[Asterisk-Users] hangup detection

[Sean Adams]

So I made the mistake of buying a Carrier Access channel bank without 
noticing the page on the wiki about the fact that they don't support 
disconnect supervision (bastards!). However, apart from that, I do have 
it working fine for incoming calls.

Is there some trick to get asterisk to detect the hangup tones from 
SBC? I've tried busydetect and callprogress as suggested, but neither 
seems to work.  The tone is not a busy tone, but that ear-piercing high 
pitched buzzer. It goes "if you'd like to make a call, please hang up 
and try again. If you need help, hang up and then dial your operator. 
BEEP BEEP BEEP etc."

I am set up here with recording gear and spectrum analyzer software, so 
I can identify the tones and timing if necessary. However I'm not sure 
how to make asterisk detect the tones, or if this work has already been 
done. Anyone know?