Wednesday, January 14, 2009


The purpose of the networking guidelines are as follows:

1. To assist schools in understanding the benefits of networking
2. To help schools place in context their current stage of networking development in their school. 3. To assist schools in planning the next stage of network development in their school.
4. To provide standard networking ‘models’ and best practice to schools that will assist schools in their network planning.

1.1. Basic of Networking
A computer network consists of a collection of computers, printers and other equipment that is connected together so that they can communicate with each other (see Advice Sheet 17 on the ICT Planning for schools pack). Fig 1 gives an example of a network in a school comprising of a local area network or LAN connecting computers with each other, the internet, and various servers.

Broadly speaking, there are two types of network configuration, peer-to-peer networks and client/server networks.
Peer to Peer Network
Peer-to-peer networks are more commonly implemented where less then ten computers are involved and where strict security is not necessary. All computers have the same status, hence the term 'peer', and they communicate with each other on an equal footing. Files, such as word processing or spreadsheet documents, can be shared across the network and all the computers on the network can share devices, such as printers or scanners, which are connected to any one computer.
Client/server networks are more suitable for larger networks. A central computer, or 'server', acts as the storage location for files and applications shared on the network. Usually the server is a higher than average performance computer. The server also controls the network access of the other computers which are referred to as the 'client' computers. Typically, teachers and students in a school will use the client computers for their work and only the network administrator (usually a designated staff member) will have access rights to the server.

Peer-to-Peer Networks vs Client/Server Networks
Peer-to-Peer Networks
· Easy to set up
· Less expensive to install
· Can be implemented on a wide range of operating systems
· More time consuming to maintain the software being used (as computers must be managed individually)
· Very low levels of security supported or none at all. These can be very cumbersome to set up, depending on the operating system being used
· Ideal for networks with less than 10 computers
· Does not require a server
· Demands a moderate level of skill to administer the network

Client/Server Networks
· More difficult to set up
· More expensive to install
· A variety of operating systems can be supported on the client computers, but the server needs to run an operating system that supports networking
· Less time consuming to maintain the software being used (as most of the maintenance is managed from the server)
· High levels of security are supported, all of which are controlled from the server. Such measures prevent the deletion of essential system files or the changing of settings
· No limit to the number of computers that can be supported by the network
· Requires a server running a server operating system
· Demands that the network administrator has a high level of IT skills with a good working knowledge of a server operating system

Components of a Network
A computer network comprises the following components:
A minimum of at least 2 computers
Cables that connect the computers to each other, although wireless communication is becoming more common (see Advice Sheet 20 for more information)
A network interface device on each computer (this is called a network interface card or NIC)
A ‘Switch’ used to switch the data from one point to another. Hubs are outdated and are little used for new installations.
Network operating system software

Structured Cabling
The two most popular types of structured network cabling are twisted-pair (also known as 10BaseT) and thin coax (also known as 10Base2). 10BaseT cabling looks like ordinary telephone wire, except that it has 8 wires inside instead of 4. Thin coax looks like the copper coaxial cabling that's often used to connect a Video Recorder to a TV.

10BaseT Cabling
When 10BaseT cabling is used, a strand of cabling is inserted between each computer and a hub. If you have 5 computers, you'll need 5 cables. Each cable cannot exceed 325 feet in length. Because the cables from all of the PCs converge at a common point, a 10BaseT network forms a star configuration.

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