Network Adapters (Network Cards, Network Boards, Network Interface Cards, NICs, Ethernet Adapters)

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Considering how complicated networking can be, network adapters are rather simple. They are among the easiest devices to install; simply follow the manufacturer's directions. Cards made by 3Com and Intel are often installed automatically by Windows. Others, including external USB models, require driver disks, but are still easy to get up and running.

Selecting a Network Adapter

Older network adapters came in myriad types, but today's cards are mostly Ethernet cards. Ethernet is a network standard that almost exclusively uses Cat 5/Cat 5e UTP (unshielded twisted pair) cables with RJ-45 connectors. RJ-45 connectors are very similar to standard RJ14 modular telephone plugs, but are twice as wide and have eight wires. Many of today's motherboards come with built-in Ethernet adapters. Ethernet transmission speeds have increased from 10 to 100 to 1000 Mbps. Older cards worked at a fixed speed, preventing their connection with any network device running at a different speed. Newer cards, however, can automatically switch to a lower-than-maximum speed to match the device they are directly connected to, be it a router, switch, hub, or other Ethernet adapter. The vast majority of Ethernet network adapters on the market will work fine for most users with home or small business networks, or high-speed Internet service that requires network adapters.

Wireless Network Adapters

Wireless models come in various types to work in desktops or laptops. They require wireless routers to work. They work similarly to cordless telephones; they have to stay within a certain distance of the base (router) to maintain a connection.

Diagnosing Network Adapter Problems

Many things can go wrong with networks, but not many problems can occur with the adapters; usually, they either work or they don't. Check in Device Manager to see if there is a problem. If reinstalling the driver doesn't fix the problem, it is probably time to replace the card.

If Device Manager indicates a working adapter, it is a good idea to check the cable. Use a tester, or swap it with a known good cable.

Note 

Make sure to use the right cable for the job. RJ45 telephone cable, if it is not Cat5 or Cat5e, will not be reliable for network transmission. There is also such a thing as a crossover cable, which is used only for a direct connection between two computers with Ethernet adapters, or between two central devices such as hubs, switches, or routers. A crossover cable won't work for a connection between a central device and a computer, and a straight-through cable won't work with a two-computer network or between two central devices. Crossover cables should be marked on the cables' insulation. If there is any doubt, you can check it with a cable tester. Please note that general networking is beyond the scope of this book.

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