RFC 3403 DDDS DNS Database October 2002 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . 3 3. DDDS Database Specification . . . . . . . . . . . . . . . . 3 4. NAPTR RR Format . . . . . . . . . . . . . . . . . . . . . . 5 4.1 Packet Format . . . . . . . . . . . . . . . . . . . . . . . 5 4.2 Additional Information Processing . . . . . . . . . . . . . 7 4.2.1 Additional Section processing by DNS servers . . . . . . . . 7 4.2.2 Additional Section processing by resolver/applications . . . 7 4.3 Master File Format . . . . . . . . . . . . . . . . . . . . . 7 5. Application Specifications . . . . . . . . . . . . . . . . . 8 6. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 8 6.1 URN Example . . . . . . . . . . . . . . . . . . . . . . . . 8 6.2 E164 Example . . . . . . . . . . . . . . . . . . . . . . . . 10 7. Advice for DNS Administrators . . . . . . . . . . . . . . . 10 8. Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . 11 10. Security Considerations . . . . . . . . . . . . . . . . . . 11 References . . . . . . . . . . . . . . . . . . . . . . . . . 12 Author's Address . . . . . . . . . . . . . . . . . . . . . . 13 Full Copyright Statement . . . . . . . . . . . . . . . . . . 14 1. Introduction The Dynamic Delegation Discovery System (DDDS) 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 describes the way in which the Domain Name System (DNS) is used as a data store for the Rules that allow a DDDS Application to function. It does not specify any particular application or usage scenario. The entire series of documents is specified in "Dynamic Delegation Discovery System (DDDS) Part One: The Comprehensive DDDS" (RFC 3401) [1]. It is very important to note that it is impossible to read and understand any document in that series without reading the related documents. The Naming Authority Pointer (NAPTR) DNS Resource Record (RR) specified here was originally produced by the URN Working Group as a way to encode rule-sets in DNS so that the delegated sections of a Uniform Resource Identifiers (URI) could be decomposed in such a way that they could be changed and re-delegated over time. The result was a Resource Record that included a regular expression that would be used by a client program to rewrite a string into a domain name. Mealling Standards Track