Network Working Group Greg Vaudreuil
Internet Draft Lucent Technologies
Expires in six months Glenn Parsons
Obsoletes: RFC 1911 Northern Telcom
March 12, 1998
Voice Profile for Internet Mail - version 2
<draft-ema-vpim-07.txt>
Status of this Memo
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documents of the Internet Engineering Task Force (IETF), its Areas,
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Copyright Notice
Copyright (C) The Internet Society (1998). All Rights Reserved.
Overview
This document profiles Internet mail for voice messaging. It
obsoletes RFC 1911 which describes version 1 of the profile. A list
of changes from that document are noted in Appendix F. As well,
Appendix A summarizes the protocol profiles of this version of VPIM.
Please send comments on this document to the EMA VPIM Work Group
mailing list: <vpim-l@ema.org>
Internet Draft VPIM v2 March 12, 1998
Working Group Summary
This profile is not the product of an IETF working group, though
several have reviewed the document. It is instead the product of the
VPIM Work Group of the Electronic Messaging Association (EMA). This
work group, which has representatives from most major voice mail
vendors and several email vendors, has held several interoperability
demonstrations between voice messaging vendors and is currently
promoting VPIM trials and deployment.
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Table of Contents
1. ABSTRACT ............................................................4
2. SCOPE ...............................................................5
2.1 Voice Messaging System Limitations ...............................5
2.2 Design Goals .....................................................6
3. PROTOCOL RESTRICTIONS ...............................................7
4. VOICE MESSAGE INTERCHANGE FORMAT ....................................8
4.1 Message Addressing Formats .......................................8
4.2 Message Header Fields ...........................................10
4.3 Voice Message Content Types .....................................16
4.4 Other Message Content Types .....................................21
4.5 Forwarded Messages ..............................................23
4.6 Reply Messages ..................................................23
4.7 Notification Messages ...........................................24
5. MESSAGE TRANSPORT PROTOCOL .........................................25
5.1 ESMTP Commands ..................................................25
5.2 ESMTP Keywords ..................................................27
5.3 ESMTP Parameters - MAIL FROM ....................................28
5.4 ESMTP Parameters - RCPT TO ......................................28
5.5 ESMTP - SMTP Downgrading ........................................29
6. DIRECTORY ADDRESS RESOLUTION .......................................29
7. IMAP ...............................................................30
8. MANAGEMENT PROTOCOLS ...............................................30
8.1 Network Management ..............................................30
9. CONFORMANCE REQUIREMENTS ...........................................30
10. SECURITY CONSIDERATIONS ...........................................31
10.1 General Directive ..............................................31
10.2 Threats and Problems ...........................................31
10.3 Security Techniques ............................................32
11. REFERENCES ........................................................33
12. ACKNOWLEDGMENTS ...................................................35
13. COPYRIGHT NOTICE ..................................................35
14. AUTHORS' ADDRESSES ................................................36
15. APPENDIX A - VPIM REQUIREMENTS SUMMARY ............................37
16. APPENDIX B - EXAMPLE VOICE MESSAGES ...............................43
17. APPENDIX C - EXAMPLE ERROR VOICE PROCESSING ERROR CODES ...........48
18. APPENDIX D - EXAMPLE VOICE PROCESSING DISPOSITION TYPES ...........49
19. APPENDIX E - IANA REGISTRATIONS ...................................50
20. APPENDIX F - CHANGE HISTORY: RFC 1911 TO THIS DOCUMENT ............52
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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.
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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.
2) Voice mail machines usually act as an integrated Message
Transfer Agent, Message Store and User Agent. There is no relaying
of messages, and RFC 822 header fields may have limited use in the
context of the limited messaging features currently deployed.
3) Voice mail message stores are generally not capable of
preserving the full semantics of an Internet message. As such, use
of a voice mail machine for gatewaying is not supported. In
particular, storage of recipient lists, "Received" lines, and
"Message-ID" may be limited.
4) Internet-style distribution/exploder mailing lists are not
typically supported. Voice mail machines often implement only
local alias lists, with error-to-sender and reply-to-sender
behavior. Reply-all capabilities using a CC list is not generally
available.
5) Error reports must be machine-parsable so that helpful responses
can be voiced to users whose only access mechanism is a telephone.
6) The voice mail systems generally limit address entry to 16 or
fewer numeric characters, and normally do not support alphanumeric
mailbox names. Alpha characters are not generally used for mailbox
identification as they cannot be easily entered from a telephone
terminal.
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2.2 Design Goals
It is a goal of this profile to make as few restrictions and additions
to the existing Internet mail protocols as possible while satisfying
the requirements for interoperability with current generation voice
messaging systems. This goal is motivated by the desire to increase
the accessibility to digital messaging by enabling the use of proven
existing networking software for rapid development.
This specification is intended for use on a TCP/IP network, however,
it is possible to use the SMTP protocol suite over other transport
protocols. The necessary protocol parameters for such use is outside
the scope of this document.
This profile is intended to be robust enough to be used in an
environment, such as the global Internet with installed-base gateways
which do not understand MIME, though typical use is expected to be
within corporate intranets. Full functionality, such as reliable
error messages and binary transport, will require careful selection of
gateways (e.g., via MX records) to be used as VPIM forwarding agents.
Nothing in this document precludes use of a general purpose MIME email
packages to read and compose VPIM messages. While no special
configuration is required to receive VPIM compliant messages, some may
be required to originate compliant structures.
It is expected that a VPIM messaging system will be managed by a
system administrator who can perform TCP/IP network configuration.
When using facsimile or multiple voice encodings, it is suggested that
the system administrator maintain a list of the capabilities of the
networked mail machines to reduce the sending of undeliverable
messages due to lack of feature support. Configuration,
implementation and management of this directory listing capabilities
is a local matter.
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3. Protocol Restrictions
This protocol does not limit the number of recipients per message.
Where possible, implementations should not restrict the number of
recipients in a single message. It is recognized that no
implementation supports unlimited recipients, and that the number of
supported recipients may be quite low. However, ESMTP currently does
not provide a mechanism for indicating the number of supported
recipients.
This protocol does not limit the maximum message length. Implementors
should understand that some machines will be unable to accept
excessively long messages. A mechanism is defined in the RFC 1425
SMTP service extensions to declare the maximum message size supported.
The message size indicated in the ESMTP SIZE command is in bytes, not
minutes or seconds. The number of bytes varies by voice encoding
format and must include the MIME wrapper overhead. If the length must
be known before sending, an approximate translation into minutes or
seconds can be performed if the voice encoding is known.
The following sections describe the restrictions and additions to
Internet mail protocols that are required to be compliant with this
VPIM v2 profile. Though various SMTP, ESMTP and MIME features are
described here, the implementor is referred to the relevant RFCs for
complete details. It is also advisable to check for IETF drafts of
various Internet Mail specifications that are later than the most
recent RFCs since, for example, MIME has yet to be published as a full
IETF Standard. The table in Appendix A summarizes the protocol details
of this profile.
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].
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4. Voice Message Interchange Format
The voice message interchange format is a profile of the Internet Mail
Protocol Suite. Any Internet Mail message containing the format
defined in this section is referred to as a VPIM Message in this
document. As a result, this document assumes an understanding of the
Internet Mail specifications. Specifically, VPIM references
components from the message format standard for Internet messages
[RFC822], the Multipurpose Internet Message Extensions [MIME], the
X.400 gateway specification [X.400], delivery status and message
disposition notifications [REPORT][DSN][DRPT][STATUS][MDN], and the
electronic business card [MIMEDIR][VCARD].
4.1 Message Addressing Formats
RFC 822 addresses are based on the domain name system. This naming
system has two components: the local part, used for username or
mailbox identification; and the host part, used for global machine
identification.
4.1.1 VPIM Addresses
The local part of the address shall be a US-ASCII string uniquely
identifying a mailbox on a destination system. For voice messaging,
the local part is a printable string containing the mailbox ID of the
originator or recipient. While alpha characters and long mailbox
identifiers are permitted, most voice mail networks rely on numeric
mailbox identifiers to retain compatibility with the limited 10 digit
telephone keypad. As a result, some voice messaging systems may only
be able to handle a numeric local part. The reception of alphanumeric
local parts on these systems may result in the address being mapped to
some locally unique (but confusing to the recipient) number or, in the
worst case the address could be deleted making the message un-
replyable. Additionally, it may be difficult to create messages on
these systems with an alphanumeric local part without complex key
sequences or some form of directory lookup (see 6).
The use of the domain naming system should be transparent to the user.
It is the responsibility of the voice mail machine to lookup the
fully-qualified domain name (FQDN) based on the address entered by the
user (see 6).
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In the absence of a global directory, specification of the local part
is expected to conform to international or private telephone numbering
plans. It is likely that private numbering plans will prevail and
these are left for local definition. However, it is recommended that
public telephone numbers be noted according to the international
numbering plan described in [E.164]. The indication that the local
part is a public telephone number is given by a preceding `+' (the `+'
would not be entered from a telephone keypad, it is added by the
system as a flag). Since the primary information in the numeric
scheme is contained by the digits, other character separators (e.g. `-
') may be ignored (i.e. to allow parsing of the numeric local mailbox)
or may be used to recognize distinct portions of the telephone number
(e.g. country code). The specification of the local part of a VPIM
address can be split into the four groups described below:
1) mailbox number
- for use as a private numbering plan (any number of digits)
- e.g. 2722@lucent.com
2) mailbox number+extension
- for use as a private numbering plan with extensions
any number of digits, use of `+' as separator
- e.g. 2722+111@Lucent.com
3) +international number
- for international telephone numbers conforming to E.164
maximum of 15 digits
- e.g. +16137637582@vm.nortel.ca
4) +international number+extension
- for international telephone numbers conforming to E.164
maximum of 15 digits, with an extension (e.g. behind a
PBX) that has a maximum of 15 digits.
- e.g. +17035245550+230@ema.org
4.1.2 Special Addresses
Special addresses are provided for compatibility with the conventions
of Internet mail. These addresses do not use numeric local addresses,
both to conform to current Internet practice and to avoid conflict
with existing numeric addressing plans. Two special addresses are
RESERVED for use as follows:
postmaster@domain
By convention, a special mailbox named "postmaster" MUST exist on all
systems. This address is used for diagnostics and should be checked
regularly by the system manager. This mailbox is particularly likely
to receive text messages, which is not normal on a voice processing
platform. The specific handling of these messages is an individual
implementation choice.
non-mail-user@domain
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If a reply to a message is not possible, such as a telephone answering
message, then the special address _non-mail-user_ must be used as the
originator's address. Any text name such as "Telephone Answering," or
the telephone number if it is available, is permitted. This special
address is used as a token to indicate an unreachable originator. For
compatibility with the installed base of mail user agents,
implementations that generate this special address MUST send a non-
delivery notification for reply messages sent to the undeliverable
address. The status code for such NDN's is 5.1.1 "Mailbox does not
exist".
