DTMF Tones In MixMonitor Recording
Hello list, Hope you are all doing fine!
I have stumbled over some piece of dialplan code in which apparently they were trying to avoid recording the DTMF tones in the wav file. It is really messy and I am not sure if this really works. So after a bit of research I
found this comment (
https://community.asterisk.org/t/asterisk-dtmf-record/65040) in which it is said:
*”Asterisk strips the DTMF from the audio stream when configured for inband, so internal stuff can react to the DTMF and so the other side does not hear the tone unless they are using inband (in which case it is regenerated)”*
So my questions are, what are the cases in which Asterisk regenerates the DTMFs? Does it cause the recording to have the tone as well, or is it only transmitted to the other leg without being generated to the recording file?
Also, what if one or both legs are RFC2833? From my tests the RFC2833
events never show up in the recording, but I just want to confirm that this is always true.
Thanks, Kind regards, Patrick Wakano
Virus-free. www.avg.com
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4 thoughts on - DTMF Tones In MixMonitor Recording
If properly configured then Asterisk will always strip and regenerate the DTMF tone. You have to purposely misconfigure things to cause it to not get stripped. IE: DTMF is actually inband but you configure it for RFC2833. Since Asterisk wouldn’t be listening to the audio stream, it would go right through and get recorded.
Thanks very much for the reply Joshua!
So I guess that setting dtmfmode=auto would be the safest choice in order to strip out the DTMFs from the recording, right?
Cheers!
Patrick Wakano
It should work. Personally I prefer explicit configuring instead of having things just try to figure out what is in use.
I agree! I have my SBC and asterisk servers all configured with rfc2833, so it should be ok! No need for auto mode!
Thanks again!
Cheers Patrick