Re: Location independence?

touch@isi.edu
Tue, 25 Feb 1997 23:38:55 -0800


From: touch@isi.edu
Date: Tue, 25 Feb 1997 23:38:55 -0800
Message-Id: <199702260738.AA03680@ash.isi.edu>
To: liberte@ncsa.uiuc.edu, touch@isi.edu
Subject: Re:  Location independence?
Cc: uri@bunyip.com

> touch@isi.edu writes:
>  > 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.

IP numbers are not looked up. That's the point.
That's why they're "locations", rather than "names".

> 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

It gets me where I want to go in the Internet.

> 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.

That's used for reverse-lookups, a somewhat superfluous function
of the DNS. That lookup is not needed to use the IP address.

I.e., the following URL is a location, not a name: (in the 
Internet sense of location):

	http://1.2.3.4/


Joe----------------------------------------------------------------------
Joe Touch - touch@isi.edu		    http://www.isi.edu/~touch/
ISI / Project Leader, ATOMIC-2, LSAM       http://www.isi.edu/atomic2/
USC / Research Assistant Prof.                http://www.isi.edu/lsam/