Cables & Connectors

So you've got your cards, now you need your cables & connections to start linking your LAN together. This will partially be determined by the connectors on your cards. Their are 3 basic types of connectors on modern cards.

The first is the BNC-style connector. This is for thinnet ethernet which is is ethernet transported over coax (also known as 10base-2). The cables are very similar to those used for your Cable TV though the end connectors are a bit different. Thinnet connects in a single long chain from computer to computer. Each card has a T shaped connector attached with the coax entering and leaving each leg of the T. A 50-ohm terminator must be installed on each end of the cable. Thinnet segments should not be longer than 600 feet.

If you have older equipment, thinnet may be your best option. Since all hosts are linked in a chain, you don't need a hub either which may save you money. Still 10base2 is on it's way out.

The most popular modern option for cabling is CAT5 which can carry both 10baseT and 100baseTX. CAT5 cable is also referred to as UTP, Unshielded Twisted Pair. CAT5 cable consists of an outer jacket holding 4 pairs (8 individual) of copper wire. It is terminated by modular RJ45 plugs which are similar to telephone plugs (known as RJ11). The Twisted Pair cabling is very similar to telephone premise wiring. CAT5 segments should not be run longer than 650 feet; the more segments connect to your hub equipment, the less length you should extend your segments without signal-boosting equipment (ie ethernet repeaters).

UTP cabling does require a hub, allowing you to connect hosts in a "star" pattern off the hub. UTP is fairly inexpensive to buy premade patch cables for. If you make a lot of cables, it's worth your while to buy the cable in bulk and tip it yourself.

To terminate CAT5, you really need a modular plug crimping tool and a CAT5 stripper. Both of these items as well as cable and tips can be purchased in a number of locations including Home Depot. 10baseT and 100baseTX uses wires 1,2,3 & 6 inside the cable jacket to provide communications. This means that technically you can use the other 2 pair in the cable for an additional connection but this is generally not a good idea.

The colors of each of the wires help in setting up the cable and there is a standard method to line up the wires in a connector to allow transmission. The wire color order for a standard RJ45 tip is orange-white,orange,green-white,blue,blue-white,green,brown-white,brown. If you've never tipped CAT5, describing it in print isn't going to help you much, so find a friend and have him show you how it's done.

Lastly your card may have a 15pin AUI port. This port typically requires the connection of an additional device, an ethernet transceiver, to operate. There's really no reason why you'd need to fool with AUI+transceiver in a home network configuration.