Misc. Dialplan Tools start dtmf
From FreeSWITCH Wiki
You can use start_dtmf in a dialplan to enable in-band DTMF detection (i.e. the detection of DTMF tones on a channel). You should do this when you want to be able to identify DTMF tones on a channel that doesn't otherwise support another signaling method (like RFC2833 or INFO).
<extension name="ivr_demo"> <condition field="destination_number" expression="5000"> <action application="answer"/> <action application="start_dtmf" /> <action application="ivr" data="demo_ivr"/> </condition> </extension>
The start_dtmf line listed above starts the start_dtmf application on this channel to allow for DTMF detection.
WARNING: Do not use the start_dtmf application and the start_dtmf_generate application together. If both are running at the same time you will cause a feedback loop to occur within FreeSWITCH itself, such that a DTMF tone from a caller will result in repetitive DTMF tones being identified by FreeSWITCH.
WARNING: If using in conjunction with ring_ready, make sure that ring_ready is called first or else it may not work.
This application uses Media BUG