title: WebRTC error - RTCPeerConnection.connectionState failed
body: <p>I have a problem with a video call project I created. I followed the steps in this video <a href="https://www.youtube.com/watch?v=_3exOT53faw&amp;ab_channel=CodeShell" rel="nofollow noreferrer">https://www.youtube.com/watch?v=_3exOT53faw&amp;ab_channel=CodeShell</a>, but I get an error because <em><strong>RTCPeerConnection.connectionState</strong></em> is <em><strong>failed</strong></em>. According to <a href="https://developer.mozilla.org/en-US/docs/Web/API/RTCPeerConnection/connectionState" rel="nofollow noreferrer">https://developer.mozilla.org/en-US/docs/Web/API/RTCPeerConnection/connectionState</a> it is because &quot;One or more of the ICE transports on the connection is in the failed state.&quot;. I don't know if I should change the servers I use, or add new ones. Any ideas?
  Here is part of the code:</p>
  <pre><code>const configuration = {
    iceServers: [
      {
        urls: [
          'stun:stun1.l.google.com:19302',
          'stun:stun2.l.google.com:19302',
        ],
      },
    ],
    iceCandidatePoolSize: 10,
  };
  peerConnection = new RTCPeerConnection(configuration);
  
    peerConnection.addEventListener('icecandidate', event =&gt; {
      if (!event.candidate) {
        console.log('Got final candidate!');
        return;
      }
      console.log('Got candidate: ', event.candidate);
      callerCandidatesCollection.add(event.candidate.toJSON());
    });
  </code></pre>