path: root/doc/rfc/rfc3801.txt

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.












Vaudreuil & Parsons         Standards Track                     [Page 1]
^L
RFC 3801                         VPIMv2                        June 2004


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









Vaudreuil & Parsons         Standards Track                     [Page 2]
^L
RFC 3801                         VPIMv2                        June 2004


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.





Vaudreuil & Parsons         Standards Track                     [Page 3]
^L
RFC 3801                         VPIMv2                        June 2004


      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.






Vaudreuil & Parsons         Standards Track                     [Page 4]
^L
RFC 3801                         VPIMv2                        June 2004


   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].







Vaudreuil & Parsons         Standards Track                     [Page 5]
^L
RFC 3801                         VPIMv2                        June 2004


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".






Vaudreuil & Parsons         Standards Track                     [Page 6]
^L
RFC 3801                         VPIMv2                        June 2004


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., 2722@lucent.com



Vaudreuil & Parsons         Standards Track                     [Page 7]
^L
RFC 3801                         VPIMv2                        June 2004


      2) mailbox number+extension
          - for use as a private numbering plan with extensions
            any number of digits, use of "+" as separator
          - e.g., 2722+111@Lucent.com

      3) +international number
          - for international telephone numbers conforming to E.164
            maximum of 15 digits
          - e.g., +16137637582@vm.nortel.ca

      4) +international number+extension
          - for international telephone numbers conforming to E.164
             maximum of 15 digits, with an extension (e.g., behind a
             PBX) that has a maximum of 15 digits.
          - e.g., +17035245550+230@ema.org

   Note that this address format is designed to be compatible with
   current usage within the voice messaging industry.  It is not
   compatible with the addressing formats of RFCs 2303-2304.  It is
   expected that as telephony services become more widespread on the
   Internet, these addressing formats will converge.

4.1.2.  Special Addresses

   Special addresses to represent the sender are provided for
   compatibility with the conventions of Internet mail.  These addresses
   do not use numeric local addresses, both to conform to current
   Internet practice and to avoid conflict with existing numeric
   addressing plans. Two special addresses are RESERVED for use as
   follows:

   postmaster@domain

   By convention, a special mailbox named "postmaster" MUST exist on all
   systems.  This address is used for diagnostics and should be checked
   regularly by the system manager. This mailbox is particularly likely
   to receive text messages, which is not normal on a voice-processing
   platform.  The specific handling of these messages is an individual
   implementation choice.

   non-mail-user@domain

   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



Vaudreuil & Parsons         Standards Track                     [Page 8]
^L
RFC 3801                         VPIMv2                        June 2004


   address from "non-mail-user".  For compatibility with the installed
   base of mail user agents, implementations MUST reject the message
   when a message addressed to "non-mail-user" is received.  The status
   code for such NDN's is 5.1.1 "Mailbox does not exist".

   Example:

          From: Telephone Answering <non-mail-user@mycompany.com>

4.1.3.  Distribution Lists

   There are many ways to handle distribution list (DL) expansions and
   none are 'standard'.  A VPIM implementation MAY support DLs.  Using a
   simple alias is a behavior closest to what many voice mail systems do
   today and what is to be used with VPIM messages.  A couple of
   important features that need special care when DLs are used are:

      Reply to the originator - (Address in the RFC822 "Reply-To:" or
                                 "From" field)
      Errors to the submitter - (Address in the MAIL FROM field of the
                                 ESMTP exchange or the "Return-Path:"
                                 RFC822 field)

   Some proprietary voice messaging protocols include only the recipient
   of the particular copy in the envelope and include no "header fields"
   except date and per-message features.  Most voice messaging systems
   do not provide for "Header Information" in their messaging queues and
   only include delivery information.  As a result, recipient
   information MAY be in either the "To:" or "Cc:" header fields. If all
   recipients cannot be presented then the recipient header fields
   SHOULD be omitted to indicate that an accurate list of recipients
   (e.g., for use with a reply-all capability) is not known.

