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ABC of ICT

Confused by talk of WAN and LAN? Pete Roythorne explains the language of school networks

Not content with linking together all the computers on our school campuses, our ICTnetwork specialists have introduced us to a new language as well. If want to know the your WANs from your LANs, read on.

It's not good enough just having a computer network installed in your school, you need to know what sort of network it is.

Networks come in a number of guises, starting with the PAN, or personal area network.

This is where computers and other devices, such as mobiles and personal digital assistants, communicate over short distances, usually a few metres - a classroom would be your typical PAN size. If you use any handheld device to transfer data to your laptop then you'll already have your own PAN.

PANnetworks will become more prominent in the classroom if handheld devices take off as a learning tool.

Next is the LAN, or local area network. This is where a group of computers and other devices are connected to each other to enable data to pass between them over limited geographical areas. Most LANs are confined to a single building or group of buildings - typically most school networks are LANs.

However, one LAN can be connected to other LANs over any distance via telephone lines and radio waves.

A system of LANs connected in this way is called a WAN, or wide area network. The best example of a WAN is the internet, but if you connected two campuses that were separated by more than just a road then you would have your own WAN.

If you're linking two or more LANs across a WAN you'll need a VPN, or virtual private network. A VPN protects data that is travelling via public routes, such as the internet.

It does this by encrypting the data so that information can be understood only by computers with the correct programmed "key"; in this way the entire network becomes "virtually" private. Virtual in this case refers to a computer-generated environment.

Then there's the VLAN, or virtual local area network. This is a LAN which has groups of computers defined in ways other than by geographic location; that is, by department, type of user or primary application. This would come into play if you had several buildings on a campus, and the geography department, say, was split over two or more buildings.

Finally, the one we're probably most familiar with, the wireless LAN or WLAN. This is the typical school wireless network, using high-frequency radio waves rather than wires to communicate across the network.

So, next time one of your techie colleagues tries to baffle you with network speak, put them firmly in their place.

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