Date: Fri, 16 Jun 2006 12:27:35 -0700 From: Darrin Chandler <dwchandler@stilyagin.com> To: "J.D. Bronson" <jbronson@wixb.com> Cc: freebsd-questions@freebsd.org Subject: Re: pf + ftp throughput Message-ID: <20060616192734.GC9804@jeeves.stilyagin.local> In-Reply-To: <7.0.1.0.2.20060616141226.00e743b0@sixcompanies.com> References: <7.0.1.0.2.20060616135513.00e743b0@sixcompanies.com> <20060616191028.GB9804@jeeves.stilyagin.local> <7.0.1.0.2.20060616141226.00e743b0@sixcompanies.com>
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On Fri, Jun 16, 2006 at 02:13:00PM -0500, J.D. Bronson wrote: > At 02:10 PM 6/16/2006, Darrin Chandler wrote: > >On Fri, Jun 16, 2006 at 01:59:01PM -0500, J.D. Bronson wrote: > >> For example...moving a 50MB file: > >> > >> 'keep state' = 11-12MB/sec over 100MB-FDX > >> 'modulate state = 6-7MB/sec over 100MB-FDX > >> > >> ..it took me a while to determine the culprit here - but I am curious > >> as to why this is the case? > > > >Since modulate state substitues its own high quality random sequence for > >the TCP stream in both directions, a wimpy CPU or similar problem could > >easily cause this, I think. Still, I'm surprised to see a 50% hit from > >using modulate state. > > Yes. I am too! > This is a P4-3.06 with 1GB ram...under almost no load...so I cant > fault the CPU this time.... The only two things that come to mind are 1) pf is using a really complex and slow random source, or 2) something is going haywire with the connection. Have your tried tcpdump on either interface (not pflog) to see if anything strange is going on (ACK storms, etc)? Just fishing at this point... -- Darrin Chandler | Phoenix BSD Users Group dwchandler@stilyagin.com | http://bsd.phoenix.az.us/ http://www.stilyagin.com/ |
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