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From: andrew@megadata.mega.oz.au (Andrew McRae)
Newsgroups: comp.protocols.tcp-ip
Subject: LAT vs telnet
Message-ID: <1991May2.012159.23962@megadata.mega.oz.au>
Date: 2 May 91 01:21:59 GMT
Sender: news@megadata.mega.oz.au
Organization: Megadata P/L, North Ryde, Sydney, Aust.
Lines: 35

I read in UnixWorld about various arguments concerning the
pros and cons of LAT as opposed to telnet, with the main
argument for LAT being it is a LOCAL transport protocol designed
to achieve less host load, less network load and overall a
much better protocol for connecting terminals to a host on a local
net. Various analyses have been seen on the net that attempt to
quantify the telnet overhead compared to LAT overhead, and
it seems a valid point is made (that telnet overhead is excessive for
what it does). Telnet of course is a TCP based protocol and so can
be routed through gateways etc. which LAT can't be (though lots
of people talk about bridging LAT).

It strikes me that the fundamental idea of LAT is sound, and it makes
good sense to lower the host overhead for local terminals (especially
when we talk about larger scale commercial sites running data entry etc.).
What people balk at is perhaps not the concept of LAT, but the fact that
it is a proprietary protocol, and while DEC licences LAT to others,
it is still not openly available i.e. lots of strings ($$) attached.

My real question is: If the concept of LAT is good enough, and the
advantages great enough, why doesn't someone define a protocol that
does the same job, but is part of TCP/IP; in other words a local telnet
protocol. I guess the biggest problem (as with some many other protocols)
is that LAT got there first, and no one is going to support any MORE
terminal protocols; but if an RFC was written, and an implementation
done, and the bugs ironed out....

Has anyone attempted to define or build a public domain LAT-style
local terminal protocol? If DEC would loosen up on LAT, that would
solve the problem, but is that likely?

Just wondering...

Andrew McRae (andrew@megadata.mega.oz.au)
Megadata Pty Ltd., North Ryde, Sydney, Australia.