Minimal PSTN address format in Internet Mail (RFC2303)
Original Publication Date: 1998-Mar-01
Included in the Prior Art Database: 2019-Feb-15
Internet Society Requests For Comment (RFCs)
This memo describes the MINIMAL addressing method to encode PSTN addresses into e-mail addresses and the standard extension mechanism to allow definition of further standard elements. [STANDARDS-TRACK]
Network Working Group C. Allocchio Request for Comments: 2303 GARR-Italy Category: Standards Track March 1998
Minimal PSTN address format in Internet Mail
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 (1998). All Rights Reserved.
This memo describes a simple method of encoding PSTN addresses in the local-part of Internet email addresses, along with an extension mechanism to allow encoding of additional standard attributes needed for email gateways to PSTN-based services.
As with all Internet mail addresses, the left-hand-side (local- part) of an address generated according to this specification, is not to be interpreted except by the MTA that is named on the right-hand-side (domain).
Since the very first e-mail to PSTN services gateway appeared, a number of different methods to specify a PSTN address as an e-mail address have been used by implementors. Two major objectives for this were
- enable an e-mail user to access these services from his/her e-mail interface;
- enable some kind of "PSTN over e-mail service" transport, to reduce the costs of PSTN long distance transmissions, and use the existing e-mail infrastructure.
Allocchio Standards Track [Page 1]
RFC 2303 Minimal PSTN in Internet Mail March 1998
This memo describes the MINIMAL addressing method to encode PSTN addresses into e-mail addresses and the standard extension mechanism to allow definition of further standard elements. The opposite problem, i.e. to allow a traditional numeric-only PSTN device user to access the e-mail transport service, is not discussed here.
All implementations supporting this PSTN over e-mail service MUST support as a minimum the specification described in this document. The generic complex case of converting the whole PSTN addressing into e-mail is out of scope in this minimal specification: there is some work in progress in the field, where also a number of standard optional extensions are being defined.
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 .
2. Minimal PSTN address
The minimal specification of a PSTN address in e-mail address is as follows:
pstn-address = pstn-mbox [ qualif-type1 ]
pstn-mbox = service-selector "=" global-phone
service-selector = 1*( DIGIT / ALPHA / "-" ) ; note that SP (space) is not allowed in ; service-selector. ; service-sel...