I have a client that has CME 4 installed on a router and they use 7921 I phones. There are 4 PSTN lines connected to the router allowing users to make external calls. The configuration is such that 2 of these lines ring out at specific users extensions while the other 2 ring out at the receptionist's desk. When users want to make external calls, they are able to use any of the available 4 lines at random.
The client now wants access restricted on the 2 first lines that ring out at 2 different users extensions such that calls going out and coming in on these lines are tied to the respective extension of the user. Access however is still granted to all users on the other 2 lines.
Can someone please help with a sample config or a know how of how to go about this?