[comp.sys.mac.comm] MacTCP over Dialup AppleTalk?

sanders@parc.xerox.com (Rex Sanders) (02/13/91)

This idea might be crazy, but maybe someone has tried.

Rather than waiting forever for MacTCP+SLIP, what about running MacTCP
over dialup AppleTalk?

By dialup AppleTalk, I'm talking about products like Shiva NetModem,
Farallon Liason, Hayes Interbridge, etc., with Shiva FastPath or
Cayman GatorBox doing AppleTalk-TCP/IP routing (see diagram below).

Can you get acceptable performance for MacX, Eudora, or NCSA Telnet
with this scheme?

Is 2400 baud uselessly slow?  Is 9600 baud usable?

The setup I have in mind is something like:

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

It's not elegant, but perhaps better than nothing.

-- Rex Sanders
   sanders.parc@xerox.com

garyf@headroom.ncsa.uiuc.edu (Gary Faulkner) (02/13/91)

In article <1991Feb13.052728.22533@parc.xerox.com>,
sanders@parc.xerox.com (Rex Sanders) writes:

Has anyone tried this configuration?? 


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

--
Gary Faulkner
National Center for Supercomputing Applications - University of
Illinois
Internet: garyf@ncsa.uiuc.edu
Disclaimer:  I've only stated my opinion, not anyone elses.

mandel@vax.anes.tulane.edu (Jeff E Mandel MD MS) (02/14/91)

In article <1991Feb13.052728.22533@parc.xerox.com> sanders@parc.xerox.com (Rex
Sanders) writes:
>This idea might be crazy, but maybe someone has tried.
>
>Rather than waiting forever for MacTCP+SLIP, what about running MacTCP
>over dialup AppleTalk?
>
>By dialup AppleTalk, I'm talking about products like Shiva NetModem,
>Farallon Liason, Hayes Interbridge, etc., with Shiva FastPath or
>Cayman GatorBox doing AppleTalk-TCP/IP routing (see diagram below).
>
>Can you get acceptable performance for MacX, Eudora, or NCSA Telnet
>with this scheme?
>
>Is 2400 baud uselessly slow?  Is 9600 baud usable?
>
>The setup I have in mind is something like:
>
> MacX---MacTCP---AppleTalk---Shiva NetModem
>                                   #
>                                   #  Telephone line
>                                   #
>Shiva FastPath---AppleTalk---Shiva NetModem
>   $
>   $  Ethernet TCP/IP
>   $
>Sun Server
>

I have used such a setup with Telebit Trailblazers and a Dataspace Telenode,
and it is bareley usable. Since most of what I want from home is mail and news,
and I have a VAX, I just use the VMS MAIL and RPI's news client, but it doesn't
diminish my ineterst in SLIP, PPP, etc. The issue no one has addressed is the
setting where you want 8 moems hanging off a terminal server, and want the
option of dialing in for LAT, telnet, or network access. I have talked to a
number of server manufacturers, and there seems little interest in putting
async Appletalk into a terminal server. Thus, SLIP or PPP seems the more likely
option. I suspect that this will be a relatively small part of the market, but
as more programs that use networks incorporate support for MacTCP, it will
become increasingly attractive to have a multiline SLIP server, especially in
multivendor environments.

Jeff E Mandel MD MS
Asst Professor of Anesthesiology
Tulane University School of Medicine
New Orleans, LA

jqj@duff.uoregon.edu (JQ Johnson) (02/14/91)

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

dhoyman@vms.macc.wisc.edu (02/15/91)

In article <1991Feb13.052728.22533@parc.xerox.com>, sanders@parc.xerox.com (Rex Sanders) writes...

> 
>By dialup AppleTalk, I'm talking about products like Shiva NetModem,
>Farallon Liason, Hayes Interbridge, etc., with Shiva FastPath or
>Cayman GatorBox doing AppleTalk-TCP/IP routing (see diagram below).
> 
>Can you get acceptable performance for MacX, Eudora, or NCSA Telnet
>with this scheme?
> 
>Is 2400 baud uselessly slow?  Is 9600 baud usable?
>
I have been trying to use the Shiva dial-in access at 2400 and then do Telnet.
But, so far I have only gotten "Host not responding" errors.  

I believe that this is due to MacTCP timing out, but am not sure.

I posted a message about this last week, but no one has been able to tell me 
if one can change MacTCP timeeout parameters. 
> 
>-- Rex Sanders
>   sanders.parc@xerox.com

Dirk Herr-Hoyman
UW-Madison, Dept. of Family Medicine and Practice
dhoyman@fammed.wisc.edu
608-262-6368