Voice Profile for Internet Mail - version 2 (VPIMv2)
draft-ietf-vpim-vpimv2r2-05
The information below is for an old version of the document that is already published as an RFC.
| Document | Type |
This is an older version of an Internet-Draft that was ultimately published as RFC 3801.
|
|
|---|---|---|---|
| Authors | Glenn Parsons , Gregory Vaudreuil | ||
| Last updated | 2015-10-14 (Latest revision 2002-02-18) | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Intended RFC status | Draft Standard | ||
| Formats | |||
| Additional resources | Mailing list discussion | ||
| Stream | WG state | (None) | |
| Document shepherd | (None) | ||
| IESG | IESG state | Became RFC 3801 (Draft Standard) | |
| Action Holders |
(None)
|
||
| Consensus boilerplate | Unknown | ||
| Telechat date | (None) | ||
| Responsible AD | Ned Freed | ||
| Send notices to | <jwn2@qualcomm.com> |
draft-ietf-vpim-vpimv2r2-05
Network Working Group Greg Vaudreuil
Internet Draft Lucent Technologies
Expires in six months Glenn Parsons
Obsoletes: RFC 2421, 2423 Nortel Networks
February 14, 2002
Voice Profile for Internet Mail - version 2
<draft-ietf-vpim-vpimv2r2-05.txt>
Status of this Memo
This document is an Internet-Draft and is in full conformance with all
provisions of Section 10 of RFC2026.
This document is an Internet Draft. Internet Drafts are working
documents of the Internet Engineering Task Force (IETF), its Areas, and
its Working Groups. Note that other groups may also distribute working
documents as Internet Drafts.
Internet Drafts are valid for a maximum of six months and may be
updated, replaced, or obsoleted by other documents at any time. It is
inappropriate to use Internet Drafts as reference material or to cite
them other than as a "work in progress".
To learn the current status of any Internet-Draft, please check the
"1id-abstracts.txt" listing contained in the Internet-Drafts Shadow
Directories on ftp.is.co.za (Africa), nic.nordu.net (Europe),
munnari.oz.au (Pacific Rim), ds.internic.net (US East Coast), or
ftp.isi.edu (US West Coast).
Abstract
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 conforming systems.
This document obsoletes RFC 2421 and describes version 2 of the profile
with greater precision. No protocol changes were made in this revision.
A list of changes from RFC 2421 are noted in Appendix F. Appendix A
summarizes the protocol profiles of this version of VPIM.
Copyright Notice
Copyright (C) The Internet Society (2002). All Rights Reserved.
Internet Draft VPIM v2 February 14, 2002
Table of Contents
1. INTRODUCTION......................................................3
1.1 Voice Messaging System Limitations ..............................4
1.2 Design Goals ....................................................5
1.3 Applicability for VPIM ..........................................5
2. REQUIREMENTS LANGUAGE.............................................6
3. PROTOCOL RESTRICTIONS.............................................6
4. VOICE MESSAGE INTERCHANGE FORMAT..................................7
4.1 VPIM Message Addressing Formats .................................7
4.2 Message Header Fields ..........................................11
4.3 MIME Audio Content Descriptions ................................19
4.4 Voice Message Content Types ....................................21
4.5 Other MIME Contents ............................................25
4.6 Delivery Status Notification (DSN) .............................27
4.7 Message Disposition Notification (MDN) .........................28
4.8 Forwarded Messages .............................................28
4.9 Reply Messages .................................................29
5. MESSAGE TRANSPORT PROTOCOL.......................................30
5.1 Base SMTP Protocol .............................................30
5.2 SMTP Service Extensions ........................................30
5.3 ESMTP - SMTP Downgrading .......................................32
6. DIRECTORY ADDRESS RESOLUTION.....................................33
7. MANAGEMENT PROTOCOLS.............................................33
7.1 Network Management .............................................33
8. CONFORMANCE REQUIREMENTS.........................................34
9. SECURITY CONSIDERATIONS..........................................35
9.1 General Directive ..............................................35
9.2 Threats and Problems ...........................................35
9.3 Security Techniques ............................................36
10. REFERENCES.......................................................37
11. ACKNOWLEDGMENTS..................................................40
12. COPYRIGHT NOTICE.................................................40
13. AUTHORS' ADDRESSES...............................................41
14. APPENDIX A - VPIM REQUIREMENTS SUMMARY...........................42
15. APPENDIX B - EXAMPLE VOICE MESSAGES..............................49
16. APPENDIX C - EXAMPLE ERROR VOICE PROCESSING ERROR CODES..........55
17. APPENDIX D - EXAMPLE VOICE PROCESSING DISPOSITION TYPES..........57
18. APPENDIX E - IANA REGISTRATIONS..................................58
18.1 Voice Content-Disposition Parameter Definition ...............58
18.2 Multipart/Voice-Message MIME Media Type Definition ...........59
19. APPENDIX F - CHANGE HISTORY: RFC 2421 (VPIM V2) TO THIS DOCUMENT.61
Vaudreuil & Parsons Expires August 14, 2002 [Page 2]
Internet Draft VPIM v2 February 14, 2002
1. Introduction
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.
Voice messaging evolved as telephone answering service into a full send,
receive, and forward messaging paradigm with unique message features,
semantics and usage patterns. Voice messaging was introduced on special
purpose computers that interface to a telephone switch and provide call
answering and voice messaging services. Traditionally, messages sent
from one voice messaging system to another were transported using analog
networking protocols based on DTMF signaling and analog voice playback.
As the demand for networking increases, there was a need for a standard
high-quality digital protocol to connect these machines. VPIM has
successfully demonstrated its usefulness as this new standard. VPIM is
widely implemented and is seeing deployment in customer networks. This
document clarifies ambiguities found in the earlier specification and is
consistent with implementation practice. The profile is referred to as
VPIM (Voice Profile for Internet Mail) in this document.
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 conforming systems.
This document obsoletes RFC 2421 and describes VPIM version 2 of with
greater precision. No protocol changes were made in this revision. A
list of changes from RFC 2421 are noted in Appendix F. Appendix A
summarizes the protocol profiles of this version of VPIM.
Please send comments on this document to the IETF VPIM mailing list:
vpim@lists.neystadt.org
Additional documents and background may be found on the VPIM web page:
http://www.vpim.org or http://www.ema.org/vpim
Vaudreuil & Parsons Expires August 14, 2002 [Page 3]
Internet Draft VPIM v2 February 14, 2002
1.1 Voice Messaging System Limitations
The following are typical limitations of voice messaging platforms that
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 typically no relaying
of messages. RFC822 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 are 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.
It should be noted that newer systems are based natively on SMTP/MIME
and do not suffer these limitations. In particular, some systems may
support media other than voice and fax.
Vaudreuil & Parsons Expires August 14, 2002 [Page 4]
Internet Draft VPIM v2 February 14, 2002
1.2 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 are 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
that do not understand MIME. 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 general-purpose MIME email
packages to read and compose VPIM messages. While no special
configuration is required to receive VPIM conforming messages, some may
be required to originate conforming structures.
It is expected that a system administrator who can perform TCP/IP
network configuration will manage a VPIM messaging system. 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 these
directory-listing capabilities are local matters.
1.3 Applicability for VPIM
VPIM is intended for the exchange of voice messages between traditional
voice messaging systems and for systems that need to interoperate with
such systems. VPIM is intended connect voice-messaging systems into
special-purpose voice messaging networks. VPIM may also be used between
message store servers and VPIM-aware clients such as web servers, TUI,
and GUI clients. VPIM is not intended or optimized for downloading to,
or sending from commercial email clients.
Internet Voice Messaging, the subject of a separate standards
initiative, is intended to enable general-purpose email clients to send
and receive voice content through general-purpose message stores in an
interoperable way. IVM may also be a suitable format for downloading
voice messages from a VPIM server to a commercial email client. It may
also be a suitable format for submission of a voice message from a
general-purpose client into a VPIM system.
