[Freeswitch-users] Need Less CPU Intensive Way to Detect Voicemail and Answering Machines

Michael Collins msc at freeswitch.org
Mon Jan 9 19:48:45 MSK 2012


FWIW,

When experimenting with outbound voice broadcasting and trying to detect
SIT tones, I stumbled across a factoid that might help, depending on your
locale. In North America, whenever I hit an answering machine or a cell
phone voicemail system the beep almost always was detected by my SIT tone
detects. It was a total accident that I even found it. IIRC, the 1776.7 Hz
tone was the one that almost always detected an answering machine/voicemail
beep.

No guarantees that it will work, but it's probably worth investigating. If
it handles 90% or more of your targets then it's at least as good as any
other type of detection you'll find.

-MC

On Mon, Jan 9, 2012 at 7:26 AM, Ken Rice <krice at freeswitch.org> wrote:

>  Detecting the tone is exactly what mod_vmd and mod_avmd do now... Not
> exactly the most efficient way to detect this sort of thing, but it does
> work
>
> K
>
>
>
> On 1/9/12 9:22 AM, "curriegrad2004" <curriegrad2004 at gmail.com> wrote:
>
> Since an answering machine creates a tone, have you looked into
> mod_spandsp's tone_detect feature? I think it does what you want it to do.
>
> On 2012-01-09 3:50 AM, "Avi Marcus" <avi at avimarcus.net> wrote:
>
> Yes, even with no other way of making it work more efficiently... 1
> machine can handle 50 calls that have actually picked up, before
> sending it to the recording.
> So your actual window is maximum 30? seconds per calls that picks up
> that mod_avmd needs to be running. So then that's 50 per 30 second
> windows so 100 calls per minute. That's 1,000 actual connected calls
> within 10 minutes. Is that within your threshold? For using ONE
> machine?
> (What happens if a person picks up? On silence it just starts the
> recording..? Or do you just have a looping first 30 seconds so it's ok
> if they miss the start?)
>
> -Avi
>
>
> On Mon, Jan 9, 2012 at 12:06 PM, Anita Hall <anita.hall at simmortel.com>
> wrote:
> > Hi David
> >
> > Question: Do you want to use only 1 machine for doing AMD on 1k+ calls ?
> If
> > not, you can distribute the load between 2 or more machines.
> >
> > Have you tried this? (from Wiki)
> >
> > For best results in getting accurate detection as well a saving system
> > resources (CPU & memory), you should do the following:
> >
> > Wait until AFTER the call has been answered before starting AVMD. In many
> > cases you may find it best to wait a few seconds after the call is
> answered
> > before starting AVMD.
> >
> > Starting AVMD before the call is answered will often result in false
> beeps
> > and wastes CPU resources.
> >
> > Once you have received the AVMD event, you should explicitly stop AVMD,
> even
> > though it will not return another event.
> >
> >
> >
> > regards,
> > Anita
> >
> >
> >
> > On Sun, Jan 8, 2012 at 7:20 AM, David Stein <dstein at ieee.org> wrote:
> >>
> >> Hello.
> >>
> >> I need to detect answering machine beeps on 1,000+ channels
> >> simultaneously.  Unfortunately, this is a real requirement, not a
> >> pseudo-requirement that can be engineered away.  This is for a mass
> >> emergency notification system for government, K-12, and higher
> education..
> >>
> >> In the past, I have done this with proprietary hardware (Dialogic and
> >> Aculab), which handles this sort of thing without overloading the host
> CPU,
> >> as the hardware's DSPs handle the detections.  I want to see if I can
> do the
> >> same thing with FreeSWITCH.
> >>
> >> Alas, I find the following warning in the wiki page for mod_avmd:
> >>
> >> AVMD (and VMD) are both very CPU intensive. You need to be aware of this
> >> fact when using it. It will drastically reduce your call capacity if
> you do
> >> not manage it correctly. On the other hand it is a very useful tool,
> and if
> >> managed properly will be a great aid for calls needing to do Voice Mail
> >> Detection.
> >>
> >>     Eric states, "You can expect about ~50 simultaneous instances on an
> >> Intel i7 920 CPU."
> >>
> >> So, it sounds like VMD and AVMD won't work for what I need to do.  I
> also
> >> don't think that the tone_detect application will work, as this requires
> >> specific frequencies (as opposed to ranges of frequencies), and
> answering
> >> machines and voicemail come with beeps at all sorts of frequencies.
> >>
> >> Does anyone know anything, either free or commercial, that I can use
> with
> >> FreeSWITCH to do this many simultaneous detections?  I know of
> commercial
> >> software-only platforms (e.g., Aculab's  Prosody S) that claim to be
> able to
> >> this, so it seems like it should be possible.
> >>
> >> Thanks in advance,
> >> David Stein
> >>
> >>
> >>
> _________________________________________________________________________
> >> Professional FreeSWITCH Consulting Services:
> >> consulting at freeswitch.org
> >> http://www.freeswitchsolutions.com
> >>
> >> 
> >> 
> >>
> >> Official FreeSWITCH Sites
> >> http://www.freeswitch.org
> >> http://wiki.freeswitch.org
> >> http://www.cluecon.com
> >>
> >> FreeSWITCH-users mailing list
> >> FreeSWITCH-users at lists.freeswitch.org
> >> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> >> UNSUBSCRIBE:
> http://lists.freeswitch.org/mailman/options/freeswitch-users
> >> http://www.freeswitch.org
> >>
> >
> >
> > _________________________________________________________________________
> > Professional FreeSWITCH Consulting Services:
> > consulting at freeswitch.org
> > http://www.freeswitchsolutions.com
> >
> > 
> > 
> >
> > Official FreeSWITCH Sites
> > http://www.freeswitch.org
> > http://wiki.freeswitch.org
> > http://www.cluecon.com
> >
> > FreeSWITCH-users mailing list
> > FreeSWITCH-users at lists.freeswitch.org
> > http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> > UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
> > http://www.freeswitch.org
> >
>
> _________________________________________________________________________
> Professional FreeSWITCH Consulting Services:
> consulting at freeswitch.org
> http://www.freeswitchsolutions.com
>
> 
> 
>
> Official FreeSWITCH Sites
> http://www.freeswitch.org
> http://wiki.freeswitch.org
> http://www.cluecon.com
>
> FreeSWITCH-users mailing list
> FreeSWITCH-users at lists.freeswitch.org
> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
> http://www.freeswitch.org
>
>
> ------------------------------
> _________________________________________________________________________
> Professional FreeSWITCH Consulting Services:
> consulting at freeswitch.org
> http://www.freeswitchsolutions.com
>
> 
> 
>
> Official FreeSWITCH Sites
> http://www.freeswitch.org
> http://wiki.freeswitch.org
> http://www.cluecon.com
>
> FreeSWITCH-users mailing list
> FreeSWITCH-users at lists.freeswitch.org
> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
> http://www.freeswitch.org
>
>
> _________________________________________________________________________
> Professional FreeSWITCH Consulting Services:
> consulting at freeswitch.org
> http://www.freeswitchsolutions.com
>
> 
> 
>
> Official FreeSWITCH Sites
> http://www.freeswitch.org
> http://wiki.freeswitch.org
> http://www.cluecon.com
>
> FreeSWITCH-users mailing list
> FreeSWITCH-users at lists.freeswitch.org
> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
> http://www.freeswitch.org
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.freeswitch.org/pipermail/freeswitch-users/attachments/20120109/3413ba2e/attachment-0001.html 


Join us at ClueCon 2011 Aug 9-11, 2011
More information about the FreeSWITCH-users mailing list