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Date:      Fri, 11 Apr 2003 18:42:57 +0200
From:      Borje Josefsson <bj@dc.luth.se>
To:        Terry Lambert <tlambert2@mindspring.com>
Cc:        David Gilbert <dgilbert@velocet.ca>
Subject:   Re: tcp_output starving -- is due to mbuf get delay? 
Message-ID:  <200304111642.h3BGgwKl087226@dc.luth.se>
In-Reply-To: Your message of Fri, 11 Apr 2003 09:32:51 PDT. <3E96EE33.FAF4FABB@mindspring.com> 

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On Fri, 11 Apr 2003 09:32:51 PDT Terry Lambert wrote:

> Borje Josefsson wrote:
> > > A good thing to look at at this point would be:
> > >
> > >       o       Clean boot of FreeBSD target
> > >       o       Run NetBSD against it
> > >       o       Save statistics
> > =

> > What type of statistics do You mean?
> =

> Dropped packets; frags; delayed acks.  The stuff you get from
> "netstat -s" and "netstat -m".
> =

> > > You mean "bandwidth delay product".  Yes, assuming you have packet
> > > loss.  From your description of your setup, packet loss should not
> > > be possible, so we can discount it as a factor.
> > =

> > Of cause packet loss is possible on a nationwide network. If I loose =
a
> > packet on the (expected) 10 second test (with NetBSD), recovering fro=
m
> > that drops performance from 900+ to ~550 Mbps. Thos shows very clearl=
y if
> > I run "netstat 1".
> =

> You are running these tests over .se's nationwide network?

One of them, I'm using GigaSunet, the nationwide network for the =

universities in Sweden. 10 Gbps to 22 cities, connecting 35 universities =

with 2,5G (redundant). This not a "research network" per se, it's the =

"production" network for the universities. If I suceeed with this, the =

next challenge (no kidding) is to try the same thing over the commodity =

Internet from here to California (or sonething similar), showing that You=
 =

don't need a "private" network for high speed communication if You do =

things right. After that I've thought of testing against Japan or New =

Zealand, which is about as far You can get from here :-)

--B=F6rje




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