Example:
From: Telephone Answering <non-mail-user@mycompany.com>
4.1.3 Distribution Lists
There are many ways to handle distribution list (DL) expansions and
none are 'standard'. Simple alias is a behavior closest to what most
voice mail systems do today and what is to be used with VPIM messages.
That is:
Reply to the originator - (Address in the RFC822 Reply-to or From
field)
Errors to the submitter - (Address in the MAIL FROM: field of the
ESMTP exchange and the Return-Path:
RFC 822 field)
Some proprietary voice messaging protocols include only the recipient
of the particular copy in the envelope and include no "headers" except
date and per-message features. Most voice messaging systems do not
provide for "Header Information" in their messaging queues and only
include delivery information. As a result, recipient information MAY
be in either the To or CC headers. If all recipients cannot be
presented (e.g. unknown DL expansion) then the recipient headers MUST
be omitted to indicate that an accurate list of recipients (e.g. for
use with a reply-all capability) is not known.
4.2 Message Header Fields
Internet messages contain a header information block. This header
block contains information required to identify the sender, the list
of recipients, the message send time, and other information intended
for user presentation. Except for specialized gateway and mailing
list cases, headers do not indicate delivery options for the transport
of messages.
Exploder lists are noted for modifying or adding to the headers of
messages that pass through them. VPIM systems MUST be able to accept
and ignore headers that are not defined here.
The following header lines are permitted for use with VPIM voice
messages:
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4.2.1 From
The originator's fully-qualified domain address (a mailbox address
followed by the fully-qualified domain name). The user listed in this
field should be presented in the voice message envelope as the
originator of the message.
Systems compliant with this profile SHOULD provide the text personal
name of the voice message originator in a quoted phrase, if the name
is available. Text names of corporate or positional mailboxes MAY be
provided as a simple string. From [RFC822]
Example:
From: "Joe S. User" <12145551212@mycompany.com>
From: Technical Support <611@serviceprovider.com>
The From address may be used for replies (see 4.6). However, if the
From address contains <non-mail-user@domain>, the user SHOULD not be
offered the option to reply, nor should notifications be sent to this
address.
4.2.2 To
The To header contains the recipient's fully-qualified domain address.
There may be one or more To: fields in any message.
Example:
To: +12145551213@mycompany.com
Systems compliant to this profile SHOULD provide a list of recipients
only if all recipients are provided. The To header MUST NOT be
included in the message if the sending message transport agent (MTA)
cannot resolve all the addresses in it, e.g. if an address is a DL
alias for which the expansion is unknown (see 4.1.3). If present, the
addresses in the To header MAY be used for a reply message to all
recipients.
Systems compliant to this profile MAY also discard the To addresses of
incoming messages because of the inability to store the information.
This would, of course, make a reply-to-all capability impossible.
4.2.3 Cc
The cc header contains additional recipients' fully-qualified domain
addresses. Many voice mail systems maintain only sufficient envelope
information for message delivery and are not capable of storing or
providing a complete list of recipients.
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Systems compliant to this profile SHOULD provide a list of recipients
only if all disclosed recipients can be provided. The list of
disclosed recipients does not include those sent via a blind copy. If
not, systems SHOULD omit the To and Cc headers to indicate that the
full list of recipients is unknown.
Example:
Cc: +12145551213@mycompany.com
Systems compliant to this profile MAY discard the Cc addresses of
incoming messages as necessary. If a list of Cc or to addresses is
present, these addresses MAY be used for a reply message to all
recipients.
4.2.4 Date
The Date header contains the date, time, and time zone in which the
message was sent by the originator. The time zone SHOULD be
represented in a four-digit time zone offset, such as -0500 for North
American Eastern Standard Time. This may be supplemented by a time
zone name in parentheses, e.g., "-0900 (PDT)". Compliant
implementations SHOULD be able to convert RFC 822 date and time stamps
into local time.
Example:
Date: Wed, 28 Jul 96 10:08:49 -0800 (PST)
The sending system MUST report the time the message was sent. If the
VPIM sender is relaying a message from a system which does not provide
a time stamp, the time of arrival at the VPIM system SHOULD be used as
the date. From [RFC822]
4.2.5 Sender
The Sender header contains the actual address of the originator if the
message is sent by an agent on behalf of the author indicated in the
From: field and MAY be present in a VPIM message.
While it may not be possible to save this information in some voice
mail machines, discarding this information or the ESMTP MAIL FROM (see
4.2.6) address will make it difficult to send an error message to the
proper destination. From [RFC822]
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4.2.6 Return Path
The Return-path header is added by the final delivering SMTP server.
If present, it contains the address from the MAIL FROM parameter of
the ESMTP exchange (see 5.1.2) to which error messages MUST be sent to
this address (see [DRPT] for additional details). Note that if the
Return-path is null ("<>"), e.g. no path, loop prevention or
confidential, a notification MUST NOT be sent. If the Return path
address is not available (either from this header or the MAIL FROM
parameter) the Sender or From addresses may be used to deliver
notifications.
4.2.7 Message-id
The Message-id header contains a unique per-message identifier. A
unique message-id MUST be generated for each message sent from a
compliant implementation.
The message-id is not required to be stored on the receiving system.
This identifier MAY be used for tracking, auditing, and returning
read-receipt reports. From [RFC822]
Example:
Message-id: <12345678@mycompany.com>
4.2.8 Reply-To
If present, the reply-to header provides a preferred address to which
reply messages should be sent (see 4.6). Typically, voice mail
systems can only support one originator of a message so it is unlikely
that this field can be supported. A compliant system SHOULD NOT send
a Reply-To header. However, if a reply-to header is present, a reply-
to sender message SHOULD be sent to the address specified (that is,
overwriting From). From [RFC822] This preferred address of the
originator must also be provided in the originator's vCard EMAIL
attribute, if present (see 4.3.3).
4.2.9 Received
The Received header contains trace information added to the beginning
of a RFC 822 message by MTAs. This is the only header permitted to be
added by an MTA. Information in this header is useful for debugging
when using an US-ASCII message reader or a header parsing tool.
A compliant system MUST add Received headers when acting as a gateway
and MUST NOT remove any. These headers MAY be ignored or deleted when
the message is received at the final destination. From [RFC822]
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4.2.10 MIME Version
The MIME-Version header indicates that the message conforms to the
MIME message format specification. Systems compliant with this
specification SHOULD include a comment with the words "(Voice 2.0)".
RFC 1911 defines an earlier version of this profile and uses the token
(Voice 1.0). From [MIME1][VPIM1]
Example:
MIME-Version: 1.0 (Voice 2.0)
This identifier is intended for information only and SHOULD NOT be
used to semantically identify the message as being a VPIM message.
Instead, the presence of the content defined in [V-MSG] SHOULD be used
if identification is necessary.
4.2.11 Content-Type
The content-type header declares the type of content enclosed in the
message. The typical top level content in a VPIM Message SHOULD be
multipart/voice-message, a mechanism for bundling several components
into a single identifiable voice message. The allowable contents are
detailed in section 4.3 of this document. From [MIME2]
4.2.12 Content-Transfer-Encoding
Because Internet mail was initially specified to carry only 7-bit US-
ASCII text, it may be necessary to encode voice and fax data into a
representation suitable for that environment. The content-transfer-
encoding header describes this transformation if it is needed.
Compliant implementations MUST recognize and decode the standard
encodings, "Binary", "7bit, "8bit", "Base64" and "Quoted-Printable".
The allowable content-transfer-encodings are specified in section 4.3.
From [MIME1]
4.2.13 Sensitivity
The sensitivity header, if present, indicates the requested privacy
level. The case-insensitive values "Personal" and "Private" are
specified. If no privacy is requested, this field is omitted.
If a sensitivity header is present in the message, a compliant system
MUST prohibit the recipient from forwarding this message to any other
user. A compliant system, however, SHOULD allow the user to reply to
a sensitive message, but SHOULD NOT include the original message
content. The sensitivity of the reply message MAY be set by the user.
If the receiving system does not support privacy and the sensitivity
is one of "Personal" or "Private", the message MUST be returned to the
sender with an appropriate error code indicating that privacy could
not be assured and that the message was not delivered. A non-delivery
notification to a private message need not be tagged private since it
will be sent to the originator. From: [X.400]
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4.2.14 Importance
Indicates the requested priority to be given by the receiving system.
The case-insensitive values "low", "normal" and "high" are specified.
If no special importance is requested, this header may be omitted and
the value assumed to be "normal".
Compliant implementations MAY use this header to indicate the
importance of a message and may order messages in a recipient's
mailbox. From: [X.400]
4.2.15 Subject
The subject field is often provided by email systems but is not widely
supported on Voice Mail platforms. For compatibility with text based
mailbox interfaces, a text subject field SHOULD be generated by a
compliant implementation but MAY be discarded if present by a
receiving system. From [RFC822]
It is recommended that voice messaging systems that do not support any
text user interfaces (e.g. access only by a telephone) insert a
generic subject header of "VPIM Message" for the benefit of text
enabled recipients.
4.2.16 Disposition-Notification-To
This header MAY be present to indicate that the sender is requesting a
receipt notification from the receiving user agent. This message
disposition notification (MDN) is typically sent by the user agent
after the user has listened to the message and consented to an MDN
being sent
Example:
Disposition-notification-to: +12145551213@mycompany.com
The presence of a Disposition-notification-to header in a message is
merely a request for an MDN described in 4.4.5. The recipients' user
agents are always free to silently ignore such a request so this
header does not burden any system that does not support it. From
[MDN].
4.2.17 Disposition-Notification-Options
This header MAY be present to define future extensions parameters for
an MDN requested by the presence of the header in the previous
section. Currently no parameters are defined by this document or by
[MDN]. However, this header MUST be parsed if present, if MDNs are
supported. If it contains a extension parameter that is required for
proper MDN generation (noted with "=required"), then an MDN MUST NOT
be sent if the parameter is not understood. See [MDN] for complete
details.
Example:
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Disposition-notification-options:
whizzbang=required,foo
4.3 Voice Message Content Types
MIME, introduced in [MIME1], is a general-purpose message body format
that is extensible to carry a wide range of body parts. It provides
for encoding binary data so that it can be transported over the 7-bit
text-oriented SMTP protocol. This transport encoding is in addition
to the audio encoding required to generate a binary object.
MIME defines two transport encoding mechanisms to transform binary
data into a 7 bit representation, one designed for text-like data
("Quoted-Printable"), and one for arbitrary binary data ("Base64").
While Base64 is dramatically more efficient for audio data, both will
work. Where binary transport is available, no transport encoding is
needed, and the data can be labeled as "Binary".
An implementation in compliance with this profile SHOULD send audio
and/or facsimile data in binary form when binary message transport is
available. When binary transport is not available, implementations
MUST encode the audio and/or facsimile data as Base64. The detection
and decoding of "Quoted-Printable", "7bit", and "8bit" MUST be
supported in order to meet MIME requirements and to preserve
interoperability with the fullest range of possible devices. However,
if a content is received in a transfer encoding that cannot be
rendered to the user, an appropriate non-delivery notification MUST be
sent.
