[asterisk-users] Using Asterisk to route call via an outbound proxy

[Joshua Colp]

Nitesh Bansal wrote:
> Hello,
>
> I want to use Asterisk to use Kamailio as an outbound proxy for routing
> calls to remote SIP end points, one option could be to use a default
> peer, but in my case, my outbound proxy can change
> based on the remote end point, so this option doesn't work.
> And another problem is that I don't know how to configure Asterisk to
> prepare the Request-URI
> based on the remote end point and not based on the outbound proxy address?
>
> What is the best way to do it?

You'll have to be specific with the channel driver in use. Speaking from 
chan_pjsip it does not have a mechanism to set the outbound proxy on a 
per-call basis, it's strictly controlled by the endpoint. You'd need 
multiple or construct endpoints dynamically (for example using the ARI 
push configuration). As for not rewriting the request URI you need to 
use loose routing by specifying ;lr in the outbound proxy URI.

Example:

sip:example.com;lr

If used in a configuration file:

sip:example.com\;lr

The '\' is so the configuration parser does not treat it as a comment.

Cheers,

-- 
Joshua Colp
Digium, Inc. | Senior Software Developer
445 Jan Davis Drive NW - Huntsville, AL 35806 - US
Check us out at: www.digium.com & www.asterisk.org