This is a VG350 that is MGCP registered to a CUCM 11.0
I understand what is going on, but not how to fix it. Essentially we have these emergency call boxes. Someone hits the button and the call box goes off-hook and hits a blank translation pattern we have set up to PLAR the call to an emergency call system. The system picks up and the call proceeds correctly. However, if the system end hangs up, leaving the call box still off-hook, the call-box side doesn't seem to transition into the on-hook state. It's like it quickly goes on-hook and then back off-hook or something because it hits the PLAR translation pattern again and calls back. This happens in a never-ending loop until we find a way to make the call box hang up first.
Is there some kind of setting to make the VG350 endpoints go back on-hook and stay on-hook as soon as the other end hangs up?