Can P2P applications learn to play fair on networks?

Mon Oct 29 01:07:13 UTC 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