title: TURN server webrtc tcp relay
body: <p>I am using <code>coturn</code> as my <code>TURN</code> server for relay in a <code>WebRTC</code> connection. What I want to achieve is <code>TCP</code> based connection and <strong>not UDP</strong>.</p>
  <p>What I have tried :
  In coturn configuration, I have set <code>no-udp</code> and <code>no-udp-relay</code> to force <code>TCP</code> based connection only.</p>
  <pre><code># Uncomment if no UDP client listener is desired.
  # By default UDP client listener is always started.
  #
  no-udp
  
  # Uncomment if no UDP relay endpoints are allowed.
  # By default UDP relay endpoints are enabled (like in RFC 5766).
  #
  no-udp-relay
  </code></pre>
  <p>Whenevere, I try to establish a connection, I get <code>turn server may be broken</code>.</p>
  <p>Possibly useful detail, A and B are trying to communicate</p>
  <ul>
  <li>on machine <code>A</code>, I get 3 UDP candidates and 3 TCP candidates</li>
  <li>on machine <code>B</code>, I get 3 UDP candidates only.</li>
  <li>both are using Firefox
  When I was reading <a href="https://developer.mozilla.org/en-US/docs/Web/API/WebRTC_API/Connectivity" rel="nofollow noreferrer">firefox documentation</a>, I see that <code>TCP</code> ice candidates type do not have any <code>relay</code> or <code>TURN</code> connection. Could this be a reason for failure ?</li>
  </ul>
  <p>The question is, what could be the reason for failure ?</p>
  <p>Edit : Here is latest issue from Chromium page <a href="https://bugs.chromium.org/p/chromium/issues/detail?id=1201700#c5" rel="nofollow noreferrer">https://bugs.chromium.org/p/chromium/issues/detail?id=1201700#c5</a></p>