Characteristics of networks
Introduction
If all the computers in a room are standalone, that means they are not connected to each other. This has a number of implications. They can't send messages to each other, can't share a file or share a piece of equipment like a printer easily and can't work on one particular computer one day, and then on a different one the next day and expect to be able to get back easily files that were saved on the first computer. If computers were connected together in some way then they would be able to do all of the above. Computers that are connected together are known as a 'network'.
Key features of networked computers
The advantages of a network of computers rather than standalone machines include:
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- Computers that are connected together can communicate with each other. Standalone machines can't.
- Users on a network can easily share resources such as printers, scanners and modems. This means that a company doesn't have to buy so much equipment and users do not waste time moving files to different machines so they can use a piece of equipment that is only available on a particular PC.
- Users on a network can share data. For example, a team might be working on a project. They can all access and work on the same files easily without having first to back them up on floppy disks, for example, and then transport them to the next team member and then reload the files.
- New software need only be added once. It can then be distributed to all other PCs automatically.
- When data files are backed up they only need to be backed-up once, centrally, at the server. With standalone machines, you would have to back up the files on every machine. This would be very time-consuming!
- Users can retrieve and work on files from any machine on a network. If one machine is being used or breaks down, you simply move to a different machine!
- Networks can be managed. This means a network manager is able through the network software to control who can access the network, when they can access it, and what files and software and hardware they are allowed to use. An audit trail of each user can be built up so that projects can be more efficiently costed, for example, by keeping track of what printouts are done in connection with what project. Users, knowing that their activities are being monitored, will also be encouraged to stay on-task and not waste the organisation's time!
- Security can be centrally managed by the network manager. They can add patches centrally, ensure virus patterns are up-to-date centrally and so on.
BUT
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- It costs more money to build a network than it does standalone machines. This is because you have to buy network cards, interconnections, a server and a Network Operating System.
- There is an additional support cost that is not insignificant. Networks are more complicated than sets of standalone machines. They need specialist knowledge to set them up and maintain them as well as time to maintain them. To do this, you would need to employ somebody with network management skills.
- Networks have machines in different locations, each of which potentially could be used to gain access to the server's hard disk and the data stored on it. This is a security headache and the need to protect data on a network from hackers adds an extra degree of complexity to a network that doesn't exist with standalone machines.
- If the server on a client-server network goes down, the whole network will be out of action. It is also possible for one faulty machine on a network to cause other machines on the network to stop working. In addition, if the cables on a network fail, problems on either individual machines or on the whole network may occur.