[unisog] Posting of Bandwidth Hogs

Rich Graves rcgraves at brandeis.edu
Sat Oct 12 18:08:12 GMT 2002

The identity of the top N users is definitely private (in fact I take steps
to hide identities from me until they're identified as a persistent
violator) but the proportion of traffic used by the unnamed top 10 and top
50 users is posted hourly at http://netinfo.unet.brandeis.edu/

The transparency of the anonymized statistics legitimizes our policies and
helps a little on the peer pressure/shame front.

We don't tell violators their "rank" to avoid nitpicking and perverse
incentives to compete/cheat. We *do* tell them "You are using X times more
bandwidth than the average user" to stress the fact that we're all in this

Our (average + 3 standard deviations) threshold typically works out to
around 11 times average, with the top 5 users at 30 times average. We send
warnings to between 30 and 50 students exceeding this threshold every
Monday. Three Mondays in a row, they lose off-campus port != 80
connectivity for a week. 50 times average sustained for more than 2 days is
considered a DoS and gets acted on immediately. Longer-term averages and
ARP changes are recorded to find students trying to work the rules, but we
don't see much of that -- it's pretty clear to most students that they'd be
stealing from their friends, not from us faceless bureaucrats.

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