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Re: How bandwidth requirement could be reduced when using thin clients?

Knut Yrvin wrote:

Great. I'll quote from the documentation by Dr A V Le Blanc at the Manchester Computing University of Manchester. I'we read the documents from the link. It's some difference between Blancs recomendations, and ours. We want to use PXE-boot or etherbooth with no local disk on the thin client to reduce the point of failure, and exclude the need for a bootloader at the local machine. Our mandate is not a dual system solution. It's Skolelinux only.

Only Linux would be nice to have, but A) The teachers would lynch me and B) Despite they develpment work we carried out on WINE for the dual boot , theres still far to many national curriculum approved packages that only work within windows. Even the schools webbased management system requires IE, despite the fixes it needs to work with other browsers would take less that a weeks work. It'll be at least 3 years before we can defenestrate the school.

Network booting creates its own set of problems of course, last year we deployed a WAN connecting all the schools in manchester to supply them with internet access. Using a 10Mb link and a linux based cache/proxy + filter in every school we were utlilising even at peak times about 20% total bandwidth and started talking about a centralised LDAP authentication server. At which point the backbone providers main exchange caught fire crippling 3/4 of the network, and pretty much stopped that idea in its tracks.

If you face a similar situation, then instead of just crippling internet access, the computers themselves would become useless, unless of course there was a local server. By having even a small amount of local drive space, say a 16Mb CF card you can provide further redundancy.

It's also a requirement to tackle 2-8 Mbps bandwidth between the schools and a central server-farm. In my experience an university often has at least 10 or 100 Mbps between buildings. It's not posible to increase the bandwidth to 10 or 100 Mbps in the near future.

IIRC When I tried to break Owens test room, it was 30 machines on 10Mb's and they all handled opening open office at the same time without difficulty. I can provide you with Owens email if its not on the presentation and your interested in harder numbers.

The last and least requirement is that the solution can't have any licencing cost.

Thats purely a requirement at the university as its being deployed across several public clusters in addition to science and engineering labs.


On two occasions I have been asked [by members of Parliament], 'Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?' I am not able rightly to apprehend the kind of confusion of ideas that could provoke such a question.

Charles Babbage

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