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   Will DDDS save us from URI madness?

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Anyone looking for information about how to get straight answers about
URIs even when they aren't easily resolved should take a look at the
Dynamic Delegation Discovery System (DDDS), one of the more recent bits
from the IETF:

DDDS starts off fairly unpromisingly:
The DDDS is an abstract algorithm for applying dynamically retrieved
string transformation rules to an application-unique string.

It gets slightly better:
The Dynamic Delegation Discovery System is used to implement lazy
binding of strings to data, in order to support dynamically configured
delegation systems.  The DDDS functions by mapping some unique string
to data stored within a DDDS Database by iteratively applying string
transformation rules until a terminal condition is reached.  This
document defines the entire DDDS standard by listing the documents that
make up the complete specification at this time.

And then finally, in
This document describes a DDDS Application for resolving URIs.  It does
not define the DDDS Algorithm or a Database.  The entire series of
documents that do so are specified in "Dynamic  Delegation Discovery
System (DDDS) Part One: The Comprehensive DDDS Standard" (RFC WWWW)
[1].  It is very important to note that it is impossible to read and
understand any document in that series without reading the related

Uniform Resource Identifiers have been a significant advance in
retrieving Internet-accessible resources.  However, their  brittle
nature over time has been recognized for several years.  The Uniform
Resource Identifier working group proposed the development of Uniform
Resource Names [8] to serve as persistent, location-independent
identifiers for Internet resources in order to overcome most of the
problems with URIs.  RFC  1737 [6] sets forth requirements on URNs.

During the lifetime of the URI-WG, a number of URN proposals were
generated.  The developers of several of those proposals met in a
series of meetings, resulting in a compromise known as the Knoxville
framework.  The major principle behind the Knoxville framework is that
the resolution system must be separate from the way names are assigned.
 This is in marked contrast to most URIs, which identify the host to
contact and the protocol to use.  Readers are referred to [7]for
background on the Knoxville framework and for additional information on
the context and purpose of this proposal.

Separating the way names are resolved from the way they are constructed
provides several benefits.  It allows multiple naming approaches and
resolution approaches to compete, as it allows different protocols and
resolvers to be used.  There is just one problem with such a separation
- how do we resolve a name when it can't give us directions to its

For the short term, DNS is the obvious candidate for the resolution
framework, since it is widely deployed and understood.  However, it is
not appropriate to use DNS to maintain information on a per- resource
basis.  First of all, DNS was never intended to handle that many
records.  Second, the limited record size is inappropriate for catalog
information.  Third, domain names are not appropriate as URNs.

Therefore our approach is to use the DDDS to locate "resolvers" that
can provide information on individual resources, potentially including
the resource itself.  To accomplish this, we "rewrite" the URI into a
Key following the rules found in the Dynamic Delegation Discovery
System (DDDS).  This document describes URI Resolution as an
application of the DDDS and specifies the use of at least one Database
based on DNS.

There are also some other useful bits about URLs, URNs, and URIs
available at http://uri.net.

Overall, I suspect the answer to my own question is "no", since piling
on specs to patch holes in other specs is rarely all that helpful.  This
may be useful for some situations, however.
Simon St.Laurent
Ring around the content, a pocket full of brackets
Errors, errors, all fall down!


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