Vaudreuil & Parsons Expires August 14, 2002 [Page 5]
Internet Draft VPIM v2 February 14, 2002
2. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [REQ].
3. Protocol Restrictions
This protocol does not limit the number of recipients per message.
Where possible, server 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.
This protocol does not limit the maximum message length. Implementers
should understand that some machines will be unable to accept
excessively long messages. A mechanism is defined in [SIZE] to declare
the maximum message size supported.
The following sections describe the restrictions and additions to
Internet mail protocols that are required to be conforming with this
VPIM v2 profile. Though various SMTP, ESMTP and MIME features are
described here, the implementer is referred to the relevant RFCs for
complete details. The table in Appendix A summarizes the protocol
details of this profile.
Vaudreuil & Parsons Expires August 14, 2002 [Page 6]
Internet Draft VPIM v2 February 14, 2002
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 [MIME1-5], the X.400 gateway specification
[X.400], and the delivery status and message disposition notifications
[REPORT][DSN][DRPT][STATUS][MDN].
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 (denoted by the
"Content-Transfer-Encoding:" MIME field) 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, either will work. Where
binary transport is available, no transport encoding is needed, and the
data can be labeled as "Binary".
4.1 VPIM Message Addressing Formats
VPIM addresses SHALL use the RFC 822 format 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 SHALL be a printable string containing the mailbox ID of the
originator or recipient. While alpha characters and long mailbox
identifiers MAY be permitted, short numeric local parts SHOULD be used
as 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 unreplyable. 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).
Vaudreuil & Parsons Expires August 14, 2002 [Page 7]
Internet Draft VPIM v2 February 14, 2002
The use of the Domain Name 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).
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:
Vaudreuil & Parsons Expires August 14, 2002 [Page 8]
Internet Draft VPIM v2 February 14, 2002
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
Note that this address format is designed to be compatible with current
usage within the voice messaging industry. It is not compatible with
the addressing formats of RFCs 2303-2304. It is expected that as
telephony services become more widespread on the Internet, these
addressing formats will converge.
4.1.2 Special Addresses
Special addresses to represent the sender 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
Vaudreuil & Parsons Expires August 14, 2002 [Page 9]
Internet Draft VPIM v2 February 14, 2002
If a reply to a message is not possible, such as a telephone-answering
message, then the special address "non-mail-user" SHOULD 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. A
conforming implementation MUST NOT permit a reply to an address from
"non-mail-user". For compatibility with the installed base of mail user
agents, implementations MUST reject the message when a message addressed
to "non-mail-user" is received. 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'. A VPIM implementation MAY support DLs. Using a simple
alias is a behavior closest to what many voice mail systems do today and
what is to be used with VPIM messages. A couple of important features
that need special care when DLs are used are:
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 or the "Return-Path:"
RFC822 field)
Some proprietary voice messaging protocols include only the recipient of
the particular copy in the envelope and include no "header fields"
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:" header fields. If all recipients cannot be
presented then the recipient header fields SHOULD be omitted to indicate
that an accurate list of recipients (e.g. for use with a reply-all
capability) is not known.
Vaudreuil & Parsons Expires August 14, 2002 [Page 10]
Internet Draft VPIM v2 February 14, 2002
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, header fields do not indicate delivery options for the transport
of messages.
Distribution list processors are noted for modifying or adding to the
header fields of messages that pass through them. VPIM systems MUST be
able to accept and ignore header fields that are not defined here.
The following header lines are permitted for use with VPIM messages:
4.2.1 From
SEND RULES
The originator's fully qualified domain address (a mailbox address
followed by the fully qualified domain name) MUST be present. Systems
conforming 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>
From: Non-mail-user@myserver.mycompany.com
Voice mail machines may not be able to support separate attributes for
the "From:" header fields and the SMTP MAIL FROM, VPIM-conforming
systems SHOULD set these values to the same address. Use of addresses
different than those present in the "From:" header field address may
result in unanticipated behavior.
RECEIVE RULES
The user listed in the "From:" field MUST be presented in the voice
message envelope of the voice messaging system as the originator of the
message, though the exact presentation is an implementation decision
(e.g., the mailbox ID or the text name MAY be presented). The "From:"
address SHOULD be used for replies (see 4.9).
Vaudreuil & Parsons Expires August 14, 2002 [Page 11]
Internet Draft VPIM v2 February 14, 2002
4.2.2 To
The "To:" field contains the recipient's fully-qualified domain address.
Example:
To: +12145551213@mycompany.com
SEND RULES
There MAY be one or more "To:" fields in any message. Systems SHOULD
provide a list of recipients only if all recipients are available.
Systems, such as gateways from protocols or legacy platforms that do not
indicate the complete list of recipients, MAY provide a "To:" line.
Because these systems cannot accurately enumerate all recipients in the
"To:" headers, recipients SHOULD NOT be enumerated.
RECEIVE RULES
Systems conforming to this profile MAY discard the addresses in the
"To:" fields if they are unable to store the information. This would,
of course, make a reply-to-all capability impossible. If present, the
addresses in the "To:" field MAY be used for a reply message to all
recipients.
4.2.3 Cc
The "Cc:" field 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 additional recipients.
SEND RULES
Conforming implementations MAY send "Cc:" lists if all recipients are
known at the time of origination. If not, systems SHOULD omit the "Cc:"
fields to indicate that the full list of recipients is unknown or
otherwise unavailable. The list of disclosed recipients MUST NOT include
undisclosed recipients (i.e., those sent via a blind copy).
Example:
Cc: +12145551213@mycompany.com
Vaudreuil & Parsons Expires August 14, 2002 [Page 12]
Internet Draft VPIM v2 February 14, 2002
RECEIVE RULES
Systems conforming to this profile MAY add all the addresses in the
"Cc:" field to the "To:" field, others MAY discard the addresses in the
"Cc:" fields. If a list of "Cc:" addresses is present, these
addresses MAY be used for a reply message to all recipients.
4.2.4 Date
The "Date:" field contains the date and time the message was sent by the
originator.
SEND RULES
The sending system MUST report the time the message was sent. The time
zone MUST be present and 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., "-0700
(PDT)".
Example:
Date: Wed, 28 Jul 96 10:08:49 -0800 (PST)
If the VPIM sender is relaying a message from a system that does not
provide a time stamp, the time of arrival at the gateway system SHOULD
be used as the date.
RECEIVE RULES
Conforming implementations SHOULD be able to convert [RFC822] date and
time stamps into local time
4.2.5 Sender
The "Sender:" field contains the actual address of the originator if an
agent on behalf of the author indicated in the "From:" field sends the
message.
SEND RULES
This header field MAY be sent by VPIM-conforming systems.
Vaudreuil & Parsons Expires August 14, 2002 [Page 13]
Internet Draft VPIM v2 February 14, 2002
RECEIVE RULES
If the address in the "Sender:" field cannot be preserved in the
recipient's message queues or in the next-hop protocol from a gateway,
the field MAY be silently discarded.
4.2.6 Return-Path
The "Return-path:" field is added by the final delivering SMTP server.
If present, it contains the address from the MAIL FROM parameter of the
ESMTP exchange (see[RFC822]). Any error messages resulting from the
delivery failure MUST be sent to this address. Note that if the
"Return-path:" is null ("<>") (e.g., a call answer message would have no
return path) delivery status notifications MUST NOT be sent.
SEND RULES
The originating system MUST NOT add this header.
RECEIVE RULES
If the receiving system is incapable of storing the return path (or MAIL
FROM) to be used for subsequent delivery errors (i.e., it is a gateway
to a legacy system or protocol), the receiving system must otherwise
ensure that further delivery errors don't happen. Systems that do not
support the return path MUST ensure that at the time the message is
acknowledged (i.e., when a DSN would be sent), the message is delivered
to the recipient's ultimate mailbox. Non-Delivery notifications SHOULD
NOT be sent after that final delivery.
4.2.7 Message-id
The "Message-Id:" field contains a globally unique per-message
identifier.
