Path: utzoo!dciem!nrcaer!scs!spl1!laidbak!att!pacbell!ames!mailrus!tut.cis.ohio-state.edu!bloom-beacon!XEROX.COM!Thompson.PA From: Thompson.PA@XEROX.COM Newsgroups: comp.dcom.telecom Subject: Re: TELECOM Digest V8 #88 Message-ID: <880601-154524-5927@Xerox> Date: 1 Jun 88 22:44:52 GMT Article-I.D.: Xerox.880601-154524-5927 Sender: daemon@bloom-beacon.MIT.EDU Organization: The Internet Lines: 24 Approved: telecom@xx.lcs.mit.edu Re: ---------------------------------------------------------------- >Subject: Three wire lines (was 2 line wiring) >Date: 27 May 88 23:48:21 GMT >Reply-To: mdf@tut.cis.osu-state.edu (Mark D. Freeman) >My house was built in the 1920's and was wired for telephone with 3 >wires. I can understand two or four, but three? Why? The three wire are TIP, RING and GROUND (or SLEEVE in the CO). In a residence phone with multi-party service it was used to split the ringing circuit. For two party service they would ring from either TIP or RING to GROUND. The conversation took place across TIP and RING. Geoff Geoffrey O. Thompson Xerox Corporation 475 Oakmead Parkway Sunnyvale, CA 94086 U.S.A Telephone: (408) 737-4690 ARPA Mail: Thompson.OSBUNorth@Xerox.COM