Welcome back
to what I'm calling the Networking Starter Pack.
This is a miniseries of lessons
covering foundational networking.
Everything you do with AWS uses networking.
Every type of interaction when you communicate with AWS,
when you create connections
between your on premises network and AWS,
it all uses networking.
Whether you're an architect,
a developer or a systems administrator,
you have to understand this fully
in order to confidently interact with AWS.
Now let's jump in and get started.
Networking can refer to many things.
Some of these are local, some global and some application,
and this series is going to step through them all.
I'm going to start with local networking,
so how data moves between devices on your local network.
Now this is foundational to everything.
It's the starting point or ending point of data
which moves across the internet.
I'm also going to be covering routing.
So how data moves across the internet
from your network through to Netflix or AWS.
When data moves across the internet,
it's moving across many interconnected networks
and so that's why local networking matters.
You have to understand that to understand the internet.
I'll be covering how data is chopped up
for reliable transit,
what network ports are and why they're used
and what sessions are and how they all help
to ensure reliable data transfer,
which is used by your applications.
Now, the best way that I found to fully understand
networking is via the OSI 7-layer model.
This is a way of breaking up networking
into seven distinct components.
We start at the bottom with physical networking
and end at the top with application networking.
Now I've included links in the lesson description,
which gives some background reading,
but this series will be explained
using this 7-layer OSI model.
It's important at the outset,
just to say that the OSI model is a conceptual thing.
It's not always how networking software is implemented,
but it does form a good foundation
so that newcomers can understand how each component works
and interacts with all of the others.
Now, this is how it looks.
Seven layers stacked on top of each other.
We start with physical then data link, then network,
transport, session, presentation and finally application.
If you ever hear the term networking stack,
that's what this is, or rather the software
which does each of these functions.
That's known as the networking stack.
Your laptop has a networking stack,
so does your phone, so does your wifi or cable router
and so does the server
that you're downloading this video from.
The layers of the OSI model
they're divided into two groupings.
We've got the media layers at the bottom,
so physical, data link and network
and then at the top, we've got the host layers,
transport, session, presentation and application.
Conceptually, think about the media layers
as dealing with how data is moved
between point A and point B
and these could be in the same local network
or on opposite sides of the planet.
The host layers again, conceptually think about this
as how the data is chopped up and reassembled for transport
and how it's formatted so that it's understandable
by both sides of a network connection.
Now I'm going to be going into much more detail on this,
over the coming lessons,
but at a high level at the top at Layer 7,
you might have a web browser such as Firefox
and a web server at the other side of the connection.
At the bottom in Layer 1,
you're going to have some kind of physical network cards
or interfaces, and then conceptually any data
from the web browser flows down
through the layers at one side,
somehow arrives at the other side
and then flows back up to the web server software.
Now this is just conceptual at this stage.
I'm going to explain how all of the pieces fit together
as we move through this lesson series.
Now some of this might seem dry and somewhat theoretical,
but I promise if you spend the time learning
all of these different layers
and the functions that they provide,
then so much more of how networking functions
at a real foundational level will make much more sense
and that's going to be really useful
when you're dealing with AWS.
So this is what we're going to be using
throughout this series.
Now the series is going to be broken up
into bite size lessons
each of which cover one or more of these layers.
I've structured it in a way
so that it will be easy to understand.
Now this seems like a good point to take a break.
So go ahead and finish this video.
And when you're ready, you can join me in the next part
where I'll be covering Layer 1 or the physical layer.