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From: jqj@duff.uoregon.edu (JQ Johnson)
Newsgroups: comp.sys.mac.comm
Subject: Re: MacTCP over Dialup AppleTalk?
Message-ID: <1991Feb13.214442.18570@ns.uoregon.edu>
Date: 13 Feb 91 21:44:42 GMT
References: <1991Feb13.052728.22533@parc.xerox.com> <6119@rex.cs.tulane.edu>
Sender: news@ns.uoregon.edu
Reply-To: jqj@duff.uoregon.edu (JQ Johnson)
Organization: University of Oregon Network Services
Lines: 69

Like Jeff Mandel, we have been experimenting with offering dialup Appletalk using Shiva NetModem/NetSerial sorts of things.  Some comments:

MacX---MacTCP---AppleTalk---Shiva NetModem
>                                   #
>                                   #  Telephone line
>                                   #
>Shiva FastPath---AppleTalk---Shiva NetModem
>   $
>   $  Ethernet TCP/IP
>   $
>Sun Server

I don't believe this configuration works.  A NetModem is not a
half-router.  To do this, you need a Shiva TeleBridge or equivalent at
each end.  What does work is:

 app/MacTCP/Shiva Dial-In software--any modem
					#
					#
 Shiva FastPath---AppleTalk---Shiva NetModem (or NetSerial+random modem)
   $
   $ Ethernet
 Sun server.

I've run a number of MacTCP applications in such a mode both at 2400b
and at 9600b.  Among the gotchas:

1/ the Shiva software takes over (redirects) the printer port on the
   Mac, so it isn't possible to print to a local Imagewriter or Appletalk
   Laserwriter while Dial-In is active.
2/ the Shiva Dial-In software is quite fragile, and their tech support
   for it seems nonexistent.  It is easy to bomb or hang it.
3/ MacTCP 1.0.1 is fairly fragile, and again is easy to bomb.
4/ We haven't been successful in getting it to work reliably with MNP4,
   MNP5, or V.42 addons, just with V.22bis and simple V.32.

Among the things that are known not to work right are:
  -	disconnecting the dial-in link to return to the builtin localtalk
	leaves the modem port in a strange state, and Comm Toolbox
	applications can't use it until it is reset.
  -	after running a MacTCP application, disconnecting the dial-in
	link to return to builtin localtalk, then reconnecting causes a
	crash.  Does not happen unless you have run a MacTCP app.
  -	SU Mac/IP:  directory listings in the Mac ftp client cause my
	Mac to hang.
  -	the setup is mostly incompatible with Ethertalk installed on the
	Mac.

I recommend that anyone who tries the configuration plan on restarting
his or her Mac each time he shuts down the dial-in connection.  And plan
on keeping a spare floppy with your System Folder around, since we believe
we have seen a number of cases of smashed system files.

On the other hand, Eudora, HyperFTP, TechMail, TechInfo, SU Mac/IP telnet,
and NCSA/BYU Telnet seem to work ok.  I even was able to telnet to my Sun
while having its filesystems mounted using Appleshare talking to a CAP
server!  Telnet response time is VERY jerky even at 9600b, but not too bad
in line-at-a-time mode since thruput is adequate (about 800B/s).  Eudora
file transfers are bearable (for some people) even at 2400b.

We'll have more data on how well this all works in the next few weeks.
Meanwhile, we sould be VERY interested in other people's experiences.

-- 
JQ Johnson
Director of Network Services		Internet: jqj@oregon.uoregon.edu
University of Oregon			voice:	(503) 346-4394
250E Computing Center			BITNET: jqj@oregon
Eugene, OR  97403-1212			fax: (503) 346-4397