What does DTMF mean?

DTMF explained: what Dual-Tone Multi-Frequency means and how keypad tones are transmitted with sipgate.

DTMF means Dual-Tone Multi-Frequency (dual-tone multi-frequency). Put more simply, these are key tones.

When do I need DTMF?

For calls to a voice computer, which requires input via key tone, this is done via DTMF. DTMF is also used for a call to the sipgate voicemail , since it asks for a PIN via key tone. But DTMF is also needed for various telephony features such as call swapping and transferring .