Path: utzoo!utgpu!watserv1!watmath!att!tut.cis.ohio-state.edu!cs.utexas.edu!yale!cmcl2!pluto!rich
From: rich@pluto.dss.com (Rich Rupp)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: LAT
Summary: terminal servers, lat, telnet
Message-ID: <4113@pluto.dss.com>
Date: 14 Jan 91 01:34:07 GMT
References: <1991Jan13.001403.2933@smsc.sony.com>
Organization: Datability Software Systems, New York, NY
Lines: 34

In article <1991Jan13.001403.2933@smsc.sony.com>, tucker@smsc.sony.com (Tim Tucker 817) writes:
> > - LAT causes less of a burden on the CPU and the network
> >       "In preliminary test using KI Research's KiNet, DR Labs found
> > [description deleted]
> Hmmm, in theory LAT is cheaper than TCP/IP, but I wonder if Digital Review
> was comparing apples and oranges?

I'm familiar with the DR Labs tests, since our VCP-1000 hardware was used
as the terminal server in both the TCP/IP/TELNET and LAT cases.

In the case of a single user on a terminal server connected into a host, LAT
wins over telnet because it's a light-weight protocol - few layers, with very
little processing required. The data buffer's can be passed off without 
telnet's requirement to look at each of the user's characters for IAC's.

If multiple sessions are from a single terminal server to the same host, the
savings is greater because of LAT's ability to multiplex data from multiple
sessions in a single packet.

We've spent a lot of time doing comparisons. We have lat implementations on
5 platforms, including system V and bsd. It is still a big win even if you
implement Rick Ace's telnet improvements.

You'll be seeing a lot of Unix box vendors offering LAT on their platforms.
It's not just for DEC compatibility. It's because in some of the new, 
multiprocessor boxes their marketing people have targeted the machines for
a large number of users and they are finding that the TCP/TELNET connections
alone drive the machines to their knees.

-- 

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Richard L. Rupp                                           rich@pluto.dss.com
Datability Inc.                              212 807 7800, Fax: 212 807 0958