Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.1 (Tek) 9/26/83; site hammer.UUCP
Path: utzoo!watmath!clyde!burl!ulysses!mhuxj!houxm!hogpc!houti!ariel!vax135!cornell!uw-beaver!tektronix!orca!hammer!steveg
From: steveg@hammer.UUCP
Newsgroups: net.followup
Subject: Re: Telecomm rates?
Message-ID: <954@hammer.UUCP>
Date: Sat, 6-Oct-84 21:20:33 EDT
Article-I.D.: hammer.954
Posted: Sat Oct  6 21:20:33 1984
Date-Received: Mon, 8-Oct-84 03:29:49 EDT
References: <3791@decwrl.UUCP> <649@hound.UUCP>
Organization: Tektronix, Wilsonville OR
Lines: 7

There is a thing on most phone lines (particularly long distance
trunks) called an echo supressor.  Part of the 103/212/VA3400 modem
protocols is a magic tone to disable these beasties as they alter the
signal and echos aren't a big problem in full duplex modems anyway
(transmitting and receiving use different frequencies).

Steve Glaser (tektronix!steveg)