The content types described in this section are identified for use
within the multipart/voice-message content. This content, which is
the fundamental part of a VPIM message, is referred to as a VPIM voice
message in this document.
Only the contents profiled subsequently can be sent within a VPIM
voice message construct to form a simple or a more complex structure
(several examples are given in Appendix B). The presence of other
contents within a VPIM voice message is an error condition and SHOULD
result in a non-delivery notification. When multiple contents are
present within the multipart/voice-message, they SHOULD be presented
to the user in the order that they appear in the message.
4.3.1 Multipart/Voice-Message
This MIME multipart structure provides a mechanism for packaging a
voice message into one container that is tagged as VPIM v2 compliant.
The semantic of multipart/Voice-Message (defined in [V-MSG]) is
identical to multipart/mixed and may be interpreted as that by systems
that do not recognize this content-type.
The Multipart/Voice-Message content-type MUST only contain the
profiled media and content types specified in this section (i.e.
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audio/*, image/*, message/rfc822 and text/directory). The most common
will be: spoken name, spoken subject, the message itself, attached fax
and directory info. Forwarded messages are created by simply using
the message/rfc822 construct.
Conformant implementations MUST send the Multipart/Voice-Message in a
VPIM message. In most cases, this Multipart/Voice-Message content
will be the top level (i.e. in the Content-Type header). Conformant
implementations MUST recognize the Multipart/Voice-Message content
(whether it is a top level content or below a mulitpart/mixed) and be
able to separate the contents (e.g. spoken name or spoken subject).
4.3.2 Message/RFC822
MIME requires support of the Message/RFC822 message encapsulation body
part. This body part is used within a multipart/voice-message to
forward complete messages (see 4.5) or to reply with original content
(see 4.6). From [MIME2]
4.3.3 Text/Directory
This content allows for the inclusion of a Versit vCard [VCARD]
electronic business card within a VPIM message. The format is
suitable as an interchange format between applications or systems, and
is defined independent of the method used to transport it. It
provides a useful mechanism to transport information about the
originator that can be used by the receiving VPIM system (see 6) or
other local applications
Each vCard MUST be contained within a Text/Directory content type
[MIMEDIR] within a VPIM message. [MIMEDIR] requires that the
character set MUST be defined as a parameter value (typically us-ascii
for VPIM) and that the profile SHOULD be defined (the value MUST be
vCard within VPIM messages).
Each VPIM message SHOULD be created with a Text/Directory (vCard
profile) content type that MUST contain the preferred email address,
telephone number, and text name of the message originator as well as
the vCard version. The vCard SHOULD contain the spoken name and role
of the originator, as well as the revision date. Any other vCard
attribute MAY also be present. The intent is that the vCard be used
as the source of information to contact the originator (e.g., reply,
call).If the text/directory content-type is included in a VPIM
message, the vCard profile [VCARD] MUST be used and MUST specify at
least the following attributes:
TEL - Public switched telephone number in international (E.164)
format (various types, typically VOICE)
EMAIL - email address (various types, typically INTERNET; the
typeVPIM is optionally used to denote the address that
supports VPIM messages(see 19.1))
VERSION - Indicates the version of the vCard profile. Version 3.0
[VCARD] MUST be used.
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The following attributes SHOULD be specified:
N - Family Name, Given Name, Additional Names, Honorific
Prefixes, and Suffixes (all present components in the
From text name MUST match)
ROLE - the role of the person identified in `N', but may be used
as an alternative to the `N' attribute when the sender is a
corporate or positional mailbox
SOUND - spoken name sound data (various types, typically 32KADPCM)
REV - Revision of vCard in ISO 8601 date format
The vCard MAY use other attributes as defined in [VCARD] or extensions
attributes not yet defined (e.g. capabilities).
If present, the spoken name attribute MUST be denoted by a content ID
pointing to an audio/* content elsewhere in the VPIM message.
A typical VPIM message (i.e. no forwarded parts), MUST only contain
one vCard -- more than one is an error condition. A VPIM message that
contains forwarded messages, though, may contain multiple vCards.
However, these vCards MUST be associated with the originator(s) of the
forwarded message(s) and the originator of the forwarding message. As
a result, all forwarded vCards will be contained in message/rfc822
contents -- only the vCard of forwarding originator will be at the
top-level.
Example:
Content-Type: text/directory; charset=us-ascii; profile=vCard
Content-Transfer-Encoding: 7bit
BEGIN:VCARD
N:Parsons;Glenn
ORG:Northern Telecom
TEL;TYPE=VOICE;MSG;WORK:+1-613-763-7582
EMAIL;TYPE=INTERNET:glenn.parsons@nortel.ca
EMAIL;TYPE=INTERNET;VPIM:6137637582@vm.nortel.ca
SOUND;TYPE=32KADPCM;ENCODING=URI: CID:<part1@VM2-4321>
REV:19960831T103310Z
VERSION: 3.0
END:VCARD
4.3.4 Audio/32KADPCM
An implementation compliant to this profile MUST use Audio/32KADPCM by
default for voice [ADPCM]. Typically this body contains several
minutes of message content, however if used for spoken name or subject
the content should be considerably shorter (i.e. about 10 and 20
seconds respectively).
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If an implementation can only handle one voice body, then multiple
voice bodies (if present) SHOULD be concatenated, and SHOULD NOT be
discarded. It is recommended that this be done in the same order as
they were sent. Note that if an Originator Spoken Name audio body and
a vCard are both present in a VPIM message, the vCard SOUND attribute
MUST point to this audio body (see 4.3.3).
While any valid MIME body header MAY be used, several headers have the
following semantics when included with this body part:
4.3.4.1 Content-Description:
This field MAY be present to facilitate the text identification of
these body parts in simple email readers. Any values may be used,
though it may be useful to use values similar to those for Content-
Disposition.
Example:
Content-Description: Big Telco Voice Message
4.3.4.2 Content-Disposition:
This field MUST be present to allow the parsable identification of
these body parts. This is especially useful if, as is typical,
more than one Audio/32KADPCM body occurs within a single level
(e.g. multipart/voice-message). Since a VPIM voice message is
intended to be automatically played upon display of the message, in
the order in which the audio contents occur, the audio contents
must always be of type inline. However, it is still useful to
include a filename value, so this should be present if this
information is available. From [DISP]
In order to distinguish between the various types of audio contents
in a VPIM voice message a new disposition parameter "voice" is
defined with the parameter values below to be used as appropriate
(see 19.2):
Voice-Message - the primary voice message,
Voice-Message-Notification - a spoken delivery notification
or spoken disposition notification,
Originator-Spoken-Name - the spoken name of the originator,
Recipient-Spoken-Name - the spoken name of the recipient if
available to the originator and present if there is ONLY one
recipient,
Spoken-Subject- the spoken subject of the message, typically
spoken by the originator
Note that there SHOULD only be one instance of each of these types
of audio contents per message level. Additional instances of a
given type (i.e., parameter value) may occur within an attached
forwarded voice message.
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Implementations that do not understand the "voice" parameter (or
the Content-Disposition header) can safely ignore it, and will
present the audio bodyparts in order (but will not be able to
distinguish between them).
Example:
Content-Disposition: inline; voice=spoken-subject;
filename=msg001.726
4.3.4.3 Content-Duration:
This field MAY be present to allow the specification of the length
of the audio bodypart in seconds. The use of this field on
reception is a local implementation issue. From [DUR]
Example:
Content-Duration: 33
4.3.4.4 Content-Language:
This field MAY be present to allow the specification of the spoken
language of the audio bodypart. The encoding is defined in [LANG].
The use of this field on reception is a local implementation issue.
Example for UK English:
Content-Language: EN-UK
4.3.5 Image/Tiff
A common image encoding for facsimile, known as TIFF-F, is a
derivative of the Tag Image File Format (TIFF) and is described in
several documents. For the purposes of VPIM, the F Profile of TIFF
for Facsimile (TIFF-F) is defined in [TIFF-F] and the image/tiff MIME
content type is defined in [TIFFREG]. While there are several formats
of TIFF, only TIFF-F is profiled for use in a VPIM voice message.
Further, since the TIFF-F file format is used in a store-and-forward
mode with VPIM, the image MUST be encoded so that there is only one
image strip per facsimile page.
All VPIM implementations that support facsimile MUST generate and read
TIFF-F compatible facsimile contents in the image/tiff;
application=faxbw sub-type encoding by default. An implementation MAY
send this fax content in VPIM voice messages and MUST be able to
recognize it in received messages. If a fax message is received that
cannot be rendered to the user (e.g. the receiving VPIM system does
not support fax), then the system MUST non-deliver the entire message
with a media not supported error.
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While any valid MIME body header MAY be used (e.g., Content-Dispostion
to indicate the filename), none are specified to have special
semantics for VPIM and MAY be ignored. Note that the content type
paramater application=faxbw MUST be included in outbound messages.
However, inbound messages with or without this parameter MUST be
rendered to the user (if the rendering software encounters an error in
the file format, some form of non-delivery notification MUST be sent
to the originator).
4.3.6 Proprietary Voice or Fax Formats
Proprietary voice or fax encoding formats or other standard formats
may be supported under this profile provided a unique identifier is
registered with the IANA prior to use (see [MIME4]). The voice
encodings should be registered as sub-types of Audio and the fax
encodings should be registered as sub-types of Image
Use of any other encoding except audio/32kadpcm or image/tiff;
application=faxbw reduces interoperability in the absence of explicit
manual system configuration. A compliant implementation MAY use any
other encoding with explicit per-destination configuration.
4.4 Other Message Content Types
An implementation compliant with this profile MAY send additional
contents in a VPIM message, but ONLY outside of the multipart/voice-
message. The content types described in this section are identified
for use with this profile. Contents not defined here MUST NOT be used
without prior explicit per-destination configuration. If an
implementation receives a VPIM message that contains content types
not specified in this profile, their handling is a local
implementation issue (e.g. the unknown contents MAY be discarded if
they cannot be presented to the recipient). Conversely, if an
implementation receives a non-VPIM message with any of the contents
defined in 4.3 & 4.4, it SHOULD deliver those contents, but the full
message handling is a local issue (e.g. the unknown contents _or_ the
entire message MAY be discarded). It is recommended that
implementations issue delivery notifications to the originator when
any form of non-delivery to the recipient occurs.
The multipart contents defined below may be sent as the top level of a
VPIM message (with other noted contents below them as required.) As
well, the multipart/mixed content can be used to form a more complex
structure (several examples are given in Appendix B). When multiple
contents are present, they SHOULD be presented to the user in the
order that they appear in the message.
