I’m not familiar with many online games. We’ve played “Age of Empires II” over the internet as well as over our home LAN. In the case of AOE II, if I remember correctly, the game provides different options for different type of connections (Direct Connect, LAN, Online, etc.).
However, I read your question & comments in regards to hardware needed in order to play on a LAN (Local Area Network). My interpretation of you question is. . . .
"What is needed to connect our computers together so that we can
So, here goes…
First of all, I am assuming that both computers have network cards (NIC’s) installed and running correctly. I am also assuming that you can set up the network.
"Is at absolutely necessary to have internet for playing a LAN game
such as Call of Duty at home with my brother?"
No. It should not be necessary to have an internet connection for you and your brother to play COD together at home. A router is a device to connect 2 different networks together (ie. internet & a home LAN). However, most routers these days have a built-in hub/switch which is 1 way to connect your computers together.
One way to connect your computers together is with a hub or switch. These are essentially the same thing but mainly differ in allocation of bandwidth. A hub shares bandwidth across all the ports. A switch runs all ports at the rated bandwidth.
For example (using round #'s to keep it simple). . . .
A 10 port, 100 Mbps hub running at max capacity runs each port
at 10 Mbps.
A 10 port, 100 Mbps switch running at max capacity runs each port
at 100 Mbps.
These devices do the same thing, they connect computer hardware together. They just do them at different speeds or bandwidth.
Another option (and probably the least expensive…~$10) would be to connect the 2 computers with a cross-over cable. A regular straight-through network cable will not work because the wire that the computers use to listen is the same and the wire they use to talk is the same.
For example, 1 computer is listening to the other computer’s ear while the other computer is talking into it’s mouth.
Computer 1 Computer 2
Talking Wire <-----> Talking Wire
Listening Wire <-----> Listening Wire
Computer 1 Computer 2
Talking Wire <-----> Listening Wire
Listening Wire <-----> Talking Wire
A hub or switch is built to direct the data coming in on the talking wire to the listening wire on the other computers. A cross-over cable does the same thing.
If you’re only connecting 2 computers together and you’re not going to connect to the internet, then the cross-over cable will work just fine.
If you will be connecting to the internet, then a 100BaseTX switch or a router with the switch built-in are my sugestions. Just make sure the switch or router matches the speed of your NIC’s.