RFC 3245 (rfc3245) - Page 2 of 10
The History and Context of Telephone Number Mapping (ENUM) Operational Decisions: Informational Documents Contributed to ITU-T Study Group 2 (SG2)
Alternative Format: Original Text Document
RFC 3245 History and Context of ENUM Operational Decisions March 2002 1. Introduction: ENUM Background Information In January 2002, in response to questions from the ITU-T Study Group 2 (referred to just as "SG2", below), specifically its group working on "Questions 1 and 2", and members of the IETF and telecommunications communities, Scott Bradner, as Area Director responsible for the ENUM work and ISOC Vice President for Standards, initiated an effort to produce explanations of the decisions made by the IETF about ENUM administration. The effort to produce and refine those documents eventually involved him, Patrik Faltstrom (author of RFC 2916), and several members of the IAB. The documents have now been contributed to ITU-T, and are being published as internal SG2 documents. This document provides the IETF community a copy of the information provided to SG2. Section 2 below contains the same content as COM 2-11-E, section 3 contains the same content as COM 2-12-E, and section 4 contains the same content as SG2 document COM 2-10-E. The documents being published within SG2 show their source as "THE INTERNET SOCIETY ON BEHALF OF THE IETF", which is a formality deriving from the fact that ISOC holds an ITU sector membership on behalf of the IETF. 2. Why one and only one domain is used in ENUM 2.1. Introduction This contribution is one of a series provided by the IETF to ITU-T SG2 to provide background information about the IETF's ENUM Working Group deliberations and decisions. This particular contribution addresses the IETF's decision that only a single domain could be supported in ENUM. 2.2. The need for a single root in the DNS In the Domain Name System (DNS), each domain name is globally unique. This is a fundamental fact in the DNS system and follows mathematically from the structure of that system as well as the resource identification requirements of the Internet. Which DNS server is authoritative for a specific domain is defined by delegations from the parent domain, and this is repeated recursively until the so-called root zone, which is handled by a well-known set of DNS servers. Note that words like "authoritative" and "delegation" and their variations are used here in their specific, technical, DNS sense and may not have the same meanings they normally would in an ITU context. Klensin Informational
