antecipate: Media relay hidden query

I received additional information following my last experiment on Google using media relay. It happens that the GTalk service also implements a full XMPP extension to provide information about its relay servers. This extension, which replaces the "google:relay" query is hidden behind the STUN extension which is documented on their developers' site.

Using my favorite client I was able to check that using the described query gives the result that can be seen bellow:

<iq type="get" to="romeo@gmail.com" id="1" ><query xmlns='google:jingleinfo'/></iq>
<iq from="romeo@gmail.com" type="result" to="romeo@gmail.com/psiC3BE970F" id="1" >
  <query xmlns="google:jingleinfo">
    <stun>
      <server host="stun.l.google.com" udp="19302" />
      <server host="stun1.l.google.com" udp="19302" />
      <server host="stun4.l.google.com" udp="19302" />
      <server host="stun3.l.google.com" udp="19302" />
      <server host="stun2.l.google.com" udp="19302" />
    </stun>
    <relay>
      <token>CAESHgoVamxzZWd1aW5lYXVAZ21haWwuY29tEOCJq4TsIRoQRWsKcIug9O8RySUrR05+tw==</token>
      <server host="relay.l.google.com" udp="19295" tcp="19294" tcpssl="443" />
      <server host="relay2.l.google.com" udp="19295" tcp="19294" tcpssl="443" />
      <server host="relay3.l.google.com" udp="19295" tcp="19294" tcpssl="443" />
      <server host="relay1.l.google.com" udp="19295" tcp="19294" tcpssl="443" />
      <server host="relay4.l.google.com" udp="19295" tcp="19294" tcpssl="443" />
    </relay>
  </query>
</iq>

To conclude, it seems that current GTalk clients (1.0.0.100) are using the HTTP/XMPP combination I described earlier, and that future versions may use this XMPP only query to discover the relay servers. In the meantime, I suppose they are waiting for the extension to be final to add it to the existing documentation…