mae-west congestion

Thu Mar 21 23:24:17 UTC 1996

> Date: Thu, 21 Mar 1996 13:48:40 -0800 (PST)
> From: matthew at scruz.net (Matthew Kaufman)
> 
> 
> If you take a look at http://ext2.mfsdatanet.com/MAE/west.ames.overlay.html
> you find that the Ames FDDI ring is totally saturated. Now, that means that
> anyone who's trading traffic over on that side, or between Ames and San Jose,
> is getting really really lousy performance.
> 
> What I don't understand is why that has _stayed_ saturated... it seems to me
> that some of the big players would have rerouted their traffic by now to avoid
> subjecting it to this, which would also have the side effect of causing the
> problem to, at least for the short term, go away.

We, too, have notices the problem, although we mostly see it in
packets bound for the MFD ring. Pings to other Ames peers seem to do
fine.

This started abruptly on about March 7th and has been consistently bad
since then. That is about the time BBN Planet started routing
everything there via AS1, but I have no idea of this is a significant
part of the problem. FWIW, MFS blames the load on the GIGAswitch,
although I don't see this indicated in the plots. They didn't give us
any estimate for improving the situation.

R. Kevin Oberman
Energy Sciences Network (ESnet)
National Energy Research Supercomputer Center (NERSC)
EMAIL: oberman at es.net		Phone: +1 510 422-6955