From owner-freebsd-net  Tue Oct  3 11:30:11 2000
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Date: Tue, 03 Oct 2000 11:29:01 -0700
From: Julian Elischer <julian@elischer.org>
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To: Garrett Wollman <wollman@khavrinen.lcs.mit.edu>, net@freebsd.org
Subject: Re: SACK in FreeBSD TCP.
References: <39DA1CEE.ADCEA934@elischer.org>
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Garrett Wollman wrote:
>
> <<On Tue, 03 Oct 2000 09:07:34 -0700, Julian Elischer <julian@elischer.org> said:
>
> > In the past I had something to do with some systems that used
> > "vegas-like"
>
> The bug in Vegas was that it broke congestion control.
>
> -GAWollman

check out the first article on this page ..

http://www.cs.inf.ethz.ch/~bolliger/

for an interesting analysis....

Unfortunatly New-reno was not in the comparison,
but your suggestion that Vegas broke congestion control is not
supported. 
Another more relevant reference is the LINUX Vegas page:

http://www.cs.washington.edu/homes/cardwell/linux-vegas/

They have quite a few results there...
Most interesting is the comment that SACK can also produce the same
gain, and that
SACK+Vegas gives littel extra gain. However  for Non-SACK clients,
Vegas can give good results without relying on the client to upgrade..

Also they point out that Vegas is a better net-citizen in that it
tends to use up less buffers in routers in the cloud.

Anyway It looks like there are definitly lots of improvements we can
still make..

-- 
      __--_|\  Julian Elischer
     /       \ julian@elischer.org
    (   OZ    ) World tour 2000
---> X_.---._/  presently in:  Perth
            v


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