4.4.1 Multipart/Mixed
MIME provides the facilities for enclosing several body parts in a
single message. Multipart/Mixed SHOULD only be used for sending
complex voice or multimedia messages. That is, as the top level
Content-Type when sending one of the following contents (in addition
to the VPIM voice message) in a VPIM message. Compliant systems MUST
accept multipart/mixed body parts. From [MIME2]
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4.4.2 Text/Plain
MIME requires support of the basic Text/Plain content type. This
content type has limited applicability within the voice messaging
environment. Compliant implementations SHOULD NOT send the Text/Plain
content-type, but SHOULD only send this content if the recipient
system is known to support it. Compliant implementations MUST accept
Text/Plain messages, however, specific handling is left as an
implementation decision. From [MIME2]
There are several mechanisms that can be used to support text on voice
messaging systems including text-to-speech and text-to-fax
conversions. If no rendering of the text is possible (i.e. it is not
possible for the recipient to determine if the text is a critical part
of the message), the entire message MUST be non-delivered and returned
to the sender with a media-unsupported error code.
4.4.3 Multipart/Report
The Multipart/Report is used for enclosing human-readable and machine
parsable notification (e.g. Message/delivery-status) body parts and
any returned message content. Compliant implementations MUST use the
Multipart/Report construct when returning messages, sending warnings,
or issuing read receipts. Compliant implementations MUST recognize
and decode the Multipart/Report content type and its components in
order to present the report to the user. From [REPORT]
Multipart/Report messages from VPIM implementations SHOULD include the
human-readable description of the error as a spoken audio/* content
(this speech SHOULD also be made available to the notification
recipient). As well, VPIM implementations MUST be able to handle (and
MAY generate) Multipart/Report messages that encode the human-readable
description of the error as text. Note that per [DSN] the human-
readable part MUST always be present.
4.4.4 Message/Delivery-status
This MIME body part is used for sending machine-parsable delivery
status notifications. Compliant implementations must use the
Message/delivery-status construct when returning messages or sending
warnings. Compliant implementations must recognize and decode the
Message/delivery-status content type and present the reason for
failure to the user. From [DSN]
4.4.5 Message/Disposition-notification
This MIME body part is used for sending machine-parsable read-receipt
message disposition notifications. Conforming implementations should
use the Message/Disposition-notification construct when sending post-
delivery message status notifications. These MDNs, however, MUST only
be sent in response to the presence of the Disposition-notification-to
header in 4.2.16. Conforming implementations should recognize and
decode the Message/Disposition-notification content type and present
the notification to the user. From [MDN]
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4.5 Forwarded Messages
VPIM version 2 explicitly supports the forwarding of voice and fax
content with voice or fax annotation. However, only the two
constructs described below are acceptable in a VPIM message. Since
only the first (i.e. message/rfc822) can be recognized as a forwarded
message (or even multiple forwarded messages), it is recommended that
this construct be used whenever possible.
Forwarded VPIM messages SHOULD be sent as a multipart/voice-message
with the entire original message enclosed in a message/rfc822 content
type and the annotation as a separate Audio/* or image/* body part.
If the RFC822 headers are not available for the forwarded content,
simulated headers with available information SHOULD be constructed to
indicate the original sending timestamp, and the original sender as
indicated in the "From" line. However, note that at least one of
"From", "Subject", or "Date" MUST be present. As well, the
message/rfc822 content MUST include at least the "MIME-Version",
"Content-Type" headers, and MAY include the "Content-Transfer-
Encoding" header. From [MIME2]
In the event that forwarding information is lost through concatenation
of the original message and the forwarding annotation, such as must be
done in a gateway between VPIM and the AMIS voice messaging protocol,
the entire content MAY be sent as a single Audio/* segment without
including any forwarding semantics.
4.6 Reply Messages
Replies to VPIM messages (and Internet mail messages) are addressed to
the address noted in the reply-to header (see 4.2.8) if it is present,
else the From address (see 4.2.1) is used. The vCard EMAIL attribute,
if present, SHOULD be the same as the reply-to address and may be the
same as the From address. While the vCard is the senders preferred
address it SHOULD NOT be used to generate a reply. Also, the Return-
path address should not be used for replies.
Support of multiple originator headers is often not possible on voice
messaging systems, so it may be necessary to choose only one.
However, implementors should note that this may make it impossible to
send error messages and replies to the proper destination.
In some cases, a reply message is not possible, such as with a message
created by telephone answering (i.e. classic voice mail). In this
case, the From field MUST contain the special address non-mail-
user@domain (see 4.1.2). The use of a null ESMTP MAIL FROM address
SHOULD also be used in this case (see 5.1.2). A receiving VPIM system
SHOULD not offer the user the option to reply to this kind of message.
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4.7 Notification Messages
VPIM Delivery Notification messages (4.4.4) must be sent to the
originator of the message when any form of non-delivery of the subject
message or its components occurs. These error messages must be sent
to the return path (4.2.6) if present, else the sender (4.2.5) or From
(4.2.1) address may be used (in that order).
VPIM Receipt Notification messages (4.4.5) should be sent to the
sender specified in the MDN header (4.2.16), only if the header is
present, and typically after the user has initiated the notification
by some action (like listening to the message).
VPIM Notification messages may be positive or negative, and can
indicate delivery at the server or receipt by the client. However,
the notification MUST be contained in a multipart/report container
(4.4.3) and SHOULD contain a spoken error message. It is recommended
that systems that do not support the notification format SHOULD still
send some form of error message when non-delivery occurs.
If a VPIM system receives a message with contents that are not
understood (see 4.3 & 4.4), its handling is a local matter, though any
VPIM voice message content SHOULD be delivered. A delivery status
notification SHOULD be generated if the message could not be delivered
because of unknown contents (e.g., on traditional voice processing
systems). In some cases, the message may be delivered (with a
positive DSN sent) to a mailbox before the determination of rendering
can be made. In this case, however, an MDN can only be sent to
indicate that the message could not be rendered if it was requested.
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5. Message Transport Protocol
Messages are transported between voice mail machines using the
Internet Extended Simple Mail Transfer Protocol (ESMTP). All
information required for proper delivery of the message is included in
the ESMTP dialog. This information, including the sender and
recipient addresses, is commonly referred to as the message
"envelope". This information is equivalent to the message control
block in many analog voice networking protocols.
ESMTP is a general-purpose messaging protocol, designed both to send
mail and to allow terminal console messaging. Simple Mail Transport
Protocol (SMTP) was originally created for the exchange of US-ASCII 7-
bit text messages. Binary and 8-bit text messages have traditionally
been transported by encoding the messages into a 7-bit text-like form.
[ESMTP] formalized an extension mechanism for SMTP, and subsequent
RFCs have defined 8-bit text networking, command streaming, binary
networking, and extensions to permit the declaration of message size
for the efficient transmission of large messages such as multi-minute
voice mail.
The following sections list ESMTP commands, keywords, and parameters
that are required and those that are optional for conformance to this
profile.
5.1 ESMTP Commands
5.1.1 HELO
Base SMTP greeting and identification of sender. This command is not
to be sent by compliant systems unless the more-capable EHLO command
is not accepted. It is included for compatibility with general SMTP
implementations. Compliant implementations MUST implement the HELO
command for backward compatibility but SHOULD NOT send it unless EHLO
is not supported. From [SMTP]
5.1.2 MAIL FROM (REQUIRED)
Originating mailbox. This address contains the mailbox to which
errors should be sent. This address may not be the same as the
message sender listed in the message header fields if the message was
received from a gateway or sent to an Internet-style mailing list.
Compliant implementations MUST implement the extended MAIL FROM
command. From [SMTP, ESMTP]
The MAIL FROM address MAY be passed as a local system parameter or
placed in a Return-Path: line inserted at the beginning of a VPIM
message. From [HOSTREQ]
Since error messages MUST be sent to the MAIL FROM address, the use of
the null address ("<>") is often used to prevent looping of error
notifications. This null address MAY also be used to note that a
particular message has no return path (e.g. a telephone answer
message). From [SMTP]
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5.1.3 RCPT TO
Recipient's mailbox. This field contains only the addresses to which
the message should be delivered for this transaction. In the event
that multiple transport connections to multiple destination machines
are required for the same message, this list may not match the list of
recipients in the message header. Compliant implementations MUST
implement the extended RCPT TO command. From [SMTP, ESMTP]
5.1.4 DATA
Initiates the transfer of message data. Support for this command is
required in the event the binary mode command BDAT is not supported by
the remote system. Compliant implementations MUST implement the SMTP
DATA command for backwards compatibility. From [SMTP]
5.1.5 TURN
Requests a change-of-roles, that is, the client that opened the
connection offers to assume the role of server for any mail the remote
machine may wish to send. Because SMTP is not an authenticated
protocol, the TURN command presents an opportunity to improperly fetch
mail queued for another destination. Compliant implementations SHOULD
NOT implement the TURN command. From [SMTP]
5.1.6 QUIT
Requests that the connection be closed. If accepted, the remote
machine will reset and close the connection. Compliant
implementations MUST implement the QUIT command. From [SMTP]
5.1.7 RSET
Resets the connection to its initial state. Compliant implementations
MUST implement the RSET command. From [SMTP]
5.1.8 VRFY
Requests verification that this node can reach the listed recipient.
While this functionality is also included in the RCPT TO command, VRFY
allows the query without beginning a mail transfer transaction. This
command is useful for debugging and tracing problems. Compliant
implementations MAY implement the VRFY command. From [SMTP]
(Note that the implementation of VRFY may simplify the guessing of a
recipient's mailbox or automated sweeps for valid mailbox addresses,
resulting in a possible reduction in privacy. Various implementation
techniques may be used to reduce the threat, such as limiting the
number of queries per session.) From [SMTP]
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5.1.9 EHLO
The enhanced mail greeting that enables a server to announce support
for extended messaging options. The extended messaging modes are
discussed in subsequent sections of this document. Compliant
implementations MUST implement the ESMTP command and return the
capabilities indicated later in this memo. From [ESMTP]
5.1.10 BDAT
The BDAT command provides a higher efficiency alternative to the
earlier DATA command, especially for voice. The BDAT command provides
for native binary transport of messages. Compliant implementations
SHOULD support binary transport using the BDAT command.[BINARY]
5.2 ESMTP Keywords
The following ESMTP keywords indicate extended features useful for
voice messaging.
5.2.1 PIPELINING
The "PIPELINING" keyword indicates ability of the receiving server to
accept new commands before issuing a response to the previous command.
Pipelining commands dramatically improves performance by reducing the
number of round-trip packet exchanges and makes it possible to
validate all recipient addresses in one operation. Compliant
implementations SHOULD support the command pipelining indicated by
this parameter. From [PIPE]
5.2.2 SIZE
The "SIZE" keyword provides a mechanism by which the SMTP server can
indicate the maximum size message supported. Compliant
implementations MUST provide the size capability and SHOULD honor any
size limitations when sending. From [SIZE]
5.2.3 CHUNKING
The "CHUNKING" keyword indicates that the receiver will support the
high-performance binary transport mode. Note that CHUNKING can be
used with any message format and does not imply support for binary
encoded messages. Compliant implementations SHOULD support binary
transport indicated by this capability. From [BINARY]
5.2.4 BINARYMIME
The "BINARYMIME" keyword indicates that the SMTP server can accept
binary encoded MIME messages. Compliant implementations SHOULD support
binary transport indicated by this capability. Note that support for
this feature requires support of CHUNKING. From [BINARY]
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5.2.5 DSN
The "DSN" keyword indicates that the SMTP server will accept explicit
delivery status notification requests. Compliant implementations MUST
support the delivery notification extensions in [DRPT].
