From your original post, I think you are confusing two different things.
1. LAN play involves hooking up PS2s on a
local area network (LAN), usually in the same building. You do this when your friends show up at your house (or workplace
) with their Playstation consoles, wheels and GT4 discs. GT4 handles all of this using the
LAN Game option in Arcade Mode.
2. Online play involves hooking up PS2s to the internet to play with others that do not live nearby. You do this when your friends live far away, and it becomes impractical to give them plane tickets, accomodation and spending money just to race you in GT4. Or, some of your friends (or complete strangers) cannot be bothered to lug their Playstations over. 👎 The solution is to use the internet to connect the consoles together. However, Polyphony Digital never completed the online mode, so
Xlink Kai is needed to simulate a local area network. The PS2s would think they are on the same LAN, while the consoles can be across the world.
Is it option one or option two?