From owner-freebsd-hackers  Mon Dec 31 11:40:40 2001
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Date: Mon, 31 Dec 2001 11:40:00 -0800 (PST)
From: Julian Elischer <julian@elischer.org>
To: Matthew Dillon <dillon@apollo.backplane.com>
Cc: Terry Lambert <tlambert2@mindspring.com>,
	Mike Silbersack <silby@silby.com>, Josef Karthauser <joe@tao.org.uk>,
	Tomas Svensson <tsn@gbdev.net>, freebsd-hackers@FreeBSD.ORG
Subject: Re: FreeBSD performing worse than Linux?
In-Reply-To: <200112311927.fBVJR0K21683@apollo.backplane.com>
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the driver should return ENOBUFS
and TCP should repect that.. 
I think it already does in fact..


On Mon, 31 Dec 2001, Matthew Dillon wrote:

> :I'm talking about capping the maximum negotiable window size
> :over the USB adapter...
> :
> :How can this cause problems, since (1) the only thing we are talking
> :about is window size, not packet size (MTU), and (2) the only thing
> :it will effect is the TCP stream post negotiation, so it should not
> :result in a slowdown for any virtual circuit other than those that
> :*NEED* a slowdown?
> :
> :-- Terry
> 
>     If you look at the tcp dump Josef sent, the server was sending 32-byte
>     (data) packets over TCP.  It only took 8 packets or so to blow up the USB
>     adapter.  8x32 = 256 bytes.  So unless you intend to cap the window size
>     at, say, 128 bytes, this will solve the ssh issue but destroy performance
>     for everything else going over the USB ethernet.
> 
> 					-Matt
> 					Matthew Dillon 
> 					<dillon@backplane.com>
> 
> 
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