In this lesson,
we're going to discuss transceivers.
Now, a transceiver is a generalized term for any device
that can both transmit and receive data.
In fact, the name transceiver is simply a linguistic blend
of the words transmitter
and receiver to create this new word of transceiver.
Each transceiver is designed to transmit,
receive data using a specific protocol though.
Now a protocol is a set of rules
and standards that govern how data is transmitted
and received over a network to ensure consistent
and reliable communication between your devices.
When it comes to our networks,
there's really two main protocols that we're going to rely on.
These are ethernet and fiber channel.
Now, ethernet is a family
of computer networking technologies
that are commonly used in our local area networks,
metropolitan area networks, and wide area networks.
As a protocol,
ethernet is used to facilitate the communication
and data transfer between your different network devices.
Ethernet defines the physical
and electrical standards
for the network cabling and connectors,
as well as the data formats
and rules for transmitting data
over that network infrastructure.
Ethernet is able to support a variety of data rates
and provides the foundational communication standard
for most wired data networks that we're going to use today,
even when we're using copper media, fiber media,
or wireless radio waves
for our data transmission in our local area networks.
Now, fiber channel is another commonly used network protocol
that you're going to come across when working
as a network technician or administrator out in the field.
Fiber channel, which is also written as FC,
is a high speed network technology that's primarily used
to connect computer data storage to servers inside
of your storage area networks.
The fiber channel protocol is known for its ability
to handle multiple gigabits of data per second,
which makes it ideal for transferring large volumes
of data reliably and quickly over your storage area network.
The fiber channel protocol can also support
both optical fiber optics and copper base media inside
of your network architecture.
The fiber channel protocols key features
include high throughput, low latency,
and advanced data integrity mechanisms
that make it the preferred choice for enterprise storage
and data intensive applications.
But how are you able
to convert data from something like ethernet
over to fiber channel
or to go from fiber channel back to ethernet?
Well, this is one reason you may opt to use a transceiver
because a transceiver can convert
or translate the data set by one protocol
into that used by another protocol.
The transceiver will convert the ethernet signal,
which is typically transmitted over copper cabling,
into a signal that can be transmitted over fiber optics
that could be compatible with something
like fiber channel standards.
This allows devices in an ethernet network to communicate
with devices in a fiber channel network,
and it facilitates data exchange between different types
of network infrastructures.
This allows the transceiver to act as a media converter
and it'll help bridge the ethernet
and fiber channel networks together.
Now, another use case for transceivers is
to convert your network connections from one type
to another type, even if you're using the same protocol
on both types of connections.
For example, in one of my previous organizations
that I worked at, we actually ran ethernet
over multimode fiber on our network.
We did this to ensure that the security concerns
were being addressed
and to combat the effects of EMI on our systems
because we were working
in a high security, military type environment,
but many of the computers we installed
on our employees desktops didn't
actually support fiber optic cable connections directly
because they had an embedded Cat 6A network port
on their motherboard.
So to overcome this limitation,
we would use media converters, known as transceivers,
to accept the ST-based fiber connections
from our closest wall jack,
and then we would use that media converter
to convert the data being received
from that fiber optic cable
as a light signal into an electrical signal
that could then be sent over a Cat 6A cable
to the motherboard's embedded network jack.
In this case, we were converting light to electrical signals
while the protocol remained the exact same on both systems
because we use ethernet on both of them
as their communication protocol.
Another common use case for transceivers
or media converters is
to convert a long distance fiber connection
between two buildings back into a copper media connection
that your computers, switches,
or routers are going to be able to use.
For example, let's pretend
that I had a new fiber optic cable run
between two office buildings on different sides of my city.
For this example, let's pretend we need
to cover about 30 miles in distance
between those two buildings.
Now, obviously, I can't use a copper cable to cover
that much distance because I'm going
to hit the 100 meter limit pretty quickly,
but a single mode fiber can easily cover
that 30 mile distance.
So I can go out and hire a company
to run the fiber between both buildings
by digging a trench all the way across the city.
This would be considered a long haul circuit
that is going to act as a metropolitan area network,
known as a MAN, or a wide area network, known as a WAN,
in my case.