5.2.6 ENHANCEDSTATUSCODES
The "ENHANCEDSTATUSCODES" keyword indicates that an SMTP server
augments its responses with the enhanced mail system status codes
[CODES]. These codes can then be used to provide more informative
explanations of error conditions, especially in the context of the
delivery status notifications format defined in [DSN]. Compliant
implementations SHOULD support this capability. From [STATUS]
5.3 ESMTP Parameters - MAIL FROM
5.3.1 BINARYMIME
The current message is a binary encoded MIME messages. Compliant
implementations SHOULD support binary transport indicated by this
parameter. From [BINARY]
5.3.2 RET
The RET parameter indicates whether the content of the message should
be returned. Compliant systems SHOULD honor a request for returned
content. From [DRPT]
5.3.3 ENVID
The ENVID keyword of the SMTP MAIL command is used to specify an
"envelope identifier" to be transmitted along with the message and
included in any DSNs issued for any of the recipients named in this
SMTP transaction. The purpose of the envelope identifier is to allow
the sender of a message to identify the transaction for which the DSN
was issued. Compliant implementations MAY use this parameter. From
[DRPT]
5.4 ESMTP Parameters - RCPT TO
5.4.1 NOTIFY
The NOTIFY parameter indicates the conditions under which a delivery
report should be sent. Compliant implementations MUST honor this
request. From [DRPT]
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5.4.2 ORCPT
The ORCPT keyword of the RCPT command is used to specify an "original"
recipient address that corresponds to the actual recipient to which
the message is to be delivered. If the ORCPT esmtp-keyword is used,
it MUST have an associated esmtp-value, which consists of the original
recipient address, encoded according to the rules below. Compliant
implementations MAY use this parameter. From [DRPT]
5.5 ESMTP - SMTP Downgrading
To ensure a consistent level of service across an intranet or the
global Internet, it is essential that VPIM compliant ESMTP be
supported at all hops between a VPIM originating system and the
recipient system. Unfortunately, in the situation where a `downgrade'
is unavoidable the expected result is not defined. A downgrade is
defined as the loss of VPIM transport features at some hop due to the
lack of support. For example, a relay hop may be forced (by the next
hop) to forward a VPIM using SMTP instead of ESMTP, or using DATA
instead of BDAT. It is recommended that the downgrading system should
continue to attempt to deliver the message, but MUST send an
appropriate delivery notification to the originator, e.g. the message
left an ESMTP host and was sent (unreliably) via SMTP.
6. Directory Address Resolution
It is the responsibility of a VPIM system to lookup the fully-
qualified domain name (FQDN) based on the address entered by the user
(if the entered address is not already a FQDN). This would typically
be an issue on systems that offered only a telephone user interface.
The mapping of the dialed target number to a routable FQDN address
allowing delivery to the destination system can be accomplished
through implementation-specific means.
To facilitate a local dial-by-name cache, an implementation may wish
to populate local directories with the first and last names, as well
as the address information extracted from received messages. It is
mandated that only address information from vCard attachments to VPIM
messages be used to populate such a directory when the vCard is
available. Addresses or names parsed from the headers of VPIM messages
SHOULD NOT be used to populate directories as it only provides partial
data. Alternatively, bilateral agreements could be made to allow the
bulk transfer of vCards between systems.
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7. IMAP
The use of client/server desktop mailbox protocols like IMAP or POP to
retrieve VPIM messages from a IMAP or POP message store is possible
without any special modifications to this VPIM specification. Email
clients (and web browsers) typically have a table for mapping from
MIME type to displaying application. The audio/*, image/tiff and
text/directory contents can be configured so that they invoke the
correct player/recorder for rendering. In addition with IMAP clients,
the first multipart/mixed content (if present) will not appear since
it is a generic part. The user instead will be presented with a
message that has (for example) audio and image contents.
8. Management Protocols
The Internet protocols provide a mechanism for the management of
messaging systems, from the management of the physical network through
the management of the message queues. SNMP should be supported on a
compliant message machine.
8.1 Network Management
The digital interface to the VM and the TCP/IP protocols SHOULD be
managed. MIB II SHOULD be implemented to provide basic statistics and
reporting of TCP and IP protocol performance. [MIB II]
9. Conformance Requirements
VPIM is a messaging application which must be supported in several
environments and be supported on differing devices. These
environments include traditional voice processing systems, desktop
voice messaging systems, store and forward relays, and protocol
translation gateways.
In order to accommodate all environments, this document defines two
areas of conformance: transport and content.
Transport conformant systems will pass VPIM messages in a store and
forward manner with assured delivery notifications and without the
loss of information. It is expected that most store and forward
Internet mail based messaging systems will be VPIM transport
compliant.
Content conformant systems will generate and interpret VPIM messages.
Conformance in the generation of VPIM messages indicates that the
restrictions of this profile are honored. Only contents specified in
this profile or extensions agreed to by bilateral agreement may be
sent. Conformance in the interpretation of VPIM messages indicates
that all VPIM content types and constructs can be received; that all
mandatory VPIM content types can be decoded and presented to the
recipient in an appropriate manner; and that any unrenderable contents
result in the appropriate notification.
A summary of the compliance requirements is contained in Appendix A.
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VPIM end systems are expected to be both transport and content
conformant. They should generate conforming content, reliably send it
to the next hop system, receive a message, decode the message and
present it to the user. Voice messaging systems and protocol
conversion gateways are considered end systems.
Relay systems are expected to be transport compliant in order to
receive and send conforming messages. However, they must also create
VPIM conforming delivery status notifications in the event of delivery
problems.
Desktop Email clients that support VPIM and are expected to be content
conformant. Desktop email clients use various protocols and API's for
exchanging messages with the local message store and message transport
system. While these clients may benefit from VPIM transport
capabilities, specific client-server requirements are out-of-scope for
this document.
10. Security Considerations
10.1 General Directive
This document is a profile of existing Internet mail protocols. To
maintain interoperability with Internet mail, any security to be
provided should be part of the of the Internet security
infrastructure, rather than a new mechanism or some other mechanism
outside of the Internet infrastructure.
10.2 Threats and Problems
Both Internet mail and voice messaging have their own set of threats
and countermeasures. As such, this specification does not create any
security issues not already existing in the profiled Internet mail and
voice mail protocols themselves. This section attends only to the set
of additional threats which ensue from integrating the two services.
10.2.1 Spoofed sender
The actual sender of the voice message might not be the same as that
specified in the Sender or From fields of the message content headers
or the MAIL FROM address from the SMTP envelope. In a tightly
constrained environment, sufficient physical and software controls may
be able to ensure prevention of this problem. In addition, the
recognition of the senders voice may provide confidence of the
sender's identity irrespecitve of that specified in Sender or From.
It should be recognized that SMTP implementations do not provide
inherent authentication of the senders of messages,nor are sites under
obligation to provide such authentication.
10.2.2 Spam
Assigning an Internet mail address to a voice mailbox opens the
possiblity of receiving unsolicited messages (either text or voice
mail). Traditionally voice mail systems operated in closed
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environments and were not susceptable to unknown senders. Voice mail
users have a higher expectation of mailbox privacy and may consider
such messages as a security breach. Many Internet mail systems are
choosing to block all messages from spam sources in an attempt to curb
this problem.
10.2.3 Message disclosure
Users of voice messaging systems have an expectation of a level of
message privacy which is higher than the level provided by Internet
mail without security enhancements. This expectation of privacy by
users SHOULD be preserved as much as possible.
10.3 Security Techniques
Sufficient physical and software control may be acceptable in
constrained environments. Further, the profile specified in this
document does not in any way preclude the use of any Internet object
or channel security protocol to encrypt, authenticate, or non-
repudiate the messages.
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References
[8BIT] Klensin, J., Freed, N., Rose, M., Stefferud, E., D. Crocker,
"SMTP Service Extension for 8bit-MIMEtransport" RFC 1426, United
Nations University, Innosoft International, Inc., Dover Beach
Consulting, Inc., Network Management Associates, Inc., The Branch
Office, February 1993.
[ADPCM] G. Vaudreuil and G. Parsons, "Toll Quality Voice - 32 kbit/s
ADPCM: MIME Sub-type Registration", Work In Progress, <draft-ema-
vpim-32kadpcm-02.txt>, November 1997.
[AMIS-A] Audio Messaging Interchange Specifications (AMIS) - Analog
Protocol Version 1, Issue 2, February 1992.
[AMIS-D] Audio Messaging Interchange Specifications (AMIS) - Digital
Protocol Version 1, Issue 3 August 1993.
[BINARY] Vaudreuil, G., "SMTP Service Extensions for Transmission of
Large and Binary MIME Messages", RFC 1830, October 1995.
[CODES] Vaudreuil, G. "Enhanced Mail System Status Codes", RFC 1893,
01/15/1996.
[MIMEDIR] F. Dawson, T. Howes, & M. Smith, "A MIME Content-Type for
Directory Information", Work In Progress, <draft-ietf-asid-mime-
direct-06.txt>, March 1998
[DISP] R. Troost and S. Dorner, Communicating Presentation Information
in Internet Messages: The Content-Disposition Header, RFC 2183,
August 1997
[DNS1] Mockapetris, P., "Domain names - implementation and
specification", RFC1035, Nov 1987.
[DNS2] Mockapetris, P., "Domain names - concepts and facilities", RFC
1034, Nov 1987.
[DRPT] Moore, K. "SMTP Service Extensions for Delivery Status
Notifications", RFC 1891, 01/15/1996
[DSN] Moore, K., Vaudreuil, G., "An Extensible Message Format for
Delivery Status Notifications", RFC 1894, 01/15/1996.
[DUR] G. Parsons and G. Vaudreuil, "Content Duration MIME Header
Definition", Work In Progress, <draft-ema-vpim-dur-02.txt>, November
1997.
[E164] CCITT Recommendation E.164 (1991), Telephone Network and ISDN
Operation, Numbering, Routing and Mobile Service - Numbering Plan
for the ISDN Era.
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[ESMTP] Klensin, J., Freed, N., Rose, M., Stefferud, E., and D. Crocker,
"SMTP Service Extensions" RFC 1869, United Nations University,
Innosoft International, Inc., Dover Beach Consulting, Inc., Network
Management Associates, Inc., The Branch Office, November 1995.
[G726] CCITT Recommendation G.726 (1990), General Aspects of Digital
Transmission Systems, Terminal Equipment - 40, 32, 24,16 kbit/s
Adaptive Differential Pulse Code Modulation (ADPCM).
[HOSTREQ] Braden, R., "Requirements for Internet Hosts -- Application
and Support", STD 3, RFC 1123, October 1989.
[LANG] Alvestrand,H., "Tags for the Identification of Languages", RFC
1766, Mar 1995
[MDN] Fajman, Roger, "An Extensible Message Format for Message
Disposition Notifications" Work In Progress, <draft-ietf-receipt-mdn-
08.txt>, January 1998
[MIB II] M. Rose, "Management Information Base for Network Management of
TCP/IP-based internets: MIB-II", RFC 1158, May 1990.
