Telephone Number Mapping A. Brown Internet Draft Nortel Networks Document: November 1999 Category: Informational ENUM Requirements Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026 [1]. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet- Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. 1. Abstract This paper defines the requirements for a DNS-based architecture and protocols for mapping a telephone number to a set of attributes (e.g., URLs) which can be used to contact a resource associated with that number. There are many possible protocols that can be considered for a telephone number mapping service. The purpose of this document is to focus discussion on a DNS-based solution. The intention is to enumerate the expectations of such a solution and to clarify the scope. 2. Conventions used in this document The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC-2119 [2]. 3. Requirements 3.1 Endpoint Address Lookup The system SHALL provide a service for the retrieval of endpoint addresses (e.g., email address, IP address, SIP address, etc. )in the form or URLs. The system SHALL also be capable of retrieving the addresses of servers, if available, which may contain this endpoint information. ENUM Requirements November 1999 3.2 Capabilities Retrieval/Negotiation The retrieval or negotiation of capabilities is beyond the scope of the system. 3.3 Retrieval of Additional Information The retrieval of additional, application-specific information (e.g., spoken name for verification purposes) is beyond the scope of the system. The system MUST provide a service for the retrieval of protocol and service information if available. 3.4 Qualification of the Request The system is not required to enable the qualification of a request by a user, for the purposes of filtering for reducing returned information or for traffic reduction. 3.5 Provisioning The scope of the architecture and protocol does not include provisioning. As well, propagation of changes to information accessible via the system is not expected to be instantaneous. 3.6 Response Timeout The system SHALL have a defined timeout mechanism. 3.7 Global Number Portability The system MUST support existing local number portability mechanisms, where applicable. It is RECOMMENDED that the system not be designed in such as way as to impede future global number portability. 3.8 Scalability The system MUST scale to handle quantities of telephone numbers and queries comparable to current and expected future PSTN usage. 3.9 Query Performance The system is not expected to respond to queries with the same performance levels as current PSTN queries. 3.10 Other PSTN Services Other PSTN type services such as Emergency 911, directory assistance 411, and other carrier codes and services accessible via phone signaling is outside the scope of ENUM. ENUM Requirements November 1999 3.11 Privacy The system MUST allow the owner of the telephone number to control the information which prospective callers may receive. 3.12 Competition The system MUST provide the capability for more than one organization to provide information on the same telephone number. 3.13 Authorization of Requests and Responses The system SHALL enable the authorization of requests and responses. 3.14 Privacy and Integrity of Requests and Responses The system SHALL enable the privacy and integrity of requests and responses. 3.15 Call Routing The system is not required to provide a service for routing calls or locating gateways to a specific service. 3.16 Service Logic The system is not responsible for employing service logic for the intelligent retrieval of information. 3.17 E.164 Numbers The system is not responsible for returning information on private numbering plans and non-E.164 numbers. The system is responsible for returning information on 1-800 and other legitimate E.164 numbers. 4. Security Considerations This document specifies several security requirements including privacy of information, and authorization, privacy and integrity or requests and responses. The system will be designed to retrieve information required to initiate an Internet telephony session. Each of these session types will have their own security threats, which should be addressed in the groups responsible for those services. 5. References 1 Bradner, S., "The Internet Standards Process -- Revision 3", BCP 9, RFC 2026, October 1996. ENUM Requirements November 1999 2 Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997 6. Acknowledgements This document is based on discussions from the ENUM working group. 7. Author's Addresses Anne Brown Nortel Networks 1050 Morrison Drive Nepean, Ontario K2H 8K7 Phone: +1 613 765 5274 Email: arbrown@nortelnetworks.com Full Copyright Statement "Copyright (C) The Internet Society (date). All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implmentation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. 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