One late night many decades ago, I chanced upon a technical description of the Touch-Tone system. The book I was reading had an explanation of how each key on a telephone sends a combination of two ...

Dual tone multi-frequency (DTMF) signaling is used on traditional analog plain old telephony service (PoTS) phones to send digits to the switching center for call routing or some other specialized ...

In the early 1960s, AT&T introduced a method of providing in-band signaling so telephone customers could place telephone calls. The system was called dual-tone multi-frequency, or DTMF. AT&T, through ...

As we all very well known that DTMF refers to Dual Tone Multi-Frequency Signaling. This DTMF is used for telecommunication signaling over analog telephone lines. Here I am listing out some of the best ...