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Posting-Version: version B 2.10.1 ggr 02/21/84; site edsel.UUCP
Path: utzoo!watmath!clyde!burl!mgnetp!ihnp4!cbosgd!cbdkc1!desoto!edsel!rib
From: rib@edsel.UUCP (RI Block)
Newsgroups: net.dcom
Subject: Re: UUUUUUUUUUUUUUUUUUUU
Message-ID: <242@edsel.UUCP>
Date: Wed, 16-May-84 22:27:12 EDT
Article-I.D.: edsel.242
Posted: Wed May 16 22:27:12 1984
Date-Received: Thu, 17-May-84 23:29:31 EDT
References: <4644@amd70.UUCP> <1293@pegasus.UUCP>
Organization: AT&T Bell Laboratories, Piscataway
Lines: 8


	The UUUUU's are the test pattern coming out of the 212A at the other end.
	Some sorts of "line noise" cause the automatic loopback test mode to
	be entered.  If you see the UUUU's, it is not your modem doing it.

Not always so. Host systems which echo what is received (like UNIX)
will cheerfully feed you back a stream of UUUUUU's that your modem might
be sending. I recall (but I don't know from where) seeing a report of
a "crash" analysis showing all the clists filled with U's.