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)