[MIME1] N. Freed and N. Borenstein, "Multipurpose Internet Mail
Extensions (MIME) Part One: Format of Internet Message Bodies", RFC
2045, Innosoft, First Virtual, Nov 1996.
[MIME2] N. Freed and N. Borenstein, "Multipurpose Internet Mail
Extensions (MIME) Part Two: Media Types ", RFC 2046, Innosoft, First
Virtual, Nov 1996.
[MIME3] K. Moore, "Multipurpose Internet Mail Extensions (MIME) Part
Three: Message Header Extensions for Non-ASCII Text ", RFC 2047,
University of Tennessee, Nov 1996.
[MIME4] N. Freed, J. Klensin and J. Postel, "Multipurpose Internet Mail
Extensions (MIME) Part Four: Registration Procedures", RFC 2048,
Innosoft, MCI, ISI, Nov 1996.
[MIME5] N. Freed and N. Borenstein, "Multipurpose Internet Mail
Extensions (MIME) Part Five: Conformance Criteria and Examples ", RFC
2049, Innosoft, First Virtual, Nov 1996.
[PIPE] Freed, N., Cargille, A., "SMTP Service Extension for Command
Pipelining" RFC 1854, October 1995.
[REPORT] Vaudreuil, G., "The Multipart/Report Content Type for the
Reporting of Mail System Administrative Messages", RFC 1892,
01/15/1996.
[REQ] S. Bradner, "Key words for use in RFCs to Indicate Requirement
Levels", RFC 2119, March 1997.
[RFC822] Crocker, D., "Standard for the Format of ARPA Internet Text
Messages", STD 11, RFC 822, UDEL, August 1982.
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[SIZE] Klensin, J, Freed, N., Moore, K, "SMTP Service Extensions for
Message Size Declaration" RFC 1870, United Nations University,
Innosoft International, Inc., November 1995.
[SMTP] Postel, J., "Simple Mail Transfer Protocol", STD 10, RFC 821,
USC/Information Sciences Institute, August 1982.
[STATUS] Freed, N. "SMTP Service Extension for Returning Enhanced Error
Codes", RFC 2034, 10/30/1996.
[TIFF-F] G. Parsons and J. Rafferty, "Tag Image File Format:
Application F", <draft-ietf-fax-tiff-09.txt>, February 1998.
[TIFFREG] G. Parsons, J. Rafferty & S. Zilles, "Tag Image File Format:
image/tiff - MIME sub-type registraion", <draft-ietf-fax-tiff-reg-
06.txt>, February 1998.
[V-MSG] G. Vaudreuil and G. Parsons, "VPIM Voice Message: MIME Sub-type
Registration", Work In Progress, <draft-ema-vpim-vmsg-02.txt> ,
November 1997.
[VCARD] Dawson, Frank, Howes, Tim, "vCard MIME Directory Profile"
<draft-ietf-asid-mime-vcard-05.txt>, March 1998.
[VPIM1] Vaudreuil, Greg, "Voice Profile for Internet Mail", RFC 1911,
Feb 1996.
[X.400] Hardcastle-Kille, S., "Mapping between X.400(1988) / ISO 10021
and RFC 822", RFC 1327, May 1992.
12. Acknowledgments
The authors would like to offer a special thanks to the Electronic
Messaging Association (EMA), especially the members of the Voice
Messaging Committee and the VPIM Work Group, for their support of the
VPIM specification and the efforts they have made to ensure its
success.
The EMA hosts the VPIM web page at http://www.ema.org/vpim.
13. Copyright Notice
"Copyright (C) The Internet Society (1998). All Rights Reserved.
This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it
or assist in its implmentation may be prepared, copied, published and
distributed, in whole or in part, without restriction of any kind,
provided that the above copyright notice and this paragraph are
included on all such copies and derivative works. However, this
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document itself may not be modified in any way, such as by removing
the copyright notice or references to the Internet Society or other
Internet organizations, except as needed for the purpose of
developing Internet standards in which case the procedures for
copyrights defined in the Internet Standards process must be followed,
or as required to translate it into languages other than English.
The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assigns.
This document and the information contained herein is provided on an
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT
NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN
WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE."
14. 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
Glenn.Parsons@Nortel.ca
Gregory M. Vaudreuil
Lucent Technologies,
Octel Messaging Division
17080 Dallas Parkway
Dallas, TX 75248-1905
United States
Phone/Fax: +1-972-733-2722
GregV@Lucent.Com
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15. Appendix A - VPIM Requirements Summary
The following table summarizes the profile of VPIM version 2 detailed
in this document. Since in many cases it is not possible to simplify
the qualifications for supporting each feature this appendix is
informative. The reader is recommended to read the complete
explanation of each feature in the referenced section. The text in
the previous sections shall be deemed authoritative if any item in
this table is ambiguous.
The conformance table is separated into various columns:
Feature - name of protocol feature (note that the indenting
indicates a hierarchy of conformance, i.e. the
conformance of a lower feature is only relevant if there
is conformance to the higher feature)
Section - reference section in main text of this document
Area - conformance area to which each feature applies:
C - content
T - transport
Status - whether the feature is mandatory, optional, or prohibited.
The key words used in this table are to be interpreted as described
in [REQ], though the following list gives a quick overview of the
different degrees of feature conformance:
Must - mandatory
Should - encouraged optional
May - optional
Should not - discouraged optional
Must not - prohibited
Footnote - special comment about conformance for a particular
feature
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VPIM version 2 Conformance
| | | | |S| |
| | | | | |H| |F
| | | | | |O|M|o
| | | |S| |U|U|o
| | | |H| |L|S|t
| |A|M|O| |D|T|n
| |R|U|U|M| | |o
| |E|S|L|A|N|N|t
| |A|T|D|Y|O|O|t
FEATURE |SECTION | | | | |T|T|e
-------------------------------------------|----------|-|-|-|-|-|-|-
| | | | | | | |
Message Addressing Formats: | | | | | | | |
Use DNS host names |4.1 |C|x| | | | |
Use only numbers in mailbox IDs |4.1.1 |C| |x| | | |
Use alpha-numeric mailbox IDs |4.1.1 |C| | |x| | |
Support of postmaster@domain |4.1.2 |C|x| | | | |
Support of non-mail-user@domain |4.1.2 |C| |x| | | |
Support of distribution lists |4.1.3 |C| |x| | | |
| | | | | | | |
Message Header Fields: | | | | | | | |
Encoding outbound messages | | | | | | | |
From |4.2.1 |C|x| | | | |
Addition of text name |4.2.1 |C| |x| | | |
To |4.2.2 |C|x| | | | |1
cc |4.2.3 |C| |x| | | |1
Date |4.2.4 |C|x| | | | |
Sender |4.2.5 |C| | |x| | |
Return-Path |4.2.6 |C| | |x| | |
Message-id |4.2.7 |C|x| | | | |
Reply-To |4.2.8 |C| | | |x| |
Received |4.2.9 |C|x| | | | |
MIME Version: 1.0 (Voice 2.0) |4.2.10 |C| |x| | | |
Content-Type |4.2.11 |C|x| | | | |
Content-Transfer-Encoding |4.2.12 |C|x| | | | |
Sensitivity |4.2.13 |C| | |x| | |
Importance |4.2.14 |C| | |x| | |
Subject |4.2.15 |C| |x| | | |
Disposition-notification-to |4.2.16 |C| | |x| | |
Disposition-notification-options |4.2.17 |C| | |x| | |
Other Headers |4.2 |C| | |x| | |
| | | | | | | |
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| | | | |S| |
| | | | | |H| |F
| | | | | |O|M|o
| | | |S| |U|U|o
| | | |H| |L|S|t
| |A|M|O| |D|T|n
| |R|U|U|M| | |o
| |E|S|L|A|N|N|t
| |A|T|D|Y|O|O|t
FEATURE |SECTION | | | | |T|T|e
-------------------------------------------|----------|-|-|-|-|-|-|-
Detection & Decoding inbound messages | | | | | | | |
From |4.2.1 |C|x| | | | |
Present text personal name |4.2.1 |C| | |x| | |
To |4.2.2 |C|x| | | | |
cc |4.2.3 |C| | |x| | |
Date |4.2.4 |C|x| | | | |
Conversion of Date to local time |4.2.4 |C| |x| | | |
Sender |4.2.5 |C| | |x| | |
Return-Path |4.2.6 |C| | |x| | |
Message ID |4.2.7 |C|x| | | | |
Reply-To |4.2.8 |C| |x| | | |
Received |4.2.9 |C| | |x| | |
MIME Version: 1.0 (Voice 2.0) |4.2.10 |C| |x| | | |
Content Type |4.2.11 |C|x| | | | |
Content-Transfer-Encoding |4.2.12 |C|x| | | | |
Sensitivity |4.2.13 |C|x| | | | |2
Importance |4.2.14 |C| | |x| | |
Subject |4.2.15 |C| | |x| | |
Disposition-notification-to |4.2.16 |C| | |x| | |
Disposition-notification-options |4.2.17 |C| | |x| | |
Other Headers |4.2 |C|x| | | | |3
| | | | | | | |
Message Content Encoding: | | | | | | | |
Encoding outbound audio/fax contents | | | | | | | |
7BIT |4.3 |C| | | | |x|
8BIT |4.3 |C| | | | |x|
Quoted Printable |4.3 |C| | | | |x|
Base64 |4.3 |C|x| | | | |4
Binary |4.3 |C| |x| | | |5
Detection & decoding inbound messages | | | | | | | |
7BIT |4.3 |C|x| | | | |
8BIT |4.3 |C|x| | | | |
Quoted Printable |4.3 |C|x| | | | |
Base64 |4.3 |C|x| | | | |
Binary |4.3 |C|x| | | | |5
| | | | | | | |
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| | | | |S| |
| | | | | |H| |F
| | | | | |O|M|o
| | | |S| |U|U|o
| | | |H| |L|S|t
| |A|M|O| |D|T|n
| |R|U|U|M| | |o
| |E|S|L|A|N|N|t
| |A|T|D|Y|O|O|t
FEATURE |SECTION | | | | |T|T|e
-------------------------------------------|----------|-|-|-|-|-|-|-
Message Content Types: | | | | | | | |
Inclusion in outbound messages | | | | | | | |
Multipart/Voice-Message |4.3.1 |C|x| | | | |
Message/RFC822 |4.3.2 |C| | |x| | |
Text/Directory |4.3.3 |C| |x| | | |
include TEL, EMAIL, VERSION |4.3.3 |C|x| | | | |
include ROLE, SOUND, N, REV |4.3.3 |C| |x| | | |
only one voice type per level |4.3.3 |C|x| | | | |
Audio/32KADPCM |4.3.4 |C|x| | | | |
Content-Description |4.3.4.1 |C| | |x| | |
Content-Disposition |4.3.4.2 |C|x| | | | |
Content-Duration |4.3.4.3 |C| | |x| | |
