Path: utzoo!attcan!uunet!husc6!bloom-beacon!mit-eddie!killer!vector!nobody From: mhw@wittsend.LBP.HARRIS.COM (Michael H. Warfield (Mike)) Newsgroups: comp.dcom.telecom Subject: Re: Tip and Ring reversal Message-ID: Date: 26 Dec 88 21:24:19 GMT Sender: chip@vector.UUCP Lines: 31 Approved: telecom-request@vector.uucp X-Submissions-To: telecom@bu-cs.bu.edu X-Administrivia-To: telecom-request@vector.uucp X-TELECOM-Digest: volume 8, issue 209, message 9 In article john@jetson.UPMA.MD.US writes: > >Hello! I need some help from TELECOM readers. There's a suggestion for >modifying our project's wiring scheme which would result in tip and ring >being reversed for some number of outlets within a house (residential, >single-pair, POTS usage). What kind of problems will this polarity >reversal cause? I've heard that a standard, old electromechanical phone >won't have any trouble, but what about answering machines, modems, and >other devices? Old style "dial" phones won't be affected, however most (if not all) modern electronic phones which derive power for their "dialing" circuits will not be able to call out. Most will be able to answer an incoming call. Phones, attachments, and accessories which use an external power supply or battery (modems, answering machines, speaker phones, memory phones, auto dialers, etc.) should work just fine since they are not "line powered" devices. This is also a word to the wise - if your touch tone phone won't dial the phone but will answer a call then tip and ring may have been reversed on you. Check for someone working on the phone systems. Over the last 10 or 15 years this has happened to me a couple of times. One time the phone man was still on the pole when I discovered the problem. He quickly fixed it and was nice enough to explain to a "technical type like me" what happened. Generally, when they're not caught in the act, your phone will magically start working again but "nobody did anything". --- Michael H. Warfield (The Mad Wizard) | gatech.edu!galbp!wittsend!mhw (404) 270-2123 / 270-2098 | mhw@wittsend.LBP.HARRIS.COM An optimist believes we live in the best of all possible worlds. A pessimist is sure of it!