Dial plan

I have a set up with a couple of analogue lines as well as a SIP trunk.

When somebody dials a local number (10 digits) the call is initially routed through the POTS lines. This is already happening.

The challenging part is how to pass the call to the SIP trunk by adding a 1 in front of the number if the 2 POTS lines are in use.

Basically the challenge is that the local phone company expects 10 digits for local area codes where as the SIP provider always expects 11 digits.

Any ideas on how to achieve this would be appreciated.


Add the one on the sip trunk pattern screen. You can the 1+NXXNXXXXXX to do this.

Thanks but what happens when the number already has 1 in front of it.

Say for example somebody is dialing 1NXXNXXXXXX does it then become 11NXXNXXXXXX?