Network Cable

Currently, three types of network cable exist: coaxial, unshielded twisted pair (UTP), and fiber. Coaxial cable (rarely used today) looks a lot like the coaxial cable used to connect your television to the cable jack or antenna. UTP looks a lot like the cable that runs from your phone to the wall jack (the jacks are a bit wider). Fiber cable looks sort of like the RCA cables used on your stereo or like the cable used on your electrical appliances in your house (two separate segments connected together). The following sections discuss UTP and fiber network cable in more detail.

Unshielded Twisted Pair

Unshielded twisted pair (UTP) uses color-coded pairs of thin copper wire to transmit data. Six categories of UTP existeach serving a different purpose:

• Category 1 (Catl) Used for voice transmissions such as your phone. Only one pair is used per lineone wire to transmit and one to receive. An RJ-11 plug is used to connect the cable to your phone and the wall.

• Category 2 (Cat2) Used in early token ring networks. Has a transmission rate of 4Mbps (million bits per second) and has the slowest data transfer rate. An RJ-11 plug is also used for cable connections.

• Category 3 (Cat3) Used for 10BASE-T networks. It has a transmission rate of 10Mbps. Three pairs of cables are used to send and receive signals. RJ-11 or RJ-45 plugs can be used for Cat3 cables, usually deferring to the smaller RJ-11. RJ-45 plugs are similar in design to RJ-11, but are larger to handle up to four pairs of wire and are used more commonly on Cat5 cables.

• Category 4 (Cat4) Used in modern token ring networks. It has a transmission rate of 16Mbps and is less and less common as companies are switching to better alternatives. RJ-45 plugs are used for cable connections.

• Category 5 (Cat5) The fastest of the UTP categories with a transmission rate of up to 1000Mbps. It is used in both 100BASE-T and 1000BASE-T networks and uses four pairs of wire. Cat5 cable came out just as 10BASE-T networks were becoming popular and isn't much more expensive than Cat3 cable. As a result, most 10BASE-T networks use Cat5 UTP instead of Cat3. Cat5 cable uses RJ-45 plugs.

• Category 6 (Cat6) Also rated at 1000Mbps, this cable is available in two forms: stranded for short runs (25-meter) and solid for up to 100-meter runs, but which should not be flexed.

Fiber Optic Cable

Fiber optic cable (fiber) is usually orange or red in color. The transmission rate is 100Mbps and has a maximum length of 62 miles. Fiber uses a two-pronged plug to connect to devices. A couple of advantages to fiber are that because it uses light instead of electricity to transmit its signal, it is free from the possibility of electromagnetic interference and is also more difficult to tap into and eavesdrop.

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