When we talk about network resources, we have
to think about how data is being moved around the network.
We break this down into two main models,
the client server model and the peer-to-peer model.
Let's start out talking about the client-server model.
The client-server model is going to use a dedicated server
to provide access to files, scanners, printers,
and other resources on the network.
Now, administration and backup is pretty easy here,
because we have one central machine, this server,
that all the resources are sitting on,
and so we can go ahead and backup that server
and we've backed up all the files.
We can configure that server
and we've configured all the accesses, right?
This makes the client server model one
of the main choices we use in business networks.
Now, when we look at the benefits of a client-server model,
it gives us that centralized administration.
There is one or a few key servers
when we can focus all of our effort there,
that gives us easier management,
again, because it's all in one or two places
because we have those few key servers that we can manage,
and it gives us better scalability,
because I can have all of my stuff in one place,
and if I need to expand, I can actually expand outward using
that through a cloud architecture
or some other additional servers,
and depending on how I need to do that,
and this will allow me to put things in tandem
using load balancing,
and it'll gimme a lot more benefits than try
to run things under the peer-to-peer model.
Now, some of those drawbacks to a client server
is that it costs more money
because it requires dedicated hardware
and dedicated operating system software.
So you might have to have something like Windows on there
or a Unix or Linux build, or something like that.
And this takes a highly-specialized skillset
to run all of these things.
And so it requires these dedicated resources,
whether they're machines or software,
or that operating system, as well
as personnel who know how to use it.
So that's kind of the bad things when we talk
about a client-server model.
With all that said, client-server is still the leading model
that we use in business networks.
Now, let's look at the other side, the peer-to-peer model.
This is where peers or other machines, like laptops
and desktops, can share resources together directly.
The administration and backup is very difficult
because all the files are located on different machines
in different places.
For example, if I wanted to share some PowerPoint slides
with you and you're sharing some Excel files with me,
these files are on both of our machines,
and now we're going to have to back up both machines
and manage both of them,
and this is going to give us two sets of permissions on them
and all that other management.
You see how this redundancy in that work
where we have to do multiple things in multiple places.
Now, if I took that
and I scaled that up to 50 machines, that gets kind
of being a nightmare, right?
Because we're going to have a lot of work there.
That's the big drawback to peer-to-peer.
Now, where is peer-to-peer useful?
Well, if you think back a decade ago,
there was a software out there called Napster,
and this was a peer-to-peer file sharing program.
Now, it happened to be used for a lot
of illegal activity like downloading music without copyright
and those type of things, but the concept behind it
is what we want to focus on here.
Each person who was part
of the network gave and received files.
It was a peer-to-peer sharing network.
Now, the benefits of peer-to-peer
was it was low-cost.
There was no infrastructure, no specialized hardware,
no dedicated hardware, none of that stuff,
because there's just software
and it allowed everyone to talk to each other as they wanted
to and share files.
You could pick a folder your hard drive
and share that out with the world.
This allowed you to create resources
and networks wherever we wanted to.
So this was kind of the thing here
is that there was no specialized operating system,
no dedicated resources, and it was very low to start up.
Now, if I wanted to create a network
and we had five computers, I might just turn one
of them into a file sharing off my local laptop,
and you can all access it.
It would be no problem.
That's the idea of a peer-to-peer.
But there's also some drawbacks
because if my machine is off now, you can't access anything.
Whereas if I had a centralized server, you still could
because that server would be on 24 hours
a day, seven days a week.
Now, what are some of the drawbacks?
Well, the biggest one is decentralized management.
Everyone can own and control their own machine
and decide what they're sharing
and what they're not sharing.
This becomes extremely inefficient when you deal
with large networks or business networks,
and it has horrible scalability.
So if I wanted to run a peer-to-peer network
for an organization the size of Facebook,
it just wouldn't work.
It would be horrible.
You'd have
to have centralized management for stuff.
Otherwise, when things get large, they get lost.
And so in business networks,
we are really going to focus on this client-server model
over peer-to-peer for the exam.
You do want to understand what a client-server model
is and a peer-to-peer model, and really what the benefits
and drawbacks are for each of them.
All the benefits on the client server model are drawbacks
on peer-to-peer, and all the drawbacks
on client-server model
are actually benefits on peer-to-peer.
They're basically opposites of each other.
If you remember that, you'll do great on the exam.