Redirecting outbound calls to the right trunk

We have a number of SIP trunks some of which are for the exclusive use for different extensions. In the past I have set up dial patterns for the outbound route that only map to the specific extension by putting the extension number in the callerID field of the dial pattern entries. For the case where there is more than one extension using the same outbound route I simply put the base extension number in the CID Num Alias field for the extension.

This past week I was trying to add in a new exclusive trunk for another user and it doesn’t work. What I did try initially was to se the CID Num Alias field of the affected extensions to the ring group number for those extensions and set the callerID value in the outbound route dial pattern entries to that value. However this failed miserably and I had though that it would have been a better way to document the usage. I then changed it to use the base extension number but that failed too for anything other than the real extension named in the callerID field.

The older definitions done this way work fine. Any ideas as to why this no longer works for new definitions? I am guessing that the only way now is to make custom outbound routes for each extension or buy the Extension Routes commercial module - which I am reluctant to do as my experience with commercial modules has been uniformly bad.

Linux Distribution: (Redhat CentOS release 6.6 (Final))
FreePBX version: (12.0.74)

Try using custom context. This is how I direct my extensions to the right trunk.

Try the (fee)free Extension Routing module, gives you Inbound Routes and Outbound Routes in Connectivity.