RTCIceServers: urls property

The RTCIceServer dictionary's urls property specifies the URL or URLs of the servers to be used for ICE negotiations. These are typically STUN and/or TURN servers.

Syntax

const iceServer = {
  urls: iceServerUrl, /* or an array or URLs: [ url1, ..., urlN ] */
  username: "webrtc", // optional
  credential: "turnpassword" // optional
};

iceServers.push(iceServer);

The value of this property may be specified as a single URL or as an array of multiple URLs.

Examples

Let's look a few examples of varying complexity.

A single ICE server

This example creates a new RTCPeerConnection which will use a STUN server at stunserver.example.org to negotiate connections.

myPeerConnection = new RTCPeerConnection({
  iceServers: [
    {
      urls: "stun:stunserver.example.org",
    },
  ],
});

Notice that only the urls property is provided; the STUN server doesn't require authentication, so this is all that's needed.

A single ICE server with authentication

The second example creates a new RTCPeerConnection which will use a TURN server at turnserver.example.org to negotiate connections. Logging into the TURN server will use the username "webrtc" and the creative password "turnpassword".

myPeerConnection = new RTCPeerConnection({
  iceServers: [
    {
      urls: "turn:turnserver.example.org",
      username: "webrtc",
      credential: "turnpassword",
    },
  ],
});

A single ICE server with multiple URLs

The next example creates a new RTCPeerConnection which will use a single TURN server which has multiple URLs. This is useful if the server is, for example, available both on "turn" and "turns" schemes, or if there's a fallback address available for the server.

Note: Keep in mind that ICE will try all the URLs you list here, so the more you include, the longer connections will take to establish.

myPeerConnection = new RTCPeerConnection({
  iceServers: [
    {
      urls: ["turns:turnserver.example.org", "turn:turnserver.example.org"],
      username: "webrtc",
      credential: "turnpassword",
    },
  ],
});

Multiple ICE servers

Finally, this example creates a new RTCPeerConnection which will use one of two servers for ICE negotiation. Each server can have one or more URLs, as demonstrated above.

myPeerConnection = new RTCPeerConnection({
  iceServers: [
    {
      urls: ["turns:turnserver.example.org", "turn:turnserver.example.org"],
      username: "webrtc",
      credential: "turnpassword",
    },
    {
      urls: "stun: stunserver.example.org",
    },
  ],
});

Two ICE servers are provided. One is a TURN server which can be accessed both over TURN and TURNS. The other is a STUN server. Any number of servers could be listed of any combination of types.

Specifications

Specification
WebRTC: Real-Time Communication in Browsers
# dom-rtciceserver-urls

Browser compatibility

BCD tables only load in the browser

See also