hey dudes i was planning to start a server with the future upcoming game unreal tournament 2007 i was wondering which internet service would better FDX or HDX (hdx is alot cheaper)
A full duplex connection simultaneously sends and receives data packets. It is typically used to connect switches together or to connect fast access devices such as workgroup servers. It is also best for services like VoIP where both parties may speak at the same time.
half duplex connections sends packets and waits for a response before sending more packets. Is is a request/response network connection and when one device is sending, all the other devices are receiving. If more than one device is sending, collusions occur and packets must be resent. Half-duplex is the most common transmission method and is adequate for normal workstation and PC connections. Most client server traffic is half duplex as is web browsing, email and ftp.
Full duplex has collisons also, it's the nature of TCP. All connections have collisions including VOIP, thus configurations get complicated to prioritize those packets so dropouts don't occur.
I don't quite understand your question. It sounds like your game hosting provider is pricing differently for enforcing either a full- or half-duplex switch connection to your server (or rented server). In both full and half, communications travels both ways and can be started from the client or server end. The request/reponse, as you put it, is part of both full and half. Almost all switches and routers are set to Auto but in large data centers it is common for connections between certain switch ports and servers to be forced to either full-duplex or half-duplex depending on the need. All gear picks full duplex to talk together, unless they are forced to half-duplex. Thus, the $400 mailroom PC and the $8000 Email server are both running at full duplex.
You may be confusing half-duplex with a half-close connection which can speed up transmissions but is rarely used by applications. An example would be the online game Battlefield 2. Whether set to full- or half-duplex, data is flowing both ways at all times. If you run around a corner to avoid getting shot, that client data goes upstream to the server and then flows back down to all other players so they also see you running around the corner. If you stand still and don't touch the mouse or keyboard for 5 minutes, you'll still be seeing players and tanks moving. If a client side player couldn't send data back to the server at will, he would have no way to move out of the way of that jeep around to run him down.
I'm not familiar with the world of game hosting so your best bet (to get the best cost) is to consult with other game server owners of your game choice to see what works for them.