RFC 2423 (rfc2423) - Page 2 of 6

VPIM Voice Message MIME Sub-type Registration

Alternative Format: Original Text Document


RFC 2423                multipart/voice-message           September 1998


   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED",  "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [REQ].

3. Voice Message Interchange

3.1 multipart/voice-message

   The MIME sub-type multipart/voice-message is defined to hold specific
   media contents that are interchanged in messages between voice
   messaging systems described in [VPIM2].  Essentially, the sub-type
   provides a simple wrapper that easily identifies the entire content
   as being the components of a single voice message.  The sub-type is
   identical in semantics and syntax to multipart/mixed, as defined in
   [MIME2].  As such, it may be safely interpreted as a multipart/mixed
   by systems that do not understand the sub-type (only the
   identification as a voice message would be lost).

   This mechanism allows the insertion of an explanatory preamble (e.g.
   VPIM voice message attached) for recipients who read the message with
   pre-MIME software, since the preamble will be ignored by MIME-
   compliant software.

   In addition to the MIME required boundary parameter, a version
   parameter is also required for this sub-type.  This is to
   distinguish, this refinement of the sub-type from the previous
   definition in [VPIM1].  The value of the version parameter is "2.0"
   if the content conforms to the requirements of [VPIM2].  Should there
   be further revisions of this content type, there MUST be backwards
   compatibility (i.e. systems implementing version n can read version
   2, and systems implementing version 2 can read version 2 contents
   within a version n).  The default version value (when the parameter
   is missing) is 1, indicating the content conforms to the requirements
   of [VPIM1].

   [VPIM2] describes the restriction that only specific media types,
   applicable to voice messaging, are valid `next-level' contents of
   this sub-type (when version=2.0).  They are: audio/*, image/*,
   message/rfc822 and application/directory.  The multipart provides for
   the packaging of as many of these contents as is necessary.

3.2 VPIM v2 Usage

   The multipart/voice-message sub-type is a primary component of the
   VPIM specification [VPIM2].  All VPIM Messages MUST contain this
   sub-type to identify the wrapping of a voice message.  The contents
   of this wrapper can vary from only one audio/32KADPCM content to a
   complex set of related and nested contents.



Vaudreuil & Parsons         Standards Track

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