RFC2423 - VPIM Voice Message MIME Sub-type Registration

Network Working Group G. Vaudreuil
Request for Comments: 2423 LUCent Technologies
Obsoletes: 1911 G. Parsons
Category: Standards Track Northern Telecom
September 1998
VPIM Voice Message
MIME Sub-type Registration
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.
Overview
This document describes the registration of the MIME sub-type
multipart/voice-message for use with the Voice Profile for Internet
Mail (VPIM). A full description of usage can be found in the VPIM v2
specification.
1. Abstract
This document describes the registration of the MIME sub-type
multipart/voice-message for use with the Voice Profile for Internet
Mail (VPIM). A full description of usage can be found in the VPIM v2
specification [VPIM2]. This document revises an earlier sub-type
registration in RFC1911 [VPIM1].
2. VPIM Scope
The VPIM specification defines a restricted profile of the Internet
multimedia messaging protocols for use between voice processing
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.
The profile is intended to specify the minimum common set of features
to allow interworking between compliant systems.
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.
Typically, if more than one audio segment is present, the first is
the spoken name of the originator, the second is the spoken subject,
and the third is the voice message itself. This order, however, MUST
NOT be assumed in any case. Further, the order that the contents
appear SHOULD be the order in which they are presented to the user.
The spoken name segment, if available, shall contain the name of the
message sender in the voice of the sender. The length of the spoken
name segment must not exceed 12 seconds.
The spoken subject segment, if available, shall contain the subject
of the message sender in the voice of the sender. The length of the
spoken subject segment must not exceed 20 seconds.
The directory information part, if present, will contain information
specific to the orginator of the voice message.
Refer to the VPIM v2 Specification for details on proper usage.
4. IANA Registration
To: ietf-types@iana.org
Subject: Registration of MIME media type
multipart/voice-message
MIME media type name: multipart
MIME suBType name: voice-message
Required parameters: boundary, version
The use of boundary is defined in [MIME2]
The version parameter that contains the value "2.0" if
enclosed content conforms to [VPIM2]. The absence of this
parameter indicates conformance to the previous version
defined in RFC1911 [VPIM1].
Optional parameters: none
Encoding considerations: 7bit, 8bit or Binary
Security considerations:
This definition identifies the content as being a voice
message. In some environments (though likely not the
majority), the loss of the anonymity of the content may be a
security issue.
Interoperability considerations:
Systems developed to conform with [VPIM1] may not conform to
this registration. Specifically, the required version will
likely be absent, in this case the recipient system should
still be able to accept the message and will be able to
handle the content. The VPIM v1 positional identification,
however, would likely be lost.
Published specification:
This document
[VPIM2]
Applications which use this media type:
Primarily voice messaging
Additional information:
Magic number(s): ?
File extension(s): .VPM
Macintosh File Type Code(s): VPIM
Person & email address to contact for further information:
Glenn W. Parsons
Glenn.Parsons@Nortel.ca
Gregory M. Vaudreuil
Greg.Vaudreuil@Octel.Com
Intended usage: COMMON
Author/Change controller:
Glenn W. Parsons & Gregory M. Vaudreuil
5. Authors" Addresses
Glenn W. Parsons
Northern Telecom
P.O. Box 3511, Station C
Ottawa, ON K1Y 4H7
Canada
Phone: +1-613-763-7582
Fax: +1-613-763-4461
EMail: Glenn.Parsons@Nortel.ca
Gregory M. Vaudreuil
Lucent Technologies
17080 Dallas Parkway
Dallas, TX 75248-1905
United States
Phone/Fax: +1-972-733-2722
EMail: GregV@Lucent.Com
6. References
[MIME2] Freed, N., and N. Borenstein, "Multipurpose Internet Mail
Extensions (MIME) Part Two: Media Types ", RFC2046, November
1996.
[MIME4] Freed, N., Klensin, J., and J. Postel, "Multipurpose Internet
Mail Extensions (MIME) Part Four: Registration Procedures",
RFC2048, November 1996.
[VPIM1] Vaudreuil, G., "Voice Profile for Internet Mail", RFC1911,
February 1996.
[VPIM2] Vaudreuil, G., and G. Parsons, "Voice Profile for Internet
Mail - version 2", RFC2421, September 1998.
[REQ] Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", BCP 14, RFC2119, March 1997.
7. Full Copyright Statement
Copyright (C) The Internet Society (1998). All Rights Reserved.
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