In this lesson, we're going to explore
the Characteristics, Capabilities,
and Applications of Copper Media.
Now, copper media has been the default type
of cable used in our network for decades, which
in turn has made them an indispensable part
of our network infrastructure.
So in this lesson, we're going to explore the 802.3 Standard
that includes these specifications
for Ethernet network protocols and its associated wiring.
The 802.3 Standard is a collection of IEE Standards
that define the physical layer
and data link layer's media access control
or MAC for a given wired Ethernet network.
Now this 802.3 Standard is commonly used
in local area networks and it provides a basis
for the operation of that network.
Inside of our wired networks, the most common type of cable
that we're going to be using is known as a twisted pair cable.
Now under the IEEE 802.3 Standard,
there are numerous different types of cables
that are going to be defined, including copper cables,
like twisted pair cables, coaxial cables, twinaxial cables,
and direct attach copper, as well as fiber optic cables
and their specifications.
So in this lesson, let's focus just
on the copper cables, including twisted pair
cables, coaxial cables, twinaxial cables,
and direct attach copper.
First, let's discuss twisted pair cables.
Now, a twisted pair cable is a type of wiring
in which two conductors
of a single circuit are twisted together for the purpose
of canceling out the electromagnetic interference
or EMI from any of the external sources and crosstalk
that might occur from neighboring cables.
Now, twisted pair cables are the preferred method
for transmitting both data and voice signals,
and they can be used for both network
and telecommunication services.
By twisting the cables, the consistency
of the data transmission is increased
and its susceptibility to noise
and interference is going to be reduced.
There are two main types
of twisted pair cables you need to be aware of.
These are unshielded twisted pair cables or UTP
and shielded twisted pair cables or STP.
Now, unshielded twisted pair cables
or UTP cables are the most common type
of twisted pair cables that are being used
in telecommunications and computer networks.
The unshielded twisted pair cable is comprised of pairs
of wires that are twisted together
without additional shielding being added to that cable.
This design makes UTP cables very lightweight, flexible,
and cost effective for a variety
of different applications, including most
of our Ethernet based local area networks.
Now, the lack of shielding inside
of these cables does make our UTP cables smaller
in diameter, easier for us to install,
and overall, they're less expensive
than shielded alternatives.
On the other hand, shielded twisted pair
or STP cables are designed with a layer of insulation
or shielding made out of copper tape, a conducting polymer
or a braided mesh of copper wires.
This shielding adds a protective layer
against the electromagnetic interference or EMI
by allowing the STP cables
to more effectively reduce their noise
and improve their signal quality.
These shielded twisted pair cables are commonly used
in environments where there's a high degree
of electromagnetic interferon because they can provide us
with a more stable and secure network connection.
As you can see, the UTP cables are available
at a lower cost.
They support easier installations
and are more suitable for a wide range
of common networking applications
where electromagnetic interference is not a big concern
in our organization.
However, UTP cables are more susceptible to EMI
and noise, which can then degrade the signal quality
over longer distances or in individual environments.
To counteract this, you should utilize
a shielded twisted pair cable
because it offers better protection against interference
and crosstalk.
This means that the STP cables are a better choice
for environments with significant EMI being present,
and this can also help us to maintain higher data rates
over longer distances than if we're using a UTP cable.
Now the biggest downside
to using shielded twisted pair cables is
that they're more expensive, they're bulkier,
and they're more difficult to install due
to that additional shielding that's being added
into that design.
Now, regardless of whether you use a shielded
or an unshielded twisted pair cable,
each cable will also be categorized using a number such
as CAT 5, CAT 5e, CAT 6, CAT 6a, CAT 7, and CAT 8.
Let's take a moment and break down each
of these different categories
in the 802.3 Ethernet standard
to better understand their speed and distance limitations.
Now, CAT 5 is the oldest category
that you're probably still going to run
across today out in the real world.
CAT 5 cables only support data transfer speeds
up to a hundred megabits per second
with a maximum cable length
of a hundred meters using frequencies of up
to 100 megahertz.
