CONTENTS

1 Scope 1
2 References
3 Definitions
3.1 General terms
3.2 E.164-specific terms
3.3 ITU-T non-numbering terms
3.4 DNS-specific terms
3.5 ENUM-related terms
4 Abbreviations
5 Background
5.1 What is ENUM
5.2 DNS zones and delegation
5.3 Tiered architecture
5.4 Overview of ENUM functions and entities
6 General administrative issues and options
6.1 Identification of ENUM Tier 1 Registry or Registries
6.2 Delegation of names from the ENUM Tier 1 Registry
6.3 Determination of ENUM Tier 2
Name Server Provider and ENUM Registrars
6.4 Validation of ENUM requests and records
6.5 Relationships of administrative structures with ENUM zone structures
6.6 Additional considerations
7 Implications of ENUM for country codes assigned to geographic areas
7.1 Administration aspects, options and interfaces
7.2 Review of consequences
7.2.1 Ease of validation of relation between E.164 number and telephony subscriber
7.2.2 Analysis of complexity and effort associated with provisioning
8 Summary and conclusion
9 Supplement history
Appendix I Typical PSTN-IP call flows using SIP
Appendix II Integrated numbering plans