Path: utzoo!attcan!uunet!husc6!think!ames!mailrus!tut.cis.ohio-state.edu!mandrill!neoucom!wtm
From: wtm@neoucom.UUCP (Bill Mayhew)
Newsgroups: comp.sys.att
Subject: Re: ph .phinit .phclr phupd ya ba dee ya ba dee yub
Summary: MNP stupidity is _not_ the OBM's fault!
Message-ID: <1259@neoucom.UUCP>
Date: 19 Jun 88 14:22:33 GMT
References: <293@uncle.UUCP> <137@limbic.UUCP> <571@sialis.mn.org>
Organization: Northeastern Ohio Universities College of Medicine
Lines: 51


As far as I know, the chipset used in the On Board Modem is the
same chipset that is used in several of the AT&T 22xx series
modems.  On the machine here, OBM doesn't seem any better or worse
than any other 1200 buad modem  (we have terrible fone lines, and
noise is copious on anything without error correction and baud
rates above 300).

The Reason MNP modems get goofed-up calling the OBM is the same
reason that MNP modems get goofed-up calling a Hayes Smartmodem on
a Vax.  (Yes, they do.)  Apparently, getty politely echoes back the
querry string from the originate modem as it tries to establish MNP
handshake.  The querry string being echoed back seems to be enough
to trick the originate end into thinking that the answerer is MNP when,
in fact, it is not.

You can probably duplicate this experiment yourself by calling a
Hayes Smartmodem or clone thereof on onther extension in your office
with nothing plugged into the RS232.  The Hayes should be set to
autoanswer.  Call it with your favorite MNP device (Trailbalzer, or
whatever).  The origninate modem should negotiate a non-MNP
connection.  Now, connect pin 2 to pin 3 on the Hayes by sticking a
piece of wire in the Holes.  This should simulate getty-babble.
Call the Hayes again.  Sha-zam!, it should look to the originate
modem like it just established a valid MNP link.

I guess you could say that if anything, getty is to blame.  More
correctly, perhaps, the MNP protocol is to blame.

One way to fix the problem would be to hack the getty source (outta
luck about this idea on the 3b1!) so that getty keeps its mouth
shut until it gets a character from the originate side that is not
part of the MNP handshake sequence.  The other solution is to get a
real MNP modem and stick it on tty000, and use that instead of OBM.
With the idigienous icky UUCP software on the 3b1, tty000 works
much better than OBM anyway.

As far as poor OBM support goes, people that I know who are using
the Honey DAN BER UUCP kit report that many of their problems with
OBM seem to disappear with HDB.  Too bad AT&T is sitting on it.
I'd really love to know what the politics of not letting us have
HDB are.  I for one would pay $$ for it, as long as it didn't cost
as much as the whole O/S or something.  (Re: $495 for the EIA
board!  I bought a 2-port EIA board for my P.C for $39.  Economy of
scale I guess.)  It suppose putting HDB on ths store (for free)
conflicts with policy, since HDB is for sale as part of BNU for some
of the other sytems.  People paying for HDB as part of BNU might be
offended.  C'est la vie.

--Bill
  for this week:  impulse!wtm@neoucom.UUCP