This historic system uses a keypad where each button generates a unique pair of audio frequencies (one high group, one low group). It replaced rotary dials and pulse signaling, drastically reducing the time required to connect a call. The term originated as a commercial brand but became the widespread colloquial name for any dual-tone multi-frequency keypad dialing.
We need to test the touch-tone dialing on this analog port to make sure the PBX registers the digits.
Also heard as
- Touch-Tone
- DTMF
Do not mix it up with
- Tone dialing: Touch-Tone is a specific historic brand name for the generic tone dialing technology.
Related terms
Tone dialing
A method of telephone signaling that uses specific audio frequencies to represent dialed digits.
Pulse dialing
A legacy telephone signaling method that rapidly connects and disconnects the line to indicate digits.
Inband
Operating within the primary communication channel rather than on a separate management connection.