SEND RULES
A globally unique message-id MUST be generated for each message sent
from a VPIM-conforming implementation.
Example:
Message-Id: <12345678@mycompany.com>
Vaudreuil & Parsons Expires August 14, 2002 [Page 14]
Internet Draft VPIM v2 February 14, 2002
RECEIVE RULES
When provided in the original message, it MUST be used when sending a
MDN. This identifier MAY be used for tracking and auditing. From
[RFC822]
4.2.8 Reply-To
If present, the "Reply-To:" header provides a preferred address to which
reply messages should be sent (see 4.9). Typically, voice mail systems
can only support one originator of a message so it is likely that this
field will be ignored by the receiving system. From [RFC822]
SEND RULES
A conforming system SHOULD NOT send a "Reply-To:" header.
RECEIVE RULES
If a "Reply-To:" field is present, a reply-to-sender message MAY be sent
to the address specified (that is, in lieu of the address in the "From:"
field). If the receiving system (e.g., multi-protocol gateway) only
supports one address for the originator , then the address in the
"From:" field MUST be used and the "Reply-To:" field MAY be silently
discarded.
4.2.9 Received
The "Received:" field contains trace information added to the beginning
of a RFC822 message by MTAs. This is the only field that may 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. From [RFC822]
SEND RULES
A VPIM-conforming system MUST add a "Received:" field. When acting as a
gateway, information about the system from which the message was
received SHOULD be included.
RECEIVE RULES
A VPIM-conforming system MUST NOT remove any "Received:" fields when
relaying messages to other MTAs or gateways. These header fields MAY be
ignored or deleted when the message is received at the final
destination.
Vaudreuil & Parsons Expires August 14, 2002 [Page 15]
Internet Draft VPIM v2 February 14, 2002
4.2.10 MIME Version
The "MIME-Version:" field MUST be present to indicate that the message
conforms to [MIME]. Systems conforming with this specification SHOULD
include a comment with the words "(Voice 2.0)". [VPIM1] defines an
earlier version of this profile and uses the token (Voice 1.0).
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 multipart/voice-message content type defined in
section 18.2 SHOULD be used if identification is necessary.
4.2.11 Content-Type
The "Content-Type:" header MUST be present to declare the type of
content enclosed in the message. The typical top-level content in a VPIM
Message SHOULD be Multipart/Voice-Message. The allowable contents are
detailed starting in section 4.4 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.
SEND RULES
An implementation in conformance with this profile SHOULD send audio
and/or facsimile data in "Binary" form when binary message transport is
available (see section 5). When binary transport is not available,
implementations MUST encode the audio and/or facsimile data as "Base64".
RECEIVE RULES
Conforming implementations MUST recognize and decode the standard
encodings, "Binary" (when binary support is available), "7bit, "8bit",
"Base64" and "Quoted-Printable" per [MIME1]. 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.
Vaudreuil & Parsons Expires August 14, 2002 [Page 16]
Internet Draft VPIM v2 February 14, 2002
4.2.13 Sensitivity
The "Sensitivity:" field, if present, indicates the requested privacy
level. If no privacy is requested, this field is omitted. The header
definition is as follows:
Sensitivity := "Sensitivity" ":" Sensitivity-value
Sensitivity-value := "Personal" / "Private" / "Company-Confidential"
SEND RULES
A VPIM-conforming implementation MAY include this header to indicate the
sensitivity of a message. If a user marks a message "Private", a
conforming implementation MUST send only the "Private" sensitivity
level. There are no VPIM-specific semantics defined for the values
"Personal" or "Company-Confidential". A conforming implementation SHOULD
NOT send the values "Personal" or "Company-Confidential". If the message
is of "Normal" sensitivity, this field SHOULD be omitted. From: [X.400]
RECEIVE RULES
If a "Sensitivity:" field with a value of "Private" is present in the
message, a conforming system MUST prohibit the recipient from forwarding
this message to any other user. A conforming system, however, SHOULD
allow the responder to reply to a sensitive message, but SHOULD NOT
include the original message content. The responder MAY set the
sensitivity of the reply message.
A receiving system MAY ignore sensitivity values of "Personal" and
"Company Confidential".
If the receiving system does not support privacy and the sensitivity is
"Private", a negative delivery status notification MUST be sent to the
originator with the appropriate status code (5.6.0) "Other or undefined
protocol status" indicating that privacy could not be assured. The
message contents SHOULD be returned to the sender to allow for a voice
context with the notification. A non-delivery notification to a private
message SHOULD NOT be tagged private since it will be sent to the
originator. From: [X.400]
A message with no privacy explicitly noted (i.e., no header) or with
"Normal" sensitivity has no special treatment.
Vaudreuil & Parsons Expires August 14, 2002 [Page 17]
Internet Draft VPIM v2 February 14, 2002
4.2.14 Importance
Indicates the requested importance to be given by the receiving system.
If no special importance is requested, this header MAY be omitted and
the value of the absent header assumed to be "normal". From: [X.400]
Importance := "Importance" ":" importance-value
Importance-value := "low" / "normal" / "high"
SEND RULES
Conforming implementations MAY include this header to indicate the
importance of a message.
RECEIVE RULES
If the receiving system does not support "Importance:", the attribute
MAY be silently dropped.
4.2.15 Subject
The "Subject:" field is often provided by email systems but is not
widely supported on voice mail platforms. From [RFC822]
SEND RULES
For compatibility with text-based mailbox interfaces, a text subject
field SHOULD be generated by a conforming implementation. 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" or "Voice Message" for the benefit of
GUI-enabled recipients.
RECEIVE RULES
It is anticipated that many voice-only systems will be incapable of
storing the subject line. The subject MAY be discarded by a receiving
system.
Vaudreuil & Parsons Expires August 14, 2002 [Page 18]
Internet Draft VPIM v2 February 14, 2002
4.3 MIME Audio Content Descriptions
4.3.1 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.
Example:
Content-Description: Big Telco Voice Message
SEND RULES
This field MAY be added to a voice body part to offer a freeform
description of the voice content. It is useful to incorporate the
values for Content-Disposition with additional descriptions. For
example, this can be used to indicate product name or transcoding
records.
RECEIVE RULES
This field MAY be displayed to the recipient. However, since it is
only informative it MAY be ignored.
4.3.2 Content-Disposition
This field MUST be present to allow the parsable identification of
body parts within a VPIM voice message. This is especially useful if,
as is typical, more than one Audio/* body occurs within a single level
(e.g. Multipart/Voice-Message). Since a VPIM voice message is
intended to be automatically played in the order in which the audio
contents occur, the audio contents MUST always be of disposition
inline. However, it is still useful to include a filename value, so
this SHOULD be present if this information is available. >From [DISP]
SEND RULES
In order to distinguish between the various types of audio contents in
a VPIM voice message a new disposition parameter "voice" is defined
with IANA (see section 18.1) with the parameter values below to be
used as appropriate:
Audio-Type := "voice" "=" Audio-type-value
Audio-type-value := "Voice-Message" / "Voice-Message-Notification" /
"Originator-Spoken-Name" /"Recipient-Spoken-Name" /"Spoken-Subject"
Vaudreuil & Parsons Expires August 14, 2002 [Page 19]
Internet Draft VPIM v2 February 14, 2002
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(s) if
available to the originator
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 or
reply voice message. If there are multiple recipients for a given
message, recipient-spoken-name MUST NOT be used.
RECEIVE RULES
Implementations SHOULD use this header. However, those that do not
understand the "voice" parameter (or the "Content-Disposition:"
header) can safely ignore it, and will present the audio body parts in
order (but will not be able to distinguish between them). If more than
one instance of the "voice" parameter type value is encountered at one
level (e.g., multiple 'Voice-Message' tagged contents) then they
SHOULD be presented together.
4.3.3 Content-Duration
The "Content-Duration:" header provides an indication of the audio
length in seconds of the segment.
Example:
Content-Duration: 33
SEND RULES
This field MAY be present to allow the specification of the length of
the audio body part in seconds.
