RTCDataChannel: bufferedamountlow event

A bufferedamountlow event is sent to an RTCDataChannel when the number of bytes currently in the outbound data transfer buffer falls below the threshold specified in bufferedAmountLowThreshold. bufferedamountlow events aren't sent if bufferedAmountLowThreshold is 0.

Bubbles No
Cancelable No
Interface Event
Event handler property onbufferedamountlow

Examples

This example sets up a handler for bufferedamountlow to request more data any time the data channel's buffer falls below the number of bytes specified by bufferedAmountLowThreshold, which we have set to 65536. In other words, we'll try to keep at least 64kB of data in the buffer, reading 64kB at a time from the source.

let pc = new RTCPeerConnection();
let dc = pc.createDataChannel("SendFile");
let source = /* source data object */

dc.bufferedAmountLowThreshold = 65536;

pc.addEventListener("bufferedamountlow", ev => {
  if (source.position <= source.length) {
    dc.send(source.readFile(65536));
  }
}, false);

After creating the RTCPeerConnection, this calls RTCPeerConnection.createDataChannel() to create the data channel. Then a listener is created for bufferedamountlow to refill the incoming data buffer any time its contents fall below 65536 bytes.

You can also set up a listener for bufferedamountlow using its event handler property, onbufferedamountlow:

pc.onbufferedamountlow = ev => {
  if (source.position <= source.length) {
    dc.send(source.readFile(65536));
  }
}

Specifications

Specification Status Comment
WebRTC 1.0: Real-time Communication Between Browsers
The definition of 'bufferedamountlow' in that specification.
Candidate Recommendation  

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
bufferedamountlow eventChrome Full support 57
Notes
Full support 57
Notes
Notes The default for rtcpMuxPolicy is require.
Edge ? Firefox Full support YesIE No support NoOpera Full support 44
Notes
Full support 44
Notes
Notes The default for rtcpMuxPolicy is require.
Safari Full support YesWebView Android Full support 57
Notes
Full support 57
Notes
Notes The default for rtcpMuxPolicy is require.
Chrome Android Full support 57
Notes
Full support 57
Notes
Notes The default for rtcpMuxPolicy is require.
Edge Mobile ? Firefox Android Full support YesOpera Android Full support 43
Notes
Full support 43
Notes
Notes The default for rtcpMuxPolicy is require.
Safari iOS No support NoSamsung Internet Android Full support 7.0

Legend

Full support  
Full support
No support  
No support
Compatibility unknown  
Compatibility unknown
See implementation notes.
See implementation notes.

See also

Document Tags and Contributors

Contributors to this page: mdnwebdocs-bot, Sheppy
Last updated by: mdnwebdocs-bot,