How to select the desired outgoing number in the trunk?

Question

Telephony

It is necessary to abandon analog lines and combine two telephone numbers in the trunk.
The question arises: how can FreePBX configure incoming / outgoing routes relative to a specific number?
Studied a legacy sip-trunk with several numbers, did not find anything that would indicate a specific number.
Where to dig and what to configure?

Answer 1

A SIP trunk is not a group of two-wire lines, among which you can choose the one you need. I suspect that the task can be reduced to the substitution of one or another Caller ID when calling from one or another internal number during an outgoing call. And what is meant by "configure incoming routes for a specific number"? If two different numbers come from the provider, set up DID as described here wiki.freepbx.org/display/F2/Inbound+Routes

Answer 2

If there is really only one SIP trunk, then you need to communicate with the provider. You may need to send some SIP headers.