Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!nsipo.arc.nasa.gov!medin
From: medin@nsipo.arc.nasa.gov (Milo S. Medin)
Newsgroups: comp.protocols.appletalk
Subject: Re: UDPTalk as a backbone
Message-ID: <31297@ames.arc.nasa.gov>
Date: 4 Sep 89 05:48:42 GMT
References: <1989Sep3.063402.22872@caen.engin.umich.edu>
Sender: usenet@ames.arc.nasa.gov
Reply-To: medin@nsipo.arc.nasa.gov.UUCP (Milo S. Medin)
Organization: NASA Science Internet Project Office
Lines: 34

Steve, I completely disagree with you.  Forcing router vendors to spend time
implementing more non-standard limited protocols is not what I want
my vendors to do.  Here at Ames, we essentially banned Ethertalk on our
large bridged backbone network.  We have not been sorry about the decision.

Ethertalk is one of the poorest implementations I have ever dealt with.  It
broadcasts way more than is needed, and generates a lot more routing traffic
than necessary.  UDPtalk or IPtalk is MUCH nicer, and all my routers can switch
IP.

We sucessfully run IPtalk through routers all the time, and some of these
routers are BSD machines, which I seriously doubt will ever understand
Ethertalk.  

Our Mac's which directly connect to ethernet speak TCP/IP on the ethernet.
It works fine.  For Mac type applications, they have localtalk interfaces
which connect to K-boxes which use the IP backbone as a transit, and can
talk to CAP machines, etc...  In general, if the application is performance
driven, it can usually by handled by IP (our Crays don't speak Appletalk)...

If Kinetics and whoever else only support Ethertalk would support IPtalk
also, we'd certainly welcome them into our market of several hundred
if not thousands of Macs.  I'm sure the people at LBL (who also ban Ethertalk
from their backbone) would also agree.  

In small networks, or even medium sized networks, I'm sure Ethertalk
works out all right.  But you judge a protocol by how well it scales,
and Ethertalk doesn't scale very well at all.  Large facilities like Ames
have a lot of unique problems to deal with.  IPtalk solves one of them.
We like it a lot.  Anyone that supports it in their products is part
of our solution space...

					Thanks,
					   Milo