Experimental

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

The read-only RTCDataChannel property protocol returns a DOMString containing the name of the subprotocol in use. If no protocol was specified when the data channel was created, then this property's value is "" (the empty string).

The permitted values of this property are defined by the Web site or app using the data channel.

The ability for each channel to have a defined subprotocol lets your app, for example, use JSON objects as messages on one channel while another channel is plaintext and another is raw binary or even some other format.

Syntax

var subProtocol = aDataChannel.protocol;

Value

A string identifying the app-defined subprotocol being used for exchanging data on the channel. If none has been established, this is an empty string ("").

Example

var pc = new RTCPeerConnection();
var dc = pc.createDataChannel("my channel", {
           protocol: "json"
});

function handleChannelMessage(dataChannel, msg) {
  switch(dataChannel.protocol) {
    case "json":
      /* process JSON data */
      break;
    case "raw":
      /* process raw binary data */
      break;
  }
}

Specifications

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

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
protocol
56
≤79
Yes
No
43
11
56
56
Yes
43
11
6.0

See also