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Date:      Sun, 7 Nov 2004 11:37:42 +0100
From:      Pawel Malachowski <pawmal-posting@freebsd.lublin.pl>
To:        freebsd-ipfw@freebsd.org
Subject:   Re: Dummynet dynamically assigned bandwidth
Message-ID:  <20041107103742.GA74864@shellma.zin.lublin.pl>
In-Reply-To: <1099822179.652.18.camel@Mobile1.276NET>
References:  <1099819314.652.13.camel@Mobile1.276NET> <20041107094433.GA56141@shellma.zin.lublin.pl> <1099822179.652.18.camel@Mobile1.276NET>

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On Sun, Nov 07, 2004 at 01:09:39PM +0300, Martes Wigglesworth wrote:

> Thanks for the reply, however, I have a subnet with eight clients and
> whenever I have the queued rule enabled, there is a significant latency
> increase, and the queues do not get full access to the pipe. I have done
> tests online, and it is fine for about the first few minutes, however,
> as the other clients use the net, the tests drop from 39KByts/s to like
> 20KByte/s and lower.  The only thing left is that the queues are
> assigning static bandwidth that is not changing in the upward direction.
> Anymore input is welcome.

I'm not sure if this will be source of Your problem, but I'm sure You are
footshooting with default size of pipe and queues, which is 50 slots.

With 128kbit/s (as showed in previous mail, BTW, this is 16KB/s) transmitting
of 50 full size packets (with MTU 1500B) requires:
50*1.5KB/16KBpS = ~4,68 seconds
This will kill TCP throughput.

Try adding something like `queue 5KBytes' parameter both to pipe and queue
definitions.


-- 
Paweł Małachowski



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