[Asterisk-Users] Answering machine detection

[Ben Hencke]

Hi all,
I would like to have basic answering machine detection for a
notification service (not spam, not telemarketing) so that I know when
I get a machine, and also to avoid starting the message during the
machine greeting.

I have found the WaitForSilence app in CVS, and this seems like it
would do exactly what I need, but does not seem to work in my setup.

I am making the call over VoIP (tryed AIX and SIP with GSM), but keep
getting errors where it calls app_waitfor(). I get these messages on
the console:

"One waitfor failed. "
"No audio available on <channel>??"


If I use IAX, the progress will wait for some silence, but still
display the error after it gets some silence. If I use SIP, it will
never wait more than a few seconds and doesn't seem to wait for any
silence at all.

Does anyone know of some other ways (ie applications)  to detect
answering machines?

Thanks in advance,
  Ben