Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!uunet!husc6!rutgers!sri-spam!mordor!lll-tis!ames!sdcsvax!ucsdhub!hp-sdd!hplabs!ucbvax!A.ISI.EDU!CERF
From: CERF@A.ISI.EDU
Newsgroups: comp.protocols.tcp-ip
Subject: Re: DSU/CSU units
Message-ID: <[A.ISI.EDU]24-Sep-87.10:16:29.CERF>
Date: Thu, 24-Sep-87 10:16:00 EDT
Article-I.D.: <[A.ISI.EDU]24-Sep-87.10:16:29.CERF>
Posted: Thu Sep 24 10:16:00 1987
Date-Received: Sat, 26-Sep-87 17:04:59 EDT
References: <8709240237.AA02350@monk.proteon.com>
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The ARPA Internet
Lines: 11

In the early days of digital voice, when T1 was invented, I recall
that every 8th bit of each 24 channel sequence (192 bits total) was
a 1 for signalling/sync purposes. That coding gave you only 56 kb/s
of digital information, but avoided any problems with regeneration.

Over time, the need for such signalling went down (after all, 1/8
of each channel was 8 kb/s which is a lot just for signalling).
It sounds as if the coding trinary coding scheme didn't account
for arbitrary data passing through repeaters. Sigh.

Vint