At around 15:00 today, the web-based quota system will be changed slightly. Logically, the system will remain the same -- you'll have the same (if not slightly higher) quotas, and the system will operate over the same fourteen day floating window.
What is changing is the implementation specifics. Instead of being calculated at 23:30 each night, quota totals will now be calculated hourly. This has the effect of reducing the "grace" period between the time you go over quota and the time you're denied access from 24 hours to just over an hour. In addition, traffic information from all of the University's caching proxy servers will be incorporated in the quota calculations, rather than the current calculate-and-merge approach. This means that the traffic totals you see at http://www.ru.ac.za/quota/ and http://www.ru.ac.za/systems/quotas/ will now more accurately reflect the amount of billable traffic you generate.
This change is necessitated by the large number of people who've been abusing the previous system, which has lead to Rhodes' international link becoming saturated.
Most users shouldn't notice the changes. They will by and large only affect those people who've already been downloading things excessively. The block lists set to come into effect with the new system are slightly longer than the current ones due to the fact that they now contain data from both proxy servers. This means that a few people who've been quietly spreading their traffic over both servers will now find their access denied.
Any bookmarks refering to the existing quota information at http://www.ru.ac.za/systems/quotas/ should be updated to reflect the new data available.