Network Working Group                                       G. Vaudreuil
Request for Comments: 3801                           Lucent Technologies
Obsoletes: 2421                                               G. Parsons
Category: Standards Track                                Nortel Networks
                                                              June 2004


        Voice Profile for Internet Mail - version 2 (VPIMv2)

Status of this Memo

  This document specifies an Internet standards track protocol for the
  Internet community, and requests discussion and suggestions for
  improvements.  Please refer to the current edition of the "Internet
  Official Protocol Standards" (STD 1) for the standardization state
  and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

  Copyright (C) The Internet Society (2004).

Abstract

  This document specifies a restricted profile of the Internet
  multimedia messaging protocols for use between voice processing
  server platforms.  The profile is referred to as the Voice Profile
  for Internet Mail (VPIM) in this document.  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.












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Table of Contents

  1.   Introduction...................................................3
       1.1.  Voice Messaging System Limitations.......................3
       1.2.  Design Goals.............................................4
       1.3.  Applicability for VPIM...................................5
  2.   Requirements Language..........................................5
  3.   Protocol Restrictions..........................................6
  4.   Voice Message Interchange Format...............................6
       4.1.  VPIM Message Addressing Formats..........................7
       4.2.  Message Header Fields....................................9
       4.3.  MIME Audio Content Descriptions.........................17
       4.4.  Voice Message Content Types.............................19
       4.5.  Other MIME Contents.....................................23
       4.6.  Delivery Status Notification (DSN)......................25
       4.7.  Message Disposition Notification (MDN)..................26
       4.8.  Forwarded Messages......................................26
       4.9.  Reply Messages..........................................27
  5.   Message Transport Protocol....................................27
       5.1.  Base SMTP Protocol......................................28
       5.2.  SMTP Service Extensions.................................28
       5.3.  ESMTP - SMTP Downgrading................................30
  6.   Directory Address Resolution..................................30
  7.   Management Protocols..........................................30
       7.1.  Network Management......................................31
  8.   Conformance Requirements......................................31
  9.   Security Considerations.......................................32
       9.1.  General Directive.......................................32
       9.2.  Threats and Problems....................................32
       9.3.  Security Techniques.....................................33
  10.  Normative References..........................................33
  11.  Acknowledgments...............................................36
  12.  Appendix A - VPIM Requirements Summary........................37
  13.  Appendix B - Example Voice Messages...........................43
  14.  Appendix C - Example Error Voice Processing Error Codes.......49
  15.  Appendix D - Example Voice Processing Disposition Types.......50
  16.  Appendix E - IANA Registrations...............................50
       16.1.  Voice Content-Disposition Parameter Definition.........51
       16.2.  Multipart/Voice-Message MIME Media Type Definition.....51
  17.  Appendix F - Change History: RFC 2421 (VPIM V2) To This Doc...53
  18.  Authors' Addresses............................................54
  19.  Full Copyright Statement......................................55









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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 Voice Profile for Internet Mail (VPIM) 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.

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.





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     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.

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.






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  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.

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].







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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.

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".






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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).  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:

     1) mailbox number
         - for use as a private numbering plan (any number of digits)
         - e.g., [email protected]



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     2) mailbox number+extension
         - for use as a private numbering plan with extensions
           any number of digits, use of "+" as separator
         - e.g., [email protected]

     3) +international number
         - for international telephone numbers conforming to E.164
           maximum of 15 digits
         - e.g., [email protected]

     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., [email protected]

  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

  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



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  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 <[email protected]>

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.

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:




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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" <[email protected]>

              From: Technical Support <[email protected]>

              From: [email protected]

  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).

4.2.2.  To

  The "To:" field contains the recipient's fully-qualified domain
  address.

  Example:

              To: [email protected]

  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.





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  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: [email protected]

  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



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  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.

  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.





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  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: <[email protected]>

  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



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  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.

4.2.10.  MIME Version

  The "MIME-Version:" field MUST be present to indicate that the
  message conforms to [MIME1-5].  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]



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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.

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]






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  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.

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.







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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.

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.








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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"

     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.



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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]

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".




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  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.

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.



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  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.

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).






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  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

  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.




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  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.

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.






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  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.

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.





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  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.




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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.





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  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).

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



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  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
  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]



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  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.

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.








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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.

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.




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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].

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



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  transport capabilities, specific client-server requirements are out-
  of-scope for this document.

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.






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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.

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.

10.  Normative References

  [8BIT]    Klensin, J., Freed, N., Rose, M., Stefferud, E. and D.
            Crocker, "SMTP Service Extension for 8bit-MIMEtransport",
            RFC 1652, July 1994.

