[Serusers] [Serdev] loose_route behaviour, detecting single Route with myself

[Martin Hoffmann]

Nils Ohlmeier wrote:
> 
> An non-2xx ACK with a preloaded route looks exactly the same then a 2xx ACK. A 
> preloaded_route() function thus has no chance to distinguish them. And I will 
> not make the rr module depending on the tm module, just to query tm all the 
> time if it knows something about this transaction or not.
> IMHO the only way to distinguish these two is the RURI. Because in a normal 
> loose route case the 2xx ACK should have non-local URI (the remote Contact) 
> as RURI. But the non-2xx ACK should have a local RURI.

Indeed. But doesn't that point towards the old behaviour? Only return
true if forwarding can be done based on a Route, otherwise the script
needs to decide what to do based on the Request-URI? Apparently, having
a Route header pointing to the proxy doesn't mean a thing.

BTW: What does loose_route() do if the topmost route doesn't point to
this proxy?

> But with this theory we are back to the original topic: is a TEL URI a local 
> URI or not.

I though that was solved. Only SIP and SIPS URI are allowed in Contact.
Your 2xx ACK will never have a TEL URI (unless the UA is broken in which
case someone should have sent a 400 back).

> Is just came to my mind that a possible solution could be to add some kind of 
> secret information to our Record-Route headers.

/me not like. Sounds like magic plus vendor specific extensions are
frowned upon in SIP.

Regards,
Martin