Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version VT2.2 2/15/84; site vortex.UUCP Path: utzoo!watmath!clyde!burl!ulysses!harpo!decvax!vortex!lauren From: lauren@vortex.UUCP (Lauren Weinstein) Newsgroups: net.flame Subject: "half-duplex" phone connections Message-ID: <261@vortex.UUCP> Date: Mon, 27-Feb-84 00:40:15 EST Article-I.D.: vortex.261 Posted: Mon Feb 27 00:40:15 1984 Date-Received: Wed, 22-Feb-84 02:08:22 EST Organization: Vortex Technology, Los Angeles Lines: 16 To the person who was screaming about "half-duplex" phone connections... Look over the archives of the fa.telecom newsgroup. Within the last month I posted a detailed discussion concerning the why's of echo suppression on long-haul toll circuits. There are good reasons why very long circuits are pseudo-half-duplex, and of course equipment can get out of adjustment from time to time and cause problems. New equipment is coming into use that will largely eliminate the need for many blocking echo suppressors, but for now you'd usually be unable to carry on an understandable conversation without them due to hybrid-induced echo effects. The circuits are actually full-duplex -- which is obvious since modems work once they've turned off the echo suppressors with their 2225 Hz. answer tones. --Lauren--