[asterisk-users] Odd hangup problem TDM400P

[joe a.]

On an Asterisk 1.2.12.1 system using a TDM400P with two FXO and two FXS modules, servicing two POTS lines:

When dialing a number, such as a bank, or pharmacy, where it is required to enter a long series of numbers via the phone's keypad, an unexpected hangup occurs.  

The hangup does *not* occur when entering the numbers, as one might initially expect, but after the called end begins to repeat back the numbers previously entered.  This happens consistently and happens from any of the analog phones, or any of the SIP phones.

I know it is related to the asterisk system as, I if I bypass the PBX by plugging an analog phone directly into one of the telco jacks, the call/transaction completes normally.  I had considered, of course, that it was a problem at their end.

For the call, I see this on the CLI:

***********************************************************
Verbosity is at least 6
    -- Starting simple switch on 'Zap/2-1'
    -- Executing Dial("Zap/2-1", "Zap/g4/w5551234") in new stack
    -- Called g4/w5551234
    -- Zap/4-1 answered Zap/2-1
    -- Attempting native bridge of Zap/2-1 and Zap/4-1
    -- Hungup 'Zap/4-1'
  == Spawn extension (localphone, 5551234, 1) exited non-zero on 'Zap/2-1'
    -- Hungup 'Zap/2-1'
***********************************************************

So one can presume that asterisk is hanging up the PSTN line, for some reason.  By why?  There is clearly not silence on the line.

Any thoughts?

joe a.