DTMF Dialed Digits Dialed Digits are multifrequency audio tones typically used for inter-register signalling of addresses during call set-up or for end-to-end device control during an established call. Depending on the system, codes are defined for the digits 0-9 of a telephone keypad and other auxiliary signals. The service provided is the transfer of dialed digits, namely, the transfer of five descriptors: digit type, digit character, start time, end time, and power level of the dual frequency pulse. Valid values are enabled and disabled.