Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!elroy.jpl.nasa.gov!decwrl!world!boris
From: boris@world.std.com (Boris Levitin)
Newsgroups: comp.sys.mac.apps
Subject: Re: 4th Dimension & Networking over the phone
Message-ID: <1990Nov25.112334.18494@world.std.com>
Date: 25 Nov 90 11:23:34 GMT
References: <1990Nov23.000340.1514@gpu.utcs.utoronto.ca> <10381@uhccux.uhcc.Hawaii.Edu>
Organization: The World @ Software Tool & Die
Lines: 48

bmartin@uhccux.uhcc.Hawaii.Edu (Brian Martin) writes:

>In article <1990Nov23.000340.1514@gpu.utcs.utoronto.ca> judge@gpu.utcs.utoronto.ca (Peter Judge) writes:
>>
>>I need to network three to five macs running a 
>>4th Dimension application. Three machines are
>>located in separate regions so I would have to 
>>connect them via telephone lines; the others would
>>be connected by cable.
>>
>>My questions are these:
>>
>>1)	How does 4th Dimension make use of modems to 
>>	share a distributed database?
>   It doesn't.

>>	Does it contain routines to implement networking
>>	over phone lines, or do I need a bridge? 
>   You would need a bridge.

>>2)	Is there recommended networking software
>>	to use with 4th Dimension (Appletalk, TOPS...)?
>    Data corruption problems have occurred with TOPS.


>Bad idea. 4D uses a file server rather than a client/server model, so phone
>line networking is next to impossible with 4D. The closest you could
>come is to mimic a distributed database design, with batch updating
>between central database and remote databases at periodic intervals.
>A more expensive approach is to use 4D as a front end to an Oracle database,
>which should support the distributed databases.

>Alternatively, you could run "headless" macs at your central
>site, each with timbuktu/remote or carbon copy mac running, and access
>these macs via v.42bis modems from your remote sites. That may
>be a reasonable implementation, since you transfer screen images rather than
>data across the phone lines. You could enter and review data on-screen, but
>you wouldn't be able to print at a remote site using this approach.

I don't see why the original poster couldn't connect his five local AppleTalk
networks using Telebridges.  Of course, this will be Chinese-water-torture-
slow, but it should work.  For a more realistic setup, the original poster
should probably go to TCP/IP over Ethernet and then connect the Ethernets.

Incidentally, Tops claims that it solved the file-corruption problems in
version 3.0.  I don't use 4th Dimension, but had a nasty corruption problem
with a distributed Excel file and Tops 2.0.  Since we installed 3.0, it hasn't
happened again in a year and a half.