Location independence?

Daniel LaLiberte (liberte@ncsa.uiuc.edu)
Wed, 26 Feb 1997 01:20:27 -0600 (CST)


From: Daniel LaLiberte <liberte@ncsa.uiuc.edu>
Date: Wed, 26 Feb 1997 01:20:27 -0600 (CST)
Message-Id: <199702260720.BAA15398@void.ncsa.uiuc.edu>
To: touch@isi.edu
Cc: uri@bunyip.com
Subject: Location independence?
In-Reply-To: <199702251830.AA12562@ash.isi.edu>

touch@isi.edu writes:
 > > |the DNS provides globally-unique, location-independent names.
 > > 
 > > If a FQDNs are locations, how does DNS provide
 > > location-independent names?
 > 
 > We're confusing the term location here, as is probably obvious.
 > 
 > The DNS provides globally-unique, 
 > 	(geographically) location-independent names.
 > 
 > FQDNs are locations, just not geographic ones.

Locations and names are both relative to some context.
FQDNs are looked up in the context of the well-known global DNS root.
Whether you call them names or locations is irrelevant if you just
call them identifiers that are looked up in some context.

An identifier that cannot be looked up in some context is not very
useful.  (But as Terry Allen would point out, it can still be useful
for comparison with other identifiers if you know that they were
uniquely created.)

I'd say that FQDNs are IP-independent and leave it at that.  Maybe
URNs should just be called URL-independent, but there are still
problems with that, namely that they live in the same URI space.  As a
matter of fact, you can look up IP numbers in a special branch of DNS.

--
Daniel LaLiberte (liberte@ncsa.uiuc.edu)
National Center for Supercomputing Applications
http://union.ncsa.uiuc.edu/~liberte/