DTMF detection

Which module is responsible for DTMF detection in asterisk

If you use VoIP, you do not want Asterisk to do DTMF detection.

However, if you need to do it, it is not done by a module, but by the Asterisk core. The code is in main/dsp.c.

Found by looking for INBAND in chan_sip.c and then looking up the library routine in the .h files.

It also looks like it isn’t done in software at all for some of the better dahdi devices.