[Asterisk-Users] hangup detection

[Steven Critchfield]

On Fri, 2004-01-02 at 12:25, Sean Adams wrote:
> 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?

Are the tones increasing in pitch? Are they the Special Information
Tones (SIT) that are also on the message when you dial a number that has
been disconnected?

If so, then they are defined somewhere in the code, at least as part of
app_zapateller since that is how it tries to get rid of telemarketers.
You could then see about adding that to the dsp routines to detect the
SIT tones and determine what to do at that time.

BTW, which CAC channel bank did you buy? The ADIT 600 should do
disconnect supervision, and I thought the AB1 did too. Are you also sure
you have that on your line so as to be detected? Your other option might
be to switch to groundstart lines which detect hangup much easier. May
be difficult to get unless you are a business though.
-- 
Steven Critchfield  <critch at basesys.com>