Set extension A busy if extension B is in use


We have a sales/customer service dep. with a number of reps receiving calls both from ACD and on their DID. They each have a Snom 720 with 2 extensions. One extension “A” is used for internal calling and their DID. The other extension “B” is used exclusively by our 3rd party call center operator console (SamWin), which requires a dedicated extension pr. user.

The SamWin will monitor if the agent’s extension “A” is in use, and pause them in the ACD so they wont receive 2 calls simultaneously.
The problem is when an agents extension “B” is in use with a call from the ACD, they may receive calls to their DID or internal extension, and they will have the big LED flashing red on their phone.

So is there any way to set extension “A” busy if extension “B” is in use so we can avoid this?

FreePBX v2.11 something (latest version).