Date: Wed, 07 Nov 2001 08:42:59 -0500 From: "Doug Reynolds" <mav@wastegate.net> To: "Bill Moran" <wmoran@potentialtech.com>, "questions@freebsd.org" <questions@freebsd.org> Subject: Re: Welders causing dial-out to fail Message-ID: <20011107134346.491EE37B417@hub.freebsd.org>
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On Tue, 06 Nov 2001 12:00:37 -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. probably the quickest solution would be to run a shielded CAT5 or CAT5E cable from the interface / phone terminal to your dialup modem bank for all four lines. and verify that when the inside lines are disconnected , the problem isn't happening. and make sure the shield on the cable is grounded. also, you might be able to put some kinda RFI filter on the welders themselves. --- doug reynolds | the maverick | mav@wastegate.net To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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