- [Craig] In this video, we take a look at client-server and peer-to-peer networks.
(uplifting piano jingle)
A server is a special computer on a network that is not used as a workstation
but is a computer dedicated to serving files and managing various other services.
Both local and wide area networks can operate either with or without a server.
A network that uses a server is called a client-server model; a network that does not use a server is called a peer-to-peer model.
Here, we see some of the notes for a client-server model.
We have a server that controls access and security to one shared file store.
The server can manage access to the internet.
The server can manage printing jobs; it can provide email services.
It can be responsible for backing up data.
And the individual clients connected to the server make requests for data and various connections.
The advantages here is it's easier to manage the security of the files on this network.
It's easier to take backups of all the shared data and it's much easier to install software updates across the network.
There are, of course, disadvantages of the client-server model; it can be expensive to set up and maintain.
It does require a certain amount of IT specialism and the server, of course, is a single point of failure.
Users will lose access if the server fails.
With the peer-to-peer model, a peer is a computer on the network and it is equal to all other peers.
The peers serve their own files to each other.
Each peer is responsible for its own security and its own backups.
And peers usually have their own printers.
You can send print jobs to another peer to process,
but that peer would need to be switched on and be able to communicate with the connected printer.
There are some advantages to the peer-to-peer model; it's very easy to maintain, we don't need specialist staff anymore.
There's now no dependency on a single central server or device.
And it's cheaper to set up; there's no expensive hardware required.
Of course, there are some disadvantages; the network is generally less secure.
Users will be responsible for managing their own backups, and it can be difficult to maintain a well-ordered file store.
Although slightly beyond the spec for GCSE, it's probably worth clearing up a common misconception about peer-to-peer networks.
The nature of a peer-to-peer network and the way it's implemented means effectively,
you can think of computers in an abstract way of being connected directly to each other.
So here on the diagram, we can see every computer is connected directly to every other on this peer-to-peer network.
This is the way the user would perceive the network.
Of course in reality, you don't have a physical cable connection to every other computer on a peer-to-peer network.
They're probably actually still wired very much like a traditional star network,
with each peer being connected to some sort of central switch or indeed, many different switches.
It's the protocol of the peer-to-peer network that allows you to
seamlessly transmit data directly from one computer to another,
even though the actual physical connections may be very separate and very different
from the layout of the logical connection that you're presented with in an exam paper.
(uplifting piano jingle)