Now, once that fiber cable reaches my building
across town though,
I need to connect it to my networks.
Now on one end of the fiber connection,
I might place a media converter
or transceiver to convert the light signal back
into the electrical signal
that my network equipment can understand and use.
So as you can see,
a media converter or a transceiver is a device
that converts media from one format to another,
like going from fiber to copper, copper to fiber.
But media converters and transceivers are also considered
to be layer one devices
because all they do is take that signal,
convert it to the new format,
and then repeat it out the other side using that new format.
These media converters
and transceivers can be used to convert all sorts
of different media types, like going from copper to fiber,
fiber to copper, coaxial to fiber,
copper to coaxial, copper to wireless,
or any other layer one to layer one conversion
that you may need to do within your networks.
In fact, I've used media converters
to take a coaxial cable signal that carries a video signal
to a fiber optic cable so I could run it
to a building across our business park
that was about a half a mile away.
Then when it got there,
we reconverted that fiber optic cable signal
back into the coaxial cable signal
that can be plugged directly into a TV
inside of that building and it worked just fine
because the media converter did all the translation
from one signal to the other
by taking that signal from the radio frequency
that was sent by the coaxial cable,
converting it into a light signal
that could be sent over the fiber optic cable
and then translated back into the radio frequency signal
that's needed by the receiving television
using another coaxial cable.
All right, now let's talk about some different form factors
of transceivers that you may come across
when working as a network technician
or network administrator.
You're going to find that in most large networks,
there's going to be many different types
of transceivers being used.
These come in different form factors like the SFP,
the SFP plus, the QSFP, the QSFP plus,
the QSFP28, and the QSFP56.
Now first, we have the SFP.
Now SFP is an older standard
and it stands for the small form factor pluggable,
and this is a compact, hot pluggable optical module
that's used with fiber connections.
Since it's hot pluggable, it can be pulled in or pulled out
without turning off the associated router or switch.
Now this SFP is considered to be a transceiver
and it supports up to 4.25 gigabits per second of speed.
Second, we have the SFP plus.
Now the SFP plus is going to stand
for the small form factor pluggable plus,
which you can probably guess it's just a faster version
of an SFP module.
SFP plus supports up to 16 gigabits per second.
So it's about four times faster than a regular SFP is.
Third, we have a QSFP.
Now the QSFP stands for the quad small form factor pluggable
and it's a compact and hot pluggable optical module
just like the SFP and SFP plus.
But the big difference here is
that the QSFP goes even faster by supporting
around 40 gigabits per second of data,
which is about 10 times faster than the standard SFP
and about two and a half times faster
than the SFP plus module.
Fourth we have a QSFP plus.
Now the QSFP plus stands
for the quad small form factor pluggable plus.
And as you might have guessed, this is similar to the QSFP,
but it is slightly faster by reaching speeds
of about 41.2 gigabits per second.
Fifth we have the QSFP28.
Now the QSFP28 stands
for the quad small form factor pluggable 28.
And as you might have guessed,
this is similar to the other QSFP models we discussed,
but this one operates at about 100 gigabits per second.
Sixth and finally, we have the QSFP56.
Now the QSFP56 stands
for the quad small form factor pluggable 56,
and it operates at speeds of up to 200 gigabits per second.
Now for the exam, you do not have to memorize the speeds
of the different transceivers,
but instead, I want you to remember
that QSFP modules are faster than SFP modules
and that all of these are just different types
of transceivers that are going to be installed
inside of a router, a switch, or other networking device
that can convert the light
that travels over a fiber optic cable
back into an electrical impulse that represents a one
or zero that our copper network switches
and cables can then understand and utilize.
So remember, if you ever need to change the physical format
of your network signals to cover a longer distance,
you can can use a transceiver or media converter
to change the electrical impulses
from your copper base network into light base signals
that can be sent over a fiber optic cable.
And then when it reaches the other side,
you're going to be able to use another transceiver
or media converter to change it back
into an electrical impulse again
so your copper media can utilize it once more.
Also, if you need to convert from one protocol to another,
like moving from ethernet to fiber channel
or from fiber channel back to ethernet,
you can do that too using a transceiver.