Introduction to networking
Defenition
is a collection of computer
and other hardware interconnected by communication
channels that allow sharing of resources and information.
Wired technologies:
The order of
the following wired technologies is, roughly, from slowest to fastest
transmission speed.
Twisted pair :wire is the most widely used medium
for telecommunication. Twisted-pair cabling consist of copper wires that
are twisted into pairs. Ordinary telephone wires consist of two insulated
copper wires twisted into pairs. Computer networking cabling consists of 4
pairs of copper cabling that can be utilized for both voice and data
transmission.
Coaxial cable: is widely used for cable
television systems, office buildings, and other work-sites for local area
networks. The cables consist of copper or aluminum wire surrounded by an
insulating layer (typically a flexible material with a high dielectric
constant), which itself is surrounded by a conductive layer. The
insulation helps minimize interference and distortion.
optical fiber:
is a glass fiber. It uses pulses of light to transmit data. Some
advantages of optical fibers over metal wires are less transmission loss,
immunity from electromagnetic radiation, and very fast transmission speed,
up to trillions of bits per second. One can use different colors of lights
to increase the number of messages being sent over a fiber optic cable

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