From owner-freebsd-net@FreeBSD.ORG Fri May 19 16:06:41 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 9CF0616A449 for ; Fri, 19 May 2006 16:06:41 +0000 (UTC) (envelope-from smithi@nimnet.asn.au) Received: from gaia.nimnet.asn.au (nimbin.lnk.telstra.net [139.130.45.143]) by mx1.FreeBSD.org (Postfix) with ESMTP id F0E0043D64 for ; Fri, 19 May 2006 16:06:34 +0000 (GMT) (envelope-from smithi@nimnet.asn.au) Received: from localhost (smithi@localhost) by gaia.nimnet.asn.au (8.8.8/8.8.8R1.4) with SMTP id CAA17202; Sat, 20 May 2006 02:06:22 +1000 (EST) (envelope-from smithi@nimnet.asn.au) Date: Sat, 20 May 2006 02:06:21 +1000 (EST) From: Ian Smith To: Mike Tancsa In-Reply-To: <6.2.3.4.0.20060519110026.05820230@64.7.153.2> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: freebsd-net@freebsd.org 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 16:06:41 -0000 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 .. > The application is low bandwidth, but doesnt deal that well with > packet loss and the phone lines in these remote locations tend to be > noisy and drop connections frequently. If by 'drop connections' you mean physical loss of line / carrier, then tuning the modem/s to be (preferably much) less aggressive about forcing the modem connection rate high - ie being easily satisfied to drop back to lower rates during hard times - has helped a lot with a dozen or so remote spots hereaboots. Finding the knobs for some modems can be hard. Assuming that V.42 error correction is working properly - forced if need be - there shouldn't =be= any data loss, however slow getting through, this side of protocol timeouts of course. I can't guess your mystery application, but often slower connections are better than dropped ones, or even ones that spend half their time trying to retrain at high rates. cheers, Ian