We use eXtv's irc channel #eXtv to communicate with all the teams. Its advised that you add the other team leader to your friends list to work out anydetails with the match, but all team captains should have irc open throughout the whole process, until your team is eliminated. From the IRC channel all server information will be given, scores reported and what eXact time the following match will be. If you would like to add eXtv's mumble you may, but the irc channel is the main form of communication.
Sorry, but i have no idea what IRC is, and I could use a bit of an explanation,