Date: Fri, 01 Nov 2002 11:08:55 -0800 From: rick norman <rick.norman@lmco.com> To: mallman@grc.nasa.gov Cc: Don Bowman <don@sandvine.com>, "'Fran.Lawas-Grodek@grc.nasa.gov'" <Fran.Lawas-Grodek@grc.nasa.gov>, Luigi Rizzo <rizzo@icir.org>, Cindy.Tran@grc.nasa.gov, freebsd-net@FreeBSD.ORG Subject: Re: Problem in High Speed and Long Delay with FreeBSD Message-ID: <3DC2D147.8357C198@lmco.com> References: <200211011909.OAA63340@guns.lerc.nasa.gov>
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Are you sure you're not hitting the top of the pipe and bouncing around in congestion avoidance ? Unless your window size limits your bw at exactly the correct amount, you'll never get the steady state bw you want. Mark Allman wrote: > > Have you checked that both sides are negotiating SACK? > > No SACK in 4.1. But, there is no loss in th connection. > > > And both sides are negotiating a window scale option sufficiently > > large? (sounds like you need a window scale option of at least 5 > > bits?) > > We're seeing a shift of 6. > > > And the socket-buffer to ttcp is actually being set as large > > as you think? (perhaps run 'ktrace' or 'truss' on ttcp and look > > for an error on the setsockopt). > > We hacked ttcp to run getsockopt() to tell us if the kernel did not > honor our setsockopt() request. All looks fine. > > Thanks! Other ideas? > > allman > > -- > Mark Allman -- BBN/NASA GRC -- http://roland.grc.nasa.gov/~mallman/ > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-net" in the body of the message -- "I'm a-goin' to stay where you sleep all day Where they hung the jerk that invented work In the Big Rock Candy Mountains" wk: 408 742 1619 rick.norman@lmco.com hm: 650 726 0677 rnorman@ikaika.com cell: 650 303 3877 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message
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