This type of cable is also referred
to as a 100 BASE-T network or under the term fast Ethernet.
CAT 5e or category five enhanced is an advancement
over this older CAT 5 cable standard.
CAT 5e will support data transfer speeds up
to 1000 megabits per second, which is also equivalent
to one Gigabit per second, and it has a maximum cable length
of a hundred meters and uses a frequency
of a hundred megahertz.
Essentially, a CAT 5e cable contains more twist
than the older CAT 5 cable, and this helps
to reduce crosstalk as the data is being transmitted
over that cable.
And this in turn provides us with better signal integrity
that allows us to support up to one Gigabit per second
of speed instead of only supporting a hundred megabits
per second of speed that
that CAT 5 cable normally supported.
This type of cable is also referred to as a 1000 BASE-T
or Gigabit Ethernet connection.
As we move into more modern cabling,
we find our next category, which is known as CAT 6.
Now, CAT 6 cables only support data transfer speeds of up
to one Gigabit per second with a maximum cable length
of 100 meters using frequencies of up to 250 megahertz.
If your cable length is 55 meters or less, then you can
also support data transfer speeds
of up to 10 Gigabits per second instead.
This type of cable is also referred to
as 10G BASE-T when it's used under 55 meters
and supports up to 10 Gigabits per second,
and it's also referred to as 10 Gigabit Ethernet.
But if you're using it as a hundred meters
or less, you're going to refer to this
as a 1000 BASE-T just like you did with CAT 5e,
and this is going to be used
to support a one Gigabit per second connection,
and therefore it'll be referred to as Gigabit Ethernet.
Next we have CAT 6a.
Now CAT 6a is known as category six augmented.
CAT 6a cables support data transfer speeds of up
to 10 Gigabits per second with a maximum cable length
of 100 meters using frequencies up to 500 megahertz.
This type of cable is also referred to as 10G BASE-T
or 10 Gigabit Ethernet.
Basically, CAT 6a has increased the crosstalk protection
over a CAT 6 cable, and this means
that CAT 6a can support data transfer speeds of up
to 10 Gigabits per second, even as far as a hundred meters,
unlike CAT 6, which was limited to 55 meters in length
when you want to operate at 10 Gigabits per second.
The next cable type we have is CAT 7.
CAT 7 cables are not actually recognized
by TIA/EIA as a standard,
but you're still going to find plenty of devices
and cables that do support CAT 7.
CAT 7 cables support data transfer speeds of up
to 10 Gigabits per second with a maximum cable length
of 100 meters just like CAT 6a does.
The difference here is
that CAT 6a only supported frequencies up
to 500 megahertz,
but CAT 7 supports frequencies all the way up
to 600 megahertz instead.
CAT 7 cables are also used to support 10G BASE-T
or 10 Gigabit Ethernet networks.
The final one we have when it comes to CATs is CAT 8.
CAT 8 is a modern advanced standard
that supports data transfer speeds of up
to 40 Gigabits per second with a maximum cable length
of only 30 meters,
and it uses frequencies up to 2000 megahertz, which is
also considered to be two gigahertz in frequency.
Now, the CAT 8 cable was designed for use
in data centers and enterprise applications
where high speed data transfer was crucial
and shorter distances such
as between two servers inside of a rack or
between two neighboring server racks could
be used by using CAT 8 cables instead
of using a fiber cable.
Now the second thing we need to look
at is to look at coaxial cables.
Now, coaxial cables also known simply
as coax, has been a fundamental part of networking
and broadcasting for decades.
Coaxial cables consist of a single copper conductor
at its core with an insulating layer
and a conductive shield wrapped around it.
Originally, most people were introduced
to coaxial cables from their use in broadband systems
like cable television systems
because these cables could carry numerous television
channels into our homes over a single coaxial cable line.
These days though, these same coaxial cables are
also being used to carry data at high speeds
over longer distances.
In most residential installations, the RG-6 coaxial cable
will be used to support faster internet speeds when
you're using a cable modem.
