Re: [urn] I-D Action: draft-ietf-urnbis-rfc3406bis-urn-ns-reg-01.txt

[Julian Reschke <[e-mail]>]

On 2012-01-10 07:22, Juha Hakala wrote:
> Hello Martin,
>
> I agree with you in many respects, but there are some differences of
> opinion as well. See below...
>
> Martin J. Dürst wrote:
>> Hello Juha,
>
>> This means that there is a strong question as to how, and to what
>> degree, the classical library-based name-location distinction is still
>> relevant and useful. With that I don't want to say that it's useless,
>> I just want to say that however many years of "practical experience"
>> you can claim, that experience may or may not transfer to a world with
>> essentially different "physical" rules.
>
>  From a library point of view, for instance the following features of
> networked resources seem to be in favour of separating identification
> from location:
>
> 1. There may be multiple copies of a single resource in different
> locations. However a resource should have one and only one identifier.

CDNs show that HTTP URIs can be used to identify a single resource that 
can have multiple copies in different locations.

> 2. Over time, there may be different resources available from a single
> location.
>
> 3. A single resource may be moved from one location to the next.
>
> 4. A digital resource may disappear (leaving only e.g. a printed
> surrogate).
>
> 5. A single file can incorporate multiple resources that should be
> identified separately; a single resource can span over multiple files.
> ...

I still don't see what this has to do with "location" vs "naming". You 
can start with a locator and overload it as a name, or you can start 
with a name and overload it as locator.

The former has been done a lot with HTTP URIs, the latter is what you 
seem to try to do with URN resolution.

In the end, where's the difference?

> There has also been discussions about persistence (or the lack of it) of
> domain names, and the need of identifying abstract entities such as

If you don't use domain names, you'll need an alternate system to 
delegate responsibilities. Who's going to run it? Who's going to 
guarantee persistence of *that* system`?

> works (which may or may not have manifestations in the Web).

"A 303 response to a GET request indicates that the requested resource 
does not have a representation of its own that can be transferred by the 
server over HTTP. The Location URI indicates a resource that is 
descriptive of the target resource, such that the follow-on 
representation might be useful to recipients without implying that it 
adequately represents the target resource. Note that answers to the 
questions of what can be represented, what representations are adequate, 
and what might be a useful description are outside the scope of HTTP and 
thus entirely determined by the URI owner(s)." -- 
<http://greenbytes.de/tech/webdav/draft-ietf-httpbis-p2-semantics-18.html#rfc.section.7.3.4>

> ...

Best regards, Julian