Content-Langauge |4.3.4.4 |C| | |x| | |
Image/tiff; application=faxbw |4.3.5 |C| | |x| | |
Audio/* or Image/* (other encodings) |4.3.6 |C| | |x| | |
Multipart/Mixed |4.4.1 |C| | |x| | |
Text/plain |4.4.2 |C| | | |x| |
Multipart/Report |4.4.3 |C|x| | | | |
human-readable part is voice |4.4.3 |C| |x| | | |
human-readable part is text |4.4.3 |C| | |x| | |
Message/delivery-status |4.4.4 |C|x| | | | |
Message/disposition-notification |4.4.5 |C| |x| | | |
Other contents |4.4 |C| | | |x| |6
| | | | | | | |
Detection & decoding in inbound messages | | | | | | | |
Multipart/Voice-Message |4.3.1 |C|x| | | | |
Message/RFC822 |4.3.2 |C|x| | | | |
Text/Directory |4.3.3 |C| |x| | | |
recognize TEL, EMAIL, VERSION |4.3.3 |C|x| | | | |
recognize ROLE, SOUND, N, REV |4.3.3 |C| |x| | | |
Audio/32KADPCM |4.3.4 |C|x| | | | |
Content-Description |4.3.4.1 |C| | |x| | |
Content-Disposition |4.3.4.2 |C| |x| | | |
Content-Duration |4.3.4.3 |C| | |x| | |
Content-Langauge |4.3.4.4 |C| | |x| | |
Image/tiff; application=faxbw |4.3.5 |C| |x| | | |
send NDN if unable to render |4.3.5 |C|x| | | | |7
Audio/* or Image/* (other encodings) |4.3.6 |C| | |x| | |
Multipart/Mixed |4.4.1 |C|x| | | | |
Text/plain |4.4.2 |C|x| | | | |
send NDN if unable to render |4.4.2 |C|x| | | | |
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| | | | | |S| |
| | | | | |H| |F
| | | | | |O|M|o
| | | |S| |U|U|o
| | | |H| |L|S|t
| |A|M|O| |D|T|n
| |R|U|U|M| | |o
| |E|S|L|A|N|N|t
| |A|T|D|Y|O|O|t
FEATURE |SECTION | | | | |T|T|e
------------------------------------------|-----------|-|-|-|-|-|-|-
| | | | | | | |
Multipart/Report |4.4.3 |C|x| | | | |
human-readable part is voice |4.4.3 |C| |x| | | |
human-readable part is text |4.4.3 |C|x| | | | |
Message/delivery-status |4.4.4 |C|x| | | | |
Message/disposition-notification |4.4.5 |C| |x| | | |
Other contents |4.4 |C| | | |x| |6
send NDN if unable to render |4.4 |C| |x| | | |
| | | | | | | |
Forwarded Messages | | | | | | | |
use Message/RFC822 construct |4.5 |C| |x| | | |
simulate headers if none available |4.5 |C| |x| | | |
| | | | | | | |
Reply Messages | | | | | | | |
send to Reply-to, else From address |4.6 |C|x| | | | |
do not send to non-mail-user |4.6 |C|x| | | | |
| | | | | | | |
Notifications | | | | | | | |
use multipart/report format |4.7 |C|x| | | | |
always send error on non-delivery |4.7 |C| |x| | | |
| | | | | | | |
Message Transport Protocol: | | | | | | | |
ESMTP Commands | | | | | | | |
HELO |5.1.1 |T|x| | | | |
MAIL FROM |5.1.2 |T|x| | | | |
support null address |5.1.2 |T|x| | | | |
RCPT TO |5.1.3 |T|x| | | | |
DATA |5.1.4 |T|x| | | | |
TURN |5.1.5 |T| | | | |x|
QUIT |5.1.6 |T|x| | | | |
RSET |5.1.7 |T|x| | | | |
VRFY |5.1.8 |T| | |x| | |
EHLO |5.1.9 |T|x| | | | |
BDAT |5.1.10 |T| |x| | | |5
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| | | | |S| |
| | | | | |H| |F
| | | | | |O|M|o
| | | |S| |U|U|o
| | | |H| |L|S|t
| |A|M|O| |D|T|n
| |R|U|U|M| | |o
| |E|S|L|A|N|N|t
| |A|T|D|Y|O|O|t
FEATURE |SECTION | | | | |T|T|e
-------------------------------------------|----------|-|-|-|-|-|-|-
| | | | | | | |
ESMTP Keywords & Parameters | | | | | | | |
PIPELINING |5.2.1 |T| |x| | | |
SIZE |5.2.2 |T|x| | | | |
CHUNKING |5.2.3 |T| |x| | | |
BINARYMIME |5.2.4,5.3.1|T| |x| | | |
DSN |5.2.5 |T|x| | | | |
ENHANCEDSTATUSCODES |5.2.6 |T| |x| | | |
RET |5.3.2 |T| |x| | | |
ENVID |5.3.3 |T| | |x| | |
NOTIFY |5.4.1 |T|x| | | | |
ORCPT |5.4.2 |T| | |x| | |
| | | | | | | |
ESMTP-SMTP Downgrading | | | | | | | |
send delivery report upon downgrade |5.5 |T|x| | | | |
| | | | | | | |
Directory Address Resolution | | | | | | | |
provide facility to resolve addresses |6 |C| |x| | | |
use vCards to populate local directory |6 |C| |x| | | |8
use headers to populate local directory |6 |C| | | |x| |
| | | | | | | |
Management Protocols: | | | | | | | |
Network management |8.1 |T| |x| | | |
-------------------------------------------|----------|-|-|-|-|-|-|-
Footnotes:
1. MUST NOT include if all recipients are not known or resolvable.
2. If a sensitive message is received by a system that does not
support sensitivity, then it MUST be returned to the originator
with an appropriate error notification. Also, a received
sensitive message MUST NOT be forwarded to anyone.
3. If the addtional headers are not understood they MAY be ignored
4. When binary transport is not available
5. When binary transport is available
6. Other un-profiled contents must only be sent by bilateral
agreement.
7. If the content cannot be presented in some form, the entire
message MUST be non-delivered.
8. When the vCard is present in a message
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16. Appendix B - Example Voice Messages
The following message is a full-featured message addressed to two
recipients. The message includes the sender's spoken name and a short
speech segment. The message is marked as important and private.
To: +19725551212@vm1.mycompany.com
To: +16135551234@VM1.mycompany.com
From: "Parsons, Glenn" <12145551234@VM2.mycompany.com>
Date: Mon, 26 Aug 93 10:20:20 -0700 (CDT)
MIME-Version: 1.0 (Voice 2.0)
Content-type: Multipart/Voice-Message; Version=2.0;
Boundary="MessageBoundary"
Content-Transfer-Encoding: 7bit
Message-ID: 123456789@VM2.mycompany.com
Sensitivity: Private
Importance: High
--MessageBoundary
Content-type: Audio/32KADPCM
Content-Transfer-Encoding: Base64
Content-Disposition: inline; voice=Originator-Spoken-Name
Content-Language: EN-US
Content-ID: part1@VM2-4321
glslfdslsertiflkTfpgkTportrpkTpfgTpoiTpdadasssdasddasdasd
(This is a sample of the base-64 Spoken Name data)
fgdhgddlkgpokpeowrit09==
--MessageBoundary
Content-type: Audio/32KADPCM
Content-Transfer-Encoding: Base64
Content-Description: Brand X Voice Message
Content-Disposition: inline; voice=Voice-Message; filename=msg1.726
Content-Duration: 25
iIiIiIjMzN3czdze3s7d7fwfHhcvESJVe/4yEhLz8/FOQjVFRERCESL/zqrq
(This is a sample of the base64 message data) zb8tFdLTQt1PXj
u7wjOyRhws+krdns7Rju0t4tLF7cE0K0MxOTOnRW/Pn30c8uHi9==
--MessageBoundary
Content-type: text/directory; charset=us-ascii; profile=vCard
Content-Transfer-Encoding: 7bit
BEGIN:VCARD
N:Parsons;Glenn;;Mr.;
EMAIL;TYPE=INTERNET:+12145551234@VM2.mycompany.com
TEL:+1-217-555-1234
SOUND;TYPE=32KADPCM;ENCODING=URI: CID:<part1@VM2-4321>
REV:19951031T222710Z
VERSION: 3.0
END:VCARD
--MessageBoundary_
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The following message is a forwarded single segment voice. Both the
forwarded message and the forwarding message contain VCARDs with
spoken names.
To: +12145551212@vm1.mycompany.com
From: "Vaudreuil, Greg" <+19725552345@VM2.mycompany.com>
Date: Mon, 26 Aug 93 10:20:20 -0700 (CDT)
MIME-Version: 1.0 (Voice 2.0)
Content-type: Multipart/Voice-Message; Version=2.0;
Boundary="MessageBoundary"
Content-Transfer-Encoding: 7bit
Message-ID: ABCD-123456789@VM2.mycompany.com
--MessageBoundary
Content-type: Audio/32KADPCM
Content-Transfer-Encoding: Base64
Content-Disposition: inline; voice=Originator-Spoken-Name
Content-Language: EN-US
Content-ID: part3@VM2-4321
glslfdslsertiflkTfpgkTportrpkTpfgTpoiTpdadasssdasddasdasd
(This is a sample of the base-64 Spoken Name data)
fgdhgd dlkgpokpeowrit09==
--MessageBoundary
Content-type: Audio/32KADPCM
Content-Description: Forwarded Message Annotation
Content-Disposition: inline; voice=Voice-Message
Content-Transfer-Encoding: Base64
glslfdslsertiflkTfpgkTportrpkTpfgTpoiTpdadasssdasddasdasd
(This is the voiced introductory remarks encoded in base64)
jrgoij3o45itj09fiuvdkjgWlakgQ93ijkpokfpgokQ90gQ5tkjpokfgW
dlkgpokpeowrit09==
--MessageBoundary
Content-type: Message/RFC822
Content-Transfer-Encoding: 7bit
To: +19725552345@VM2.mycompany.com
From: "Parsons, Glenn, W." <+16135551234@VM1.mycompany.com>
Date: Mon, 26 Aug 93 8:23:10 -0500 (EST)
Content-type: Multipart/Voice-Message; Version=2.0;
Boundary="MessageBoundary2"
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0 (Voice 2.0)
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--MessageBoundary2
Content-type: Audio/32KADPCM
Content-Transfer-Encoding: Base64
Content-Disposition: inline; voice=Originator-Spoken-Name
Content-Language: EN-US
Content-ID: part6@VM2-4321
glslfdslsertiflkTfpgkTportrpkTpfgTpoiTpdadasssdasddasdasd
(This is a sample of the base-64 Spoken Name data) fgdhgd
dlkgpokpeowrit09==
--MessageBoundary2
Content-type: Audio/32KADPCM
Content-Disposition: inline; voice=Voice-Message
Content-Transfer-Encoding: Base64
glslfdslsertiflkTfpgkTportrpkTpfgTpoiTpdadasssdasddasdasd
(This is the original message audio data) fgwersdfmniwrjj
jrgoij3o45itj09fiuvdkjgWlakgQ93ijkpokfpgokQ90gQ5tkjpokfgW
dlkgpokpeowrit09==
--MessageBoundary2
Content-type: text/directory; charset=us-ascii
Content-Transfer-Encoding: 7bit
BEGIN:VCARD
N:Parsons;Glenn;W;Mr.;
EMAIL;TYPE=INTERNET:+16135551234@VM2.mycompany.com
TEL:+1-613-555-1234
SOUND;TYPE=32KADPCM;ENCODING=URI: CID:<part6@VM2-4321>
REV:19951031T222710Z
END:VCARD
--MessageBoundary2--
--MessageBoundary
Content-type: text/directory; charset=us-ascii
Content-Transfer-Encoding: 7bit
BEGIN:VCARD
N:Vaudreuil;Greg;;Mr.;
SOUND;TYPE=32KADPCM;ENCODING=URI: CID:<part3@VM2-4321>
EMAIL;TYPE=INTERNET,VPIM:+19725552345@VM2.mycompany.com
TEL:+1-972-555-2345
REV:19951031T222710Z
VERSION: 3.0
END:VCARD
--MessageBoundary--
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The following example is for a message returned to the sender by a
VPIM gateway at VM1.company.com for a mailbox which does not exist.
