XS Server Services

These are services that the School server will provide. Additional services under consideration for deployment are listed separately.

Please help by adding links to existing pages discussing these topics, if you are aware of them

Library

Are any books (digital documents) downloaded to the laptops, or is most content accessed from the School server?

Caching

How much of the library is local and how much is simply a cache of a larger regional/country library ? Can a transparent HTTP cache applied to a centralized library server provide the desired user experience (quick access to common books and access to a large catalog of books)?

Traditional Media

What is mechanism for user submissions of traditional (static) media to the library? The centralized library will probably have a human-filtered request mechanism. What about the local library? Will teachers (and students) have a place to put resources they create where all can retrieve?

Collaborative and Dynamic Media

What about local wikis? Should they be supported on the School server? To some extent, a Wiki may be used as the means for uploading and cataloging static media local to the school library.

Network Router

The School server is first and foremost a node in the wireless mesh which provides connectivity to the larger internet.

A starting assumption is that it is largely a transparent router. It does not perform any network address translation, and very little packet filtering. It will perform bandwidth shaping to ensure fair access to the internet.

HTTP Caching

The only packet filtering proposed is a transparent proxy on port 80, which will allow a caching of commonly accessed HTTP (web) content to occur locally. This will reduce the load on the internet connection, as well as the response time seen by a user. This may be relied upon to implement the School library.

Name Resolution and Service Discovery

The School server will use and support the use of [Zeroconf] techniques for device name declaration and service discovery.

Should it also support traditional DNS (exporting the mDNS names)?

Bandwidth Fairness

The School server should implement a bandwidth fairness algorithm which prevents a single user from dominating the use of the internet connection. The problem is that the short-term fairness algorithms used by TCP give P2P software equal consideration as users trying to access a document over the web. By biasing the queueing algorithm based on usage over the past 4 to 24 hours, we can protect the random browser from the heavy downloader.

The problem is that due to our mesh network, we may really be penalizing a remote classroom relayed through a single node.

We could bias the bandwidth allocation based on remote port (e.g. favoring web access to port 80), but this solution seems less than optimal.

Backup

What are the plans for providing additional storage to users of the XO laptops? Is this a backup (sync) or just storage for content `overflowed' from the laptops ? Should the school provide automatic backup of the laptop contents ?