By far, Ethernet has to be the most popular networking
technology in the world.
It is used in practically every organization
to connect devices and be able to connect us together
using the internet.
To be able to make all of these Ethernet connections work,
we use many different types of cabling,
different types of equipment, and different types
of connector.
These days, our modern Ethernet networks
will use fiber and twisted pair copper,
but you may run into other types of connectors as well.
One common technology used across many
of these different Ethernet standards
is baseband technology.
This means there is a single frequency that's
using the entire medium.
That means across this wired connection or fiber connection,
we are using a single type of frequency
to be able to transmit these Ethernet signals.
This is different than a broadband connection.
With broadband connectivity, you have a single wire,
but you're sending many different frequencies
across that wire, effectively sharing
the medium for all of those different communications
channels.
If you have some older 10-megabit Ethernet
cable running over twisted pair wire,
then you're probably using the 10BASE-T standard.
The 10 would be for 10-megabit, the BASE
would be for the baseband technology that's
used on that wire, and generally, you'd
see a T or a TX at the end to specify that that is twisted
pair.
10BASE-T uses two pairs of wire within that cable, which
is different than the four pair that we commonly
see with gigabit Ethernet technology,
and this only requires Category 3 cable.
This goes back a number of years,
and Category 3 was perfectly acceptable to run
10-megabit Ethernet.
The maximum distance supported with 10BASE-T Ethernet
is a 100-meter distance.
We increased the speed of our Ethernet networks 10 times
and created 100-megabit Ethernet.
This is 100BASE-TX.
Sometimes you'll see this referred to as fast Ethernet,
although these days, 100-megabit Ethernet is not the fastest
that you will commonly find.
This also used two pairs of wires within that cable,
and it uses a minimum of Category 5 cable extended
over a 100-meter maximum distance.
We improved the Ethernet technologies
and introduced 1000BASE-T, or what
is known as gigabit Ethernet over Category 5 cabling.
This uses all four pairs of wires within that single cable,
and although Category 5 cabling is now deprecated,
we tend to see Category 5e used in its place.
This move to use all four pairs of wires within the cable
is very different than the two pair that was used
for 10BASE-T or 100BASE-TX.
That's why you'll sometimes see some patch cables that
only have two pairs of wires run inside of them
because they were made for the older standards.
And if you try to use those with 1000BASE-T,
you won't be able to get gigabit speeds.
As with 10BASE-T and 100BASE-TX, the maximum
allowed distance in the 1000BASE-T standard
is 100 meters.
Increasing these speeds again by a factor of 10,
we can support 10GBASE-T standard, or 10 gig Ethernet
over copper with this four pair balanced twisted pair cabling.
This uses a higher frequency to communicate
across this connection.
Normally, 125 megahertz was the frequency of signal
that you would see on a gigabit Ethernet cable.
For 10GBASE-T, we're using frequencies of 500 megahertz.
That increased frequency rate translates
into more data being sent across this connection.
10GBASE-T requires a minimum of Category 6 cabling,
and if you're using unshielded cable,
the maximum supported distance for the 10GBASE-T standard
is 55 meters.
If you're using shielded cables, you
can go up to 100 meters in length.
There's also Category 6A cabling,
that A stands for Augmented, and Category 6A
can support 10GBASE-T over shielded
or unshielded cabling up to 100 meters.
One of our newer Ethernet standards is 40GBASE-T,
and as the name implies there, this
is 40 gigabit per second Ethernet
over twisted pair cabling using all four of the pairs
within that cable.
This requires a minimum of Category 8 cable,
and it only allows communication up
to 30 meters based on the 40GBASE-T standard.
When you add fiber as a method of communicating
between devices, you can extend the speeds and distances
of this Ethernet signal.
100-megabit Ethernet over fiber can be used with the 100BASE-FX
standard.
This is a pair of multi-mode fiber.
In fact, it uses some of the same fiber technologies
that we used back in the FDDI networking days,
for those of you that remember back to those time frames.
Just as there are Ethernet standards for copper cabling,
there are also Ethernet standards for fiber.
If you wanted to send 100-megabit Ethernet
over fiber, you could use the 100BASE-FX standard.
This uses a pair of multi-mode fiber.
In fact, it's the same fiber type
that we were using for the older FDDI technologies,
so this standard would allow us to move between FDDI
to the new 100BASE-FX by using the same fiber that we
have already run.
This commonly uses lasers to be able to send that light
and can communicate over half-duplex
to a maximum distance of 400 meters, and using full-duplex,
we can go to 2 kilometers.
There's a less expensive version of this 100-megabit Ethernet
over fiber standard with the 100BASE-SX.
This allows us to communicate 100-megabit Ethernet
using LED optics, which tend to be less expensive.
But this also limits our distance
to be able to send this signal to 300 meters.
If you're running gigabit Ethernet
over fiber connections, you might be using 1000BASE-SX.
This is gigabit Ethernet using a short wavelength laser.
And as the name implies, this is a shorter distance
than a longer wavelength laser that we'll look at in a moment.
This allows us distances over multi-mode fiber
to extend 220 meters to 550 meters
depending on the type of fiber that you're using.
If you wanted to have a longer distance that's supported,
you might want to use the 1000BASE-LX standard.
This is also gigabit Ethernet, but it's using long wavelength
laser to send the light.
On multi-mode fiber, you can extend this to 550 meters,
and for single-mode fiber, you can go
to a distance of 5 kilometers.
10-gigabit Ethernet standards are also
available for fiber connections.
The 10GBASE-SR, or Short Range, uses multi-mode fiber
to be able to extend 26 to 400 meters depending
on the type of fiber that you're using.
If you want to go very long distances using
10-gigabit Ethernet, you might want
to use the 10GBASE-LR standard, the LR is Long Range,
and using single-mode fiber, we can extend that
to 10 kilometers as its maximum distance.
You've seen some examples of using Ethernet signals
over fiber, but it would be useful
if we could send multiple types of signals
over the same strand of fiber.
We're able to do that using a technology
called WDM, or Wavelength-Division
Multiplexing, where we can have bidirectional communication
over a single stranded fiber for multiple types of signals.
This uses different wavelengths for each carrier
that we happen to be sending across that fiber.
You can think of this as sending different colors of a signal
over the same strand of fiber.
One common type of WDM is Coarse Wavelength-Division
Multiplexing, or CWDM.
This is the 10GBASE-LX4 standard using four separate
3.125-gigabit per second carriers at four different
wavelengths.
If you want to fit more signal over that fiber,
you might want to use DWDM, that's
Dense Wavelength-Division Multiplexing, and it is dense.
This is multiple carriers on a single fiber.
You can have 160 signals and increase the total throughput
to approximately 1.6 terabits per second.
Multiplexing is in the name.
That's what's really happening when we send this traffic
through this fiber.
Here are three different sources of signal
going into the multiplexer being then sent
across a single fiber, and on the other side,
we're demultiplexing those signals
onto their separate streams.