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:




Vaudreuil & Parsons         Standards Track                     [Page 9]
^L
RFC 3801                         VPIMv2                        June 2004


4.2.1.  From

   SEND RULES

   The originator's fully qualified domain address (a mailbox address
   followed by the fully qualified domain name) MUST be present.
   Systems conforming with this profile SHOULD provide the text personal
   name of the voice message originator in a quoted phrase, if the name
   is available.  Text names of corporate or positional mailboxes MAY be
   provided as a simple string.  From: [RFC822]

   Example:

               From: "Joe S. User" <12145551212@mycompany.com>

               From: Technical Support <611@serviceprovider.com>

               From: Non-mail-user@myserver.mycompany.com

   Voice mail machines may not be able to support separate attributes
   for the "From:" header fields and the SMTP MAIL FROM, VPIM-conforming
   systems SHOULD set these values to the same address.  Use of
   addresses different than those present in the "From:" header field
   address may result in unanticipated behavior.

   RECEIVE RULES

   The user listed in the "From:" field MUST be presented in the voice
   message envelope of the voice messaging system as the originator of
   the message, though the exact presentation is an implementation
   decision (e.g., the mailbox ID or the text name MAY be presented).
   The "From:" address SHOULD be used for replies (see 4.9).

4.2.2.  To

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

   Example:

               To: +12145551213@mycompany.com

   SEND RULES

   There MAY be one or more "To:" fields in any message.  Systems SHOULD
   provide a list of recipients only if all recipients are available.





Vaudreuil & Parsons         Standards Track                    [Page 10]
^L
RFC 3801                         VPIMv2                        June 2004


   Systems, such as gateways from protocols or legacy platforms that do
   not indicate the complete list of recipients, MAY provide a "To:"
   line. Because these systems cannot accurately enumerate all
   recipients in the "To:" headers, recipients SHOULD NOT be enumerated.

   RECEIVE RULES

   Systems conforming to this profile MAY discard the addresses in the
   "To:" fields if they are unable to store the information.  This
   would, of course, make a reply-to-all capability impossible.  If
   present, the addresses in the "To:" field MAY be used for a reply
   message to all recipients.

4.2.3.  Cc

   The "Cc:" field contains additional recipients' fully qualified
   domain addresses.  Many voice mail systems maintain only sufficient
   envelope information for message delivery and are not capable of
   storing or providing a complete list of additional recipients.

   SEND RULES

   Conforming implementations MAY send "Cc:" lists if all recipients are
   known at the time of origination.  If not, systems SHOULD omit the
   "Cc:" fields to indicate that the full list of recipients is unknown
   or otherwise unavailable.  The list of disclosed recipients MUST NOT
   include undisclosed recipients (i.e., those sent via a blind copy).

   Example:

               Cc: +12145551213@mycompany.com

   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



Vaudreuil & Parsons         Standards Track                    [Page 11]
^L
RFC 3801                         VPIMv2                        June 2004


   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.





Vaudreuil & Parsons         Standards Track                    [Page 12]
^L
RFC 3801                         VPIMv2                        June 2004


   RECEIVE RULES

   If the receiving system is incapable of storing the return path (or
   MAIL FROM) to be used for subsequent delivery errors (i.e., it is a
   gateway to a legacy system or protocol), the receiving system must
   otherwise ensure that further delivery errors don't happen.  Systems
   that do not support the return path MUST ensure that at the time the
   message is acknowledged (i.e., when a DSN would be sent), the message
   is delivered to the recipient's ultimate mailbox.  Non-Delivery
   notifications SHOULD NOT be sent after that final delivery.

4.2.7.  Message-id

   The "Message-Id:" field contains a globally unique per-message
   identifier.

   SEND RULES

   A globally unique message-id MUST be generated for each message sent
   from a VPIM-conforming implementation.

