RTCDataChannel.protocol

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 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

Browser compatibility

[1] The interface is called DataChannel instead of the standard RTCDataChannel in Firefox; however, a binding has been in place since Firefox 24 which allows either name to be used.

See also

• WebRTC
• RTCDataChannel
• RTCPeerConnection.createDataChannel()