[Asterisk-Users] Re: call progress - what are the sticking points?

[Gilad Ben-Yossef]

Joe Greco wrote:

> More difficult is the problem of knowing when the remote end has gone
> away.  Reversal, loop break, dial tone, and just plain silence are not
> all that unusual as methods of detection.  In some cases, you do actually
> need to infer that the remote has gone away.
> 


I understand that the phone company (sometime) doesn't provide 
information about remote hangup on POTS lines. What bugs me is the 
simple question - how does your average 10$ answering machine detects 
the hang up?

I'm guessing the obvious - DSP and some heuristics as to what a "hangup" 
sounds like and it sounds to me that it isn't all that hard to do in 
Asterisk (since it's done in those cheap machines) but I would be very 
glad to hear some tips from someone that knows a little better then me.

Thanks,
Gilad


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Gilad Ben-Yossef <gilad at codefidence.com>
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