Cache Guide
The government has committed to provide all schools with broadband Internet access by 2006. The DfES has also recognised the need to encourage the use of caching (local storage of content) to assist in the efficient use of existing bandwidth within both broadband and non-broadband connected schools (although non-broadband schools will derive greater immediate benefit). Becta has issued the minimum specification to assist schools in their purchase of caching equipment. What is 'caching'?Caching is the technique of storing previously requested data (usually ftp and http web traffic) geographically closer to those who require it. The Internet is rich in caches as they save both time and bandwidth. For example, if an Internet Service Provider has a cache, and one of its customers requests a web page from a US site, the cache will automatically add a copy of this page to its data store as it passes through. If another customer then requests this same web page, it will be delivered directly from the cache, hence saving the delays of requesting and retrieving the data from the original US site. The most efficient form of caching is when data is stored on a cache server installed within your own network. This is particularly successful where Internet controls are also in place to restrict web access to a pre-defined list of web sites, as they could all eventually be cached locally.Why do you need a cache?E-learning packages put an enormous strain on school networks and it is vital that content delivery methods keep pace. Even a 10Mbps connection is insufficient for the simultaneous delivery of the emerging e-learning content to multiple users when a single digital video stream alone could require 1.5Mbps! For e-learning material to be effectively used in schools, it needs to come from a local source that stores the original data in a structured way that enables speedy retrieval and delivery of the content. Once you have a cache, will you notice the difference?Teachers and learners will be able to access cached content in school as they would do when accessing it on the Internet without experiencing download delays. The technology itself is invisible to the end user but provides a marked increase in performance where the bandwidth of a schools Internet connection and/or the number of potential simultaneous users would otherwise make the use of such materials impractical.How do I know if a cache will meet my needs?In order to guide you, Becta has issued a minimum
specification for caching systems (
A couple of important points from this document: What should the cache be able to do?
How big should the cache be?Storage should be sized to offer best performance in line with your requirements
Espresso & Open Cache equipmentEspresso Primary is a very large service, and grows weekly. Local storage is the only viable way of accessing this rich digital media consistently and instantly to simultaneous users across a school network. Espresso is incredibly rich with video, data and interactive elements and therefore requires a dedicated 'cache' on your network to provide users with instant access to this mass of material. When you look at Espresso video or websites, you are not venturing onto the World Wide Web, but are staying within your network. This has the advantage of providing instant access to our videos and web pages.Pre-loaded, ready-to-go!Schools will find it easy to subscribe to Espresso as we are offer the option to buy pre-loaded caches with our video-rich content automatically included. We are working with a variety of hardware companies such as Equiinet on this solution. The Equiinet CachePilot meets and exceeds all the points of Becta's specifications specification. We also work with other cache partners who also meet the specifications. The cache server can be updated weekly with Espresso Content via:
The Equiinet CachePilot includes:
The CP20 Cache includes
You can purchase Espresso pre-loaded on a cache with any of our partners who are all Becta approved and up to specification:
The Espresso ExpertiseWe recognise that the use of cache servers and the specification are new to some LAs and also to other content providers in the marketplace. Espresso has years of experience in installing, configuring and updating caches. We have long believed in the importance of combining broadband and caching, a position that the government and Becta have recently acknowledged and promoted. |
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