RECEIVE RULES
The use of this field on reception is a local implementation issue.
From [DUR]
Vaudreuil & Parsons Expires August 14, 2002 [Page 20]
Internet Draft VPIM v2 February 14, 2002
4.3.4 Content-Language:
This field MAY be present to allow the specification of the spoken
language of the audio body part. The encoding is defined in [LANG].
Example for UK English:
Content-Language: en-UK
SEND RULES
A sending system MAY add this field to indicate the language of the
voice. The determination of this (e.g., automated or user-selected)
is a local implementation issue.
RECEIVE RULES
The use of this field on reception is a local implementation issue.
It MAY be used as a hint to the recipient (e.g., end-user or an
automated translation process) as to the language of the voice
message.
4.4 Voice Message Content Types
The content types described in this section are identified for use
within the Multipart/Voice-Message content. This content is referred to
as a "VPIM message" in this document and is the fundamental part of a
"VPIM message".
Only the contents profiled can be sent within a VPIM voice message
construct (i.e., the Multipart/Voice-Message content type) 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 not permitted. In the absence of a bilateral agreement, conforming
implementations MUST NOT create a message containing prohibited
contents. In the spirit of liberal acceptance, a conforming
implementation MAY accept and render prohibited content. Systems unable
to accept or render prohibited contents MAY discard the prohibited
contents as necessary to deliver the acceptable content. 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.
Some deployed implementations based on a common interpretation of the
original VPIM v2 specification reject messages with prohibited content
rather than discard the unsupported contents. For interoperability with
these systems, it is especially important that prohibited contents not
be sent within a Multipart/Voice-Message.
Vaudreuil & Parsons Expires August 14, 2002 [Page 21]
Internet Draft VPIM v2 February 14, 2002
4.4.1 Multipart/Voice-Message
This MIME multipart structure provides a mechanism for packaging a voice
message into one container that is tagged as VPIM v2 conforming. The
sub-type is identical in semantics and syntax to multipart/mixed, as
defined in [MIME2]. As such, it may be safely interpreted as a
multipart/mixed by systems that do not understand the sub-type (only the
identification as a voice message would be lost).
In addition to the MIME required boundary parameter, a version parameter
is also required for this sub-type. This is to distinguish this
refinement of the sub-type from the previous definition in [VPIM1]. The
value of the version parameter is "2.0" if the content conforms to the
requirements of this specification. Should there be further revisions
of this content type, there MUST be backwards compatibility (i.e.
systems implementing version n can read version 2, and systems
implementing version 2 can read version 2 contents within a version n).
SEND RULES
The Multipart/Voice-Message content-type MUST only contain the profiled
media and content types specified in this section (i.e. Audio/*,
Image/*, and Message/RFC822). The most common will be: spoken name,
spoken subject, the message itself, and an attached fax. Forwarded
messages are created by simply using the Message/RFC822 construct.
Conformant implementations MUST use Multipart/Voice-Message in a VPIM
message. In most cases, this Multipart/Voice-Message Content-Type will
be the top level but may be included within a Message/RFC822 if the
message is forwarded or within a multipart/mixed when more than one
message is being forwarded.
RECEIVE RULES
Conformant implementations MUST recognize the Multipart/Voice-Message
content (whether it is a top-level content or contained in a
Multipart/Mixed) and MUST be able to separate the contents (e.g. spoken
name or spoken subject).
The semantic of Multipart/Voice-Message (defined in section 18.2) is
identical to Multipart/Mixed and may be interpreted as that by systems
that do not recognize this content-type.
Vaudreuil & Parsons Expires August 14, 2002 [Page 22]
Internet Draft VPIM v2 February 14, 2002
4.4.2 Message/RFC822
SEND RULES
MIME requires support of the Message/RFC822 message encapsulation body
part. This body part SHOULD be used within a Multipart/Voice-Message to
forward complete messages (see 4.8) or to reply with original content
(see 4.9). From [MIME2]
RECEIVE RULES
The receiving system MUST accept this format and SHOULD treat this
attachment as a forwarded message. The receiving system MAY flatten the
forwarding structure (i.e., remove this construct to leave multiple
voice contents or even concatenate the voice contents to fit in a
recipient's mailbox), if necessary.
4.4.3 Audio/32KADPCM
SEND RULES
An implementation conforming to this profile MUST send Audio/32KADPCM by
default for voice [ADPCM]. This encoding is a moderately-compressed
encoding with a data rate of 32 kbits/second using moderate processing
resources. Typically, this body contains several minutes of message
content; however, if used for spoken name or subject the content is
expected to be considerably shorter (i.e. about 5 and 10 seconds
respectively).
RECEIVE RULES
Receivers MUST be able to accept and decode Audio/32KADPCM. If an
implementation can only handle one voice body, then multiple voice
bodies (if present) SHOULD be concatenated, and MUST NOT be discarded.
If concatenated, the contents SHOULD be in the same order they appeared
in the multipart.
4.4.4 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 within Multipart/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.
SEND RULES
Vaudreuil & Parsons Expires August 14, 2002 [Page 23]
Internet Draft VPIM v2 February 14, 2002
All VPIM implementations that support facsimile MUST generate TIFF-F
compatible facsimile contents in the Image/TIFF subtype using the
application=faxbw encoding by default. If the VPIM message is a voice-
annotated fax, the implementation SHOULD send this fax content in
Multipart/Voice-Message. If the message is a simple fax, an
implementation MAY send it without using the Multipart/Voice-Message to
be more compatible with fax-only (RFC 2305) implementations.
While any valid MIME body header MAY be used (e.g., Content-Disposition
to indicate the filename), none are specified to have special semantics
for VPIM and MAY be ignored. Note that the content-type parameter
application=faxbw MUST be included in outbound messages.
RECEIVE RULES
Not all VPIM systems support fax, but all SHOULD accept it within the
multipart/voice-message. Within a Multipart/Voice-Message, a receiving
system that cannot render fax content SHOULD accept the voice content of
a VPIM message and discard the fax content. Outside a Multipart/Voice-
Message, a recipient system MAY reject (with appropriate NDN) the entire
message if it cannot store or is not capable of rendering a message with
fax attachments. VPIM conforming systems MAY support fax outside of
(or without) the Multipart/Voice-Message.
Some deployed implementations based on a common interpretation of the
original VPIM V2 specification reject messages with fax content within
the Multipart/Voice-Message rather than discard the unsupported
contents. These systems will return the message to the sender with an
NDN indicating lack of support for fax.
Vaudreuil & Parsons Expires August 14, 2002 [Page 24]
Internet Draft VPIM v2 February 14, 2002
4.5 Other MIME Contents
The following MIME contents (with the exception of multipart/mixed in
section 4.5.1) MAY be included within a multipart/voice message. Other
contents MUST NOT be included. Their handling is a local implementation
issue. Multipart/mixed is included to promote interoperability with a
wider range of systems and also to allow the creation of more complex
multimedia messages (with a VPIM message as one part).
4.5.1 Multipart/Mixed
This common MIME content-type allows the enclosing of several body parts
in a single message.
SEND RULES
A VPIM voice message (i.e., multipart/voice-message) MAY be included
within a message with a Multipart/Mixed top-level content type.
Typically, this would only be used when mixing non-voice and non-fax
contents with a voice message.
RECEIVE RULES
Such a message is not itself a VPIM message and the handling of such a
construct is outside the scope of the VPIM profile. However, an the
spirit of liberal acceptance, a conforming implementation MUST accept
and render a VPIM voice message contained in a Multipart/Mixed.
4.5.2 Text/Directory
SEND RULES
This content was profiled in the original specification of VPIM v2 as a
means of transporting contact information from the sender to the
recipient. This usage did not find widespread adoption and is no longer
a feature of VPIM V2. Conforming implementations SHOULD NOT send the
Text/Directory content type.
RECEIVE RULES
For compatibility with an earlier specification of VPIM v2, the
Text/Directory content type MUST be accepted by a conforming
implementation, but need not be stored, processed, or rendered to the
recipient.
