In this section of the course,
we're going to discuss wide-area networks.
At this point,
it's time for us to start moving outside
of our local area networks
by using routers and switches
and connecting to a larger wide-area network.
You see, so far we've covered switching
within our local area networks,
and we introduced the concepts of routing,
which allowed us to leave that local area network
and connect to other networks or subnets,
but we really haven't discussed
how we actually connect to those other networks
and communicate over longer distances,
and that is exactly what a wide-area network connection
or a WAN connection is going to be used for.
Now, let's take a quick look back
at computer networking over time,
because back in the early 1990s,
we had this thing that we talked about
called the Pareto Principle or the 80/20 rule.
Now, the Pareto Principle
actually comes from the business world,
but as we apply it to networks,
it used to be said that 80% of your traffic
stayed inside your local area network,
and only 20% went out to the WAN or the wide-area network.
Now for that reason,
it was really common for a large organization
to only have a small external connection,
something in the range
of 1.44 megabits per second, for example,
and that would have been plenty for their needs.
After all, if only 20% of their network traffic
had to cross the wide-area network
to reach another network or service,
we could use a slower and cheaper
low bandwidth WAN connection
and still meet the needs of our business and its end users.
Today, though, that Pareto Principle
has really been flipped on its head.
These days, it's more like 80% of your traffic
goes out of your network
and only 20% stays within the local area network.
Let's consider your daily use of a computer at work,
at school, or at home.
Are you using things like cloud?
Well, are you using something like Google Drive and Dropbox,
or Google Docs, and Office 365?
All of these are cloud-based applications
that exist outside of your network,
and you're probably spending a large portion of your day
doing things like watching online videos,
scrolling your newsfeed on Facebook,
or even making voiceover internet protocol calls
to your family and friends.
All of these things require us to leave the LAN
and then send data over the WAN.
So in this section of the course,
we're going to discuss wide-area networks
with a singular focus on Domain 1: Networking Concepts.
We're going to be focused on
just one objective here, Objective 1.5,
and this states
that you must be able to compare and contrast
transmission media and transceivers.
Now first, we're going to discuss fiber optic connections
and how those are used in wide-area networks.
Then, we'll discuss cable or DOCSIS connections
that are used in our wide-area network connections.
Next, you're going to learn about an older technology
called a DSL or digital subscriber line,
that was very popular back in the late 1990s
and kept this popularity until fairly recently.
Now it's still used heavily in a lot of parts of the world,
so we're still going to cover it here in this section.
After that, we'll talk about satellite connections
and how they work,
including more traditional
geosynchronous orbital satellites,
and the newer lower latency,
low earth orbit satellites
used by companies like Starlink.
Then, we'll discuss the different types
of cellular connections that we can use
as a wide-area network connection,
including those in our smartphones, tablets, hotspots,
and fixed cellular home internet devices.
Next, we'll explore microwave connections
and how they're used in business parks, campuses,
and metropolitan areas to provide a high-speed,
point-to-point connection
between two different networks.
After that, we'll look at the different types of lease lines
that you may choose to use
in your wide-area network connections.
Then, we'll cover MPLS connections,
which stands for the Multi-Protocol Label Switching.
Now, we'll talk about how MPLS is used
for wide-area network connections
by your internet service providers
to move your data across the internet much more efficiently.
After that, I'm going to do a quick demonstration to show you
the different kinds of wide-area network connections
that you may see when you're working out in the field
and servicing a small office
or home office environment.
Finally, we'll take a short quiz
to see what you learned during this section of the course,
and review your answers
to ensure you know why the right answers were right
and the wrong answers were wrong.
So if you're ready,
let's get started with our coverage
of wide-area networks in this section of the course.