From owner-freebsd-net Mon Nov 4 10:22:50 2002 Delivered-To: freebsd-net@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 4C7F837B401 for ; Mon, 4 Nov 2002 10:22:49 -0800 (PST) Received: from sheffield.cnchost.com (sheffield.concentric.net [207.155.252.12]) by mx1.FreeBSD.org (Postfix) with ESMTP id 7671543E42 for ; Mon, 4 Nov 2002 10:22:48 -0800 (PST) (envelope-from bakul@bitblocks.com) Received: from bitblocks.com (adsl-209-204-185-216.sonic.net [209.204.185.216]) by sheffield.cnchost.com id NAA21028; Mon, 4 Nov 2002 13:22:45 -0500 (EST) [ConcentricHost SMTP Relay 1.15] Message-ID: <200211041822.NAA21028@sheffield.cnchost.com> To: Fran.Lawas-Grodek@grc.nasa.gov Cc: Cindy.Tran@grc.nasa.gov, freebsd-net@FreeBSD.ORG, Mark.Allman@grc.nasa.gov Subject: Re: Problem in High Speed and Long Delay with FreeBSD In-reply-to: Your message of "Fri, 01 Nov 2002 11:20:01 EST." <20021101112001.E3259@grc.nasa.gov> Date: Mon, 04 Nov 2002 10:22:44 -0800 From: Bakul Shah Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org > Your suggestion of increasing the -l seems to have made a positive > impact -- tests this morning with a higher buffer length size of 8192 > gave us a better throughput of 44Mbps. Now the time sequence plot > shows a window usage of 1.5MB as opposed to the previous 1MB usage. > > We still don't understand as to why we are not getting a larger > window usage when we are requesting a 3MB socket buffer. (BTW, > a typo in my example testing commands, left out a "0" in the > "-b".) Since *something* is making a difference, you may wish to try changing one independent parameter at a time. For instance, do you get different throughput numbers with -l = 16k, 32k, and so on? What is the limit? You will want to decrease the -n parameter correspondingly so as to not keep waiting longer and longer! Similarly try changing other limits one at a time. If you can, try to use the *same* non-FreeBSD machine at one end and characterize send and recv performance of FreeBSD separately. This ought to help you figure out where the bottleneck may be. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message