[comp.protocols.appletalk] Modem AppleTalk access want

Wolfgang_Naegeli.TSRS_ED@TSRSQM.ED.ORNL.GOV (Wolfgang Naegeli) (09/02/89)

         Reply to:   Modem AppleTalk access wanted
Mark Frost writes:

> We have a campus appletalk network running here at UCSC and are
> getting a growing number of faculty members who are asking to
> have net access from home. I understand that this capability exists
> (from companies like Shiva).
> I know nothing about products that provide this service.

Shiva sells two NetModems that have a DIN-8 serial port requiring an AppleTalk
connector on one side and a single modular phone jack on the other side. They
are Hayes compatible. One runs up to 1200 baud, the other up to 2400 baud. We
use the 2400 baud version very successfully.

They come with a control panel device that allows you to tell whether it should
emulate the printer port or the modem port on the Mac (or disable modem
emulation).  The nice thing is that this allows LocalTalk-connected Macs to have
a modem connection and still have a serial port available for other devices. Of
course, they need to have AppleTalk plugged in on the printer port. (You'll have
both serial ports free if you have an EtherTalk card connecting to the NetModem
through a LocalTalk router.)

The cdev also lets you sepcify what to do with incoming calls:  Ignore them,
have yourself informed by a dialog box (on dial-in, the modem first prompts the
caller for his/her name, which is shown in the dialog box) with buttons to
ignore this call or answer it.  When you press answer, the caller gets a message
to hold on for a few moments while the respondent is launching a
telecommunications program.

The last option in the CDEV is to automatically connect. This requires that a
telecommunications program is running on the machine to handle the call and the
option should be selected by only on machine on the network.
There is also a Chooser device for selecting the NetModem.

After doing these configurations, when you launch a program that is set to
communicate on the port that you have told the NetModem to emulate, the picture
of the front panel of a modem is added to the menu bar with status lights
indicating the modems state.  The Mac's speaker gives you all the sounds of
dialing, line noise, connection, etc. that you would hear from the speaker of a
regular modem.

If you have option-key-selected multiple modems in the Chooser, the software
will find one that is free.  If the one or all modems are already in use by some
other user(s), a dialog box will tell you so, and you can chose to give up or
get one when it becomes available. In the latter case, you can do something else
while the Shiva software is periodically polling the modem(s) in the background.

We have been using a NetModem V2400 for almost one year. It works particularly
well since version 3.1 of the PROM and software came out. We now use it even to
give QuickMail users access to their Mailcenter which they can do with
QuickRemote from a Mac or with any dumb ASCII terminal emulator. There is now
also NetModem software for MS-DOS machines equipped with a LocalTalk board.

There is also a remote AppleTalk adev called dial-in (that works under the
Network cdev and allows you to redirect AppleTalk from Built-in to Remote with
many configuration options for the type of modem or serial communication line
you want to use.  It supports speeds from 1200 to 56k baud.

I have succeeded in using laserprinters, TOPS, and AppleShare remotely, but let
me tell you that at 2400 baud it is terribly slow. The software automatically
adjusts AppleTalk timing parameters, but still, certain services sometimes time
out at this pace. I'd say you need at least a 9600 baud connection for remote
AppleTalk to be marginally worth the effort.  The reason is that there is a
tremendous amount of overhead for AppleTalk communication with, for example, an
AppleShare file server.

Using Kermit or ZModem you could exchange the same files at several times the
speed that you get with remote AppleTalk. Thus, if you need remote file sharing,
you'd do much better running Red Ryder Host on one of your machines that can
retrieve the files from the server and blast them out over the modem line much
more rapidly.

For e-mail, you are much better off using QuickRemote or a terminal emulation
program such as FreeTerm to access the MailCenter rather than using your regular
QuickMail DA to log into the MailCenter over a remote AppleTalk connection.

Finally (though I have not tried it) I believe that Timbuktu Remote would not
only give you much more functionality (complete control of your Mac at the
office) but probably also better performance for accessing AppleTalk services
vial your host Mac that handles all the AppleTalk overhead.

Shiva also sells a NetSerial device with three serial ports, to which you can
attach high-speed modems and use the same Shiva software. That is why it
supports 56k baud. That's really great for extending AppleTalk between remote
offices.  But for you, the problem is that probably few of your faculty are
willing to invest into a 9.6 or 19.2 k baud modem, and thus remote AppleTalk is
unlikely to be very practical. What we really need is ISDN in our homes ...

The Shiva Internet Manager allows you to set an administrator password for the
modem, to enable or disable remote AppleTalk access, to restrict AppleTalk
access to the modem's local AppleTalk zone, and to set a single password for
AppleTalk access. (If we were using it regularly, this would be a security
problem for us. We would need personal user passwords, and access auditing,
which is presently not supported.)

To sum up, the NetModem is a great idea and saves us a lot of money in avoiding
modem purchases for users who need a modem infrequently (we have many who use a
modem less than one our per week on average). For serious remote AppleTalk use,
the slow NetModems are virtually useless (but I guess Shiva will soon come out
with a 9600 baud or faster version???). If you don't want to spend big bucks,
pursue one or several of the alternatives to remote AppleTalk, which
incidentally also provide better security.

If I am not mistaken, you can also use Inforspere's Liaison Macontosh server
software to set up remote AppleTalk through the server's modem port.  But again,
you would need high-speed modems for it to be a practical solution.

Disclaimer:  Other than being a satisfied user and having beta-tested some of
the Shiva software and firmware, I have no affiliation with Shiva or any of the
other companies whose products I mentioned above. The opinions expressed are my
own and not endorsed by my employer or the sponsors of my work.

Wolfgang N. Naegeli
Oak Ridge National Laboratory
Internet: wnn@dsunx1.dsrd.ornl.gov (128.219.96.46)
Bitnet:   wnn@ornlstc         Fax: 615-574-3895      Phone: 615-574-6143