  [ADPCM]   Vaudreuil, G. and G. Parsons, "Toll Quality Voice - 32
            kbit/s Adaptive Differential Pulse Code Modulation (ADPCM)
            MIME Sub-type Registration", RFC 3802, June 2004.

  [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] Dawson, F., Howes, T. and M. Smith, "A MIME Content-Type
            for Directory Information", RFC 2425, September 1998.

  [DISP]    Troost, R. 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", RFC 1035, November 1987.





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  [DNS2]    Mockapetris, P., "Domain names - concepts and facilities",
            RFC 1034, November 1987.

  [DRPT]    Moore, K., "Simple Mail Transfer Protocol (SMTP) Service
            Extension for Delivery Status Notifications (DSNs)", RFC
            3461, January 2003.

  [DSN]     Moore, K. and G. Vaudreuil, "An Extensible Message Format
            for Delivery Status Notifications", RFC 3464, January 2003.

  [DUR]     Parsons, G. and G. Vaudreuil, "Content Duration MIME Header
            Definition", RFC 3803, June 2004.

  [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., "Simple Mail Transfer Protocol", RFC 2821,
            April 2001.

  [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",
            BCP 47, RFC 3066, January 2001.

  [MDN]     Hansen, T., Ed. and G. Vaudreuil, Ed., "Message Disposition
            Notification", RFC 3798, May 2004.

  [MIB II]  Rose, M., "Management Information Base for Network
            Management of TCP/IP-based internets:  MIB-II", RFC 1213,
            March 1991.

  [MIME1]   Freed, N. and N. Borenstein,  "Multipurpose Internet Mail
            Extensions (MIME) Part One: Format of Internet Message
            Bodies", RFC 2045, November 1996.

  [MIME2]   Freed, N.  and N. Borenstein,  "Multipurpose Internet Mail
            Extensions (MIME) Part Two: Media Types ", RFC 2046,
            November 1996.






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  [MIME3]   Moore, K., "Multipurpose Internet Mail Extensions (MIME)
            Part Three: Message Header Extensions for Non-ASCII Text ",
            RFC 2047, November 1996.

  [MIME4]   Freed, N., Klensin, J. and J. Postel,  "Multipurpose
            Internet Mail Extensions (MIME) Part Four: Registration
            Procedures", RFC 2048, November 1996.

  [MIME5]   Freed, N. and N. Borenstein,  "Multipurpose Internet Mail
            Extensions (MIME) Part Five: Conformance Criteria and
            Examples ", RFC 2049, November 1996.

  [PIPE]    Freed, N.and A. Cargille, "SMTP Service Extension for
            Command Pipelining" STD 60, RFC 2920, September 2000.

  [REPORT]  Vaudreuil, G., "The Multipart/Report Content Type for the
            Reporting of Mail System Administrative Messages", RFC
            3462, January 2003.

  [REQ]     Bradner, S., "Key words for use in RFCs to Indicate
            Requirement Levels", BCP 14, RFC 2119, March 1997.

  [RFC822]  Crocker, D., "Standard for the Format of ARPA Internet Text
            Messages", STD 11, RFC 822, August 1982.

  [SIZE]    Klensin, J., Freed, N. and K. Moore, "SMTP Service
            Extensions for Message Size Declaration" STD 10, RFC 1870,
            November 1995.

  [STATUS]  Freed, N., "SMTP Service Extension for Returning Enhanced
            Error Codes", RFC 2034, October 1996.

  [TIFF-F]  Parsons, G. and J. Rafferty, "Tag Image File Format:
            Application F", RFC 2306, March 1998.

  [TIFFREG] Parsons, G.,  Rafferty, J. and S. Zilles, "Tag Image File
            Format: image/tiff - MIME sub-type registration", RFC 2302,
            March 1998.

  [V-MSG]   Vaudreuil, G. and G. Parsons, "VPIM Voice Message MIME
            Sub-type Registration", RFC 2423, September 1998.

  [VCARD]   Dawson, F. and T. Howes, "vCard MIME Directory Profile" RFC
            2426, September 1998.

  [VPIM1]   Vaudreuil, G., "Voice Profile for Internet Mail", RFC 1911,
            February 1996.




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  [VPIM2]   Vaudreuil, G. and G. Parsons, "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.

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.





































