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Re: Can P2P applications learn to play fair on networks?

  • From: Sean Donelan
  • Date: Sun Oct 28 21:11:03 2007

On Sun, 28 Oct 2007, Mikael Abrahamsson wrote: 
If you performed a simple Google search, you would have discovered many
universities around the world having similar problems.

The university network engineers are saying adding capacity alone isn't solving their problems.

You're welcome to provide proper technical links. I'm looking for ones that say that 10GE didn't solve their problem, not the ones saying "we upgraded from T3 to OC3 from our campus of 30k student dorms connected with 100/100 and it's still overloaded", because that's just silly.

In the mean time:

http://www.d.umn.edu/itss/resnet/bandwidth.html

   Second, we know based on experience that it won't work just to double
   our bandwidth. It won't work to triple our bandwidth (at triple the
   cost). Based on studies, we'd likely need to increase the bandwidth by
   a factor  of ten or more. And based on our analysis of the traffic that
   is filling the ResNet pipe, we'd be buying that bandwidth to provide
   more access to file-sharing programs, not to meet academic needs.

http://www.educause.edu/ir/library/powerpoint/MAC0402.pps

   Astronomic growth of P2P pegs Resnet bandwidth at whatever cap happens
   to be in place
   Good Users impacted as well as P2P users

http://www.denison.edu/offices/computing/policies/packet_shaping.html
   To make it even more difficult of a challenge, a number of popular
   applications like Kazaa, BitTorrent, and other "peer-to-peer" file
   sharing applications intentionally try to capitalize on all available
   bandwidth the system the software is running on has at its fingertips.
   If our internet traffic was not shaped to ensure equitable use a very
   small number of systems could easily clog our internet connection
   making it unusable.

http://uwadmnweb.uwyo.edu/BENICE/Bandwidth.asp

   TSS decided to up the campus bandwidth from 10 to 30 Mbps. That fall
   all the students returned and for some really strange reason, they ate
   up every bit of the old and new bandwidth. The rest of campus was
   crippled. The ResNetters were filling the 30 Mbps outbound pipe 24
   hours a day, every day.
   [...]
   In December of 2001, TSS implemented a new scheme called
   packet-shaping, which looks at the types of traffic going through and
   only slows the traffic going to and from file-sharing programs.

And of course, if you still believe just adding bandwidth will solve the
problems

ftp://ftp.ee.lbl.gov/papers/congavoid.ps.Z