Voice Messaging Directory: Address Resolution Services
draft-vaudreuil-vpimdir-ars-00

Abstract

The telephone number delegation and call routing system is a hierarchitecal system. ITU standard E.164 defines the structure of the telephone number as follows: {country code) (Nationally significant part) The country code may be from one to three digits, and the total length may be up to 16 digits. The nationally significant portion may be arbitraily divided on any number boundary. In many countries numering plans, the divisions are not uniform, that is, the 'area codes' or 'City codes' may be of varying lengths within a single country and the total number of digits may be variable. Within this flexiblity, it is always the case that the delegation of authority is done left-to-right. With this assumption, a numbering tree can be built on a digit-by-digit basis can represent any of these hierarchical structures. DNS permits the delegation of authority on arbitary boundaries such that a delegation to country code '1', '44', and '972' can all coexist under a single numbering plan root. The same applies for 'area codes', 'City codes' or 'service selectors' within numbering plans. The protocol mechanics outlined in this document are devised in such a manner that the clients do not need any knowledge of the numbering plan itself to correctly construct a query of the Address Resolution Service. The client may mechanically collect digits, format the query, and receive a response to any telephone number in the world.

Authors

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)