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callSession.sendDtmf()

DTMF stands for Dual-Tone Multi-Frequency. It's the system used for telephone signaling over analog telephone lines in the voice-frequency band. DTMF allows the user to dial numbers and send commands by pressing keys on a telephone keypad.

How It Works:

  • Each key on the keypad generates two simultaneous tones—one from a high-frequency group and one from a low-frequency group.
  • These combined tones are unique to each key and can be decoded by the telephone system to identify which button was pressed.

ABCD are less commonly used but are part of the DTMF standard. They were originally intended for special signaling in military and network control systems.

This method is used to send a DTMF. However, receving DTMF is not supported, as it is not supported by WebRTC.

Sample

await callSession.sendDtmf(dtmf);

Inputs

Parameters Description
dtmf A string containing only the following characters: 0123456789*#ABCD.

Outputs

None.