[OpenSER-Users] Rewriting the to header

[Iñaki Baz Castillo]

El Sábado, 15 de Marzo de 2008, shiebar at post.tau.ac.il escribió:
> Hi Inaki,
>
> I have already read it but probably missed this important detail.
> Thanks for the  advice. I will read it again more carefully.

In resume:
The real destination is the Request-Uri (except if there is a "Route" header).
"To" header jist means the **original** destination. For example:


- A calls B so it generates an INVITE like:
  INVITE B at domain1 SIP/2.0
  To: B at domain1
  From: A at domain1
(note Request-Uri = "To" header)

- A sends the INVITE to the proxy responsible for domain1.

- The proxy has has a diversion to C at domain2 for B.

- Proxy rewrites the request-Uri and sends the INVITE to C:
  INVITE C at domain2 SIP/2.0
  To: B at domain1
  From: A at domain1

- The INVITE arrives to the inbound proxy of C, who rewrites the Request-Uri 
with the location of C AoR and sends the INVITE to it:
  INVITE C at ip_c SIP/2.0
  To: B at domain1
  From: A at domain1


When the INVITE arrives to C it knows that the original destination was B.
In conclusion, the "To" header is just valid for this purpose and no more. It 
has NOTHING to do with the real destination of the call (except in the 
original INVITE in which "To" and RURI are the same).


Hope it helps ;)

Regards.

-- 
Iñaki Baz Castillo