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12.  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













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                          VPIM version 2 Conformance
                                                        | | | | |S| |
                                             |          | | | | |H| |F
                                             |          | | | | |O|M|o
                                             |          | | |S| |U|U|o
                                             |          | | |H| |L|S|t
                                             |          |A|M|O| |D|T|n
                                             |          |R|U|U|M| | |o
                                             |          |E|S|L|A|N|N|t
                                             |          |A|T|D|Y|O|O|t
  FEATURE                                    |SECTION   | | | | |T|T|e
  -------------------------------------------|----------|-|-|-|-|-|-|-
                                             |          | | | | | | |
  Message Addressing Formats:                |          | | | | | | |
    Use DNS host names                       |4.1       |C|x| | | | |
    Use only numbers in mailbox IDs          |4.1.1     |C| |x| | | |
    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         Standards Track                    [Page 38]

RFC 3801                         VPIMv2                        June 2004


                                             |          | | | | |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         Standards Track                    [Page 39]

RFC 3801                         VPIMv2                        June 2004


                                                        | | | | |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         Standards Track                    [Page 40]

RFC 3801                         VPIMv2                        June 2004


                                            |           | | | | |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         Standards Track                    [Page 41]

RFC 3801                         VPIMv2                        June 2004


                                                        | | | | |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.
  4.  When binary transport is not available.
  5.  When binary transport is available.





Vaudreuil & Parsons         Standards Track                    [Page 42]

RFC 3801                         VPIMv2                        June 2004


  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.

13.  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: [email protected]
To: [email protected]
From: "Parsons, Glenn" <[email protected]>
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: [email protected]
Sensitivity: Private
Importance: High



























Vaudreuil & Parsons         Standards Track                    [Page 43]

RFC 3801                         VPIMv2                        June 2004


--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==

--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- -                         -                         -

The following message is a forwarded single segment voice.  Both the
forwarded message and the forwarding message contain the senders spoken
names.

     To: [email protected]
     From: "Vaudreuil, Greg" <[email protected]>
     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: [email protected]




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     --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==






























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     --MessageBoundary
     Content-type: Message/RFC822
     Content-Transfer-Encoding: 7bit

     To: [email protected]
     From: "Parsons, Glenn, W." <[email protected]>
     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         Standards Track                    [Page 46]

RFC 3801                         VPIMv2                        June 2004


  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 <[email protected]>
     Message-ID: <[email protected]>
     Subject: Returned voice message
     To: [email protected]
     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; [email protected]
     Final-Recipient: rfc822; [email protected]
     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

















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     --RAA14128.773615765/VM1.COMPANY.COM
     content-type: Message/RFC822

     [original VPIM message goes here]

     --RAA14128.773615765/VM1.COMPANY.COM--

  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" <[email protected]>
Message-ID: <[email protected]>
Subject: Voice message played
To: [email protected]
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;[email protected]
Final-Recipient: rfc822;[email protected]
Original-Message-ID: <[email protected]>
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         Standards Track                    [Page 48]

RFC 3801                         VPIMv2                        June 2004



14.  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

     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




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     Message marked private, but     5.3.3 Permanent system error
     system is not private capable         - not feature capable

15.  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

16.  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.











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16.1.  Voice Content-Disposition Parameter Definition

  To: [email protected]

  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.

16.2.  Multipart/Voice-Message MIME Media Type Definition

  To: [email protected]
  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]








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     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

     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
     [email protected]

     Gregory M. Vaudreuil
     [email protected]

  Intended usage: COMMON




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  Author/Change controller:

     Glenn W. Parsons & Gregory M. Vaudreuil

17.  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.





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18.  Authors' Addresses

  Gregory M. Vaudreuil
  Lucent Technologies
  7291 Williamson Rd
  Dallas, TX  75214
  United States

  EMail: [email protected]


  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: [email protected]































Vaudreuil & Parsons         Standards Track                    [Page 54]

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19.  Full Copyright Statement

  Copyright (C) The Internet Society (2004).  This document is subject
  to the rights, licenses and restrictions contained in BCP 78, and
  except as set forth therein, the authors retain all their rights.

  This document and the information contained herein are provided on an
  "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
  OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
  ENGINEERING TASK FORCE DISCLAIM 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.

Intellectual Property

  The IETF takes no position regarding the validity or scope of any
  Intellectual Property Rights or other rights that might be claimed to
  pertain to the implementation or use of the technology described in
  this document or the extent to which any license under such rights
  might or might not be available; nor does it represent that it has
  made any independent effort to identify any such rights.  Information
  on the procedures with respect to rights in RFC documents can be
  found in BCP 78 and BCP 79.

  Copies of IPR disclosures made to the IETF Secretariat and any
  assurances of licenses to be made available, or the result of an
  attempt made to obtain a general license or permission for the use of
  such proprietary rights by implementers or users of this
  specification can be obtained from the IETF on-line IPR repository at
  http://www.ietf.org/ipr.

  The IETF invites any interested party to bring to its attention any
  copyrights, patents or patent applications, or other proprietary
  rights that may cover technology that may be required to implement
  this standard.  Please address the information to the IETF at ietf-
  [email protected].

Acknowledgement

  Funding for the RFC Editor function is currently provided by the
  Internet Society.









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