Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!lll-winken!telecom-request From: rees@pisa.citi.umich.edu (Jim Rees) Newsgroups: comp.dcom.telecom Subject: Re: More on Frequency-Selective Ringing Message-ID: Date: 28 Mar 91 17:40:43 GMT Sender: Telecom@eecs.nwu.edu Reply-To: rees@citi.umich.edu (Jim Rees) Organization: University of Michigan IFS Project Lines: 17 Approved: Telecom@eecs.nwu.edu X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@eecs.nwu.edu X-Telecom-Digest: Volume 11, Issue 253, Message 8 of 10 In article , kitty!larry@uunet.uu.net (Larry Lippman) writes: > The [late, great] Bell System philosophy was dead set against > frequency-selective ringing. Using polarity-dependent superimposed > ringing, four unique parties could be signaled. Eight-party lines > used coded ringing, and could be dialed directly since there were SxS > connectors arranged for automatic coded ringing selection. I don't know what our old (Bell System) switch was before it was replaced with a 1A some time in the late '70s, but it had ringback on 491x. Different values of 'x' would give eight different coded rings plus continuous ring. I miss this feature. Our current switch doesn't even have a ringback number that I can find (I've tried all the test prefixes, and located all kinds of tones, battery, terminated-no-battery, and so on, but no ringback).