Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/18/84; site im4u.UUCP
Path: utzoo!linus!philabs!cmcl2!seismo!ut-sally!im4u!jsq
From: jsq@im4u.UUCP (John Quarterman)
Newsgroups: net.mail
Subject: Re: Understanding mail addresses?
Message-ID: <604@im4u.UUCP>
Date: Tue, 29-Oct-85 13:24:40 EST
Article-I.D.: im4u.604
Posted: Tue Oct 29 13:24:40 1985
Date-Received: Fri, 1-Nov-85 01:18:59 EST
References: <639@ecsvax.UUCP>
Reply-To: jsq@im4u.UUCP (John Quarterman)
Organization: U. Texas CS Dept., Austin, Texas
Lines: 49

In article <639@ecsvax.UUCP> hes@ecsvax.UUCP (Henry Schaffer) writes:
>I've seen a rash of multipart addresses recently, with the parts
>separated by ".", and usually ending in EDU, e.g.
>jsq@IM42.UTEXAS.EDU
>userid@uiucuxa.CSU.UIUC.EDU
>The first also said something about The ARPA INTERNET, while the
>second appeared to be on usenet.
>From left to right (after the "@") the format seems to be something
>like   cpu.department.university.EDU
>A brief explanation of this format would be appreciated.  Also, what
>is EDU?
>--henry schaffer  n c state univ

Presumably part of what you are referring to is my signature (see below).

First of all, it's not IM42, it's IM4U.  IM4U is an alien robot butler.
Think of that and say IM4U out loud a few times and it will be obvious....

Someone else has explained in a followup about the top level domains
EDU, COM, ORG, GOV, etc., which are replacing the old single top level
domain ARPA in the ARPA Internet.  (Perhaps it is time to post RFC883,
which is the detailed explanation of domains, to net.sources again.)

Doubtless many people are still in the dark as to what the ARPA Internet
is, though.  The ARPANET was the original long-haul packet switching
network, and it started in 1969.  ARPA is an acronym for the Advanced
Research Projects Agency, now more accurately known as the Defense
Advanced Research Projects Agency (DARPA), an arm of the Department
of Defense of the U.S. Government.  This is the agency which has been
largely responsible for funding much research in many major areas
of computer science in the States.  The ARPANET, for instance, was
the proof of concept for packet switching networks and a testbed
for protocol development.

In 1983, the ARPANET split into two parts, ARPANET (research) and
MILNET (military).  Both these networks run the TCP/IP protocol suite,
as do some hundreds of others (Ethernets, token rings, and broadbands
at universties, companies, and government agencies, long-haul satellite
nets, packet radio nets) which are connected to them.  Because of the
nature of addressing, the whole collection of networks looks like one
big network to the user.  The whole thing is called the ARPA Internet.

End of history lesson.

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