RFC 3405 (rfc3405) - Page 2 of 10

Dynamic Delegation Discovery System (DDDS) Part Five: URI

Alternative Format: Original Text Document


RFC 3405          DDDS URI.ARPA Assignment Procedures       October 2002


   8.    The URN Registration in the URI.ARPA zone  . . . . . . . . .  7
   9.    IANA Considerations  . . . . . . . . . . . . . . . . . . . .  7
   10.   Security Considerations  . . . . . . . . . . . . . . . . . .  7
   11.   Acknowledgements . . . . . . . . . . . . . . . . . . . . . .  7
   12.   References . . . . . . . . . . . . . . . . . . . . . . . . .  8
   13.   Author's Address . . . . . . . . . . . . . . . . . . . . . .  9
   14.   Full Copyright Statement . . . . . . . . . . . . . . . . . . 10

1. Introduction

   This document defines the policies and procedures for inserting
   Naming Authority Pointer (NAPTR) records into the 'URI.ARPA' and
   'URN.ARPA' zones for the purpose of resolving Uniform Resource
   Identifiers (URIs) according to "Dynamic Delegation Discovery System
   (DDDS) Part Four:  The URI Resolution Application" (RFC 3402) [2],
   which is an Application that uses the Domain Name System (DNS) based
   DDDS Database.  All of these concepts are defined in RFC 3401 [1].
   It is very important to note that it is impossible to correctly
   understand this document without reading RFC 3401 and the documents
   it specifies.

   RFC 3403 defines a how DNS is used as a DDDS database that contains
   URI delegation rules (sometimes called resolution hints).  That
   document specifies that the first step in that algorithm is to append
   'URI.ARPA' to the URI scheme and retrieve the NAPTR record for that
   domain-name.  I.e., the first step in resolving "http://foo.com/"
   would be to look up a NAPTR record for the domain "http.URI.ARPA".
   URN resolution also follows a similar procedure but uses the
   'URN.ARPA' zone as its root.  This document describes the procedures
   for inserting a new rule into the 'URI.ARPA' and 'URN.ARPA' zones.

2. URI Resolution vs URN Resolution

   RFC 3402 [2] defines how both URI [7] resolution and URN [6]
   resolution work when DNS is used as the delegation rule (or hint)
   database.  Specifically it says that the initial instructions
   ('hints') for DNS-based resolution of URIs are stored as resource
   records in the 'URI.ARPA' DNS zone.

   Since a URN is a URI scheme, a hint for resolution of the URI prefix
   'urn:' will also be stored in the 'URI.ARPA' zone.  This rule states
   that the namespace id [6] is extracted, 'URN.ARPA' is appended to the
   end of the namespace id, and the result is used as the key for
   retrieval of a subsequent NAPTR record [4].







Mealling                 Best Current Practice

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