On 12-12-2013 12:53, Henrik Thostrup Jensen wrote:
The reason we made identifiers hierarchial is because we wanted a hierarchial model, including the identifiers.
NML allows a hierarchy (using relations), even though it's identifers are non-hierarchical. FYI, an earlier attempt was to also make the identifiers hierarchical as "domain -> node -> port -> link" (See section 8.2 of GFD 202). However there were some use cases where this didn't apply. For example, NSI deviated from this hierarchy, only using "domain -> port", and requesting a "domain -> subdomain" hierarchy. For that reason, NML clearly chose non-hierarchical identitifiers, and specified that in GFD 202. If you are saying "we made identifiers hierarchical", which identifiers do you mean? Do you plan to create a new document describing a different type of identifiers, possibly using a different prefix?
I don't care about URNs. They add exactly zero value to the system. I have yet to see a good argument for why "urn:ogf:network:nordu.net:2013:ps?vlan=1701" is better than "nordu.net:ps?vlan=1701"
Prefixes are used to ensure globally uniqueness (and thus prevention of identifier collisions). It is debatable if that is a real concern or not. (My personal opinion is not to show the urn:ogf:network" to users in a GUI, but keep it in the protocol, the few bytes of overhead are not worth a discussion.) A secondary use is that it allows easier detection of the type of identifiers. For example, imagine some like yourself decides that the current urn:ogf:network identifier syntax is not good. For example cuse you like to add more hierarchy to it. In that case, it is easy to define a new prefix (e.g. "urn:ogf:whatever:") and define a better syntax for those identifiers, and convince the community to start using those identifiers. I may not be convinced, but at least that approach would not lead to incompatible software. Freek -- Freek Dijkstra | Group Leader & Network Expert | Infrastructure Services | SURFsara | | Science Park 140 | 1098 XG Amsterdam | +31 6 4484 7459 | | Freek.Dijkstra@surfsara.nl | www.surfsara.nl | Available on Mon | Tue | Thu | Fri |