Re: telephone URLs, comments on draft-antti-telephony-url-04

Patrik =?iso-8859-1?Q?F=E4ltstr=F6m?= (paf@swip.net)
Tue, 30 Jun 1998 11:02:53 +0200


Message-Id: <v04011708b1be56240161@[192.168.111.25]>
In-Reply-To: <000c01bda402$3b466180$15d0000d@copper-208.parc.xerox.com>
Date: Tue, 30 Jun 1998 11:02:53 +0200
To: "Larry Masinter" <masinter@parc.xerox.com>,
        "Vaha-Sipila Antti (NMP)" <antti.vaha-sipila@nmp.nokia.com>
From: Patrik =?iso-8859-1?Q?F=E4ltstr=F6m?=  <paf@swip.net>
Cc: <uri@Bunyip.Com>, <eva@nic-se.se>
Subject: RE: telephone URLs, comments on draft-antti-telephony-url-04

At 01.36 -0700 98-06-30, Larry Masinter wrote:
>Patrik, I don't understand your argument, you're right. I don't understand
>what is different between:
>
>  "When an area code changes, the phone numbers do, by definition
>    but maybe to the same number within the new area"
>
>and
>
>  "When the host name changes, the URLs do, by definition
>    but maybe to the same path with the different hostname"

...and I don't understand you :-)

I.e. the problem I see is that we use different criteria when talking about
hierarichal names, which in turn leads into the space of relative names.

The criteria I have used is that not only two names are in the same
namespace (at a perticular moment) but also that the namespace can change
without any changes in the namespace specific name. If both of these
criteria are true, then we can use the generic URI syntax, relative URI's
etc etc.

For the second criteria to be true, it is a must that the naming of each
object in the namespace be made in the namespace itself and independent of
other namespaces (or subnamespaces).

A http URL fulfils these criteria because after the name of the (virtual)
host can change without the rest of the path / filename changes. This is
turn because the filenames are allocated on the host itself, inside the
namespace. One can of course, as you point out, split a server or do
something else, but that is a choice one makes. ISBNs are also hierarichal
from my point of view because of the same arguments.

Regarding phone numbers, there is a difference though. The numbers are not
arbitrary allocated inside one areacode, but each number is allocaded
individually. If the areacode change it is a choice to _keep_ the number
(if possible), not the other way around.

I see a difference between these two namespaces, but more important, I have
my definition of what a hierarichal namespace is (above) and I want to have
comments on that separately from the discussion on weather the phone
numbers fulfils the criteria or not.

    Patrik