Typical Networking Connector (RJ-45)

The Telecommunications Industry Association (TIA) and Electrical Industries Alliance (EIA) define standards for cables and connectors. For instance, they define how to use an RJ-45 connector for LANs and options for several types of UTP cabling. (You can learn more about TIA and EIA by going to their websites, at http://www.tiaonline.org and http://www.eia.org.)

If you have never seen an RJ-45 connector, and you use Ethernet LANs at work or school, you could remove the cable from your PC's network card and look at it. In most cases, the cable will be using an RJ-45 connector. (Ethernet is by far the most popular type of LAN today. You'll read more about it in the next several chapters.)

The EIA/TIA defines standards for which wires fit into which pins when you make a cable for use with Ethernet. Two of those standards are shown in Figure 4-8.