Web/API/RTCDataChannel/bufferedAmountLowThreshold

This is an experimental technologyCheck the Browser compatibility table carefully before using this in production.

The RTCDataChannel property bufferedAmountLowThreshold is used to specify the number of bytes of buffered outgoing data that is considered "low." The default value is 0. When the number of buffered outgoing bytes, as indicated by the bufferedAmount property, falls to or below this value, a bufferedamountlow event is fired. This event may be used, for example, to implement code which queues more messages to be sent whenever there's room to buffer them. Listeners may be added with onbufferedamountlow or addEventListener().

The user agent may implement the process of actually sending data in any way it chooses; this may be done periodically during the event loop or truly asynchronously. As messages are actually sent, this value is reduced accordingly.

bufferedamountlow events are not fired after the data channel is closed.

Syntax

var threshold = aDataChannel.bufferedAmountLowThreshold;

aDataChannel.bufferedAmountLowThreshold = threshold;

Value

The number of queued outgoing data bytes below which the buffer is considered to be "low."

Example

In this snippet of code, bufferedAmountLowThreshold is set to 64kB, and a handler for the bufferedamountlow event is established by setting the RTCDataChannel.onbufferedamountlow property to a function which should send more data into the buffer by calling send().

var dc = peerConnection.createDataChannel("File Transfer");
dc.bufferedAmountLowThreshold = 65535;

dc.onbufferedamountlow = function() {
  /* use send() to queue more data to be sent */
};

Specifications

Specification	Status	Comment
WebRTC 1.0: Real-time Communication Between BrowsersThe definition of 'RTCDataChannel.bufferedAmountLowThreshold' in that specification.	Candidate Recommendation	Initial specification.

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`bufferedAmountLowThreshold` Experimental'	Chrome Full support 56	Edge Full support ≤79	Firefox Full support Yes	IE No support No	Opera Full support 43	Safari Full support Yes	WebView Android Full support 56	Chrome Android Full support 56	Firefox Android No support No	Opera Android Full support 43	Safari iOS No support No	Samsung Internet Android Full support 6.0

Legend

Full support: Full support
No support: No support
Experimental. Expect behavior to change in the future.': Experimental. Expect behavior to change in the future.