Xref: utzoo comp.unix.i386:3187 comp.dcom.modems:5329
Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!uwm.edu!mailrus!cornell!uw-beaver!uw-entropy!dataio!shiloh!rwing!pat
From: pat@rwing.UUCP (Pat Myrto {rwing})
Newsgroups: comp.unix.i386,comp.dcom.modems
Subject: Re: uugetty under ISC 2.02
Summary: uugetty <--> modem deadly embrace
Keywords: uugetty
Message-ID: <1074@rwing.UUCP>
Date: 26 Feb 90 19:00:26 GMT
References: <1008@iitwest.iit.edu>
Organization: Very Little Organization, Seattle WA
Lines: 28

In article <1008@iitwest.iit.edu>, vrona@iitwest.iit.edu (Dave Veona) writes:
> 
> I am having a problem with uugetty under ISC UNIX 2.02.  Once in a while
> the transmit and receive lights on my modem glow continuously.  To quote
> someone in this newsgroup, "the computer is having a shouting match with
> the modem".  

The shouting match you see can be a noise burst, such as from a
dropped carrier, going into uugetty, which echos the chars back (as
when logging in).  The modem, in turn echos these chars back to
uugetty, forming a closed loop.   You probably notice the system
response slowing down, possibly to a crawl when this goes on, and
sometimes can result in a panic crash with some systems.

The fix is to have command echo OFF on the modem (ATE0).  This means
in the Dialers chat scripts, echo checking must not be turned on,
since, of course, it will fail.  Just configure the modem to reset
with command echo off (include ATE0 in the commands given before you
store the setup in EEPROM).  In my experience with modern modems, echo
checking is not needed, so command echo serves no useful purpose - it
just permits the 'deadly embrace' you describe to occur.

Hope this helps....
-- 
pat@rwing                                       (Pat Myrto),  Seattle, WA
                            ...!uunet!pilchuck!rwing!pat
      ...!uw-beaver!uw-entropy!dataio!/
WISDOM:    "Travelling unarmed is like boating without a life jacket"