The RTCDTMFSender
interface provides a mechanism for transmitting DTMF codes on a WebRTC RTCPeerConnection
. You gain access to the connection's RTCDTMFSender
through the RTCRtpSender.dtmf
property on the audio track you wish to send DTMF with.
The primary purpose for WebRTC's DTMF support is to allow WebRTC-based communication clients to be connected to a public-switched telephone network (PSTN) or other legacy telephone service, including extant voice over IP (VoIP) services. For that reason, DTMF can't be used between two WebRTC-based devices, because there is no mechanism provided by WebRTC for receiving DTMF codes.
<div id="interfaceDiagram" style="display: inline-block; position: relative; width: 100%; padding-bottom: 11.666666666666666%; vertical-align: middle; overflow: hidden;"><svg style="display: inline-block; position: absolute; top: 0; left: 0;" viewbox="-50 0 600 70" preserveAspectRatio="xMinYMin meet"><a xlink:href="https://developer.mozilla.org/en-US/docs/Web/API/EventTarget" target="_top"><rect x="1" y="1" width="110" height="50" fill="#fff" stroke="#D4DDE4" stroke-width="2px" /><text x="56" y="30" font-size="12px" font-family="Consolas,Monaco,Andale Mono,monospace" fill="#4D4E53" text-anchor="middle" alignment-baseline="middle">EventTarget</text></a><polyline points="111,25 121,20 121,30 111,25" stroke="#D4DDE4" fill="none"/><line x1="121" y1="25" x2="151" y2="25" stroke="#D4DDE4"/><a xlink:href="https://developer.mozilla.org/en-US/docs/Web/API/RTCDTMFSender" target="_top"><rect x="151" y="1" width="130" height="50" fill="#F4F7F8" stroke="#D4DDE4" stroke-width="2px" /><text x="216" y="30" font-size="12px" font-family="Consolas,Monaco,Andale Mono,monospace" fill="#4D4E53" text-anchor="middle" alignment-baseline="middle">RTCDTMFSender</text></a></svg></div>
a:hover text { fill: #0095DD; pointer-events: all;}
Properties
RTCDTMFSender.toneBuffer
Read only- A
DOMString
which contains the list of DTMF tones currently in the queue to be transmitted (tones which have already been played are no longer included in the string). SeetoneBuffer
for details on the format of the tone buffer.
Event handlers
RTCDTMFSender.ontonechange
- An
EventHandler
to handle thetonechange
event, which is sent each time an outbound tone starts or finishes playing.
Methods
RTCDTMFSender.insertDTMF()
- Given a string describing a set of DTMF codes and, optionally, the duration of and inter-tone gap between the tones,
insertDTMF()
starts sending the specified tones. CallinginsertDTMF()
replaces any already-pending tones from thetoneBuffer
. You can abort sending queued tones by specifying an empty string (""
) as the set of tones to play.
Example
tbd
Specifications
Specification | Status | Comment |
---|---|---|
WebRTC 1.0: Real-time Communication Between Browsers The definition of 'RTCDTMFSender' in that specification. |
Working Draft |
Browser compatibility
Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|---|
Basic support | (Yes) | (Yes) | 52 (52) | No support | ? | ? |
Feature | Android | Chrome | Firefox Mobile (Gecko) | Firefox OS | IE Phone | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|---|
Basic support | ? | (Yes) | 52.0 (52) | ? | No support | ? | ? |