Date: Tue, 6 Nov 2001 12:54:57 -0500 From: Michael Lucas <mwlucas@blackhelicopters.org> To: Bill Moran <wmoran@potentialtech.com> Cc: questions@FreeBSD.ORG Subject: Re: Welders causing dial-out to fail Message-ID: <20011106125456.A96442@blackhelicopters.org> In-Reply-To: <3BE81735.7020302@potentialtech.com>; from wmoran@potentialtech.com on Tue, Nov 06, 2001 at 12:00:37PM -0500 References: <3BE81735.7020302@potentialtech.com>
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Actually, I've been there. Sort of. Heavy electrical equipment can play utter hell on badly-shielded data lines. Voice and data use very different frequencies; interference that can destroy can leave the other untouched. I hear everyone bellowing "An analog modem is very different than a data line!" I would not be surprised if something like this was happening there. And people kind of expect faxes to look lousy. :) You might seriously look at the phone line you're using; run a shielded phone line and see if your problem goes away. On Tue, Nov 06, 2001 at 12:00:37PM -0500, Bill Moran wrote: > This may be a little off-topic ... > I have a client who I installed a FreeBSD proxy server for. > It uses pppd to dial out on demand. Right from the start, the > client has been having problems with the reliability of the > dial-out. To make a long story short, after a lot of testing > and speculating, we determined that its electric welders in the > shop causing the problem. There are five resistance welders in > the shop and when all five are working, the Internet connection > is simply unusable. If two or three are in use, the Internet > is slow, the connection drops a lot and has to dial 2 or 3 times > to get a connection. If nobody is welding, the Interenet > connection works perfectly. > The interference exists on all 4 phone lines, it's audable at > times on the voice lines (but never very bad) and has never > been bad enough to disrupt the fax machine. > We had the phone company (Verizon) come in and they basically > said, "Our wiring isn't the problem, you may want to have this > building rewired." > Does anyone have any experience with this kind of thing? Rewiring > the building is pretty much cost-prohibitive. Verizon did install > a noise filter at their junction box, but the improvement is very > minimal. > We're searching a few avenues for a solution, one being the > manufacturers of the welding machines, but I thought I'd put the > question out to this list and see if anyone else has worked through > and found a solution for a problem like this. > > TIA > -- > Bill Moran > Potential Technology > http://www.potentialtech.com > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-questions" in the body of the message -- Michael Lucas mwlucas@blackhelicopters.org http://www.blackhelicopters.org/~mwlucas/ Big Scary Daemons: http://www.oreillynet.com/pub/q/Big_Scary_Daemons To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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