From owner-freebsd-net@FreeBSD.ORG Tue May 23 10:16:26 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 2FDF816A421 for ; Tue, 23 May 2006 10:16:26 +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 6D23E43D46 for ; Tue, 23 May 2006 10:16:24 +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 UAA07940; Tue, 23 May 2006 20:15:36 +1000 (EST) (envelope-from smithi@nimnet.asn.au) Date: Tue, 23 May 2006 20:15:35 +1000 (EST) From: Ian Smith To: Mike Tancsa In-Reply-To: <6.2.3.4.0.20060521154616.11bd1d60@64.7.153.2> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: freebsd-net@freebsd.org, Brian Candler 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: Tue, 23 May 2006 10:16:26 -0000 Hi Mike, On Sun, 21 May 2006 at 16:03:39 -0400, Mike Tancsa wrote: > Correct. Its always dialing into a terminal server that is connected > via PRIs. Usually Lucent PM3, sometimes Cisco 5800s depending on the > location they dial from. I guess you won't want to be messing with their configs, then .. > > > The internal USR seems to correctly see the carrier drop and PPP > > > hence sees it. However, the 2 external Intels I am experimenting > > > with on the USB serial ports do not. I suspect thats part of the > > > reason the DCD is not working. Perhaps incorrect init string or > > > something with the USB-Serial. Note, I only have the internal USRs > > > deployed in the field right now > > > >Don't know about USB modems. Do USR still use their own chipsets, or > >what? In any case, they're probably highly tunable and well documented. > > Actually, they are just regular external modems connected to USB to > serial adaptors (using the uftdi driver) I had a browse through /sys/dev/usb/{uft,ucom}* but was well out of my depth .. it =looks= like DCD (aka RLSD) changes should be picked up ok; perhaps you're right about some odd init string or such - good luck! > >Not V.90 full tilt, anyway. If 45333 is sort of usual for this one, > >then I'd probably try telling it to connect no higher than maybe 41333 > >or 40000; often about 10-15% or so less than 'normal' can make all the > >difference. If you can afford the bandwidth, go for slow and solid .. > > > Yes, for sure I will try and lower the speeds a bit, but ultimately I > want to deal with situations where the carrier drops and the modem > has to redial. The client is willing to put in an extra phone line > if it would make the link more reliable. Typically these sites are > too remote for other types of transport. I think if I can get mp > working with reliable dcd I think that should do it. Fair enough. Chances of losing two lines at once are pretty small, unless there are district-wide problems, given you get DCD going .. cheers, Ian