[Freeswitch-dev] DTMF duration unit

François Delawarde fdelawarde at wirelessmundi.com
Mon Feb 4 13:54:07 MSK 2013

Hi all,

I don't clearly get what unit we should use in dtmf-duration parameters
(core min-dtmf-duration / max-dtmf-duration and sofia dtmf-duration).

The variable name and some parts of the code/wiki imply it's in
milliseconds (for example in sofia.c, we can see a line saying
profile->dtmf_duration = 100;).

However, the default values in switch_types.h suggest the values should
be based on timestamp like in RTP. Something like:

minimum = 400 @ 8kHz => 50ms
default = 2000 @ 8kHz => 250ms
maximum = 192000 @ 8kHz => 24s

If the later is the right one, should I change values when using WB
codecs that are NOT sampling at 8kHz?

Also, is the "unit" consistent across all endpoint modules?


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