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From: mark@cbosgd.UUCP (Mark Horton)
Newsgroups: net.mail,net.news.group
Subject: Re: Anybody interested in NameDroppers?
Message-ID: <1386@cbosgd.UUCP>
Date: Tue, 5-Jun-84 00:29:16 EDT
Article-I.D.: cbosgd.1386
Posted: Tue Jun  5 00:29:16 1984
Date-Received: Fri, 1-Jun-84 06:59:43 EDT
References: <574@hou3c.UUCP> <280@basser.SUN> <434@erix.UUCP>
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	In fact, we are considering setting up a domain for access to a
	bunch of non-UNIX (imagine!) VAXen here, and would like
	opinions on the best way to go about it. Are "local" domains a
	la DEC and SUN are emerging as some kind of de facto standard,
	rather than subdomains (user@host.subdomain.UUCP)?

For anyone considering setting up their own domain, I'd like to offer
some advice based on the direction the ARPA Internet appears to be headed.

A name like foo@mulga.SUN is not really a local domain.  It appears to the
rest of the world to be a top level domain, if it ever escapes from your
own organization.  (And you can be sure that if you have access to UUCP
or any other large electronic mail network that it will get out.)

The Internet has set up specific guidelines for top level domains.  In
general, there will not be many top level domains, and it's hard to get
one.  The latest ARPA proposal had 6 of them: ARPA, DDN, EDU, COR, GOV,
and PUB - the first 2 amount to special treatment for ARPANET and MILNET,
the other 4 attempt to categorize everyone else as educational, corporate,
government, or public.  No, nobody is happy with this, and it probably
will be changed again, but it gives you an idea of what a top level domain is.

The requirements for being a top level domain will almost certainly include
(1) having a responsible person, (2) having a robust registry and nameserver,
(3) being large.  ("large" is currently defined as "over 1000 hosts", but
this is also being debated, perhaps it will be defined in terms of users or
traffic.)

UUCP will meet the requirements, the UUCP project is currently building a
map and software to use it, and we have over 2000 hosts.  DEC could also
qualify if they wanted to, as the DEC ENET has over 2000 hosts.  Ditto for
IBM's VNET.  Smaller networks are not clear - the SUN network in Australia
and BITNET would not qualify as top level domains under the current rules.
AT&T has over 600 hosts but currently plans to be a subdomain of UUCP.
HP may wind up as a subdomain of UUCP as well.

So what do you do?  Well, my advice is to organize your subdomain as a tree
and give it a name, but plan on attaching it in as a subdomain of some other
domain at some future date.  UUCP will probably allow subdomains shortly
after the main domain starts working, but the rules haven't been established
yet.  Likely subdomains of UUCP include ATT, HP, and EUR (or some other
preferred abbreviation for Europe.)

For example, if I had a small company called, say, TPC, with 5 hosts,
I might name them after something original, like letters of the alphabet,
and designate one as the gateway:

			TPC
                    /  / | \  \
	           A  B  C  D  E

where "A.TPC" is the gateway, also known as TPC.  Then I might generate
addresses like "Mark.Horton@TPC" or "mark@D.TPC".  I would fully expect
someone to eventually start yelling at me, saying "there is no top level
domain TPC, you can't use that address".  So I would be keeping my ear to
the ground, watching for a parent domain to hook into, and as soon as a
suitable parent appeared, I would attach the TPC tree, generating addresses
like "Mark.Horton@TPC.USA.UUCP", (assuming that "USA.UUCP" was the parent
domain.)  If a parent appears before somebody yells at me, great.  If somebody
yells before a parent appears, well, we have to call ourselves something.
However, while calling ourselves an illegal name, we should expect some
of our mail to be dropped on the floor by hosts that don't understand it.

By the way, don't subdivide your domain into subdomains unless you have
no alternative.  One level should be sufficient for hundreds of hosts.
If you attach in at the 2nd level, you could find your users having to
list their addresses as A.CB.OHIO.TPC.USA.UUCP, when A.TPC.USA.UUCP is
much easier for users to type and no harder to implement.  If you want
to subdivide administratively, fine, but don't make it show up in the
domain names of hosts.

	Mark Horton