[Asterisk-Users] Adtran TA750, any chance of working MWI ?

[Steve Creel]

I have a bunch of existing AT&T/Lucent/Avaya 2500YMGP sets with LED
message waiting lights.  Do I stand any chance of getting the Adtrans to
light these?

What I know so far:

When you pick up the telephone, the LED flashes.
If you plug two telephones in, picking up one flashes the LED on the
other.
Hanging the telephone up will flash the LED.
Incoming calls flash the LED.
Stutter dialtone is there and functioning.
Debugs in chan_zap reveal that do_monitor sees there are messages, and
tries to update MWI status.
The Adtran is putting out 50 volts when on hook (either with or without a
message waiting).  If 'On Hook Messaging' is enabled (I think this is for
ADSI ?), the voltage is closer to 40v.

I'm at a loss as to what to do, could anyone offer some pointers?

Many thanks,
Steve