Found this in my PeerGuardian log just now: All the other blocks are my Steam client, I don't have their entire IP range unblocked yet. There seems to be a pattern on the outgoing side, Steam is systematically looking for a connection. Only difference is that all the others are TCP, outging to port 27031, and not trying a DoD server. Found very little regarding port 5203, apparently it's the official port for the "targus-tnts2" protocol. Found even less about what that protocol actually is, but it seems to be some sort of VOIP number lookup system, the IP Phone equivalent of ANI. Why is that originating from my PC, and why is it going to a DOD server? Found this link to an Avaya Targus software solution users manual, which states: So a response similar to that to the IP in my logs would mean it's definately trying to connect to a DoD Targus server. Only problem is that I'm too scared to actually try and telnet out.