These RG-6 cables have a heavier center copper core,
which makes it great for high bandwidth
and higher frequency applications like cable modems
and digital video transmission systems.
In the old days, there was actually an older standard
for coaxial cables known as RG-59,
but this isn't commonly used anymore
because it is an inner copper core that's much thinner
than an RG-6 cable.
And these older RG-59 cables can only really be used
in analog video and closed circuit television installations
because of their lower bandwidth
and lower frequency capabilities.
Now, when it comes
to coaxial cables, the data transfer speeds associated
with an RG-6 coaxial cable really does depend
on the specific application you're using,
but most modern coaxial cables can support speeds of up
to one Gigabit per second at a distance of up to 300 meters.
Now, a newer form of coaxial cabling is referred
to as direct attach copper or DAC cables.
Direct attach copper cables are a form
of fixed assembly copper cabling that's used
to connect switches, routers, firewalls, and servers,
and they're primarily used within server racks inside
of a data center or within close range
of your network infrastructure's hardware.
These direct attach copper cables come
with connectors already attach when you purchase them,
and they're really favored for their cost effectiveness
and reduced power consumption as compared
to fiber optics when they're used for short distances.
Direct attach cables can operate at a maximum data speed
of a hundred Gigabits per second at 15 meters
or less when using an active cable
or 100 Gigabits per second at seven meters
or less when you're using passive cables.
These direct attach cables can
also support high speed data transmissions
with speeds of 10 Gigabits per second,
40 Gigabits per second,
or up to a hundred Gigabits per second depending
on the distance being covered,
and this makes them well suited
for interconnect applications
between two servers, routers, switches, or other devices.
Another coaxial cable you may hear mentioned
is what we refer to as a twinaxial cable.
Now, a twinaxial cable is often a component
of a direct attach copper assembly,
and it's considered another specialized form of cabling.
Unlike a traditional coaxial cable,
a twinaxial cable consists
of two separate insulated copper conductors
that are run parallel within the same outer shield.
This twinaxial cable design is optimized
for short range, high speed differential
signaling applications.
Twinaxial cables are commonly used for SFP+,
which is a small form factor pluggable plus
or QSFP, which is a quad small
form factor pluggable direct attach application
between two different routers or switches.
These twinaxial cables provide a reliable solution
for high frequency transmissions
and offer superior signal integrity over shorter distances.
As compared to a traditional unshielded cable,
twinaxial cables are less susceptible
to electromagnetic interference,
which is a significant advantage
in tightly packed data centers where signal interference can
become a major issue for your network.
These twinaxial cables can support data transfer speeds
of 10 Gigabits per second, 25 Gigabits per second,
40 Gigabits per second, or 100 Gigabits per second
at a distance of up to 100 meters
for the 10 Gigabit per second cables,
or as short as seven meters
for the 100 Gigabit per second cables.
The last thing we need to discuss is the difference
between plenum and non-plenum cables.
Now, plenum cables are designed
with fire-retardant plastic jackets
that are made from materials such as PVC or FEP.
PVC is poly vinyl chloride,
and FEP is Fluorinated Ethylene Propylene.
This is used to prevent flames from spreading
and reduces the amount of smoke produced
during the fire of those cables.
These characteristics are essential for the cables
that run in the plenum spaces
of our buildings, which are those areas typically used
to route air circulating for heating, ventilation,
and air conditioning systems.
Since these spaces have an abundant supply of oxygen
and can facilitate the rapid spread of fire, these cables
that are installed here must adhere
to strict fire safety standards,
and that's why we use plenum-rated cables
because these plenum-rated cables meet
the stringent requirements
of the National Fire Protection Association
and the National Electrical Code.
Although they are more expensive, their use is critical
in minimizing the risks associated with fire and smoke
in building spaces where air circulation can occur outside
of your duct work.
Now, non-plenum cables
on the other hand, are what we use most of the time
in our home office networks.
