One document matched: draft-ema-vpim-voicemsg-00.txt
draft-ema-vpim-voicemsg-00.txt
Internet Draft Stuart McRae
Expires in six months Lotus Development October 22, 1999
Internet Voice Messaging
<draft-ema-vpim-voicemsg-00.txt>
Status of this Memo
This document is an Internet-Draft and is in full conformance
with all provisions of Section 10 of RFC2026.
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1. Abstract
This document provides for the carriage of voicemail messages
over the Internet.
The concept described in this document was originally called VPIM
v3. This term has been dropped to reflect the fact that it is not
a successor format to VPIM v2, but rather an alternative
specification for a different application.
2. Introduction
People naturally communicate using their voices, and this is
preferable to typing for many forms of communication. Therefore,
if voice messaging is standardised in Internet mail it will be
possible for users to use this preferred means of communication,
when appropriate, as well as enabling new devices without
keyboards to be developed which allow users to participate in
electronic messaging when mobile, or in a hostile environments,
or in spite of disabilities.
There are currently a number of implementations of systems which
will transmit a voicemail messages over the Internet using
SMTP/MIME. However these systems suffer from a lack of
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interoperability because various aspects of such a message have
not hitherto been standardised.
Specifically, there are three classes of solution of this form
voicemail messages in an SMTP/MIME compliant e-mail system when
received, subsequently allowing retrieval from a mail client or
the telephone; unified messaging solutions which store voicemail currently in use: unified messaging solutions which save
messages in a proprietary e-mail system which then get forwarded
through a gateway to SMTP/MIME for Internet transmission; and
voicemail systems conforming to the Voice Profile for Internet
Messaging (VPIM v2 as defined in RFC 2421 [VPIM2]) for forwarding
messages to remote voicemail systems. Note that VPIM v2 was
designed to allow two voicemail systems to exchange messages -
not to allow a voicemail system to interoperate with a desktop
e-mail client.
These solutions suffer from a lack of interoperability when an
Internet mail recipient receives such a message because there is
no standard definition for how a voicemail message should be
represented in SMTP/MIME, resulting in messages which cannot be
read by the recipient (because of the encoding used), or simply
look ugly.
This document therefore proposes a standard mechanism for
representing a voicemail message within SMTP/MIME, and a standard
encoding for the audio content, which unified messaging systems
and mail clients MUST implement to ensure interoperability. By
using a standard SMTP/MIME representation, and a widely
implemented audio encoding, this will also permit most users of
e-mail clients not specifically implementing the standard to
still access the voicemail message. In addition, this document
describes features an e-mail client SHOULD implement to allow it
to display voicemail message in a more friendly, context
sensitive way to the user, and intelligently provide some of the
additional functionality typically found in voicemail systems
(such as responding with a voice message instead of e-mail).
This document is partly derived from VPIM v2 [VPIMV2], from an
original proposal for VPIM v3 [VPIMV3], and from an a simple
version of that specification [SIMPLEV3]. It is intended to be
based on the VPIM v3 goals document [GOALS], as revised at
subsequent meetings (this document is currently being revised and
reissued).
It is highly desirable that unified messaging mail clients also
be able to interoperate with voicemail servers. This is possible
today, providing the client implements VPIM v2 [VPIMV2] in
addition to this specification, and uses it to construct messages
to be sent to a voicemail server. Separate work may be undertaken
in the VPIM Working Group to provide further interoperability
between clients implementing this specification and voicemail
systems implementing VPIM.
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For more information on VPIM v2 and the activities of the VPIM
3. Conventions Used in this Document working group, see
"MAY" in this document are to be interpreted as defined in "Key
words for use in RFCs to Indicate Requirement Levels" [KEYWORDS].
4. Mes ge Format http://www.ema.org/vpim/. The key words "MUST", "MUST NOT", "SHOULD", "SHOULD NOT", and
All messages MUST conform with the Internet Mail format as
described in DRUMS [DRUMS]. Any content type is allowed to be in
a message.
The top level content type on origination of a new, forwarded or
reply message SHOULD be either multipart/mixed or sa
multipart/related. Top level content of audio/wav MUST be
supported for receipt, to interoperate with clients capable of
generating suitably encoded voice content but not supporting this
specification in full.
The top level content type on origination of a delivery
notification message MUST be multipart/report.
Work is currently underway to define a mechanism to indicate the
primary content type of a message (i.e. to characterise a message
as being a voicemail message, rather than an e-mail with a WAV
file attached). It is also desirable to identify critical
contents (e.g. the voice message the use actually sent), as
opposed to any subsidiary attachments, to ensure that these are
not discarded. These two concepts could be indicated separately,
or combined. This document will be updated once that work has
generated an Internet Draft.
