[Freeswitch-users] Skypiax: not able to detect "Inband" dtmf tones from pstn call?

Scott Torr scott.torr.fs at letterboxes.org
Tue Dec 22 06:57:05 PST 2009

ubuntu-8.04.3-server-amd64.iso (update/upgrade)
FreeSWITCH Version 1.0.trunk (15787)


<extension name="Indial_to_fs_via_skypeIN">
  <condition field="destination_number" expression="^501$">
    <action application="start_dtmf" />
    <action application="record_session"
    <action application="playback" data="/root/Hello_16000.wav" />

fs>console loglevel 7

If I dial 501 from from a sip phone using "inband" dtmf I can see the
dtmf tones being detected and decoded by fs in the debug log.

If however I use a pstn phone and dial my skypeIN telephone number the
call comes into fs via skypiax but when I generate dtmf tones on the
phone they are not detected or decoded by fs.

If I take the record_session file and spectrum analyze the recorded
tones appear to be within spec.

Can anybody suggest why this is not working for me? 

Is the correct sample rate being used in libteletone_detect.c?
Does the Goertzel algorithm work for other sample rates other than

I'm not sure why I can not get this to work?

Scott Torr

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