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Date: Mon, 5 Oct 2009 21:56:32 +0800
From: Eugene Grosbein <eugen@kuzbass.ru>
To: rihad <rihad@mail.ru>
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Cc: freebsd-net@freebsd.org
Subject: Re: dummynet dropping too many packets
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On Mon, Oct 05, 2009 at 05:18:29PM +0500, rihad wrote:

> >You've mentioned previously: "The pipes are fine, each normally having
> >100-120 concurrent consumers (i.e. active users)."
> >This IS competition between TCP flows inside each pipe.
> >
> Well, each user gets instantiated with a new copy of the pipe. Each such 
> user counts towards the limit imposed by hash_size*max_chain_len for 
> that pipe only. It would have been competition had I used dst-ip dst-ip 
> 0xffffff00 or similar and not dst-ip 0xffffffff, _then_ all 256 users 
> (determined by the mask) would compete for the pipe's bandwidth. So the 
> only competition is in the uplink at our main Cisco, I guess.

Hmm, yes, you are rigth. I've missed 'mask'.

Try to disable net.inet.ip.dummynet.io_fast to see if there is a bug
in 'fast' dummynet mode.

Eugene Grosbein