Revision 1046942 of RTCConfiguration

<p>{{APIRef("WebRTC")}}{{draft}}</p>

<p>The <strong><code>RTCConfiguration</code></strong> dictionary is used to provide configuration options for an {{domxref("RTCPeerConnection")}}. It may be passed into the constructor when instantiating a connection, or used with the {{domxref("RTCPeerConnection.getConfiguration()")}} and {{domxref("RTCPeerConnection.setConfiguration()")}} methods, which allow inspecting and changing the configuration while a connection is established.</p>

<p>The options include ICE server and transport settings and identity information.</p>

<h2 id="Properties">Properties</h2>

<dl>
 <dt>iceServers</dt>
 <dd>An array of RTCIceServer objects, each describing one server which may be used by the ICE agent; these are typically STUN and/or TURN servers.</dd>
 <dt>iceTransportPolicy</dt>
 <dd>The current ICE transport policy; this must be one of the values from the RTCIceTransportPolicy enum. If this isn't specified, <code>"all"</code> is assumed.</dd>
</dl>

<h3 id="RTCIceServer_Properties">RTCIceServer Properties</h3>

<table class="standard-table">
 <thead>
  <tr>
   <th scope="col">Name</th>
   <th scope="col">Type</th>
   <th scope="col">Description</th>
  </tr>
 </thead>
 <tbody>
  <tr>
   <td><code>urls</code></td>
   <td>{{domxref("DOMString")}}, {{jsxref("Array")}}</td>
   <td>Either a string specifying a single STUN or TURN server's URI to use, or an array of strings specifying multiple URIs for servers with multiple addresses.</td>
  </tr>
  <tr>
   <td><code>username</code></td>
   <td>{{domxref("DOMString")}}</td>
   <td>An account username (optional)</td>
  </tr>
  <tr>
   <td><code>credential</code></td>
   <td>{{domxref("DOMString")}}</td>
   <td>The password associated with username, if given (optional)</td>
  </tr>
 </tbody>
</table>

<p>Avoid specifying an unnecessarily large number of URLs in the <code>urls</code> property; the startup time for your connection will go up substantially. Every server in the list will be contacted and tried out before one is selected to be used for negotiation.</p>

<div class="note">
<p>Older versions of the WebRTC specification included an <code>url</code> property instead of <code>urls</code>; this was changed in order to let you specify multiple addresses for each server in the list, as shown in the example below.</p>
</div>

<h2 id="Constants">Constants</h2>

<p>{{page("/en-US/docs/Web/API/RTCPeerConnection", "RTCIceTransportPolicy enum", 0, 1)}}</p>

<h2 id="Example">Example</h2>

<pre class="brush: js">
var configuration = { iceServers: [{
                          urls: "stun:stun.services.mozilla.com",
                          username: "[email protected]", 
                          credential: "webrtcdemo"
                      }, {
                          urls: ["stun:stun.example.com", "stun:stun-1.example.com"]
                      }]
};

var pc = new RTCPeerConnection(configuration);</pre>