Sally Hadland, talks about the lack of bandwidth in Europe; current policies on charging for it and how institutions can take steps to make best use of what bandwidth they have by caching and using mirror sites. Also described is how using HENSA's mirror sites can help save on transatlantic bandwidth.
Bandwidth in Europe or lack of it is an issue much discussed amongst many institutions at the moment. Recent comparisons by Internet Service Providers have noted that bandwidth is more expensive in Europe and depending on the country, can cost five to ten times as much as it does in the United States. Coupled with this problem is the increasingly slow link to the US from European countries. In light of these issues, it has been identified by many institutions that measures need to be taken to make best use of the already allocated bandwidth.
One way of doing this is to set your browser to find a cached copy of the document, software or web site that you require. The National Janet Web Caching Service (JWCS) in the UK has been set up to support UK academic institutions and provide a caching centre for them. There are also several European projects based on web caching. The TERENA Task Force on WWW Cache Coordination has set up a project in collaboration with the JWCS to look at the impact of caches on networks. The DESIRE project is setting up a network of web caches to serve not only local and national users but also international users.
It is important for all European institutions to think about any way that they can not only save bandwidth but save money. This was made even more of an urgent issue for UK universities when the implementation of charging for transatlantic bandwidth began on August 1st. Universities have had to reorganise their policy on Internet use and think about ways that they can save money whilst still providing the resources that students and lecturers need. The charging for all incoming traffic through the transatlantic gateway means that costs will be incurred when getting information from not just North American sites but almost all overseas destinations outside Europe.
For the most part, this year won't be too much of a strain on the pocket. It has been stated that the JWCS is free in the first year and the Higher Education Funding Councils are subsidising usage for Higher Education Institutions up to an extent. But next year when the Cache could be a charging service and the subsidy disappears it will be a different matter altogether.
This year universities in the UK have been given the time they need to set in motion any plans for saving money before they are faced with the more realistic bill next year. Some universities will be setting up local caches to process requests before they go to the JWCS. This will mean their users will have two chances to find a locally stored copy of the information or web page they need before making the trip through the transatlantic gateway.
Many of the measures recently publicised to better use bandwidth have been in the realm of caching and not much about the importance of mirror sites has really been heard. Using mirror sites is the other way of saving money and bandwidth by going directly to sources in the UK that copy or 'mirror' the information that you need.
A mirror site is a site that copies or 'mirrors' another site. This means that the mirror site holds a complete up-to-date copy of a site but can be located in a different part of the world. Accessing the mirror site saves time online and saves bandwidth as the user may access a mirror site in the UK but the originating site could be in the US. Mirrors also hold information that can't be cached and can offer valuable additional services such as searching.
HENSA is the UK's higher education mirror site funded by the Joint Information Systems Committee (JISC) of the UK Higher Education Funding Councils. Though targeted at universities and research institutions within the UK, access is currently available to all-comers free of charge. The information is mirrored overnight at the low peak time so up-to-date mirrors are available from all over the world.
HENSA holds software and other data, which notoriously takes a long time to download from sites abroad. By downloading software using the HENSA site you are saving money as HENSA is a free service and there is no need to use the transatlantic link. Just as important, you are saving your time as HENSA's network of several servers ensure a faster download. HENSA holds over 80 mirrors of software, data and information. The platforms supported are Windows 3.11, 95/98 and NT, Apple Macintosh, Acorn Archimedes, Palmtops and the Unix platform including Solaris, SunOS and Unix clones for PCs such as Linux and FreeBSD.
HENSA doesn't always just replicate the mirror but tries to provide a more user-friendly interface to the sometimes unintuitive ftp file structure of a mirror. Users have the opportunity to open .zip, .tar and self unpacking .exe files and look inside and retrieve any information files that may help them to decide whether it is the program they require, before downloading. The HENSA search engine has been developed in-house so it is tailored specifically to the way the collections are organised. This is so the maximum information and matching results are returned. HENSA also provides help to users in the form of userguides on-line and an email and telephone helpline.
Among the many HENSA mirrors are Netscape, Microsoft, TUCOWS, Adobe, 3Com, Gnu, Apache, Linux, and FreeBSD. Other non-software collections include the Classical Midi Archives, the Uunet archive and Request for Comment documents. HENSA provides information and software from browsers and programming tools to database programs, screensavers and other subject based academic software. The academic subject software section is produced in collaboration with the Computers in Teaching Initiative (CTI) subject centres.
Figure 1: HENSA: Software Collections by Mirror |
It is clear that importance is going to increase for bandwidth saving tools as the problem of transatlantic bandwith is only going to become more of an issue. Local caches will become more widespread and use of them encouraged. Using mirror sites will be essential for saving bandwidth costs and time online. In the meantime HENSA will continue to provide a free, up-to-date collection of mirror sites.
If you have any comments on this article, please contact the editors (exploit-editor@ukoln.ac.uk).
Sally graduated from Liverpool John Moores University in 1993 with BA
(Hons) in Librarianship and Information Studies. She went on to work as an
Information Officer at the National Council for Educational Technology
(NCET), now BECTa and later as Internet Development Officer with
responsibility for the NCET Website. She has worked as the HENSA
Information Officer since July 1997 and is responsible for helpdesk and
user support, development of on-line and printed publicity materials, the
acquisition of mirror sites, and liason with other services.
For citation purposes:
Sally Hadland, "Look in the Mirror for Bandwidth Savings," Exploit Interactive, issue 1, 10 April 1999
URL: <http://www.exploit-lib.org/issue1/hensa/>
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