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Date: Sat, 1 Jul 95 21:11:49 EDT
From: jleppek@suw2k.ess.harris.com (James Leppek)
Message-Id: <9507020111.AA00633@borg.ess.harris.com>
To: freebsd-questions@freefall.cdrom.com
Subject: Re: tcpblast
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Pete,

You may have something there.
if I leave the mtu at 16384 I get a thruput of 2.1 Mbytes/s
but it drops to .1 after a few test. If I change the mtu
to 1500 a get a thruput of 1.3Mbytes/s but no stalls.

Would it be better to change the default mtu for lo0 to a smaller
value as a default??  If I use an mtu of 6000 the thruput is at 2Mbytes/s
with no stalls.

Hmmm is this thread starting to belong in hackers :-)

Jim

> From pete@silver.sms.fi Sat Jul  1 13:45:34 1995
> Date: Sat, 1 Jul 1995 10:40:44 +0300
> From: Petri Helenius <pete@sms.fi>
> To: Jim Leppek <jleppek@harris.com>
> Cc: freebsd-questions@freefall.cdrom.com
> Subject: tcpblast 
> 
> Jim Leppek writes:
>  > I was running the following:
>  > 
>  > tcpblast 127.0.0.1 <some blocks>
>  > 
>  > and got some strange results would anyone care to explain them?
>  > this is on a DX4/100 16Meg, X is running with three idle xterms.
>  > the system is a 2.0.5R, only the test is active, no build worlds 
>  > or anything :-)
>  > 
>  > (the use of my hostname, localhost, or 127.0.0.1 makes no difference)
>  > 
>  > these tests were run in a row, I just "up arrowed" and changed
>  > the number of blocks.
>  > 
>  > The thruput varies greatly, is this normal?
> 
> Would it be possible that because of the large MTU of the loopback-
> interface you are experiencing TCP deadlock?
> 
> Pete
>