In this lesson, we're going to do a quick review
of the different specifications, limitations,
considerations, and applications of network cables.
First, let's consider the different specifications
and limitations of our twisted pair
of copper cables in terms of throughput, speed and distance.
CAT 5, also known as fast ethernet
or 100BASE-TX operates at 100 megabits per second
at distance of up to a hundred meters.
CAT 5e known as gigabit ethernet,
or 1000BASE-T operates at 1000 megabits per second,
or one gigabit per second at distance of up to 100 meters.
CAT 6, also known as 1000BASE-T or 10GBASE-T
can operate at 1000 megabits per second,
or one gigabit per second at a distance up
to a hundred meters, or it can reach speeds
of 10 gigabits per second at a distance of up to 55 meters.
Cat 6a and CAT 7 are also known as 10GBASE-T,
and both of these operate at 10 gigabits per second
at distance of up to a hundred meters.
CAT 8 is also known as 40GBASE-T,
and it operates at 40 gigabits per second at distance
of up to 30 meters.
Alright, let's consider the different specifications
and limitations of our coaxial
and twinaxial copper cables
in terms of throughput, speed
and distance, coaxial cables can support speeds of up
to a hundred megabits per second at a distance of up
to 500 meters when using ethernet.
Now, coaxial cables can offer us this longer distance
over a twisted pair cable,
but they can't reach the higher speeds
that twisted pair cables can reach in our modern
networks.
Twinaxial cables though can support higher speeds of up
to 10 gigabits per second,
but they're limited to a distance
of only five meters or less.
Newer twinaxial cables can also increase their speeds up
to 100 gigabits per second at a maximum
distance of seven meters.
But again, these are not mainstream in use yet.
Next, let's consider the different specifications
and limitations of our fiber cables,
in terms of throughput, speed
and distance, 100BASE-FX operates at 100 megabits per
second at distance of up
to two kilometers using a multimode fiber.
100BASE-SX is going to operate at 100 megabits per second
at distance of up to 300 meters using a multimode fiber.
1000BASE-SX is going to operate at 1000 megabits per second
or one gigabit per second for distance of up to 220 meters
to 500 meters or more using a multimode fiber.
1000BASE-LX is going to operate at 1000 megabits per second
or one gigabit per second at a distance of up
to 550 meters using a multimode fiber
and up to five kilometers
if we're using a single mode fiber,
now 10GBASE-SR is going to operate at 10 gigabits per second
at distance of up to 400 meters using a multimode fiber.
10GBASE-LR is going to operate at 10 gigabits per second
at distance of up to 10 kilometers
using a single mode fiber.
Next, we need to discuss some cable considerations such
as shielded versus unshielded and plenum versus riser rated.
First, we have two types of
twisted pair cable, shielded
and unshielded, at their core, both shielded
and unshielded twisted pair cables are created
the exact same way.
The only difference is that shielded twisted pair cables
have each of their individual pairs
of wires wrapped in a foil shielding.
This gives them a little bit more protection from EMI.
Then all four of those wrapped pairs are also wrapped
with another foil layer for some additional protection.
This extra shielding does help protect the shielded twisted
pair cables from electromagnetic interference
and power frequency interruptions,
but it does add cost to it making shielded,
twisted pair more expensive than unshielded twisted pair,
so you really only use it
for specific business cases and applications.
For example, let's say you're running a network inside
of a radio station or an airport, those areas are placed
with a lot of electromagnetic interference,
so you probably want to opt to use shielded twisted pair
to provide the network with
a little bit of extra protection.
Additionally, if you're running a twisted pair network
inside of a factory with heavy machinery
or generators, it's also going to be a good idea
to use shielded twisted pair here
because there's extra frequencies of EMI
that are going to be exposed to your cables.
Now, if you're truly worried about electromagnetic
interference or EMI though it would actually be a better
idea to upgrade to a fiber based network
because fiber cables are truly immune to EMI
because they rely on light signals instead
of electrical impulses to send their data.
Now, unshielded twisted pair of cabling on the other hand,
is also used in a lot of our local area networks
because it's inexpensive, easy to install, lightweight,
and really flexible.
Regardless of whether you're going to use shielded
twisted pair or unshielded twisted pair, you need
to keep your cable lengths under the maximum recommended
length of 100 meters.
Next, we have to think about plenum versus
riser rated cables.
Now, plenum cables are going to be used when the cable is going to
be run in the spaces between the ceiling
and the floor above it, such as where you put your heating
and air conditioning duct work.
Now, these plenum cables have a higher fire rating
and they're designed with fire retardant plastic jackets
that use low smoke PVC
or fluorinated ethanol polymer known as FEP.
Now, usually plenum rated cables are going to be used when
you're running cables horizontally in your building
across a particular level.
Riser cables, on the other hand, are going to be used
to run network cables vertically
between the floors in a building inside a cable riser
or an elevator shaft.
These riser cables are used in non plenum areas as well.
These cables are built with special coatings that allow them
to self extinguish,
and they prevent the flame from burning through the cable
and traveling upwards between the floors.
Now, building codes are specific to the location
of the building itself, and they're going to be determined
by your state or county that you live in.
In general, most fire
and building codes will allow plenum cables
to be used in both plenum and riser spaces,
but riser cables can only be used in the risers
and not in plenum spaces.
This is because riser cables are not made from PVC or FEP,
and therefore they can actually release chemicals
and smoke into the air ducts if they caught fire.
Finally, let's take a look at some cable applications you
may come across when working as a network technician.
These include things like rollover
and console cables, crossover cables,
and power over ethernet.
Now, a rollover or console cable is a type
of null modem cable that's used
to connect a computer terminal to a router's console port.
This cable is typically flat
and has a light blue color to it
to help you distinguish it from other networking cables.
Typically, one side of the cable has an RJ 45 connector
that's used to connect directly to a router's console port.
The other side of the cable traditionally has a DB nine
serial connection that'll connect to a laptop computer.
This specialized cable is used to allow the technician
to directly connect to the router
and make changes to the configuration as a form
of out-of-band communication.
Now, a crossover cable is a special type of network cable
that's used to connect two ethernet devices directly.
So if you have two computers
and you don't have a switch or router between them,
you can use a crossover cable to connect them.
They're also used to send and receive data
by enabling complex data transfers between two computers,
two routers, or two other network devices.
Usually a crossover cable is created
by using a TIA 568 B pinout on one side of the cable
and the TIA 568 A pinout on the other side of the cable.
If you need to connect a computer to a computer, a router
to a router, a switch to a switch,
then you're going to use a crossover cable.
Now finally, we have power over ethernet.
Power over ethernet, or POE is a technology
that passes electrical power over a twisted pair of ethernet
cables to power devices.
Now, this can be done to go to a wireless access point,
an IP camera or VoIP phone to give them data
and power on the same cable.
This enables one cable to give you both data
and electrical power to these power devices instead
of having to have a separate cable for each,
make it really easy to install things like
IP security cameras.
To support power over ethernet, you need
to have at least a category 5E
or better copper twisted pair cable.
Otherwise, it's not going to function right
and it could be dangerous.
Now, power over ethernet can provide 15.4 to 60 watts
of power using two of the twisted pairs inside of the cable,
or you can get 60 to a 100 watts
of power if you're using all four
of the twisted pairs inside of a cable.
Just like other twisted pair cable installations,
power over ethernet can only transmit data
and power up to the maximum distance of 100 meters.
Alright, I know that was a lot of information
and I gave it to you really quick,
but I hope you found this quick review of copper
and fiber cables and all their different specifications,
limitations, considerations,
and applications helpful as you're preparing for your exam.