What Is Cross-Over Cable?
In a Ethernet networking environment – like in a family home with multiple PCs that are wired – the computers must all connect to a central router. The router takes all the bits being sent out by the computers and relays them onto the other devices on the network. However, a crossover cable can be used to connect two devices directly, without the need for a router in the middle. It simply reverses some of the pins so that the output on one computer is being sent to the input of another. In the years before my family had Internet, I used this to play 2-player network games!
This is one use for a cross-over cable; the other is to expand a network by connecting another network switch, thereby giving you more ports. It’s always handy to have a length of cross-over cable around!