Telephone Number Mapping                                       A. Brown
Internet Draft                                          Nortel Networks
Document: <draft-ietf-enum-rqmts-00.txt>                       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].

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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


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