Vaudreuil & Parsons Expires August 14, 2002 [Page 25]
Internet Draft VPIM v2 February 14, 2002
4.5.3 Proprietary Voice or Fax Formats
Use of any other encoding except the required codecs reduces
interoperability in the absence of explicit knowledge about the
capabilities of the recipient. A conforming implementation SHOULD NOT
use any other encoding unless a unique identifier is registered with the
IANA prior to use (see [MIME4]). The voice encodings SHOULD be
registered as subtypes of Audio. The fax encodings SHOULD be registered
as subtypes of Image.
SEND RULES
Proprietary voice encoding formats or other standard formats SHOULD NOT
be sent under this profile unless the sender has a reasonable
expectation that the recipient will accept the encoding. In practice,
this requires explicit per-destination configuration information
maintained either in a directory, personal address book, or gateway
configuration tables.
RECEIVE RULES
Systems MAY accept other Audio/* or Image/* content types if they can
decode them. Systems which receive Audio/* or Image/* content types
which they are unable to deposit or unable to render MUST return the
message (and SHOULD include the original content) to the originator with
an NDN indicating media not supported.
4.5.4 Text/Plain
MIME requires support of the basic Text/Plain content type (with the US-
ASCII character set). This content type has limited applicability
within the voice-messaging environment. However, because VPIM is a MIME
profile, MIME requirements SHOULD be met.
SEND RULES
Conforming VPIM implementations SHOULD NOT send the Text/Plain content-
type. Implementations MAY send the Text/Plain content-type outside the
Multipart/Voice-Message.
Vaudreuil & Parsons Expires August 14, 2002 [Page 26]
Internet Draft VPIM v2 February 14, 2002
RECEIVE RULES
Within a Multipart/Voice-Message, the Text/Plain content-type MAY be
dropped from the message, if necessary, to deliver the audio/fax
components. The recipient SHOULD NOT reject the entire message if the
text component cannot be accepted or rendered.
Outside a Multipart/Voice-Message, conforming implementations MUST
accept Text/Plain; however, specific handling is left as an
implementation decision. From [MIME2]
Some deployed implementations based on a common interpretation of the
original VPIM V2 specification reject messages with any text content
rather than discard the unsupported contents. These systems will return
the message to the sender with an NDN indicating lack of support for
text.
4.6 Delivery Status Notification (DSN)
A DSN is a notification of delivery (positive DSN), non-delivery
(negative DSN), or temporary delivery delay (delayed DSN). The top-
level content-type of a DSN is Multipart/Report, which is defined in
[REPORT]. The content-type which distinguishes DSN's from other types
of notifications is Message/Delivery-Status, which is defined in [DSN].
SEND RULES
A VPIM-compliant implementation MUST be able to send DSN's that conform
to [REPORT] and [DSN]. Unless requested otherwise, a non-delivery DSN
MUST be sent when any form of non-delivery of a message occurs.
A VPIM-compliant implementation SHOULD provide a spoken delivery status
in the "human-readable" body part of the DSN, but MAY provide a textual
status.
RECEIVE RULES
A VPIM-compliant implementation MUST be able to receive DSN's that
conform to [REPORT] and [DSN].
A VPIM-compliant implementation MUST be able to receive a DSN whose
"human-readable" body part contains a spoken delivery status phrase or a
textual description. Though subsequent use of the phrase or text is a
local implementation issue, the intent of the DSN MUST be presented to
the end user.
Vaudreuil & Parsons Expires August 14, 2002 [Page 27]
Internet Draft VPIM v2 February 14, 2002
4.7 Message Disposition Notification (MDN)
An MDN is a notification indicating what happens to a message after it
is deposited in the recipient's mailbox. An MDN can be positive
(message was read/played/rendered/etc.) or negative (message was deleted
before recipient could see it, etc.). The top-level content-type of a
MDN is Multipart/Report, which is defined in [REPORT]. The content-type
which distinguishes MDN's from other types of notifications is
Message/Disposition-Notification, which is defined in [MDN].
SEND RULES
A VPIM-compliant implementation SHOULD support the ability to request
MDNs. This is done via the use of the "Disposition-Notification-To:"
header field as defined in [MDN].
A VPIM-compliant implementation SHOULD support the ability to send MDNs,
but these MDNs MUST conform to [REPORT] and [MDN].
When sending an MDN, a VPIM-compliant implementation SHOULD provide a
spoken message disposition in the "human-readable" body part of the MDN,
but MAY provide a textual status.
RECEIVE RULES
A VPIM-compliant implementation SHOULD respond to an MDN request with an
MDN response.
A VPIM-compliant implementation MUST be able to receive MDNs that
conform to [REPORT] and [MDN], if it is capable of requesting MDNs. If
a VPIM-compliant implementation is capable of receiving MDNs, it MUST be
able to receive a MDN whose "human-readable" body part contains a spoken
message disposition phrase or a textual disposition description. Though
subsequent use of the phrase or text is a local implementation issue,
the intent of the MDN MUST be presented to the end user.
4.8 Forwarded Messages
VPIM v2 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.
Vaudreuil & Parsons Expires August 14, 2002 [Page 28]
Internet Draft VPIM v2 February 14, 2002
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 header fields are not available for the forwarded content,
simulated header fields with available information SHOULD be constructed
to indicate the original sending timestamp, and the original sender as
indicated in the "From:" field. 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:", and "Content-Type:"
header fields. From [MIME2]
In the event that forwarding information is lost, the entire audio
content MAY be sent as a single Audio/* segment without including any
forwarding semantics. An example of this loss is an AMIS message being
forwarded through an AMIS-to-VPIM gateway.
4.9 Reply Messages
VPIM v2 explicitly supports replying to received messages.
Support of multiple originator header fields in a reply message is often
not possible on voice messaging systems, so it may be necessary to
choose only one when gatewaying a VPIM message to another voice message
system. However, implementers should note that this may make it
impossible to send DSN's, MDN's, and replies to their proper
destinations.
In some cases, replying to a message is not possible, such as with a
message created by telephone answering (i.e. classic voice mail). In
this case, the From field SHOULD contain the special address non-mail-
user@domain (see 4.1.2). The recipient's VPIM system SHOULD NOT offer
the option to reply to this kind of message (unless an outcalling
feature is offered - - which is out of scope for VPIM).
Vaudreuil & Parsons Expires August 14, 2002 [Page 29]
Internet Draft VPIM v2 February 14, 2002
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 messaging
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 Base SMTP Protocol
A conforming system MUST implement all mandatory SMTP and ESMTP
commands. Any defined optional command or parameter MAY be supported.
5.2 SMTP Service Extensions
VPIM utilizes a number of SMTP Service Extensions to provide full-
featured voice messaging service. The following extensions are profiled
for use with VPIM:
5.2.1 DSN Extension
The DSN extension defines a mechanism which allows an SMTP client to
specify (a) DSN's should be generated under certain conditions, (b)
whether such DSN's should return the contents of the message, and (c)
additional information, to be returned with a DSN, that allows the
sender to identify both the recipient(s) for which the DSN was issued,
and the transaction in which the original message was sent.
The DSN extension MUST be supported by VPIM conforming implementations.
In addition, beyond the requirements of [DRPT], conforming
implementations MUST support NOTIFY parameter on the RCPT command to
allow indication of when the originator requests a notification. The
Vaudreuil & Parsons Expires August 14, 2002 [Page 30]
Internet Draft VPIM v2 February 14, 2002
RET parameter SHOULD be supported to return the original message with
the notification. Parameters ORCPT and ENVID MAY also be supported.
From [DRPT]
5.2.2 SIZE Extension
The SIZE extension defines a mechanism whereby an SMTP client and server
may interact to give the server an opportunity to decline to accept a
message (perhaps temporarily) based on the client's estimate of the
message size. From [SIZE]
The SIZE extension MUST be supported by VPIM-compliant implementations.
