Vijay Kamath wrote:
> At SIPIT11, we found an issue when we want to configure a local outbound
> proxy using the procedures specified in rfc3261(sec 8.1.2).
>
> Here is a sample INVITE which we send :-
>
> INVITE sip:1.2.3.4:5060 SIP/2.0
> To:ua1<sip:[EMAIL PROTECTED]:5060>
> From:sipit1<sip:[EMAIL PROTECTED]>;tag=52792329608rc880
> Call-ID:130920245025z2qi
> CSeq:2 INVITE
> Via:SIP/2.0/UDP 65.243.118.179:5060;branch=z9hG4bK56241282309bvhjg
> Contact:sip:65.243.118.179
> Route:ua1<sip:[EMAIL PROTECTED]:5060>
>
> We found that some implentations that didn't support loose-routing,
> never looked at the topmost ROUTE header for determining the target set.
> They just look at the request-uri which would be that of the proxy
> itself, since it is a strict-router.
So you are using a strict-routing proxy (rfc2543) with a pre-loaded
route (specified in rfc3261). Certainly mixes things up nicely :-)
> So the proxy responds with 404, as the user part was missing in
> the request-uri.
The user part is optional in the R-URI.
> Is this a backward compatibility problem with older proxies?
It's not the question of backward compatibility or loose-routing; it
boils down to a mis-behaving proxy.
Since the request identifies a resource on the proxy (as indicated
in the R-URI), the proxy now has to make a decision on what to do with
the request; i.e. if it should send it forward, or generate a final
response (assuming it is not a stateless proxy).
Since the request has a Route header, the proxy should have removed the
Route header and put it in the R-URI and send the request there (note
that the topmost Route header does not have a ;lr, so the proxy's
behavior degenerates to a strict-router and hence the rewrite on the
R-URI -- in your case, the proxy was a strict router anyway, so it
would have done this as its default behavior).
Regards,
- vijay
--
Vijay K. Gurbani vkg@{lucent.com,research.bell-labs.com,acm.org}
Wireless Networks Group/Internet Software and Services
Lucent Technologies/Bell Labs Innovations, 2000 Lucent Lane, Rm 6G-440
Naperville, Illinois 60566 Voice: +1 630 224 0216
_______________________________________________
Sip-implementors mailing list
[EMAIL PROTECTED]
http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
