Re: re URN, URL, URI

Jerome McDonough (jmcdonou@library.berkeley.edu)
Thu, 22 Oct 1998 08:48:13 -0700

At 06:55 AM 10/22/98 -0700, Terry Allen wrote:
>There is a generally available resolution mechanism, through DNS, but
>it has not implemented except on a test basis so far as I know. URNs,
>of course, may be useful within more constrained contexts. Note that
>URN resolution won't happen for you without some effort on your part.
>
>| * Where would the service reside(client/server)?
>
>You would want to have resolution hints on the client end, and be
>able to check your cache for documents you already have; otherwise
>consult RFC 2168 for the DNS approach.
>

Just a further note on this resolution architecture issue: there appears
to be a growing interest in an architecture in which a proxy sits between
clients and DNS, in order to resolve certain URNs within a local context
rather than the global one specified by DNS NAPTR records. Example: You're
running a library, and have a client within the library trying
to resolve an ISBN for a book that you hold in electronic format. The
client contacts a resolution proxy that you run. The proxy first checks
to see if the work is held locally, and if so, returns the URL for that
copy. If there's no local copy, then the proxy contacts DNS for a NAPTR
record for the official URN resolver(s) for the URN's namespace. Ron Daniel
and Mike Mealling also developed this on an experimental basis in the work
that Terry mentioned at Los Alamos, using Apache for the proxy services.

Jerome McDonough -- jmcdonou@library.Berkeley.EDU | (......)
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