Non-plenum cables are not designed
with the same stringent fire-retardant properties
and therefore they're not suitable for use
in plenum spaces.
Typically, these cables have jackets made
from less expensive materials
that do not have enhanced fire-resistant characteristics
of those plenum-rated cables.
These non-plenum cables are typically used
in spaces where there's no environmental air return, such as
between walls, in conduit,
and in other areas where the potential
for fire to propagate through open air spaces is much lower.
While they're more cost effective
than plenum cables, they do produce more smoke
and toxic fumes when they're exposed to flame,
and this makes them a really bad choice for any areas
that could contribute to the spread
of fire throughout a building.
For installations
that don't require the stringent fire safety standards
of plenum-rated cables though, non-plenum cables provide
a practical and economical solution for us to use.
Now remember, there are a few different ways for us
to categorize our copper cables.
First, we can categorize them
as either twisted pair or coaxial.
Then if we're looking
at twisted pair cables, we classify them
as either shielded or unshielded twisted pair,
and then we assign them a CAT number like CAT 5,
CAT 5e, CAT 6, CAT 6a, CAT 7, or CAT 8.
Then we finally can classify them as either being plenum
or non-plenum-rated cables.
On the other hand, if we're categorizing our cable
as coaxial cable, we can then determine
if it's a standard coaxial cable,
a direct attach copper cable or a twinaxial cable
to best classify its capabilities, limitations,
and use cases.
When it comes to copper media, it's important
that you remember the basic speed
and distance for each type of cable.
So let's review those one more time
before we end this lesson.
CAT 5 cables can go 100 meters at 100 megabits per second.
CAT 5e cables can go 100 meters at one Gigabit per second.
CAT 6 cables can go 100 meters at one Gigabit per second,
or 55 meters at 10 Gigabits per second.
CAT 6a cables can do 100 meters at 10 Gigabits per second.
CAT 7 cables can do 100 meters at 10 Gigabits per second,
and CAT 8 cables can do about 30 meters at 25
to 40 Gigabits per second.
Now, as a quick reminder, all these CAT cables are limited
to a hundred meters in length except
for CAT 6, which is limited to 55 meters,
if you want to provide the maximum speed
of 10 Gigabits per second
and CAT 8, which is limited to 30 meters.
When it comes to speed, you can start with CAT 5
at 100 megabits per second and then step up
by a factor of 10 as you move up the scale.
So CAT 5 is 100 megabits per second,
but CAT 5e is 1000 megabits per second, which is
also written as one Gigabit per second.
CAT 6 is either one Gigabit per second, like CAT 5e,
or you can reach 10 Gigabits per second with a cable
at 55 meters or less, which again increases
by a factor of 10 in terms of speed.
CAT 6a is always going to be 10 Gigabits per second,
which is 10 times higher than CAT 5e and CAT 6
with that longer 100 meter cable.
And CAT 7 will remain
at 10 Gigabits per second, just like CAT 6.
But then when we go to CAT 8, it increases again,
but this time it goes from 10 Gigabits per second
to 25 or 40 Gigabits per second depending on
that cable length.
On the coaxial cable side, you'll find
that a traditional RG-6 coaxial cable can support speeds
of up to one Gigabit per second added length
of around 300 meters.
Twinaxial cables have a much shorter distance
of only 10 meters, but it does support much higher speeds
by going up to 10 Gigabits per second or more.
Direct attach cables are the newest
and most modern copper cable type, and they support speeds
of up to 100 Gigabits per second at a distance of 15 meters
for active cables and only up to a distance of seven meters
for passive cables at 100 Gigabits per second.
Now, I know that was a ton of facts and figures,
and I do recommend that you take a little time offline
to study these numbers from your notes
because they will be important
during your troubleshooting and network design work
as a network technician out in the real world.
Even though much of the world is slowly moving over
to fiber, copper media will remain a vital part
of our network infrastructure for years to come
because it provides us with a versatility
and robustness required for various networking needs
at a lower price and is much easier to install
and maintain for many applications
and workplace environments than fiber is.