[Nsi-wg] Identifiers

[Freek Dijkstra]

Jerry Sobieski wrote:

> Q1.)  Is the proposed NML naming convention
> "urn:ogf:network:<DNSname>:<year>:<opaque part>" used for all
> topological objects?  Or is it *only* for naming STPs?

It will be used for all topological objects.

> Q1.b)  Is "urn:ogf:network:" now to be used solely for NML topology? or
> will that namespace be available for naming other objects or subspaces
> related to other aspects of grid networking in general?

Other objects may use the "urn:ogf:network" namespace.

The urn:ogf:network specification formally only defines a procedure to
generate a persistent, globally unique identifiers, with minimal risk of
name collisions, and without creating a new registry. It is recommended
that these identifiers are used for identifying network objects, but if
someone likes to give a urn:ogf:network identifier to his newborn child,
I will not sue :)

> Q2.) Is it *required* that the NML naming element that follows "network"
> be specifically a DNS domain name?   I.e. Why does NML require a DNS
> name?   In essence, the *DNS requirement* makes the the domain naming
> registry the authority that guarantees uniqueness for OGF URNs. 
> right?    Further, requiring DNS names makes it difficult for end users
> to name their own network(s) as not every STP resides where a DNS name
> is clear or appropriate or valid.

The *combination of DNS and date* (typically a year, but it was
suggested that year+month or year+month+day should be allowed too) is a
easy way to create a persistent globally unique prefix to denote a
registry ("namespace organisation" according to GFD.191).

So the DNS name + year combination identifies an organisation, not a
network element. We think that this is an easy requirement for an
organisation, and less hassle than setting up a formal registry where
users (including end users) can register a namespace.

> Q2.b) Since NSI Networks are "service domains" rather than comprehensive
> hardware infrastructure, they may not map directly or uniquely to
> specific DNS domains.  For instance, there is nothing preventing a
> number of collaborating organizations from pooling their resources into
> a single NSI Network service domain.  How would the DNS mapping be
> applied in this scenario?

See above. Again, all that the DNS + year combination does is create a
globally unique, persistent prefix. It has no other meaning. The only
implication of "urn:ogf:network:chucknorriskicksass.com:2008:18348975"
is that whoever assigned it was administrative owner of the domain name
in 2008. It does not imply that it still owned by the same person, or
that the resource in question has anything to do with said domain.


> Q3.)  What does the DNS name level represent in terms of NML?  I.e. why
> have it at all ?  What are the NML requirements for object names that
> requires DNS names in them (or the year value that follows the DNS
> element..)

NML only requires that if an object is given an identifier, that
identifier is globally unique (thus not used before) and persisten (thus
will not be used again for something else). This identifier MAY
(SHOULD?) be a urn:ogf:network namespace, but it is likely not a MUST.
The urn:ogf:network thing is only there to make it easy to create such
globally unique, persistent identifier.

So once an object has been given an identifier, that identifier sticks.
The identifier will always point to that resource, even if it's
properties change, is decommissioned or whoever assigned that identifier
runs out of business.

> Q4.) There is a <year> following the DNS element in the NML convention. 
> Why?   In particular, what authority is responsible for naming
> topological objects under a "ogf:network:<DNS name>:" name space?  Is
> this truly necessary?  This feels rather  convoluted and questionable...
> - we certainly do not need it for the NSI naming...

The year (actually: date) is intrinsic part of the combination of DNS +
Year that uniquely identifies the organisation that assign identifiers.
It is added the the DNS name to prevent the situation where an
organisation runs out of business and the DNS registration if handed out
to another organisation who subsequently also likes to assign URNs.

Regards,
Freek