Re: [Sip] Review of sip-outbound-13

["Francois Audet" <audet at nortel.com>]

> > For 10, I believe that it would work if an upstream evil B2BUA does 
> > topology hiding since the proxy uses the Via in the Request and not 
> > the Path in the response.
> [JRE] What I meant was, if a proxy receives a REGISTER 
> request with only a single element in the Via header field, 
> how does it know whether the request came from a UA or from a 
> topology-hiding B2BUA? This is probably an unlikely situation 
> for a REGISTER request (UA -> B2BUA -> proxy), but can we rule it out?

Ah, "upstream" vis-a-vis the UAC, as opposed to "upstream" vis-a-vis the
outbound proxy.

Of course a B2BUA can screw things up. If one decides to have a 
B2BUA between the Outbound proxy and the UAC (which seems to be a weird
place for putting it), then obviously the B2BUA would have to comply to
outbound for outbound to work. I would think that normally, the B2BUA would
be on the other side or the outbound proxy, or even co-located with it.

There are plenty of opportunities for a B2BUA to mess things up. I don't 
believe it would make sense to say anything about it. 
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