Calling Line Identification for Voice Mail Messages
RFC 3939

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• 09

Network Working Group                                         G. Parsons
Request for Comments: 3939                                   J. Maruszak
Category: Standards Track                                Nortel Networks
                                                           December 2004

          Calling Line Identification for Voice Mail Messages

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 (2004).

Abstract

   This document describes a method for identifying the originating
   calling party in the headers of a stored voice mail message.  Two new
   header fields are defined for this purpose: Caller_ID and
   Called_Name.  Caller_id is used to store sufficient information for
   the recipient to callback, or reply to, the sender of the message.
   Caller-name provides the name of the person sending the message.

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RFC 3939              Calling Line Identification          December 2004

Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  2
   2.  Conventions Used in this Document. . . . . . . . . . . . . . .  3
   3.  Calling Line Identification Field. . . . . . . . . . . . . . .  3
       3.1.  Internal Call. . . . . . . . . . . . . . . . . . . . . .  4
       3.2.  External Call. . . . . . . . . . . . . . . . . . . . . .  4
       3.3.  Numbering Plan . . . . . . . . . . . . . . . . . . . . .  4
       3.4.  Date Header. . . . . . . . . . . . . . . . . . . . . . .  5
   4.  Caller Name Field. . . . . . . . . . . . . . . . . . . . . . .  5
   5.  Formal Syntax. . . . . . . . . . . . . . . . . . . . . . . . .  6
       5.1.  Calling Line Identification Syntax . . . . . . . . . . .  6
       5.2.  Caller Name Syntax . . . . . . . . . . . . . . . . . . .  6
       5.3.  Examples . . . . . . . . . . . . . . . . . . . . . . . .  6
   6.  Other Considerations . . . . . . . . . . . . . . . . . . . . .  6
   7.  Security Considerations. . . . . . . . . . . . . . . . . . . .  7
   8.  IANA Considerations. . . . . . . . . . . . . . . . . . . . . .  7
   9.  References . . . . . . . . . . . . . . . . . . . . . . . . . .  8
       9.1.  Normative References . . . . . . . . . . . . . . . . . .  8
       9.2.  Informative References . . . . . . . . . . . . . . . . .  8
   10. Acknowledgments. . . . . . . . . . . . . . . . . . . . . . . .  9
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 10
   Full Copyright Statement . . . . . . . . . . . . . . . . . . . . . 11

1.  Introduction

   There is currently a need for a mechanism to identify the originating
   party of a voice mail message, outside of the "FROM" header
   information.  The telephone number and name of the caller are
   typically available from the telephone network, but there is no
   obvious header field to store this in an Internet Mail message.

   This information is intended for use when the VPIM message format is
   used for storing "Call Answer" voice messages in an Internet Mail
   message store, i.e., the calling party leaves a voice message for the
   recipient, who was unable to answer the call.  The implication is
   that there is no RFC 2822 address known for the originator.

   [VPIMV2R2] suggests the originating number be included as an Internet
   address, using the first method shown below.  There are several other
   ways to store this information, but they all involve some
   manipulation of the "From" field.  For example:

      1. From: "416 555 1234" <non-mail-user@host>
      2. From: "John Doe" <4165551234@host>
      3. From:  unknown:;

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RFC 3939              Calling Line Identification          December 2004

   Since any of these is a forced translation, it would be useful to
   store the calling party's name and number as presented by the
   telephone system to the called party without manipulation.  This
   would allow the calling party's information to be displayed to the
   recipient (similar to it appearing on the telephone) and also allow
   future determination of an Internet address for the originator (if
   one exists).  Note that there is no requirement to store meta-data
   (e.g., type of number, presentation restricted), as this information
   is not presented to the called party and is generally not available
   to voice mail systems.  The intent is to store the available
   information to an analog (non-ISDN) phone (e.g., per [T1.401] in
   North America).

   [RFC2076] currently lists "phone" as an Internet message header which