From owner-freebsd-hackers@FreeBSD.ORG Wed Jul 9 12:24:40 2003 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 125DF37B401 for ; Wed, 9 Jul 2003 12:24:40 -0700 (PDT) Received: from Chow.corp.media.net (rottie.media.net [66.113.65.4]) by mx1.FreeBSD.org (Postfix) with ESMTP id 6932F43FAF for ; Wed, 9 Jul 2003 12:24:39 -0700 (PDT) (envelope-from max.clark@media.net) Received: from MCLARK (76.0.6.10.IN-ADDR.ARPA [10.6.0.76]) by Chow.corp.media.net (Netscape Messaging Server 4.15) with SMTP id HHRV2800.LCN; Wed, 9 Jul 2003 12:20:32 -0700 From: "Max Clark" To: "Dan Nelson" Date: Wed, 9 Jul 2003 12:29:04 -0700 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2911.0) In-Reply-To: <20030709190214.GL39506@dan.emsphone.com> X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 Importance: Normal cc: freebsd-hackers@freebsd.org Subject: RE: What ever happened with this? "eXperimental bandwidth delay product code" X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 09 Jul 2003 19:24:40 -0000 > 6000000/8*.220 = 165Kbytes or 1.32Mbit/s I understand the BDP concept and the calculation to then generate the tcp window sizes. What I don't understand is this... How in the world is a windows 2000 box running commercial software able to push this link to 625KByte/s (5Mbit/s)???? How can I get similar results with FreeBSD? I don't care about any other traffic on the network at the same time as my transfer, just the raw performance of my transfer. Thanks, Max -----Original Message----- From: Dan Nelson [mailto:dnelson@allantgroup.com] Sent: Wednesday, July 09, 2003 12:02 PM To: Max Clark Cc: freebsd-hackers@freebsd.org Subject: Re: What ever happened with this? "eXperimental bandwidth delay product code" In the last episode (Jul 09), Max Clark said: > When you say it's got a specific purpose, I am looking for something > that will dynamically tune a 6Mbit/s, 220ms network link for bulk > (500MB) file transfers. Is this what I think it is, or should I be > looking at something else? Unless you're doing multiple simultaneous TCP connections it'll only slow you down. Your bw*delay product is 6000000/8*.220 = 165Kbytes, so telling ncftp to set its so-bufsize to say 200K, and telling your ftp daemon to do the same thing, should be all you need. -- Dan Nelson dnelson@allantgroup.com