If you are trying to setup a local network or LAN at home then you probably already know you need an ethernet cable and maybe even a hub or a switch. If things were that easy it would be great, but matters are only made more difficult when you discover that there are different kinds of ethernet cables. Do you get a patch cable or a crossover cable? What’s the difference between the two? The problem is that both of these cables look identical, and unless you specifically ask for help there is a good chance that the sales person will assume you know which one you need and say nothing at all. It is not until later when you get home that you find out you’ve purchased the wrong cable as they are not interchangeable. Here is a quick guide to help clarify the difference between patch and crossover cables.
For most of the time the kind of cable you will need is called a patch cable. Patch cables are the most widely used and generic form of ethernet cable available today. Put simply they are referred to as straight though cables. What this means is that wire 1 on one end of the cable comes out as wire 2 on the other end. The wires run straight through and do not swap or change along the way. This kind of cable is used for connecting computers to hubs, switches or routers. If you are setting up an ordinary LAN or just connecting your computer to a router, then this is the type of cable you’ll need. It simply transfer data along specified wires and does nothing beyond this. Crossover cables, as you may already guessed from the name, actually do something to the wires along the way.
Crossover cables actually crossover. Meaning that wire 1 on one end does not come out as wire 1 on the other end. The wires are crossed over and this is why if you try to use this kind of cable in the previous setup, nothing will work. The data along the way changes wires and it means that the router or hub you are trying to connect your computer to has no way of understanding the information that it is receiving. So when would you need a crossover cable? These cables are used for connecting two computers together directly or connecting two hubs or switches together directly. This is done so that the wires are swapped over to match the correct pins on the receiving end. If you’ve ever looked at a hub or switch, you may have noticed a port called an uplink port. This uplink port functions exactly how a crossover cable does. You can use this uplink port to connect two switches together with a patch cable because the uplink port actually crosses over the wires internally and makes it possible to receive data directly from another switch.
While patch and crossover cables may look the same, they are used for two very different situations. Connecting networks or computers together directly will require a crossover cable. However, if you are connecting computers to a switch, hub or router then a patch cable is what you’ll need.