Date: Thu, 7 Jul 1994 17:16:05 -0400
From: Mail Delivery Subsystem <MAILER-DAEMON@vm.company.com>
Message-Id: <199407072116.RAA14128@vm1.company.com>
Subject: Returned voice message
To: 2175552345@VM2.mycompany.com
MIME-Version: 1.0 (Voice 2.0)
Content-Type: multipart/report; report-type=delivery-status;
boundary="RAA14128.773615765/VM1.COMPANY.COM"
--RAA14128.773615765/VM1.COMPANY.COM
Content-type: Audio/32KADPCM
Content-Description: Spoken Delivery Status Notification
Content-Disposition: inline; voice= Voice-Message-Notification
Content-Transfer-Encoding: Base64
glslfdslsertiflkTfpgkTportrpkTpfgTpoiTpdadadffsssddasdasd
(This is a voiced description of the error in base64)
jrgoij3o45itj09fiuvdkjgWlakgQ93ijkpokfpgokQ90gdffkjpokfgW
dlkgpokpeowrit09==
--RAA14128.773615765/VM1.COMPANY.COM
Content-type: message/delivery-status
Reporting-MTA: dns; vm1.company.com
Original-Recipient: rfc822; 2145551234@VM1.mycompany.com
Final-Recipient: rfc822; 2145551234@VM1.mycompany.com
Action: failed
Status: 5.1.1 (User does not exist)
Diagnostic-Code: smtp; 550 Mailbox not found
Last-Attempt-Date: Thu, 7 Jul 1994 17:15:49 -0400
--RAA14128.773615765/VM1.COMPANY.COM
content-type: message/rfc822
[original VPIM message goes here]
--RAA14128.773615765/VM1.COMPANY.COM--
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The following example is for a read receipt sent to the original
sender for a message which has been played. This delivered VPIM
message was received by a corporate gateway and relayed to a
unified mailbox.
Date: Thu, 7 Jul 1994 17:16:05 -0400
From: "Greg Vaudreuil" <22722@vm.company.com>
Message-Id: <199407072116.RAA14128@exchange.company.com>
Subject: Voice message played
To: 2175552345@VM2.mycompany.com
MIME-Version: 1.0 (Voice 2.0)
Content-Type: multipart/report;
Report-type=disposition-notification;
Boundary="RAA14128.773615765/EXCHANGE.COMPANY.COM"
--RAA14128.773615765/EXCHANGE.COMPANY.COM
Content-type: Audio/32KADPCM
Content-Description: Spoken Disposition Notification
Content-Disposition: inline; voice= Voice-Message-Notification
Content-Transfer-Encoding: Base64
glslfdslsertiflkTfpgkTportrpkTpfgTpoiTpdadadffsssddasdasd
(Voiced description of the disposition action in base64)
jrgoij3o45itj09fiuvdkjgWlakgQ93ijkpokfpgokQ90gdffkjpokfgW
dlkgpokpeowrit09==
--RAA14128.773615765/EXCHANGE.COMPANY.COM
Content-type: message/disposition-notification
Reporting-UA: gregs-laptop.dallas.company.com (Unified FooMail 3.0)
Original-Recipient: rfc822;22722@vm.company.com
Final-Recipient: rfc822;Greg.Vaudreuil@foomail.company.com
Original-Message-ID: <199509192301.12345@vm2.mycompany.com >
Disposition: manual-action/MDN-sent-automatically; displayed
--RAA14128.773615765/EXCHANGE.COMPANY.COM
Content-type: message/rfc822
[original VPIM message goes here]
--RAA14128.773615765/EXCHANGE.COMPANY.COM--
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17. Appendix C - Example Error Voice Processing Error Codes
The following common voice processing errors and their corresponding
status codes are given as examples. Text after the error codes are
intended only for reference to describe the error code.
Implementations should provide implementation specific informative
comments after the error code rather than the text below.
Error condition RFC 1893 Error codes
----------------------------- --------------------------------
Analog delivery failed 4.4.0 Persistent connection error
because remote system is busy - other
Analog delivery failed 4.4.1 Persistent protocol error
because remote system is - no answer from host
ring-no-answer
Remote system did not answer 5.5.5 Permanent protocol error
AMIS-Analog handshake ("D" in - wrong version
response to "C" at connect
time)
Mailbox does not exist 5.1.1 Permanent mailbox error
- does not exist
Mailbox full or over quota 4.2.2 Persistent mailbox error
- full
Disk full 4.3.1 Persistent system error
- full
Command out of sequence 5.5.1 Permanent protocol error
- invalid command
Frame Error 5.5.2 Permanent protocol error
- syntax error
Mailbox does not support FAX 5.6.1 Permanent media error
- not supported
Mailbox does not support TEXT 5.6.1 Permanent media error
- not supported
Sender is not authorized 5.7.1 Permanent security error
- sender not authorized
Message marked private, but 5.3.3 Permanent system error
system is not private capable - not feature capable
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18. Appendix D - Example Voice Processing Disposition Types
The following common voice processing disposition conditions and their
corresponding MDN Disposition (which contains the disposition mode,
type and modifier, if applicable) are given as examples. Implementors
should refer to [MDN] for a full description of the format of message
disposition notifications.
Notification event MDN Disposition mode, type & modifier
------------------------------ -------------------------------------
Message played by recipient, manual-action/MDN-sent-automatically;
receipt automatically returned displayed
Message deleted from mailbox manual-action/MDN-sent-automatically;
by user without listening deleted
Message cleared when mailbox manual-action/MDN-sent-automatically;
deleted by admin deleted/mailbox-terminated
Message automatically deleted automatic-action/
when older than administrator MDN-sent-automatically; deleted/
set threshold expired
Message processed, however manual-action/MDN-sent-automatically;
audio encoding unknown - processed/error
unable to play to user Error: unknown audio encoding
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19. Appendix E - IANA Registrations
19.1 vCard EMAIL Type Definition for VPIM
To: ietf-mime-directory@imc.org
Subject: Registration of new parameter for text/directory MIME type
EMAIL
Type name: EMAIL
Type purpose: To specify the electronic mail address for
communication with the object the vCard represents (defined in
[VCARD]).
Type encoding: 8bit
Type value: A single text value.
Type special notes: The type may include the type parameter "TYPE" to
specify the format or preference of the electronic mail address. The
TYPE parameter values previously defined include: "internet" to
indicate an Internet addressing type, "x400" to indicate a X.400
addressing type and "pref" to indicate a preferred-use email address
when more than one is specified. The value of "vpim" is defined to
indicate that the address specified supports VPIM messages. Other
IANA registered address type may also be specified. The default email
type is "internet". A non-standard value may also be specified.
Type example:
EMAIL;TYPE=internet,vpim:jqpublic@xyz.dom1.com
19.2 Voice Content-Disposition Parameter Definition
To: IANA@IANA.ORG
Subject: Registration of new Content-Disposition parameter
Content-Disposition parameter name: voice
Allowable values for this parameter:
Voice-Message - the primary voice message,
Voice-Message-Notification - a spoken delivery notification
or spoken disposition notification,
Originator-Spoken-Name - the spoken name of the originator,
Recipient-Spoken-Name - the spoken name of the recipient if
available to the originator and present if there is ONLY one
recipient,
Spoken-Subject- the spoken subject of the message, typically
spoken by the originator
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Description:
In order to distinguish between the various types of audio contents in
a VPIM voice message a new disposition parameter "voice" is defined
with the preceding values to be used as appropriate. Note that there
SHOULD only be one instance of each of these types of audio contents
per message level. Additional instances of a given type (i.e.,
parameter value) may occur within an attached forwarded voice message.
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20. Appendix F - Change History: RFC 1911 to this Document
The updated profile in this document is based on the experience of a
proof of concept demonstration of VPIM at EMA'96 in April 1996 and a
subsequent demonstration of products at EMA'97 in April 1997. This
version of the profile is significantly different from the previous
described in [VPIM1]. The changes are categorized as general,
content, transport and conformance. They are detailed below:
1. General
- All definitions are now contained in separate documents that are
referenced by this profile. The new documents include:
- a refined multipart/voice-message definition
- a refined (i.e., added nibble order) audio/32KADPCM definition
- the definitions of TIFF-F and image/tiff for fax images
- the Content-Duration definition
- Changed the Voice version to 2.0
- Added Table of Contents and more examples
- Various editorial updates to improve readability
- Added more security considerations
2. Content
- Modified multipart/voice-message content type by dropping the
positional dependence of contents while restricting its contents to
voice message specific content types
- Explicitly indicated other contents that may be present ina
multipart/mixed content type
- Explicitly defined the forwarding model using message/RFC822
- Explained the use of reply-to and from headers for addressing
message replies
- Deprecated the special "loopback" address because of security
concerns and its use only for testing
- Defined the non-mail-user reserved address to support the case in
which replies to the originator are not possible
- Eliminated the text name in the "To" and "CC" headers.
Deprecated ordering of text names in the "From" header.
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- Added support for facsimile using TIFF-F in an image/tiff;
application=faxbw content type
- Profiled vCard in the text/directory body part for transport of
directory information about the originator
- Loosened text restriction
- Added additional details on delivery and receipt notifications
- Added support for message disposition notifications, also known
as read receipts.
- Added suggested addressing formats
- Described handling of private messages
- Described the handling of non-profiled contents in VPIM messages
- Described the use of Content-Disposition to semantically identify
audio contents
3. Transport
- Moved binary support to optional
- Added optional ESMTP keywords for return of content, enhanced
status codes, original recipient, and envelope ID
- Described use of null MAIL FROM address
4. Compliance
- Added an explicit section on conformance specifying conformance
to content or transport
- Improved conformance table in Appendix A
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