Over time, some online play networks relying on Lobby-Servers were created by computer game companies, and later (usually for financial reasons) dismantled. Good examples are the WON servers or the heartbeat servers for Star Trek: Voyager Elite Force. The problem is, that there are games, for which the lobby servers are essential for online play. Are those lobby servers down, the online play is practically impossible (without using solutions like VPN). For some games there are workarounds, like starting parameters for the game binary, which make them connect to a certain address and port. For some the lobby server address can be changed. For many of those games GameRanger makes it possible to play online, incl. chat rooms. The list of currently supported games can be found here. You can download GameRanger from here.