Kick out the jams
In the brilliant new world of broadband we read about so often, we are supposed to be a mere mouse-click away from multimedia, streaming video and CD-quality audio. So how come so many of us are left feeling less than impressed by the worldwide wait, rather than the World Wide Web?
The truth is that the sheer volume of traffic on the information superhighway can severely narrow the route to broadband - and schools are finding that having their own cache servers can cut their waiting times.
A cache is a store of information that is designed to improve the accessibility or availability of data. In web terms, a cache is a place where temporary copies of web pages are kept. Caching minimises the number of times identical web objects are transferred from remote websites to a school PC by retaining copies of them in a cache server (essentially a high-capacity PC box).
Subsequent requests for previously cached objects result in the cached copy of the object being returned to the user from the cache store. The result is little or no extra network traffic over the internet link and an increase in the speed of delivery. Teachers and learners can access cached content in the school just as they normally would when accessing it via the internet, but this content is delivered much faster than it would be without the caching system. Another advantage with cached video over streamed video from a website is that when stored locally you can manipulate it and you are not just tied to watching it.
To be 100 per cent effective the cache has to be placed as near to the learner as possible, so it's better for each school to have its own cache device than to provide one upstream somewhere in the local authority or at the internet provider's location. Similarly, within a school's local area network (LAN), the cache needs to sit as near as possible to the internet gateway so that all web requests will pass through it.
"But we've got broadband - why do we need a cache?" I hear you ask. Sadly, the demand for content will ultimately outstrip even the "broadest" broadband connection.
Think of it as being a bit like the development of the M25. Need I say more? As soon as it's open it starts to get clogged up. But caching is more like park-and-ride. Even a 10Mbps connection is insufficient for the simultaneous delivery of e-learning content to many students at a time when a single digital video stream alone could require 1.5Mbps. Caching is the answer.
Caching solutions are available from a number of hardware suppliers who have formed partnerships with software publishers to provide preinstalled content (see box). The schools technology agency Becta has published a minimum specification for the hardware and most of the suppliers actually exceed this by a considerable margin. Without exception, they feature very user-friendly interfaces for setup and maintenance. They all allow you to set how many "layers" deep you want websites to be cached. They are pretty foolproof and deny you outright, should you decide you want to cache the entire internet.
Typically, these cache solutions cost between pound;2,000 and pound;3,000. But before this strikes fear into those in schools that are yet to be equipped with caches, the Government has seen the light and you can now use your e-learning credits to buy both the cache device and the content on board. In the case of Espresso, for example, this can be spread over three years. But, like all things ICT, there is a "total cost of ownership" and the ongoing costs will include updates and regular maintenance.
To avoid the obvious chaos and ultimate management nightmare of every school in the country opting for a different solution, the Government is actively insisting that each local education authority takes the lead here and provides not just advice, but also offers schools a consistent caching policy and a standard hardwarecontent solution that includes an updates and maintenance package. This takes the responsibility off the shoulders of individual schools and places it firmly with the LEA. And rightly so.
Schools are in the business of using all that wonderful content to enhance teaching and learning - not to have the headache of purchasing, maintaining and troubleshooting a caching solution.
Two organisations showing the way forward here are the London Grid for Learning and the Northern Grid for Learning, both of which are actively engaged in deciding what content should be made available, how it can be used and dealing with all maintenance issues. If your school hasn't been offered a cache yet, you should be asking your LEA some serious questions: Where is the cache? What content is to be provided? What is the LEA policy on caching and what are the contractual costs of updates and maintenance? You don't have to do it alone - the LEA is obligated.
For a curriculum destined to become increasingly multi-sensory in delivery, local storage is the only viable way of accessing media-rich, digital content consistently and instantly across a school network. The cache can be configured to act as your gateway to the Web, provide quicker access to any regularly requested website and deliver its materials efficiently to every learner.
Cache Device Suppliers Software partners
Avantis Ltd Granada Learning ContentCache (Primary Zone, Secondary Zone, Just Like School etc)
Atomwide Negotiable between LEA requirements and software publisher(s)
Equiinet Espresso, Immersive (Kar2ouche), Sherston Software, KnowledgeBox, Eazyspeak, 4Learning
Freedom2 Espresso, Big Bus, Actis, Granada Learning
Pearson Broadband Longman, 4Learning, Dorling Kindersley, Puffin, Pelican, Pearson Broadband.
RM plc LEABroadband content, 3rd party content
CACHE IN HAND
Becta's specifications for a cache solution
* Avantis LtdGranada Learning
* Espresso (above)
* Longmans (KnowledgeBox)
* RM plc