Lots of different cables and network devices can be
used to allow computers to properly communicate with each other.
By the end of this lesson,
you'll be able to identify and describe various networking cables and networking devices.
Computer Networking is a huge part of the day to day role of many IT Specialists,
and knowing how to differentiate
different network devices will be essential to your success.
Let's start with the most basic component of a wired network: cables.
Cables are what connect different devices to each
other allowing data to be transmitted over them.
Most network cables used today can be split into two categories, copper and fiber.
Copper cables are the most common form of networking cable.
They're made up of multiple pairs of copper wires inside plastic insulator.
You may already know that computers communicate in
binary which people represent with ones and zeros.
The sending device communicates binary data across
these copper wires by changing the voltage between two ranges.
The system at the receiving end is able to interpret these voltage changes as
binary ones and zeros which can then be translated into different forms of data.
The most common forms of copper twisted pair cables used in networking are Cat5,
Cat5e, and Cat6 cables.
These are all shorthand ways of saying category five or category six cables.
These categories have different physical characteristics like the number of twists in
the pair of copper wires that result in different usable lengths and transfer rates.
Cat5 is older and has been mostly replaced by Cat5e and Cat6 cables.
From the outside, they all look about the same,
and even internally, they're very similar to the naked eye.
The important thing to know is that differences in how
the twisted pairs are arranged inside these cables can
drastically alter how quickly data can be sent across
them and how resistant these signals are to outside interference.
Cat5e cables have mostly replaced
those older Cat5 cables because their internals reduce crosstalk.
Crosstalk is when an electrical pulse on
one wire is accidentally detected on another wire.
So, the receiving end isn't able to understand the data causing a network error.
Higher level protocols have methods for detecting
missing data and asking for the data a second time.
But of course, this takes up more time.
The higher quality specifications of
a Cat5e cable make it less likely that data needs to be re-transmitted.
That means, on average,
you can expect more data to be transferred in the same amount of time.
Cat6 cables follow an even more strict specification to avoid crosstalk,
making those cables more expensive.
Cat6 cables can transfer data faster and more reliably than Cat5e cables can,
but because of their internal arrangement,
they have a shorter maximum distance when used at higher speeds.
The second primary form of networking cable is known as Fiber,
short for fiber optic cables.
Fiber cables contain individual optical fibers which
are tiny tubes made out of glass about the width of a human hair.
These tubes of glass can transport beams of light.
Unlike copper, which uses electrical voltages,
fiber cables use pulses of light to represent the ones and zeros of the underlying data.
Fiber is even sometimes used specifically in environments where there's a lot of
electromagnetic interference from outside sources
because this can impact data being sent across copper wires.
Fiber cables can generally transport data quicker than copper cables can,
but they're much more expensive and fragile.
Fiber can also transport data
over much longer distances than copper can without suffering potential data loss.
Now you know a lot more about the pros and cons of fiber cables, but keep in mind,
you'll be way more likely to run into fiber cables in
computer data centers than you would in an office or at home.