GSTN Address Element Extensions in E-mail Services
RFC 2846

Network Working Group                                       C. Allocchio
Request for Comments: 2846                                    GARR-Italy
Category: Standards Track                                      June 2000

           GSTN Address Element Extensions in E-mail Services

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2000).  All Rights Reserved.

Abstract

   There are numerous applications where there is a need for interaction
   between the GSTN addressing and Internet addressing.  This memo
   defines a full syntax for one specific case, where there is a need to
   represent GSTN addresses within Internet e-mail addresses. This full
   syntax is a superset of a minimal syntax which has been defined in
   [1].

1. Introduction

   The possible elements composing a "Global Switched Telephone Network
   (GSTN) address in e-mail" (also known as the Public Switched
   Telephone Network - PSTN) can vary from a minimum number up to a
   really large and complex collection. As noted the minimal format and
   general address syntax have been defined in [1], along with the
   mechanism needed to define additional address elements. This memo
   uses this extension mechanism to complete the syntax for representing
   GSTN addresses within e-mail addresses and contains the IANA
   registrations for all newly defined elements.

   In particular, the following additional address elements shall be
   defined:

   -  the detailed definition of GSTN number formats, in order to cover
      various alternative standard GSTN numbering schemes, (i.e. gstn-
      phone, sub-addr-spec and post-dial)

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RFC 2846       GSTN Address Extensions in E-mail Services      June 2000

   -  the message originator and/or recipient specification (pstn-
      recipient)

   GSTN addresses in e-mail MAY contain additional elements defined and
   registered in other specifications (see for example "T33S" element in
   [2]), but they MUST use definitions contained in this memo for those
   elements specified here.

   In particular, "service-selector" names and "qualif-type1" elements
   MUST be registered with IANA, and published within the "ASSIGNED
   NUMBERS" document. This provides a standard mechanism for extending
   the element sets and should avoid unnecessary duplication. IANA
   Registration form templates for the purpouse of registering new
   elements are provided in Appendix B. In addition the IANA
   consideration section of this document defines the procedures
   required to proceed with new registrations.

   A collection of forms for already defined "service-selector" and
   "qualif-type1" elements is listed in appendix C and appendix D
   respectively.

   In particular, efforts have been made to maintain compatibility with
   elements defined in existing e-mail gateway services and standard
   specifications. For example, to the extent possible, compatibility
   has been maintained with the MIXER [3] gateways specifications.

1.1 Relationship with Internet addressing other than e-mail

   Even if in this memo we focus on e-mail addresses, a number of
   elements defined in this specification can also be used for other
   specifications dealing with embedding GSTN addresses into other
   addresses: for example there is some work in progress about URLs
   specification which adopts similar definitions, with slight changes
   in the global syntax due to specific URL format.

1.2 Terminology and Syntax conventions

   In this document the formal definitions are described using ABNF
   syntax, as defined into [4]. We will also use some of the "CORE
   DEFINITIONS" defined in "APPENDIX A - CORE" of that document. The
   exact meaning of the capitalised words

   "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD",
   "SHOULD NOT", "RECOMMENDED",  "MAY", "OPTIONAL"

   is defined in reference [5].

Allocchio                   Standards Track                     [Page 2]
RFC 2846       GSTN Address Extensions in E-mail Services      June 2000

2. GSTN extended number and pstn-mbox extended format