Using WebMeetings with the Kopano Turn server

All of our clients are behind a firewall and proxy server. Exactly which meachine needs access to which servers?

Since the changes are made to the plugin config file I though the client might be contacting the turnauth.kopano.com server, but I can find no evidence that it is trying. I know for a fact it isn’t trying to use the proxy server!

Anyway because it can’t reach the server, I get the following error:
error

There was suppose to be an image w/ the error message…
Anyway the error message is “Accessing the Kopano WebMeetings TURN authentication service failed.”