Hi Guys,

I’ve been working at setting up a couple of FreeSwitch nodes as a topology hiding SBCs that handles both ingress traffic from my

providers/peers and pass traffic up to an openser router that then routes call across the cluster of SBCs through which they reach the destination.

I have OpenSIPS/SER setup doing DB route lookups and ENUM with LCR/Serial forking etc.

My question is what would be the best way to send a call out to a destination choosen by the OpenSER router?

For example:

SIP Provider -- >  SBC --- > OpenSER ---- ( route lookup returns 123.123.123.4 as dest )  -- > SBC  --- > 123.123.123.4

I was thinking something along the lines of adding a “X-Route-To: +1NXXNXXXXXX@123.123.123.4” with openser

and then something like this in the SBC…

  <context name="from-sipcore">

    <extension name="outboundroute">

        <action application="bridge" data="sofia/external/${sip_h_X-Route-To}" />

    </extension>

  </context>

Is this a wise approach, is there anything I could do to do this better?

I’d like to keep the logic in the SBCs as simple as possible.

I am pretty familiar with SIP but my knowledge fades when it gets into the nitty gritty of routing… ie the Contact: and Via: headers

and all that good stuff.

I should also state I have two profiles defined one for the internal/private “core” network and one for the outside “external” network.

Any thoughts on this at all would be greatly appreciated.

Am I missing something in the SIP spec that would allow for this is a standardized way?

Regards,

-Adam