Why do you think on the Mitels when you transfer an incoming call to an out side line the CO trunks dont disconnect. They can stay connected for months and months. This only happens when I used the cordless phone (ONS ports) I do have far end supervision enabled on the trunks.
Check your settings in form 13. Try setting far end answer supervision to no. Also check disconnect timer.
Dropping the disconnect timer down to the minimum setting (100ms)makes the trunks much more sensitive to disconnect signals, and takes care of that problem 95% of the time.
Are you using the ONS ports as looped back C.O. ports on a test/lab system? If so, most mitel systems give NO disconnect signal on ONS ports.
Lightinghorse, This is with real CO lines.
westerntelephone, are you sure its not supposed to be yes?
fifty5footer, I will try what you suggested.
I was looking at a system remotely, and CO trunks were set to no, T-1 set to yes.