Minimal PSTN address format in Internet Mail
RFC 2303
Document | Type |
RFC - Proposed Standard
(March 1998; No errata)
Obsoleted by RFC 3191
|
|
---|---|---|---|
Author | Claudio Allocchio | ||
Last updated | 2013-03-02 | ||
Stream | Internent Engineering Task Force (IETF) | ||
Formats | plain text html pdf htmlized (tools) htmlized bibtex | ||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 2303 (Proposed Standard) | |
Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | (None) | ||
Send notices to | (None) |
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 Notice Copyright (C) The Internet Society (1998). All Rights Reserved. IESG NOTE 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). 1. Introduction 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 [7]. 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 [6]. 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-selector MUST be handled as a case ; INSENSITIVE string by implementations. Specifications adopting the "pstn-address" definition MUST define a unique case insensitive "service-selector" element to identify the specific messaging service involved. These specifications MUST also define which minimal "qualif-type1" extensions, if any, MUST be supported for the specified service. Implementations confirming to these minimal requirements specification are allowed to ingnore any other non-minimal extensions address element which can be present in the "pstn-address". However, Allocchio Standards Track [Page 2] RFC 2303 Minimal PSTN in Internet Mail March 1998 conforming implementations MUST preserve all "qualif-type1" address elements they receive. The generic "qualif-type1" element is defined as: qualif-type1 = "/" keyword "=" string keyword = 1*( DIGIT / ALPHA / "-" ) ; note that SP (space) is not allowed in keyword string = PCHAR ; note that printable characters are %x20-7E As such, all "pstn-address" extensions elements MUST be defined in the "qualif-type1" form. 2.1 Minimal "global-phone" definition We now define the minimal supported syntax for global-phone: global-phone = "+" 1*( DIGIT , written-sep ) written-sep = ( "-" / "." ) The use of other dialling schemas for PSTN numbers (like private numbering plans or local dialling conventions) is also allowed.Show full document text