5.2.3 ENHANCEDSTATUSCODES Extension
The ENHANCEDSTATUSCODES extension defines a mechanism whereby an SMTP
server augments its responses with the enhanced mail system status codes
defined in [CODES]. These codes can then be used to provide more
informative explanations of error conditions. From [STATUS]
The ENHANCEDSTATUSCODES extension SHOULD be supported by VPIM-compliant
implementations.
5.2.4 PIPELINING Extension
The PIPELINING extension defines a mechanism whereby an SMTP server can
indicate the extent of its ability to accept multiple commands in a
single TCP send operation. Using a single TCP send operation for
multiple commands can improve SMTP performance significantly. From
[PIPE]
The PIPELINING extension SHOULD be supported by VPIM-compliant
implementations.
5.2.5 CHUNKING Extension
The CHUNKING extension defines a mechanism that enables an SMTP client
and server to negotiate the use of the message data transfer command
"BDAT" (in alternative to the DATA command) for efficiently sending
large MIME messages.
From [BINARY]
The CHUNKING extension MAY be supported by VPIM-compliant
implementations.
Vaudreuil & Parsons Expires August 14, 2002 [Page 31]
Internet Draft VPIM v2 February 14, 2002
5.2.6 BINARYMIME Extension
The BINARYMIME extension defines a mechanism that enables an SMTP client
and server to negotiate the transfer of unencoded binary message data
utilizing the BDAT command.
From [BINARY]
The BINARYMIME extension MAY be supported by VPIM-compliant
implementations. Note that [BINARY] specifies that if BINARYMIME is to
be supported, then CHUNKING has to be supported by definition.
5.3 ESMTP - SMTP Downgrading
The SMTP extensions suggested or required for conformance to VPIM fall
into two categories. The first category includes features that increase
the efficiency of the transport system such as SIZE, BINARYMIME, and
PIPELINING. In the event of a downgrade to a less-functional transport
system, these features can be dropped with no functional change to the
sender or recipient.
The second category of features is transport extensions in support of
new functions. DSN and ENHANCEDSTATUSCODES provide essential
improvements in the handling of delivery status notifications to bring
email to the level of reliability expected of Voice Mail. To ensure a
consistent level of service across an intranet or the global Internet,
it is essential that VPIM-conforming ESMTP support the DSN extension at
all hops between a VPIM originating system and the recipient system. In
the situation where a "downgrade" is unavoidable a relay hop may be
forced (by the next hop) to forward a VPIM message without the ESMTP
request for delivery status notification. It is RECOMMENDED that the
downgrading system should continue to attempt to deliver the message,
but MUST send an appropriate delivery status notification to the
originator, e.g. the message left an ESMTP host and was sent relayed to
a non-DSN-aware destination, and this may be the last DSN received.
Vaudreuil & Parsons Expires August 14, 2002 [Page 32]
Internet Draft VPIM v2 February 14, 2002
6. Directory Address Resolution
It is the responsibility of a VPIM system to provide the fully-qualified
domain name (FQDN) of the recipient 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 offer 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 cache, an implementation may wish to populate
local directories with the first and last names, as well as the senders'
spoken name information extracted from received messages. Addresses or
names parsed from the header fields of VPIM messages MAY be used to
populate directories.
7. 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
VPIM-conforming machine.
7.1 Network Management
The digital interface to the VM and the TCP/IP protocols MAY be managed.
MIB II MAY be implemented to provide basic statistics and reporting of
TCP and IP protocol performance. [MIB II]
Vaudreuil & Parsons Expires August 14, 2002 [Page 33]
Internet Draft VPIM v2 February 14, 2002
8. Conformance Requirements
VPIM is a messaging application that will 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-conformant.
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 conformance requirements is contained in Appendix A.
VPIM end systems are expected to be both transport- and content-
conformant. Voice messaging systems and protocol conversion gateways
are considered end systems.
Relay systems are expected to be transport-conformant 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 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.
Vaudreuil & Parsons Expires August 14, 2002 [Page 34]
Internet Draft VPIM v2 February 14, 2002
9. Security Considerations
9.1 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 Internet security infrastructure, rather
than a new mechanism or some other mechanism outside of the Internet
infrastructure.
9.2 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 that ensue from integrating the two services.
9.2.1 Spoofed sender
The actual sender of the voice message might not be the same as that
specified in the "Sender:" or "From:" message header fields 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
sender's voice may provide confidence of the sender's identity
irrespective 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.
9.2.2 Unsolicited voice mail
Assigning an Internet mail address to a voice mailbox opens the
possibility of receiving unsolicited messages (either text or voice
mail). Traditionally, voice mail systems operated in closed
environments and were not susceptible 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 unknown sources in an attempt to curb this
problem.
9.2.3 Message disclosure
Users of voice messaging systems have an expectation of a level of
message privacy that 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.
Vaudreuil & Parsons Expires August 14, 2002 [Page 35]
Internet Draft VPIM v2 February 14, 2002
9.3 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.
Vaudreuil & Parsons Expires August 14, 2002 [Page 36]
Internet Draft VPIM v2 February 14, 2002
10. References
[8BIT] Klensin, J., Freed, N., Rose, M., Stefferud, E., D. Crocker, "SMTP
Service Extension for 8bit-MIMEtransport" RFC 1652, United Nations
University, Innosoft International, Inc., Dover Beach Consulting, Inc.,
Network Management Associates, Inc., The Branch Office, July 1994.
[ADPCM] G. Vaudreuil and G. Parsons, "Toll Quality Voice - 32 kbit/s ADPCM:
MIME Sub-type Registration", RFC 2422, September 1998. Revised by:
<draft-ietf-vpim-vpimv2r2-32k-03.txt>, February 2002.
[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 3030, December 2000.
[CODES] Vaudreuil, G. "Enhanced Mail System Status Codes", RFC 1893,
January 1996.
[MIMEDIR] F. Dawson, T. Howes, & M. Smith, "A MIME Content-Type for
Directory Information", RFC 2425 September 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, replaced by <draft-moore-rfc1891bis-00.txt>,
Work-in-Progress
[DSN] Moore, K., Vaudreuil, G., "An Extensible Message Format for Delivery
Status Notifications", RFC 1894, replaced by <draft-vaudreuil-1894bis-
00>, January 1996.
[DUR] G. Parsons and G. Vaudreuil, "Content Duration MIME Header
Definition", RFC 2424, September 1998. Revised by: <draft-ietf-vpim-
vpimv2r2-dur-03.txt>, February 2002.
Vaudreuil & Parsons Expires August 14, 2002 [Page 37]
Internet Draft VPIM v2 February 14, 2002
[E164] CCITT Recommendation E.164 (1991), Telephone Network and ISDN
Operation, Numbering, Routing and Mobile Service - Numbering Plan for
the ISDN Era.
[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 3066,
January 2001.
[MDN] RFC 1891 updated by Vaudreuil, G, and Hansen, T, "An Extensible
Message Format for Message Disposition Notifications", <draft-
vaudreuil-mdnbis-03.txt> Work-in-progress.
[MIB II] M. Rose, "Management Information Base for Network Management of
TCP/IP-based internets: MIB-II", RFC 1213, March 1991.
[MIME1] N. Freed and N. Borenstein, "Multipurpose Internet Mail Extensions
(MIME) Part One: Format of Internet Message Bodies", RFC 2045,
Innosoft, First Virtual, November 1996.
[MIME2] N. Freed and N. Borenstein, "Multipurpose Internet Mail Extensions
(MIME) Part Two: Media Types ", RFC 2046, Innosoft, First Virtual,
November 1996.
[MIME3] K. Moore, "Multipurpose Internet Mail Extensions (MIME) Part
Three: Message Header Extensions for Non-ASCII Text ", RFC 2047,
University of Tennessee, November 1996.
[MIME4] N. Freed, J. Klensin and J. Postel, "Multipurpose Internet Mail
Extensions (MIME) Part Four: Registration Procedures", RFC 2048,
Innosoft, MCI, ISI, November 1996.
