I have a lobby phone that I would love to be unable to call outside our office. I just want it to be able to dial our 4 digit extensions. Im just not sure how this is done. Can a route be written in such a way to block that extension? Is this something that would need to be done on the phone instead on the PBX? Not sure where to start looking.
Without the module, create a route with only the 4 digits in the dial plan and put the extension in the Caller ID field. Place that route as the first one.
I used an unsupported module called Custom Contexts to define a different context for extensions in public space (that I don’t want users dialling out over a trunk on).
It made life really easy, and better still I defined a rule list of numbers that could be dialled such as emergency 000 and our Technical Support number (which is free call from our SIP trunks).