Computing Service Newsletter 236 (April 2008)

Mail, News and Information Services

• Managed Web Server
• Status of Eudora
• Improvements to Hermes
• Withdrawal of old mailing list system
• Changes to the web cache
• Change to Raven
• Athens passwords
• Usability testing
• Streaming Media Service

Managed Web Server [headline article]

In Newsletter 233 (July 2007) we reported that work was proceeding on the upgrade for the Managed Web Server. MWS2 is now in service and we are in the process of migrating sites. Just over half the MWS sites are now on the new server. We are grateful to the webmasters of several sites who have fixed anomalies we have identified in their pages prior to migration, and also to Philosophy's webmaster who helped us solve a CGI/mail-related problem.

The new system is more maintainable and scalable than its predecessor and should last well into the future.

For further information on Managed Web Servers see http://www.cam.ac.uk/cs/instadmin/mws/

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Status of Eudora

Users of Eudora may wish to note that Qualcomm is no longer selling or providing technical support for Eudora. The Paid mode commercial versions of Eudora are no longer available; the Sponsored mode versions of Eudora continue to be available for download. An open source version of Eudora is being developed by Mozilla and will be free of charge.

For more details see http://www.eudora.com/

Improvements to Hermes [headline article]

We have made two significant changes to Hermes over the Easter Vacation.

Multilingual Hermes Webmail

Since it was created, the webmail service has only supported the ISO 8859 Latin-1 (Western European) repertoire of characters. Users who needed support for languages outside that scope had to use an MUA such as Thunderbird or Outlook. In the intervening time UTF-8 has become the standard representation of the universal character set (Unicode) in network applications. The webmail service has been upgraded to use UTF-8 instead of Latin-1, so it now supports many languages including Chinese, Japanese, Greek, Russian, Arabic, Hebrew, etc.

Further increase to Hermes quotas

We have increased the standard storage quota on Hermes to 1GB. Anyone who previously had a quota less than the new limit has been upgraded.

At the same time we have increased the maximum size of an individual message from 25MB to 50MB. This allows for attachments up to about 35MB plus space for the encoding overhead. The message size limit is the same for all Hermes users. You should be aware that many other organizations on the Internet have lower limits than Cambridge, for example, Yahoo! 31MB, GMail 28MB, Hotmail 10MB. This means that while a large message may be handled without problems by our email systems, it may be rejected when they try to transfer it to another organization.

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Withdrawal of old mailing list system

The old mailing list system, managed via the Hermes terminal-based menu system, has now been disabled entirely. Since January the management interface has been disabled, though the lists continued to work. This allowed us to monitor which of the remaining 1975 old-style lists were still in use. Fourteen lists were migrated to Mailman, leaving the rest to be disabled when the old system was turned off. The total number of lists managed by the new web-based Mailman service is over 4800.

Changes to the web cache [headline article]

The current hardware providing the web cache is nearing the end of its expected life. The UCS has considered replacing it, but feels that the needs of the University would be better met by replacing it with a more general service. When the web cache was introduced a decade ago, the University's network capacity was considerably smaller, and the cost to the University of network access was based on the quantity of transatlantic traffic. At that time the web cache reduced the charges significantly and improved browsing speed. Technology has moved on since then. Our network capacity has increased dramatically and much web content is not cacheable with the result that the cache makes very little difference to the University's total traffic or browsing speed. This, together with the increased use of private, CUDN-only IP addresses by the University, has led us to the decision to replace the web cache by a NAT (Network Address Translation) system.

A NAT system will enable machines on the CUDN to access a wider range of Internet services from private, CUDN-only IP addresses. At present, these systems must proxy through the web cache to access the outside world and are limited to web traffic.

The web cache has already been reconfigured so that it no longer caches content, though it continues to provide a proxying service, and the centrally provided configuration files have been modified so that requests from user systems with global IP addresses will go directly to their destination.

The remaining steps currently have no time estimates:

We will implement a NAT system, and further alter the centrally provided configurations so that those with CUDN-only private IP addresses (beginning with 172) are routed via the NAT system. Before finally decommissioning the web cache, we will attempt to contact all users with manually configured browsers still using the web cache (where individually identifiable) or their computing support staff, so that they can update their configurations. Note that "browsers" includes any programs that use HTTP to download material, for example some media players and software update systems.

These changes will provide a better service to users of private CUDN-only IP addresses as described above. Apart from that, they should only affect users who have configured their browsers manually to use the web cache (rather than using the recommended automatic configuration URL at http://www.cam.ac.uk/proxyconfig.pac or WPAD, the "automatic configuration" method supported by some browsers). Users whose browsers do use the recommended automatic configuration URL or WPAD will be handled automatically as we modify those services appropriately.

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Change to Raven

We are proposing to change the default behaviour of Raven when users who have already identified themselves go to another Raven-protected site.

Up to now, the Raven server has been configured by default to ask users before releasing their identity to each site visited. This behaviour makes it difficult to implement web applications that integrate content from multiple Raven-protected servers. We therefore propose to implement a new behaviour and to make this the default. In future, Raven's default behaviour will be to release an already-established identity without further interaction to University web sites (that is, those using URLs containing host names ending cam.ac.uk). For other sites Raven will still require confirmation, to prevent a user's identity being disclosed, without their knowledge or consent, to third-party web sites not operated by the University.

Users will, as at present, be able to select how they actually want Raven to behave (on a session-by-session basis, or by default). They will be able either to select the new behaviour explicitly, to select the old default of asking each time before releasing an identity, to allow their identity to be released to any site without further interaction, or to suppress Raven's 'Single Sign On' functions completely.

The new behaviour will become available during the coming months, and the change to the default behaviour will follow at a later date.

Athens passwords

Users of Athens passwords (for access to University Library electronic resources) are reminded that these will cease to work at the end of July 2008. They are replaced by Raven (supporting the Shibboleth protocol). No new Athens passwords are being issued.

Existing unexpired classic Athens accounts will continue to work until the end of July 2008, but the Library would like to encourage people using such accounts to move to Raven as soon as possible. The transition is simple and means that you need to remember fewer passwords. Further information and guidance is provided at the University Library website at: http://www.lib.cam.ac.uk/electronicresources/athenschanges.html

Usability testing

The Information Provision Group within the Computing Service has been carrying out usability tests for the new University pages. The group is now equipped to carry out similar tests for other sites, and has started to do this on a trial basis, having already done some work for the Fitzwilliam Museum. We envisage this running alongside a redevelopment plan for all or a discrete part of a website.

We have a limited amount of effort we can offer, but anyone within the University interested in having a study carried out for them should contact Helen.Sargan@ucs.cam.ac.uk to discuss it.

Streaming Media Service

Work has started on the next version of the SMS, which will be a fully-supported service, following the current pilot.

The throughput for jobs has been increased six fold since the pilot was launched.

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