Network Topography In Schools

This document compares Thick and Thin network topographies and their suitability for the school environment.

What are Thick and Thin clients?

You're already familiar with Thick clients. These are full 'normal' PCs composed of a monitor, processor, hard drive, memory and CD/DVD drive. They can run on their own without any need to be connected to a network.

A Thin client could be described as a 'lite' version of a regular PC. It could compose of just a monitor, processor and memory. This is because all of the storage of the programs and data is held on a server running Terminal Services.

Thin Clients

Example Thin Clients

This is the smallest thin client you can get. It replaces the existing network LAN socket with this miniature PC. This model, from Chip PC, has sockets for a monitor, four USB slots and mic/speaker connections. A Thin client like this would also save on electricity bills as it draws just 1% of the power of a regular PC.

This client is currently of limited use in a school environment as it runs Windows CE .NET rather than XP.

A more common Thin client is a bit bigger, although still significantly smaller than a regular PC. This model, from HP, is around 20cm high and 20cm wide, runs Windows XP and has four USB ports, 1 Serial, 1 Parallel, 1 PS/2, and a network connection port.

The HP t5710 (pictured) currently retails for less than £200.

Advantages of Thin Clients

Thin clients have the following major advantages:

• Purchase Cost - the cost of buying individual Thin clients is significantly less than their Thick alternatives.
• Ownership Cost - Thin clients have less to go wrong and require very little maintenance.
• Reliability - because they don't have their own mass storage Thin clients are extremely reliable.
• Space - their small footprint makes Thin clients suitable for classrooms
• Security - not only are Thin clients less desirable to thieves they are also much easier to protect from viruses and other malicious software

Disadvantages of Thin Clients

Of course there are some important disadvantages of thin clients:

• Compatibility - not all software is designed with Terminal Services in mind. Microsoft Office is designed to run in this enviroment and so is Supernova and JAWS but will Clicker, ChooseIt Maker and Writing With Symbols? A lot of software will not easily run over Terminal Services and some will not run at all.
• Server - you need to have a pretty good server as it has to take on a lot more work than a server on a regular network with Thick clients.
• Bandwidth - the pipeline that connects your server to your clients needs to be wide enough to send multimedia to many computers simultaneously. You'll need at least 100 Mbits/s, but 1000 Mbits/s would be better.
• Technical Support - your school technician may know how to change ink in a printer and even set up a Windows server but would he or she be able to set-up and manage the complexities of Terminal Services?

Are things getting Thinner?

There is some evidence that things are getting thinner through a set of developing technologies which the media is referring to as Web 2.0. Many programs that you would receive on a CDROM and install locally are now available in their entirety on the web. This means that local computers, 'clients', could start requiring less storage for programs. Here are some good examples:

Writely is a free online alternative to Microsoft Word. The program runs straight from your web browser without the need to download anything. It reads Microsoft Word files and stores documents securely with a backup every ten seconds.

Many games and activities suitable for special needs are available on web sites like Priory Woods School .

Like Writely these activities run directly from the websites they are hosted on.