We use Grandstream 2140 phones with GXP2200EXT side module with some BLF's. The server is issabel 4 with asterisk 16. I am trying to get the BFL to show the phone is in DND mode. I have been able to change the phone to use server side DND by doing the following:
Accounts -> Account 1 -> Feature code
Do Not Disturb (DND)
Now pressing the mute button on the 2140 sends the DND commands to the server. The BLF will momentarily turn red while the server IVR message plays to say we are in DND, but then goes back to green whe complete. The phone screen displays we are in DND mode. When I ring the extension I am getting a busy. So everything great except the BLF is not showing red on this phone or any other phone that is monitoring this extension. What do I need to do to tell issable to honor DND correctly.