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 (C) The Internet Society (2000). All Rights Reserved.
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
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 , 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
- 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)
Allocchio Standards Track [Page 1]RFC 2846 GSTN Address Extensions in E-mail Services June 2000
- the message originator and/or recipient specification (pstn-
GSTN addresses in e-mail MAY contain additional elements defined and
registered in other specifications (see for example "T33S" element in
), 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
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  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 . 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 .
Allocchio Standards Track [Page 2]RFC 2846 GSTN Address Extensions in E-mail Services June 20002. GSTN extended number and pstn-mbox extended format