The dtmf verb generates a string of dtmf digit signals. These are sent as RTP payloads using RFC 2833.

{
  "verb": "dtmf",
  "dtmf": "0276",
  "duration": 250
}

You can use the following options in the dtmf action:

option	description	required
dtmf	a string containing a sequence of dtmf digits (0-9,*,#)	yes
duration	the length of each digit, in milliseconds, Defaults to 500	no