From owner-freebsd-net@FreeBSD.ORG Fri May 19 19:32:23 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 87DE816A422 for ; Fri, 19 May 2006 19:32:23 +0000 (UTC) (envelope-from cswiger@mac.com) Received: from pi.codefab.com (pi.codefab.com [199.103.21.227]) by mx1.FreeBSD.org (Postfix) with ESMTP id 938F743D45 for ; Fri, 19 May 2006 19:32:22 +0000 (GMT) (envelope-from cswiger@mac.com) Received: from localhost (localhost [127.0.0.1]) by pi.codefab.com (Postfix) with ESMTP id 643B45F7A; Fri, 19 May 2006 15:32:21 -0400 (EDT) X-Virus-Scanned: amavisd-new at codefab.com Received: from pi.codefab.com ([127.0.0.1]) by localhost (pi.codefab.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id zrtG4yUfU0bw; Fri, 19 May 2006 15:32:20 -0400 (EDT) Received: from [192.168.1.251] (pool-68-160-242-211.ny325.east.verizon.net [68.160.242.211]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by pi.codefab.com (Postfix) with ESMTP id 355C55DAC; Fri, 19 May 2006 15:32:20 -0400 (EDT) Message-ID: <446E1D41.9070301@mac.com> Date: Fri, 19 May 2006 15:32:17 -0400 From: Chuck Swiger User-Agent: Thunderbird 1.5.0.2 (Windows/20060308) MIME-Version: 1.0 To: freebsd-net@freebsd.org References: <446E1868.8020704@elischer.org> In-Reply-To: <446E1868.8020704@elischer.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Mike Tancsa Subject: Re: improving transport over lossy links ? 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, 19 May 2006 19:32:24 -0000 Julian Elischer wrote: > Ian Smith wrote: >> On Fri, 19 May 2006 at 11:06:48 -0400, Mike Tancsa wrote: >> >> I am looking for a way to improve the reliability of a lossy link >> (dialup from remote sites). I am going to try multilink PPP but was >> wondering if something like ng_one2many might work as well ? Does >> anyone have any suggestions for avenues to explore ? For multilink >> ppp, does mpd offer any better performance / reliability over the >> stock ppp ? >> >> No idea whether these options may help, but .. > mpd does well, bit keep the mtu on the interface relatively small if > you have a lot of line noise. > I have not tried ppp with multilink. Agreed. If you can live with doing so, using an MTU of around 512 worked pretty well back in the days that I was using a 19200 baud DOV (data over voice modem) that tended to experience line noise & hence packet drops when you got an incoming voice call; if you've got a high-noise environment, well, that would be similar. Of course, you should make sure that obvious fixes like replacing phone cabling or re-punching down the phone lines at your demarc (assuming you have 66 or 110 blocks) doesn't help. -- -Chuck