The RTCPeerConnection.setConfiguration() method sets the current configuration of the RTCPeerConnection based on the values included in the specified object. This lets you change the ICE servers used by the connection and which transport policies to use.

The most common use case for this method (and even then, probably not a very common use case) is to replace the set of ICE servers to be used. Two potential scenarios in which this might be done:

• The RTCPeerConnection was instantiated without specifying any ICE servers. If, for example, the RTCPeerConnection() constructor was called with no parameters, you would have to then call setConfiguration() to add ICE servers before ICE negotiation could begin.
• Renegotiation of the connection is needed, and a different set of ICE servers needs to be used for some reason. Perhaps the user has moved into a new region, so using new regional ICE servers is necessary, for example. In this situation, one might call setConfiguration() to switch to new regional ICE servers, then initiate an ICE restart.

configuration

An object which provides the options to be set. The changes are not additive; instead, the new values completely replace the existing ones. See RTCPeerConnection() for more information on what options are allowed.

InvalidAccessError DOMException

Thrown if one or more of the URLs specified in configuration.iceServers is a TURN server, but complete login information is not provided (that is, either the RTCIceServer.username or RTCIceServer.credential is missing, or if RTCIceServer.credentialType is "password" and RTCIceServer.credential is not a string). This prevents successful login to the server.

InvalidModificationError DOMException

Thrown if the configuration includes changed identity information, but the connection already has identity information specified. This happens if configuration.peerIdentity or configuration.certificates are set and their values differ from the current configuration. This may also be thrown if there are changes to configuration.bundlePolicy or configuration.rtcpMuxPolicy, or to configuration.iceCandidatePoolSize when RTCPeerConnection.setLocalDescription() has already been called.

InvalidStateError DOMException

Thrown if the RTCPeerConnection is closed.

SyntaxError DOMException

Thrown if the configuration.iceServers contains no URLs or if one of the values in the list is invalid.

NotSupportedError DOMException

Thrown if configuration.iceServers contains a URL with a scheme that is not supported.

In this example, it has already been determined that ICE restart is needed, and that negotiation needs to be done using a different ICE server.

const restartConfig = {
  iceServers: [
    {
      urls: "turn:asia.myturnserver.net",
      username: "[email protected]",
      credential: "topsecretpassword",
    },
  ],
};

myPeerConnection.setConfiguration(restartConfig);

myPeerConnection
  .createOffer({ iceRestart: true })
  .then((offer) => myPeerConnection.setLocalDescription(offer))
  .then(() => {
    // send the offer to the other peer using the signaling server
  })
  .catch(reportError);

First, a new object is created, restartConfig, specifying the new ICE server and its credentials. This is then passed into setConfiguration(). ICE negotiation is restarted by calling createOffer(), specifying true as the value of the iceRestart option. From there, we handle the process as usual, by setting the local description to the returned offer and then sending that offer to the other peer.

• RTCPeerConnection.getConfiguration()
• RTCPeerConnection()
• RTCPeerConnection