Date: Thu, 10 Mar 2005 21:52:50 -0800 From: Luigi Rizzo <rizzo@icir.org> To: jim song <jingmin.song@gmail.com> Cc: freebsd-ipfw@freebsd.org Subject: Re: why my dummynet queue not work? Message-ID: <20050310215250.A65126@xorpc.icir.org> In-Reply-To: <d018391a050310213469df3025@mail.gmail.com>; from jingmin.song@gmail.com on Fri, Mar 11, 2005 at 01:34:10PM %2B0800 References: <d018391a050310200327a01c48@mail.gmail.com> <20050311043933.GA28686@odin.ac.hmc.edu> <d018391a050310213469df3025@mail.gmail.com>
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On Fri, Mar 11, 2005 at 01:34:10PM +0800, jim song wrote: > Brooks, > > Actually I use the freebsd box as an router. I set the tcp window in > another two windows box running iperf (iperf -w 5M). > > Before I add in the pipes, the throughputs could reach 300M, but after > I config in the two pipes(200M bandwidth, 25ms delay), the throughput > degrade to about 5M. but the bandwidth is at most 1 window/RTT, where the window is min(sockbuf_size, TCP_window). With your pipe setting you have 50-100ms RTT, so the above would suggest that your effective window is around 500kbit or roughly 64KBytes. all consistent with an improper window setting luigi > BTW, is there some limitations to tcp connections passing through a > router? > > Thanks, > --Jingmin > > On Thu, 10 Mar 2005 20:39:33 -0800, Brooks Davis > <brooks@one-eyed-alien.net> wrote: > > > > Why are you using the queue parameter at all? If you just want to > > emulate a pipe there is usually no need to do that. Have you adjusted > > your socket buffers in addition to your max TCP window size? > > > > -- Brooks > > > _______________________________________________ > freebsd-ipfw@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-ipfw > To unsubscribe, send any mail to "freebsd-ipfw-unsubscribe@freebsd.org"
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