An implementation MAY use the multipart/voice-message content
type as described in [VPIMVM] to package audio content together
as a voice message in a manner conformant with VPIM v2 [VPIMV2].
5. Transport
All transport MUST support Internet Mail transport (SMTP/ESMTP)
as described in DRUMS [DRUMS].
6. Addressing
Any valid Internet Mail address MAY be used.
It is desirable to be able to use and onramp/offramp for delivery
of a voicemail message to a user, which will result in specific
addressing requirements, based on service selectors as defined in
[SELECTOR]. Further work on these requirements is in progress.
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It is desirable to permit the use of a directory service to map
7. Notifications
DSN MUST be supported. All of messages MUST result the E.164 phone number of the recipient into an SMTP mailbox
in a NDN.
Partial (to indicate that one or more contents could not be address. How this might be achieved is currently under study. non-delivery DSNs
stored/relayed by the receiving MTA) SHOULD be supported.
MDN SHOULD be supported. Partial MDNs (to indicate that one or
more contents could not be rendered) SHOULD also be supported.
Work on defining partial MDNs and DSNs is currently in process.
8. Voice Contents
Voice messages may be contained at any location within a message
and MUST be contained in an audio/* content-type. The VOICE
parameter described in [VPIMV2] SHOULD be used to identify the
any spoken names or spoken subjects (as distinct from voice
message contents).
The originators and recipients spoken names SHOULD be included
with messages as separate audio contents. If a vCard is also
included these MAY be referenced from the vCard, or included
inline with a vCard. External references SHOULD NOT be used.
An implementation MAY determine the recipient capabilities before
the sending of a message and choose a codec accordingly (e.g.
Using Content Negotiation). In the absence of such recipient
knowledge, implementations MUST use MS-GSM - indicated via
audio/msgsm or "audio/wav; codec=31". [refs tbd]
Recipients MUST be able to play such MS-GSM messages, and SHOULD
be able to play G.726 (indicated as audio/32kadpcm) for
interoperability with VPIM v2 [VPIMV2].
An implementation MAY be able to play messages encoded with other
codecs (either natively or via transcoding) but MUST be able to
record MS-GSM.
An implementation MAY support interoperability with VPIM v2
[VPIMV2], in which case it MUST be able to play G.726 (indicated
as audio/32kadpcm).
9. Fax Contents
Fax contents SHOULD be carried according to RFC 2305 [tbd]
10. Compatibility with Voicemail Systems supporting VPIM
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Separate work will be undertaken to investigate mechanisms to
improve interoperability with voicemail systems implementing VPIM
v2, or successor specifications.
11. References
[VPIMV2] Vaudreuil, G., Parsons, G., "Voice Profile for
Internet Mail - version 2", RFC 2421, September 1998.
[KEYWORDS] Bradner, S., "Key Words for use in RFCs To Indicate
Requirement Levels", RFC 2119, March 1997.
[MIME] Freed, N., Borenstein, N., "Multipurpose Internet Mail
Extensions (MIME) Part One: Format of Internet Message
Bodies", RFC 2045, November 1996.
[GOALS] Di Silvestro, Laile, "Goals for VPIM v3",
<draft-ema-vpimv3-goals-00.txt>, Work in Progress.
[VPIMVM] G. Vaudreuil and G. Parsons, "VPIM Voice Message: MIME
Sub-type Registration", RFC 2423, September 1998.
[VPIMV3] Vaudreuil, G., Parsons, G., "Voice Profile for
Internet Mail - version 3", <draft-ema-vpimv3-00.txt>,
Work in Progress.
[DRUMS] Resnick, P., "Internet Message Format Standard",
<draft-ietf-drums-msg-fmt-07.txt>, Work in Progress.
[SIMPLEV3] Parsons, G., " Voice Profile for Internet Mail -
Version 3: A Simple Approach"
<draft-ema-vpim-simplev3-00.txt>
[SELECTOR] Allocchio, C., _Minimal PSTN address format in
Internet Mail_, RFC 2303, March 1998.
12. Security Considerations
TBD
13. Author's Address
Stuart J. McRae
Lotus Development
43 Seymour Gardens
Twickenham, TW1 3AR,
United Kingdom
Phone: +44 181 891 1896
Fax: +44 1784 499 112
Email: stuart_mcrae@lotus.com
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14. Full Copyright Statement
This document and translations of it may be copied and furnished "Copyright (C) The Internet Society (1999). All Rights Reserved.
to others, and derivative works that comment on or otherwise
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Standards process must be followed, or as required to translate
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The limited permissions granted above are perpetual and will not
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Internet Draft Internet Voice Messaging October 22, 1999 | PAFTECH AB 2003-2026 | 2026-04-23 06:15:18 |