The read-only dtmf property on the RTCRtpSender interface returns a RTCDTMFSender object which can be used to send DTMF tones over the RTCPeerConnection . See Using DTMF for details on how to make use of the returned RTCDTMFSender object.
Syntax
var dtmfSender = RTCRtpSender.dtmf;
Value
An RTCDTMFSender which can be used to send DTMF over the RTP session, or null if the track being carried by the RTP session or the RTCPeerConnection as a whole doesn't support DTMF.
Only audio tracks can support DTMF, and typically only one audio track per RTCPeerConnection will have an associated RTCDTMFSender
Example
tbd
Specifications
| Specification | Status | Comment | 
|---|---|---|
| WebRTC 1.0: Real-time Communication Between Browsers The definition of 'RTCRtpSender.dtmf' in that specification. | Working Draft | 
Browser compatibility
| Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) | 
|---|---|---|---|---|---|---|
| Basic support | ? | No support | 52 (52) | No support | ? | No support | 
| Feature | Android | Chrome | Firefox Mobile (Gecko) | Firefox OS | IE Phone | Opera Mobile | Safari Mobile | 
|---|---|---|---|---|---|---|---|
| Basic support | ? | ? | 52.0 (52) | ? | No support | ? | No support |