:[email protected] <mailto:ram%[email protected]>* > > From:<sip:[email protected] > <mailto:sip%[email protected]><http://www.example.com/>>;tag=3234233 > > Call-ID: [email protected] > <mailto:[email protected]> > > CSeq: 234902 REGISTER > > Max-Forwards: 70 > > Via: SIP/2.0/UDP 192.0.2.21:5060;branch=z9hG4bKkdjuw > > Contact:<sip:[email protected] <mailto:sip%[email protected]>> > > l: 0 > > Same answer as for 2. > > > 4. Unknown URI Schema in Contact Header > > > > REGISTER sip:example.com <http://example.com><sip:example.com > <http://example.com>> SIP/2.0 > > To: sip:[email protected] <mailto:sip%[email protected]> > > From:<sip:[email protected] > <mailto:sip%[email protected]><http://www.example.com/>>;tag=3234233 > > Call-ID: [email protected] > <mailto:[email protected]> > > CSeq: 234902 REGISTER > > Max-Forwards: 70 > > Via: SIP/2.0/UDP 192.0.2.21:5060;branch=z9hG4bKkdjuw > > Contact:<*test:[email protected] <mailto:test%[email protected]>*> > > l: 0 > > Contact URI is syntactically incorrect. At least in this case its > possible to leave it out of the response, so you can send a > syntactically correct response. > > A proxy doesn't need to process the Contact, so it could forward the > request, or it can reject it. > > A registrar could reject the request, or if it wants to be extremely > tolerant it could simply ignore the Contact and process the REGISTRAR as > a poll - returning the contacts that are currently registered. > > In all of the cases above, if an error response is sent then I think 400 > is the best that you can do, because there is really a syntax error, not > just an invalid uri scheme. > > Thanks, > Paul > > > These message are pass through proxy to registrar. Can you please > anyone > > help me in the *Proxy and Registrar Behavior*.???? > > _______________________________________________ > Sip-implementors mailing list > [email protected] > <mailto:[email protected]> > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors > > > > > -- > Regards, > Keerthi _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
