Page 46 - NetWork-En-V3

8.3.1 Twisted Pair
Twisted pair cables use electrical signals to
transmit data and are currently the most
popular for connecting local network
devices. They resemble telephone wires but
consist of 8 internal copper wires with
different colors, where each pair of the eight is twisted together.
This type of cable is divided into two categories:
1. Shielded Twisted Pair (STP): In this type, the internal cables are shielded with

aluminum foil to protect signals from any electromagnetic interference in the
cable's surroundings.
2. Unshielded Twisted Pair (UTP): This type of cable is not shielded.
A connector with two RJ45 connectors is used to connect the ends of the copper cable
to devices. The connector consists of 8 small copper pins installed in a plastic body.
The internal wires in the cable are connected to these pins, and in turn, they are
connected to the network card. When preparing the ends of the copper cable and
connecting them to the RJ45 connector, the connection can be done in two ways:
• Straight Cable: Used to connect two different types of devices, such as a computer
with a data switch.
• Crossover Cable: Used to connect similar devices, such as two computers.
The following image illustrates the arrangement of the internal wires in the RJ45
connector in both cases.

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