The DTMF Tone Detection parameter is used to enable or disable the DTMF tone detector. When disabled, DTMF signals are digitized locally the same way as voice, and converted at the remote end to analog tones with varying pulse widths.
When enabled, DTMF signals are not digitized locally. Instead, the local voice channel sends a set of coded commands to the remote end, where the DTMF tones are regenerated with a uniform pulse width of 100 milliseconds.