Open up Evernote, mini whiteboards

 2 minutes – write down as many as you can think of

 Peripherals, eg printers & scanners can be shared by several workstations so reducing the cost – the quality of 1 device purchased can be better than individual devices  Access to data is controlled by usernames & passwords and associated access rights, can ensure that security is not breached  Access to applications software can be controlled centrally, so that use of software licences is legal  Backups & virus checking can be controlled centrally

Chapter 3

 The advantages and disadvantages of: ◦ Client-Server Networks & ◦ Peer-to-Peer Networks

 Different types of networks have different needs.  These needs are based on the size of the network and the types of data that need to be transmitted from one computer to another.  The size of an organisation can determine the type of network used also.  Do consider the context/scenario when answering an exam type question

Server

 Large organisations are likely to have more than one server.  Each server carries out a different role on the network: ◦ Manage printing ◦ Manage ◦ Manage files  Once connected to the servers clients will have access to features such as: ◦ Dedicated storage ◦ Files (if the user has the access rights) ◦ Software used within the company ◦ Peripheral devices such as printers and scanners (if connected)

 P2P networks require no server.  Each connected computer performs its own functions but can share files and resources.  Each computer is considered equal to it’s peers.  These types of networks are usually found in the home or in smaller organisations and are much easier to set up compared to Client-Server networks.

 P2P networks have been at the forefront of piracy battles between entertainment companies and those who download their products illegally.  Applications such as BitTorrent and Limewire have allowed people to share and download entertainment free of charge very easily.

 Originally BitTorrent was developed to share files easily over networks.  However, the benefits of this technology was soon exploited by file sharers to pirate music, films and even games across the Internet.  This has led some entertainment organisations, such as Sony, to take some controversial steps in protecting their media.  For instance, they shipped out their music CDs with a piece of software that secretly installed on your computer that prevented you from copying the CD.

Client-ServerPeer-to-Peer Files are all located on the server so backing up is a lot easier than backing up each individual computer separately. Each computer needs to have its files managed individually – Backing up can take longer. Anti-virus software is managed centrally. All computers are protected as files are managed in one place. Each computer must have it’s virus software updated individually. If managed poorly, it could result in some computers not being up to date. Most of the processing occurs centrally, this means clients have more processing power available. Processing is shared amongst computers which could result in slower performance, especially if lots of computers are trying to use the services of one computer at the same time.

Client-ServerPeer-to-Peer Data and applications are available to any client connected, provided they have access rights. The user has to use the same computer each time in order to work on their files. Security is managed centrally and securely. Security can be ‘ad-hoc’ meaning some users may have access to printers and files and other might not. Software can be installed quickly across a network from the central server. Software must be installed on each machine separately which takes up a lot of human resource time. Servers are very costly due to their large processing power, huge storage capability and memory. They also tend to need to be stored in an air conditioned room. All the computers can run normally, sharing resources only when requested. This is a very cheap way to run a network.

Client-ServerPeer-to-Peer If a server fails then the entire network is unable to operate. If a single computer goes down then the remaining computers are unaffected. They may lose the ability to print if the computer controlling the printer is the computer that goes down...but the printer can be connected to another machine if required. Network managers are required to run this type of network – this can be quite costly. A reasonably competent user of ICT can set up a P2P network. The use of in-built wizards in most operating systems has made this even easier. If applications are run from the server it can cause lots of network traffic thus slowing down the network. Network traffic is minimal as most tasks are carried on the individual computers.

 Describe three advantages of networking computers.  What is the main difference between a client-server and a P2P network?  Describe two disadvantages of a client-server network.  Describe two disadvantages of a P2P network.  Describe two advantages of a P2P network.