Path: utzoo!attcan!uunet!husc6!linus!alliant!steckel
From: steckel@Alliant.COM (Geoff Steckel)
Newsgroups: comp.dcom.modems
Subject: Re: V.32 will dominate the marketplace (Was: Re: Which is best?)
Summary: need error flag propagation
Message-ID: <2628@alliant.Alliant.COM>
Date: 15 Nov 88 22:29:59 GMT
References: <2261@looking.UUCP> <1248@nusdhub.UUCP> <14515@mimsy.UUCP> <14533@mimsy.UUCP> <721@lts.UUCP>
Reply-To: steckel@alliant.Alliant.COM (Geoff Steckel)
Distribution: na
Organization: Alliant Computer Systems, Littleton, MA
Lines: 27

One reason the 'I want a wire' camp exists is that I have yet to see a
"smart" (= special protocol) modem provide an adequate 'there were errors'
signal to the host.  This is also a problem with many of the ISO protocols,
though they are getting smarter.

It really doesn't help, of course, that RS-232 does not provide error
signalling, so hosts aren't equipped with any way the logical hardware
could send the message upwards.

Result: people run TCP/IP, X.25, uucp, kermit, [xyzabcdef]modem, etc., etc.
to get guaranteed delivery and error recovery.

With a 'dumb' modem I get errors, but the connection stays in place.  The
higher level program will (it had better!) detect errors, retry, and log
success or failure.  This is relatively soft degradation.  With a "error
correcting" modem, I get catastrophic degradation - it hangs up.  Real useful.
That was X.25's solution until recently as well.

"Smart" systems should be integrated with error handling all the way to
the user.  

What we REALLY need is a standard host-to-modem protocol with error recovery
and error signalling.  This way the modems could be as smart as they dared,
and the user would have some way to figure out what's going on.  Until then,
I want a wire.

	geoff steckel (steckel@alliant.COM)