Date: Tue, 16 Jul 1996 09:37:35 +0530 From: A JOSEPH KOSHY <koshy@india.hp.com> To: count@key.hole.fi Cc: davidg@freebsd.org, current@freebsd.org Subject: Re: FreeBSD with 100Mbit ethernet card? Message-ID: <199607160407.AA224560056@fakir.india.hp.com>
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>>>> "c" == "Bror 'Count' Heinola" <count@key.hole.fi>
>>>> "dg" == "David Greenman" <davidg@freebsd.org>
c> Well, when I transfer files from an Ultra 1 with fast ethernet I
c> can 'put' them at over 5Mbytes/sec but when I 'get' them from
c> the BSD box they don't come faster than about 1.5Mbytes/sec.
On 2.1.0-RELEASE:
I noticed this behaviour too when debugging my driver for the HP PC Lan Plus
card. To cut a long story short, I took dumps of the TCP traffic while
transferring a large (2MB) file between machines.
m/c 1 <---------------------------> m/c 2
|
|
v
m/c 3
To cross check I took simultaneous dump from a third machine.
In summary, it seemed that when FreeBSD is the recipient, sometimes
packets are received but acknowledgements aren't sent out i.e. they get `lost'.
This causes a timeout and subsequent slow-start. This behaviour was noticed
when there are lots of packets flowing in, but not when the FreeBSD box was
the sender.
I haven't found time to investigate further yet. Indeed I have to check
if the latest -current has this behaviour.
Koshy
<koshy@india.hp.com> My Personal Opinions Only.
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