From owner-freebsd-questions@FreeBSD.ORG Sat Aug 21 18:18:52 2004 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 83CA816A4CE for ; Sat, 21 Aug 2004 18:18:52 +0000 (GMT) Received: from dan.emsphone.com (dan.emsphone.com [199.67.51.101]) by mx1.FreeBSD.org (Postfix) with ESMTP id 3AD4F43D45 for ; Sat, 21 Aug 2004 18:18:52 +0000 (GMT) (envelope-from dan@dan.emsphone.com) Received: (from dan@localhost) by dan.emsphone.com (8.12.11/8.12.11) id i7LIIpm9030542; Sat, 21 Aug 2004 13:18:51 -0500 (CDT) (envelope-from dan) Date: Sat, 21 Aug 2004 13:18:51 -0500 From: Dan Nelson To: "R. W." Message-ID: <20040821181851.GA18053@dan.emsphone.com> References: <200408211348.29086.list-freebsd-2004@morbius.sent.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200408211348.29086.list-freebsd-2004@morbius.sent.com> X-OS: FreeBSD 5.2-CURRENT X-message-flag: Outlook Error User-Agent: Mutt/1.5.6i cc: freebsd-questions@freebsd.org Subject: Re: Equitable Sharing between TCP Sockets X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 21 Aug 2004 18:18:52 -0000 In the last episode (Aug 21), R. W. said: > I'm using 5.21 on a desktop computer with a dial-up modem. I tend to > have several applications simultaneously sharing the connection, and > I'm finding that this aspect isn't working as well as it does under > windows 98. > > Under windows each tcp socket would tend to receive at about the same > rate, and intermittent, interactive applications would quickly gain > their fair share. Under FreeBSD a couple of sockets at a time tend to > hog most of the bandwidth, and interactive applications get frozen > out. I don't know what Windows is doing right, but I'm guessing it > has some kind collective management of tcp window sizes, probably > tied-in with the slow-start algorithm. It's more likely that Windows 98's 8k TCP window size is the main factor. FreeBSD defaults to 32768 which is way too high for a modem. 5.2.1 does have a dynamic window-scaling algorithm to improve latency, but it only applies to outgoing streams. Try putting these in /etc/sysctl.conf and see if they help: net.inet.tcp.rcvspace=8192 net.inet.tcp.sendspace=8192 -- Dan Nelson dnelson@allantgroup.com