[Kamailio-Users] Request uri vs registered contact

[Olle E. Johansson]

12 aug 2009 kl. 12.29 skrev Iñaki Baz Castillo:

> El Miércoles, 12 de Agosto de 2009, Olle E. Johansson escribió:
>> Anyway, there's some work in the IETF to handle the register for
>> multiple DID's, since the way it's used now clearly violates what's  
>> in
>> the RFCs and there is an obvious need to register for "SIP trunks".
>
> I implemented this in an "ellegant" way:
>
> - The SIP trunk (Asterisk?) registers with Contact "s at IP" (or any  
> contact).
> - It has associated 3 PSTN numbers in the proxy/registrar.
> - When the proxy receives a call for one of these 3 numbers it  
> changes the
> RURI according to the location of the client (lookup("location"))  
> and adds a
> header whose value is the dialed PSTN number in E164 format:
>    P-Dialed-Number: +34987654321

You could have used Remote-party-id with party=called as well.
In fact, if you start testing various equipment you realize that you  
have to deliver this information in multiple ways.

>
> So:
> - "To" remains unchanged.
> - RURI arriving to the client matches its registration's Contact.
> - The client must inspect a custom header to know the real  
> destination number
> of the call.
>
> However, I've read some RFC with a similar solution (I think it uses  
> "P-
> Called-Party" header, but later the complex "History" header  
> appeared and...).
>
Yes, in the future a PSTN gateway propably should add sip-history with  
this information.
The draft for the update doesn't mention gateways or b2bua's much, so  
it still needs feedback I guess.

/O