[MIME5] N. Freed and N. Borenstein, "Multipurpose Internet Mail Extensions
(MIME) Part Five: Conformance Criteria and Examples ", RFC 2049,
Innosoft, First Virtual, November 1996.
[PIPE] Freed, N., Cargille, A., "SMTP Service Extension for Command
Pipelining" RFC 2920, September 2000.
Vaudreuil & Parsons Expires August 14, 2002 [Page 38]
Internet Draft VPIM v2 February 14, 2002
[REPORT] Vaudreuil, G., "The Multipart/Report Content Type for the
Reporting of Mail System Administrative Messages", RFC 1892, replaced
by <draft-vaudreuil-rfc1892bis-00.txt> work-in-progress.
[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.
[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, October 1996.
[TIFF-F] G. Parsons and J. Rafferty, "Tag Image File Format: Application
F", RFC 2306, March 1998.
[TIFFREG] G. Parsons, J. Rafferty & S. Zilles, "Tag Image File Format:
image/tiff - MIME sub-type registraion", RFC 2302, March 1998.
[V-MSG] G. Vaudreuil and G. Parsons, "VPIM Voice Message MIME Sub-type
Registration", RFC 2423, September 1998.
[VCARD] Dawson, Frank, Howes, Tim, "vCard MIME Directory Profile" RFC 2426,
September 1998.
[VPIM1] Vaudreuil, Greg, "Voice Profile for Internet Mail", RFC 1911, Feb
1996.
[VPIM2] Vaudreuil, Greg, Parsons, Glenn, "Voice Profile for Internet Mail,
Version 2", RFC 2421, September 1998.
[X.400] CCITT/ISO, "CCITT Recommendations X.400/ ISO/IEC 10021-1, Message
Handling: System and Service Overview", December 1988.
Vaudreuil & Parsons Expires August 14, 2002 [Page 39]
Internet Draft VPIM v2 February 14, 2002
11. 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 IETF VPIM Work Group, for their support of
the VPIM specification and the efforts they have made to ensure its
success.
12. Copyright Notice
"Copyright (C) The Internet Society (2002). 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 implementation 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 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."
Vaudreuil & Parsons Expires August 14, 2002 [Page 40]
Internet Draft VPIM v2 February 14, 2002
13. Authors' Addresses
Glenn W. Parsons
Nortel Networks
P.O. Box 3511, Station C
Ottawa, ON K1Y 4H7
Canada
Phone: +1-613-763-7582
Fax: +1-613-763-2697
Email: GParsons@NortelNetworks.com
Gregory M. Vaudreuil
Lucent Technologies
7291 Williamson Rd
Dallas, TX 75214
United States
Phone/Fax: +1-972-733-2722
Email: GregV@ieee.org
Vaudreuil & Parsons Expires August 14, 2002 [Page 41]
Internet Draft VPIM v2 February 14, 2002
14. 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 - required in the absence of a compelling
need to omit.
May - optional
Should not - prohibited in the absence of a compelling
need.
Must not - prohibited
Footnote - special comment about conformance for a particular feature
Vaudreuil & Parsons Expires August 14, 2002 [Page 42]
Internet Draft VPIM v2 February 14, 2002
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| | | |
Numbers in mailbox IDs follow E.164 |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: | | | | | | | |
Sending outbound messages | | | | | | | |
From |4.2.1 |C|x| | | | |
Addition of text name |4.2.1 |C| |x| | | |
Same value as MAIL FROM |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 |4.7 |C| |x| | | |
Other Headers |4.2 |C| | |x| | |
| | | | | | | |
Vaudreuil & Parsons Expires August 14, 2002 [Page 43]
Internet Draft VPIM v2 February 14, 2002
| | | | |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
-------------------------------------------|----------|-|-|-|-|-|-|-
Receiving 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| | |
MDN requested |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 |4.7 |C| |x| | | |
Other Headers |4.2 |C|x| | | | |3
| | | | | | | |
Message Content Encoding: | | | | | | | |
Sending outbound audio/fax contents | | | | | | | |
7BIT |4.2.12 |C| | | | |x|
8BIT |4.2.12 |C| | | | |x|
Quoted Printable |4.2.12 |C| | | | |x|
Base64 |4.2.12 |C|x| | | | |4
Binary |4.2.12 |C| |x| | | |5
Receiving inbound message contents | | | | | | | |
7BIT |4.2.12 |C|x| | | | |
8BIT |4.2.12 |C|x| | | | |
Quoted Printable |4.2.12 |C|x| | | | |
Base64 |4.2.12 |C|x| | | | |
Binary |4.2.12 |C|x| | | | |5
| | | | | | | |
Vaudreuil & Parsons Expires August 14, 2002 [Page 44]
Internet Draft VPIM v2 February 14, 2002
| | | | |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: | | | | | | | |
Sending outbound messages | | | | | | | |
Multipart/Voice-Message |4.4.1 |C|x| | | | |
Message/RFC822 |4.4.2 |C| |x| | | |
Audio/32KADPCM |4.4.3 |C|x| | | | |
Content-Description |4.3.1 |C| | |x| | |
Content-Disposition |4.3.2 |C|x| | | | |
Content-Duration |4.3.3 |C| | |x| | |
Content-Language |4.3.4 |C| | |x| | |
Image/TIFF; application=faxbw |4.4.4 |C|x| | | | |7
Text/Directory |4.5.2 |C| | | |x| |9
Text/plain |4.5.4 |C| | | |x| |
Audio/* or Image/* (other encodings) |4.5.3 |C| | | |x| |
Other contents |4.5 |C| | | | |x|
Multipart/Mixed |4.5.1 |C| | |x| | |
Text/plain |4.5.4 |C| | |x| | |
Multipart/Report |4.6, 4.7 |C|x| | | | |
human-readable part is voice |4.6, 4.7 |C| |x| | | |
human-readable part is text |4.6, 4.7 |C| | |x| | |
Message/Delivery-Status |4.6 |C|x| | | | |
Message/Disposition-Notification |4.7 |C| |x| | | |
Other contents |4.5 |C| | | |x| |6
Receiving in inbound messages | | | | | | | |
Multipart/Voice-Message |4.4.1 |C|x| | | | |
Message/RFC822 |4.4.2 |C|x| | | | |
Audio/32KADPCM |4.4.3 |C|x| | | | |
Content-Description |4.3.1 |C| | |x| | |
Content-Disposition |4.3.2 |C| |x| | | |
Content-Duration |4.3.3 |C| | |x| | |
Content-Language |4.3.4 |C| | |x| | |
Image/TIFF; application=faxbw |4.4.4 |C| |x| | | |8
Text/Directory |4.5.2 |C|x| | | | |9
Text/plain |4.5.4 |C| | |x| | |
Audio/* or Image/* (other encodings) |4.5.3 |C| | |x| | |
Other contents |4.5 |C| | |x| | |
Multipart/Mixed |4.5.1 |C| | |x| | |
Vaudreuil & Parsons Expires August 14, 2002 [Page 45]
Internet Draft VPIM v2 February 14, 2002
| | | | | |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
------------------------------------------|-----------|-|-|-|-|-|-|-
| | | | | | | |
Text/plain |4.5.4 |C|x| | | | |
Multipart/Report |4.6, 4.7 |C|x| | | | |
human-readable part is voice |4.6, 4.7 |C|x| | | | |
human-readable part is text |4.6, 4.7 |C|x| | | | |
Message/Delivery-Status |4.6 |C|x| | | | |
Message/Disposition-Notification |4.7 |C| |x| | | |
Other contents |4.5 |C| | |x| | |6
| | | | | | | |
Forwarded Messages | | | | | | | |
use Message/RFC822 construct |4.8 |C| |x| | | |
simulate headers if none available |4.8 |C| |x| | | |
| | | | | | | |
Reply Messages |4.9 |C|x| | | | |
send to Reply-To, else From address |4.2.8 |C| | |x| | |
send to non-mail-user |4.9 |C| | | |x| |
| | | | | | | |
Notifications | | | | | | | |
use Multipart/Report format |4.6, 4.7 |C|x| | | | |
always send error on non-delivery |4.6 |C|x| | | | |
send error messages to return-path |4.2.6 |C|x| | | | |
| | | | | | | |
Message Transport Protocol: | | | | | | | |
Base ESMTP Commands | | | | | | | |
HELO |5.1 |T|x| | | | |
MAIL FROM |5.1 |T|x| | | | |
RCPT TO |5.1 |T|x| | | | |
DATA |5.1 |T|x| | | | |
TURN |5.1 |T| | | | |x|
QUIT |5.1 |T|x| | | | |
RSET |5.1 |T|x| | | | |
VRFY |5.1 |T| | |x| | |
EHLO |5.1 |T|x| | | | |
BDAT |5.1 |T| | |x| | |5
Vaudreuil & Parsons Expires August 14, 2002 [Page 46]
Internet Draft VPIM v2 February 14, 2002
| | | | |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 | | | | | | | |
DSN |5.2.1 |T|x| | | | |
NOTIFY |5.2.1 |T|x| | | | |
RET |5.2.1 |T| |x| | | |
ENVID |5.2.1 |T| | |x| | |
ORCPT |5.2.1 |T| | |x| | |
SIZE |5.2.2 |T|x| | | | |
ENHANCEDSTATUSCODES |5.2.3 |T| |x| | | |
PIPELINING |5.2.4 |T| |x| | | |
CHUNKING |5.2.5 |T| | |x| | |
BINARYMIME |5.2.6 |T| | |x| | |
| | | | | | | |
ESMTP-SMTP Downgrading | | | | | | | |
send delivery report upon downgrade |5.3 |T|x| | | | |
| | | | | | | |
Directory Address Resolution | | | | | | | |
provide facility to resolve addresses |6 |C| |x| | | |
use headers to populate local directory |6 |C| | |x| | |
| | | | | | | |
Management Protocols: | | | | | | | |
Network management |7.1 |T| | |x| | |
-------------------------------------------|----------|-|-|-|-|-|-|-
Footnotes:
1. SHOULD leave blank 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 additional header fields are not understood they MAY be
ignored
Vaudreuil & Parsons Expires August 14, 2002 [Page 47]
Internet Draft VPIM v2 February 14, 2002
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 fax is supported.
