From owner-freebsd-net@FreeBSD.ORG Fri Aug 25 14:19:30 2006 Return-Path: X-Original-To: freebsd-net@freebsd.org 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 5C83216A4DF for ; Fri, 25 Aug 2006 14:19:30 +0000 (UTC) (envelope-from pete@he.iki.fi) Received: from silver.he.iki.fi (helenius.fi [193.64.42.241]) by mx1.FreeBSD.org (Postfix) with ESMTP id 8E71143D4C for ; Fri, 25 Aug 2006 14:19:28 +0000 (GMT) (envelope-from pete@he.iki.fi) Received: from localhost (localhost [127.0.0.1]) by silver.he.iki.fi (Postfix) with ESMTP id C5993BBFD; Fri, 25 Aug 2006 17:19:25 +0300 (EEST) Received: from silver.he.iki.fi ([127.0.0.1]) by localhost (silver.he.iki.fi [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id u4JpPvoz6Dm6; Fri, 25 Aug 2006 17:19:23 +0300 (EEST) Received: from [IPv6:2001:670:84:0:39bb:8797:1025:e0cd] (unknown [IPv6:2001:670:84:0:39bb:8797:1025:e0cd]) by silver.he.iki.fi (Postfix) with ESMTP; Fri, 25 Aug 2006 17:19:20 +0300 (EEST) Message-ID: <44EF06E9.1070003@he.iki.fi> Date: Fri, 25 Aug 2006 17:19:21 +0300 From: Petri Helenius User-Agent: Thunderbird 1.5.0.5 (Windows/20060719) MIME-Version: 1.0 To: Morgan References: <02df01c6c84c$dcd564c0$4345a8c0@phobos> In-Reply-To: <02df01c6c84c$dcd564c0$4345a8c0@phobos> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-net@freebsd.org Subject: Re: Optimizing a high-latency connection X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 25 Aug 2006 14:19:30 -0000 Increase sendspace an recvspace depending which way your data is going: net.inet.tcp.sendspace: 57344 net.inet.tcp.recvspace: 256000 TCP window scaling is enabled by default nowadays if I remember correctly. Pete Morgan wrote: > Hi. > > I'm trying som file transfers across the globe. The RTT is almost 400ms and > the transfer rate is painfully slow. There are 24 router hops on the path > and I assume most of the problem is there but I wonder if there are any > sysctl variables I can trim on my side to help this problem slightly? I seem > to understand that there need to be an ACK received for at least every other > packet or at least every 100ms for the data flow to proceed uninterrupted > but I'm no expert in this field so please correct me if I'm wrong. Assuming > this IS correct, are there any sysctl variables I can optimize to change > this behaviour or will that affect low latency connections negatively. Any > other suggestions? > > Regards > Morgan > > > _______________________________________________ > freebsd-net@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-net > To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org" > >