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Path: utzoo!linus!philabs!cmcl2!seismo!ut-sally!jsq
From: jsq@ut-sally.UUCP (John Quarterman)
Newsgroups: net.lan
Subject: Ethertips
Message-ID: <2394@ut-sally.UUCP>
Date: Thu, 18-Jul-85 13:47:48 EDT
Article-I.D.: ut-sally.2394
Posted: Thu Jul 18 13:47:48 1985
Date-Received: Sat, 20-Jul-85 17:11:48 EDT
Distribution: net
Organization: U. Texas CS Dept., Austin, Texas
Lines: 41

We're moving two thirds of our CS department into a new building here.
It will be wired with an Ethernet, which will be connected (probably
through an IP subnet gateway) to our other networks on campus, and to
the outside world through the ARPANET.  Many people will be using
workstations, and will access larger machines only over the network.
Others may connect through a data switch, such as a MICOM, which would
be connected to a few large machines on the network.  We are wondering
about the feasibility of doing away with the data switch, by using
Ethertips scattered around the building instead.

What I mean by an Ethertip is an Ethernet network node which serves
as a terminal concentrator and provides access to other hosts on the
network.  Something like the old ARPANET TIPs or the current ARPA
Internet TACs.

Specifically, I am interested in the following information for such devices:
	Product name.
	Vendor (name and contact information).
	Number of terminals it can handle.
	Cost.
	Protocols used above the network layer:  TCP/IP/{telnet|rlogin}
		preferred, XNS possibly plausible.  CHAOSNET, PUP,
		and especially 3BNET need not apply.
	Some sort of estimate of the network and host load entailed.

While I realize a network login generally puts more load on a host than
a direct terminal login, yet, judging by the amount of network login
traffic we see from workstations, and by people logged in first on a
hardwired line and then across a network to another machine, it seems
unlikely that eliminating the data switch would raise the number of
network logins by a factor of two, and probably by less than 50 per
cent.  So the dollar cost of the Ethertip per line, compared to that of
a more ordinary data switch, is the major consideration.


If someone has done a summary of this subject recently, please mail it to me.
Otherwise, please mail comments to me, and I will summarize to this newsgroup.
-- 

John Quarterman,   UUCP:  {ihnp4,seismo,harvard,gatech}!ut-sally!jsq
ARPA Internet and CSNET:  jsq@ut-sally.ARPA, soon to be jsq@sally.UTEXAS.EDU