Network Cables

A network cable is a specialised wire used for the electrical transmission of digital data. The cable connects computers together to form a data communication network. The cable and the data closely follow Ethernet specifications and standards. The category number defines the type of cable. CAT5 and CAT6 are the most widely used in modern computer networks.

Types / Categories

CAT5 (currently CAT5e) and CAT6 (currently CAT6a) are the most commonly found and used cables. Also known as 1000Base-T, they follow the IEEE 802.3ab specifications. Ideal for building gigabit networks, they have a maximum speed of 1000 Mbps, and a distance limitation of 100 m. This length limit is from the router to the computer.

CAT6a

Category 6a, also known as Augmented CAT6 cable, exceeds the 10-gigabit requirements by doubling the operating frequency to 500 MHz. It has a distance limitation of 100 m.

CAT7

Category 7 specification meets and exceeds the 10 Gigabit requirements. It consists of four pairs of wires rated to operate at a maximum frequency of 600 MHz over a maximum distance of 100 m.

Due to the high frequency of operation, individual shielding of each pair is required to eliminate internal crosstalk. There is also an additional foil shield over the cable.

Uses

If you were to be building an internet connection from your router to the computer, then you could use either of these cables.

For internet speeds less than 1 Gbps, CAT5e cable would be sufficient. For speeds less than 10 Gbps, CAT6a cable would be sufficient. CAT5e, CAT6a, and CAT7 cables connect computers to a hub less than 100 m apart.

Stranded vs. Solid Core

Use solid core cable when running long lengths of wire from the hub or patch panel, to the wall socket. For short lengths such as patching cable that connects the PC to the wall socket, use stranded core.

If you are using solid core wire, you should use the Insulation Displacement Connector (IDC) socket for a good reliable connection. For the stranded core you should use the Insulation Piercing Connector (IPC) socket.

Shielded and Unshielded

The most commonly used wire is U/UTP, which has no shielding and is therefore very cheap. The most commonly used shielded wire is U/FTP, which has an outer foil shield. A shielded wire is obviously more reliable as the metal shield blocks electromagnetic noise, and helps to prevent data signal corruption.

Shielding individual pairs of wires within the network cable eliminates internal crosstalk, however an outer cable shield blocks electromagnetic noise entering the cable from outside, and there are also combinations of the two schemes. An outer shielded cable usually has a metal foil layer and a special un-insulated grounding wire called the 'drain'.

Plenum Rated Cable

If you are installing cable for the home or office use, you should first check the fire regulation section of the building code, and your insurance policy coverage with reference to cable types and usage. Plenum rated cables are slower to burn and produces less smoke than standard ordinary cables that are made of PVC. Many offices and buildings have a legal requirement that only plenum cable may be used.

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