All this business about namespace URNs...

[Ron Daniel]

Just to clarify a point or two in Jerry's message:

> Most of the URN crowd has been reluctant to put URN resolution on to
> DNS.
> 
[Ron Daniel]  Very true. Cowards that we are, none of us
would like to be fingered as the person responsible for
breaking the global Domain Name System. 

> My take on looking over the URN Working 
> Group's documents is that the default assumption by the IETF
> is that client software will first turn to DNS and ask where it can
> find a
> resolver
> for a particular URN namespace (DNS will use NAPTR records to identify
> resolvers
> for particular URN name spaces) and then go to the resolver identified
> by DNS
> to resolve particular URNs. 
[Ron Daniel]  A couple of clarifications. The main point
is that the DNS itself is not used for looking up individual
documents, instead it is used for locating 'resolvers' which
hold databases of lots of document IDs and locations.
Also, we want people to use this method LAST, not first. Use
local resolvers first. (For example, to resolve UUID URNs
someone might write some code that first looked into the
client machine's registry. Catalogs could also be used
for local resolution info). If that fails, try a workgroup
or enterprise resolver. (For example, at Los Alamos we used to
have a demo resolver which was a proxy server that trapped URNs,
looked to see if they were from a namespace our library knew a
lot about, and sent them to the library's resolver if they were.
Only if that failed or if they were from another namespace did
we try using the NAPTR-based resolution.

regards,
Ron



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