[Asterisk-Users] Control access to external dialing

[Luke Catranis]

Wondering if anyone could give me a tip on controlling access under the
following scenario.

I have an ATA connected to a legacy pbx as a trunk line. I want to
control who can make calls on this trunk. I cannot set restrictions on
the users via the pbx, so I would like to be able to assign a passcode
for people so they can dial out using this trunk line...