8. If the fax content cannot be presented it MAY be dropped.
9. Handling of a vCard in text/directory is no longer defined.
Vaudreuil & Parsons Expires August 14, 2002 [Page 48]
Internet Draft VPIM v2 February 14, 2002
15. 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, spoken
subject 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-Disposition: inline; voice=Spoken-Subject
Content-Language: en-US
Content-ID: part2@VM2-4321
glslfdslsertiflkTfpgkTportrpkTpfgTpoiTpdadasssdasddasdasd
(This is a sample of the base-64 Spoken Subject data)
fgdhgddlkgpokpeowrit09==
Vaudreuil & Parsons Expires August 14, 2002 [Page 49]
Internet Draft VPIM v2 February 14, 2002
--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- - - -
Vaudreuil & Parsons Expires August 14, 2002 [Page 50]
Internet Draft VPIM v2 February 14, 2002
The following message is a forwarded single segment voice. Both the
forwarded message and the forwarding message contain the senders 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==
Vaudreuil & Parsons Expires August 14, 2002 [Page 51]
Internet Draft VPIM v2 February 14, 2002
--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)
--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--
--MessageBoundary--
Vaudreuil & Parsons Expires August 14, 2002 [Page 52]
Internet Draft VPIM v2 February 14, 2002
The following example is for a DSN sent to the sender of a message 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
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--
Vaudreuil & Parsons Expires August 14, 2002 [Page 53]
Internet Draft VPIM v2 February 14, 2002
The following example is for an MDN sent to the original sender for a
message that 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
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--
Vaudreuil & Parsons Expires August 14, 2002 [Page 54]
Internet Draft VPIM v2 February 14, 2002
16. Appendix C - Example Error Voice Processing Error Codes
The following common voice processing errors and their corresponding
status codes are given as examples. The text after the error codes is
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 4.4.1 Persistent connection error
because remote system is busy - busy
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
Vaudreuil & Parsons Expires August 14, 2002 [Page 55]
Internet Draft VPIM v2 February 14, 2002
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
Vaudreuil & Parsons Expires August 14, 2002 [Page 56]
Internet Draft VPIM v2 February 14, 2002
17. 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. Implementers 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
Vaudreuil & Parsons Expires August 14, 2002 [Page 57]
Internet Draft VPIM v2 February 14, 2002
18. Appendix E - IANA Registrations
There are no changes to the registration per [DISP] of the voice content
disposition parameter defined in the earlier VPIM V2 document, RFC 2421.
There are no changes to the registration per [MIME4] of the
Multipart/voice-message content type defines in the earlier VPIM v2
document, RFC 2423.
Both are presented here for information.
18.1 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
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.
Vaudreuil & Parsons Expires August 14, 2002 [Page 58]
Internet Draft VPIM v2 February 14, 2002
18.2 Multipart/Voice-Message MIME Media Type Definition
To: ietf-types@iana.org
Subject: Registration of MIME media type
Multipart/voice-message
MIME media type name: multipart
MIME subtype name: voice-message
Required parameters: boundary, version
The use of boundary is defined in [MIME2]
The version parameter that contains the value "2.0" if
enclosed content conforms to [VPIM2R2]. The absence of this
parameter indicates conformance to the previous version
defined in RFC 1911 [VPIM1].
Optional parameters: none
Encoding considerations: 7bit, 8bit or Binary
Security considerations:
This definition identifies the content as being a voice
message. In some environments (though likely not the
majority), the loss of the anonymity of the content may be a
security issue.
Interoperability considerations:
Systems developed to conform with [VPIM1] may not conform to
this registration. Specifically, the required version will
likely be absent, in this case the recipient system should
still be able to accept the message and will be able to
handle the content. The VPIM v1 positional identification,
however, would likely be lost.
Published specification:
This document
Applications that use this media type:
Primarily voice messaging
Vaudreuil & Parsons Expires August 14, 2002 [Page 59]
Internet Draft VPIM v2 February 14, 2002
Additional information:
Magic number(s): none
File extension(s): .VPM
Macintosh File Type Code(s): VPIM
Person & email address to contact for further information:
Glenn W. Parsons
gparsons@nortelnetworks.com
Gregory M. Vaudreuil
gregv@ieee.org
Intended usage: COMMON
Author/Change controller:
Glenn W. Parsons & Gregory M. Vaudreuil
Vaudreuil & Parsons Expires August 14, 2002 [Page 60]
Internet Draft VPIM v2 February 14, 2002
19. Appendix F - Change History: RFC 2421 (VPIM V2) to this Document
The updated profile in this document is based on the implementation and
operational deployment experience of several vendors. The changes are
categorized as general, content, transport and conformance. They are
summarized below:
1. General
- Various and substantial editorial updates to improve readability.
- Separated send rules from receive rules to aid clarity.
- Clarified the behavior upon reception of unrecognized content
types expected with the interworking between voice and unified
messaging systems. (e.g. Unsupported non-audio contents should be
discarded to deliver the audio message.)
- Reworked the sensitivity requirements to align them with X.400.
Eliminated dependencies upon the MIXER documents.
- Reorganized the content-type descriptions for clarity
2. Content
- Changed handling of received lines by a gateway to SHOULD NOT delete
in a gateway. In gateways to systems such as AMIS, it is not possible
to preserve this information. It is intended that such systems be
able to claim conformance.
- Eliminated the vCard as a supported VPIM V2 content type.
- Merged in text from RFC 2423 (Multipart/voice-message)
3. Transport
- None
4. Conformance
- Aligned the table of Appendix A to the requirements in the text.
Vaudreuil & Parsons Expires August 14, 2002 [Page 61]