[Freeswitch-dev] FXS bridged on FXO ports and DTMF - Deja Vu

Moises Silva moises.silva at gmail.com
Sun Jul 4 08:20:25 PDT 2010

The tone on/off conditions should be, minimum on 40ms and 50ms off.

I recommend you to record a call with those double digit detections. If you
can reproduce them yourself by dialing quickly it'd be even better. Once you
have the recording you can run libteletone on the recorded audio (see
libs/freetdm/src/detect_dtmf.c) and may be start tweaking it. You could also
run spandsp dtmf detector over the recorded audio to see if does a better
job (I'd think so).

Another way to test if spandsp does better is to disable dtmf detection
completely from freetdm (the disable_dtmf dial plan app does that) and then
use spandsp_start_dtmf application on the dialplan (see mod_spandsp).

I'd be interested in looking at the recording too, you can send it to my
email if you want me to take a look. You can record all the read/write audio

ftmod trace /path/prefix <span> [<chan>]

That starts recording all incoming and outgoing data on the channel (if no
channel is specified all channels on the span are recorded), the specified
prefix will be used for each of the files. The recording starts immediately
(although if there is no call then most likely no one is reading/writing to
the channel), you must stop the recording when done with:

ftmod notrace <span> [<chan>]

Moises Silva
Senior Software Engineer
Sangoma Technologies Inc. | 50 McIntosh Drive, Suite 120, Markham ON L3R 9T3
t. 1 905 474 1990 x 128 | e. moy at sangoma.com

On Sat, Jul 3, 2010 at 4:22 AM, Jeroen C. van Gelderen <jeroeng at thegreek.com
> wrote:

> > If however you have this issue even with HW EC,
> >call Sangoma tech support and we will be happy to look at the issue.
> I wish this was Sangoma hardware esp. with hardware ec :)
> My DTMF "bouncing" issues were indeed caused by echo but now that I've got
> OSLEC running (thanks for patching that) calls are echo-free and crystal
> clear.
> The issue now is that my users dial their transfers (-say- #44) reasonably
> fast and that often causes two successive DTMF digits to be detected as one
> (#4).
> In order to reliably reach the extension the clerk cannot dial more than
> one
> digit per second. That seems excessively slow. I suspect there must be a
> knob somewhere to tune that (in libteletone)? Other causes to look for?
> Cheers,
> -Slim
> _______________________________________________
> FreeSWITCH-dev mailing list
> FreeSWITCH-dev at lists.freeswitch.org
> http://lists.freeswitch.org/mailman/listinfo/freeswitch-dev
> UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-dev
> http://www.freeswitch.org
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.freeswitch.org/pipermail/freeswitch-dev/attachments/20100704/b4472716/attachment.html 

More information about the FreeSWITCH-dev mailing list