RFC 2421 (rfc2421) - Page 3 of 56

Voice Profile for Internet Mail - version 2

RFC 2421                        VPIM v2                   September 1998


1. Abstract

   A class of special-purpose computers has evolved to provide voice
   messaging services.  These machines generally interface to a
   telephone switch and provide call answering and voice messaging
   services.  Traditionally, messages sent to a non-local machine are
   transported using analog networking protocols based on DTMF signaling
   and analog voice playback.  As the demand for networking increases,
   there is a need for a standard high-quality digital protocol to
   connect these machines.  The following document is a profile of the
   Internet standard MIME and ESMTP protocols for use as a digital voice
   messaging networking protocol. The profile is referred to as VPIM
   (Voice Profile for Internet Mail) in this document.

   This profile is based on earlier work in the Audio Message
   Interchange Specification (AMIS) group that defined a voice messaging
   protocol based on X.400 technology.  This profile is intended to
   satisfy the user requirements statement from that earlier work with
   the industry standard ESMTP/MIME mail protocol infrastructures
   already used within corporate intranets. This second version of VPIM
   is based on implementation experience and obsoletes RFC 1911 which
   describes version 1 of the profile.

2. Scope

   MIME is the Internet multipurpose, multimedia messaging standard.
   This document explicitly recognizes its capabilities and provides a
   mechanism for the exchange of various messaging technologies,
   primarily voice and facsimile.

   This document specifies a restricted profile of the Internet
   multimedia messaging protocols for use between voice processing
   server platforms.  These platforms have historically been special-
   purpose computers and often do not have the same facilities normally
   associated with a traditional Internet Email-capable computer.  As a
   result, VPIM also specifies additional functionality as it is needed.
   This profile is intended to specify the minimum common set of
   features to allow interworking between compliant systems.

2.1 Voice Messaging System Limitations

   The following are typical limitations of voice messaging platform
   which were considered in creating this baseline profile.

     1) Text messages are not normally received and often cannot be
     easily displayed or viewed.  They can often be processed only via
     text-to-speech or text-to-fax features not currently present in
     many of these machines.



Vaudreuil & Parsons         Standards Track