[Asterisk-Users] Hangup Detection (revisited)

[Darrick Hartman]

A little background.  I'm integrating asterisk as the voicemail service
for an old Meridian/Norstar pbx which has an ATA-2 connected.  The ATA-2
is used to connect an analog device (such as a voice modem) to the pbx.
 In the past we've used vgetty and a voice modem with varying degrees of
success.

The problem is the ATA-2 does not provide disconnect supervision.  When
the outside caller hangs up, the line just goes silent.  No busy signal.
   If the inside analog device hangs up the call, the ATA-2 then
provides a dial tone.

Right now, we've been using silence detection in voicemail to determine
when the call ends.  This works most of the time.  On longer calls (say
more than 5 minutes), sometimes the silence detection does not function
and the call continues (with a bunch of recorded silence) until the
maximum voicemail length limit is reached.

Obviously, busy-detect is not going to work.  The current silence
threshold is set at the default 128.  The FXO module is configured with
Kewl Start signalling.  Would I get better results (or any different
results) if I switched to Loop Start?

Any other ideas?

Thanks,

Darrick
-- 
Darrick Hartman
DJH Solutions, LLC
http://www.djhsolutions.com