It uses a third server to facilitate initial p2p connections but I keep loosing/fail to connect to this server. I don't know if it's because of many restarts during development or something else.
Windows Defender nukes this from orbit, making it nearly impossible to ship to clients in a trusting fashion. But I guess any program which punches through the firewall is suspect.
I learned this from the older X-files DVDs, which have some unusually good special features.