Networking Cables

Networking Cable is the medium through which information usually moves from one network device to

another. There are several types of cable which are commonly used with LANs. In some cases, a network

will utilize only one type of cable, other networks will use a variety of cable types. The type of cable

chosen for a network is related to the network's topology, protocol, and size. Understanding the

characteristics of different types of cable and how they relate to other aspects of a network is necessary

for the development of a successful network.

Types of Networking Cables

1. Twisted Pair: Twisted Pair Cabling is a form of wiring in which pairs of wires (the forward and

return conductors of a single circuit) are twisted together for the purposes of canceling out

electromagnetic interference (EMI) from other wire pairs and from external sources. This type of

cable is used for home and corporate Ethernet networks.

There are two types of twisted pair cables: Shielded, Unshielded.

Unshielded Twisted Pair (UTP) Cable: The quality of UTP may vary from telephone-grade wire to

extremely high-speed cable. The cable has four pairs of wires inside the jacket. Each pair is

twisted with a different number of twists per inch to help eliminate interference from adjacent

pairs and other electrical devices. The tighter the twisting, the higher the supported transmission

rate and the greater the cost per foot. The EIA/TIA (Electronic Industry

Association/Telecommunication Industry Association) has established standards of UTP and

rated six categories of wire (additional categories are emerging).

Shielded Twisted Pair (STP) Cable: Although UTP cable is the least expensive cable, it may be

susceptible to radio and electrical frequency interference (it should not be too close to electric

motors, fluorescent lights, etc.). If you must place cable in environments with lots of potential

interference, or if you must place cable in extremely sensitive environments that may be

Figure 1 UTP & STP

Networking Cables

susceptible to the electrical current in the UTP, shielded twisted pair may be the solution.

Shielded cables can also help to extend the maximum distance of the cables.

Shielded twisted pair cable is available in three different configurations:

Each pair of wires is individually shielded with foil.

There is a foil or braid shield inside the jacket covering all wires (as a group).

There is a shield around each individual pair, as well as around the entire group of wires

(referred to as double shield twisted pair).

2. Coaxial Cable: First invented in

the 1880s, "coax" was best known

as the kind of cable that connected

television sets to home antennas.

Coaxial cable is also a standard for

10 Mbps Ethernet cables. When 10

Mbps Ethernet was most popular,

during the 1980s and early 1990s,

networks typically utilized one of

two kinds of coax cable - thinnet

(10BASE2 standard) or thicknet

(10BASE5). These cables consist of

an inner copper wire of varying

thickness surrounded by insulation and other shielding. Their stiffness caused network

administrators difficulty in installing and maintaining thinnet and thicknet.

3. Fiber Optic Cable: Fiber optic cabling consists of a center glass core surrounded by several

layers of protective materials). It transmits light rather than electronic signals eliminating the

problem of electrical interference. This makes it ideal for certain environments that contain a

large amount of electrical interference. It has also made it the standard for connecting networks

between buildings, due to its immunity to the effects of moisture and lighting.

Fiber optic cable has the ability to transmit signals over much longer distances than coaxial and

twisted pair. It also has the capability to carry information at vastly greater speeds. This capacity

broadens communication possibilities to include services such as video conferencing and

interactive services. The cost of fiber optic cabling is comparable to copper cabling; however, it is

more difficult to install and modify. 10BaseF refers to the specifications for fiber optic cable

carrying Ethernet signals.

Figure 2 Co-axial Cable

Networking Cables

The center core of fiber cables is made from glass or plastic fibers. A plastic coating then

cushions the fiber center, and kevlar fibers help to strengthen the cables and prevent breakage.

The outer insulating jacket made of teflon or PVC.

4. USB Cables: Universal Serial Bus (USB) cables connect a

computer with a peripheral device (keyboard or mouse) rather

than to another computer for networking. However, special

adapters (sometimes called dongles) also allow connecting an

Ethernet cable to a USB port indirectly. USB cables feature

twisted-pair wiring.

5. Serial and Parallel Cables: Because many PCs in the 1980s and early 1990s lacked Ethernet

capability, and USB had not been developed yet, serial and parallel interfaces that are obsolete

on modern computers were sometimes used for PC-to-PC networking. So-called null model

cables , for example, connected the serial ports of two PCs enabling data transfers at speeds

between 0.115 and 0.45 Mbps.

6. Ethernet (Crossover) Cable: Null modem cables are one example of the category of

crossover cables. A crossover cable joins two network devices of the same type, such as two PCs

or two network switches.

The use of Ethernet crossover cables was especially common on older home networks years ago

when connecting two PCs directly together. Externally, Ethernet crossover cables appear nearly

identical to ordinary (sometimes also called straight-through), the only visible difference being

the order of color-coded wires appearing on the cable's end connector. Manufacturers typically

Figure 3 Fibre Optic Cable

Figure 4 USB Cable

Networking Cables applied special distinguishing marks to their crossover cables for this reason. Nowadays, though,

most home networks utilize routers that have built-in crossover capability, eliminating the need

for these special cables.

Figure 5 Colour Coding for Ethernet Cable Figure 6 Difference b/w Ethernet Cable

Figure 7 Types of Cable n Speed

Networking Cables

7. Patch Cable: A patch cable is an electrical or optical cable used to connect one electronic or

optical device to another for signal routing. Devices of different types (e.g. a switch connected to

a computer, or a switch connected to a router) are connected with patch cords. It is a very fast

connection speed. Patch cords are usually produced in many different colors so as to be easily

distinguishable,[2] and are relatively short, perhaps no longer than two meters.