   Example:

               Message-Id: <12345678@mycompany.com>

   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



Vaudreuil & Parsons         Standards Track                    [Page 13]
^L
RFC 3801                         VPIMv2                        June 2004


   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]



Vaudreuil & Parsons         Standards Track                    [Page 14]
^L
RFC 3801                         VPIMv2                        June 2004


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]






Vaudreuil & Parsons         Standards Track                    [Page 15]
^L
RFC 3801                         VPIMv2                        June 2004


   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.







Vaudreuil & Parsons         Standards Track                    [Page 16]
^L
RFC 3801                         VPIMv2                        June 2004


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.








Vaudreuil & Parsons         Standards Track                    [Page 17]
^L
RFC 3801                         VPIMv2                        June 2004


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.



Vaudreuil & Parsons         Standards Track                    [Page 18]
^L
RFC 3801                         VPIMv2                        June 2004


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".




Vaudreuil & Parsons         Standards Track                    [Page 19]
^L
RFC 3801                         VPIMv2                        June 2004


   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.



Vaudreuil & Parsons         Standards Track                    [Page 20]
^L
RFC 3801                         VPIMv2                        June 2004


   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).






Vaudreuil & Parsons         Standards Track                    [Page 21]
^L
RFC 3801                         VPIMv2                        June 2004


   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.




Vaudreuil & Parsons         Standards Track                    [Page 22]
^L
RFC 3801                         VPIMv2                        June 2004


   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.






Vaudreuil & Parsons         Standards Track                    [Page 23]
^L
RFC 3801                         VPIMv2                        June 2004


   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.





Vaudreuil & Parsons         Standards Track                    [Page 24]
^L
RFC 3801                         VPIMv2                        June 2004


   RECEIVE RULES

   Within a Multipart/Voice-Message, the Text/Plain content-type MAY be
   dropped from the message, if necessary, to deliver the audio/fax
   components.  The recipient SHOULD NOT reject the entire message if
   the text component cannot be accepted or rendered.

   Outside a Multipart/Voice-Message, conforming implementations MUST
   accept Text/Plain; however, specific handling is left as an
   implementation decision.  From: [MIME2]

   Some deployed implementations based on a common interpretation of the
   original VPIM V2 specification reject messages with any text content
   rather than discard the unsupported contents.  These systems will
   return the message to the sender with an NDN indicating lack of
   support for text.

4.6.  Delivery Status Notification (DSN)

   A DSN is a notification of delivery (positive DSN), non-delivery
   (negative DSN), or temporary delivery delay (delayed DSN).  The top-
   level content-type of a DSN is Multipart/Report, which is defined in
   [REPORT].  The content-type which distinguishes DSN's from other
   types of notifications is Message/Delivery-Status, which is defined
   in [DSN].

   SEND RULES

   A VPIM-compliant implementation MUST be able to send DSN's that
   conform to [REPORT] and [DSN].  Unless requested otherwise, a non-
   delivery DSN MUST be sent when any form of non-delivery of a message
   occurs.

   A VPIM-compliant implementation SHOULD provide a spoken delivery
   status in the "human-readable" body part of the DSN, but MAY provide
   a textual status.

   RECEIVE RULES

   A VPIM-compliant implementation MUST be able to receive DSN's that
   conform to [REPORT] and [DSN].

   A VPIM-compliant implementation MUST be able to receive a DSN whose
   "human-readable" body part contains a spoken delivery status phrase
   or a textual description.  Though subsequent use of the phrase or
   text is a local implementation issue, the intent of the DSN MUST be
   presented to the end user.




Vaudreuil & Parsons         Standards Track                    [Page 25]
^L
RFC 3801                         VPIMv2                        June 2004


4.7.  Message Disposition Notification (MDN)

   An MDN is a notification indicating what happens to a message after
   it is deposited in the recipient's mailbox.  An MDN can be positive
   (message was read/played/rendered/etc.) or negative (message was
   deleted before recipient could see it, etc.).  The top-level
   content-type of a MDN is Multipart/Report, which is defined in
   [REPORT].  The content-type which distinguishes MDN's from other
   types of notifications is Message/Disposition-Notification, which is
   defined in [MDN].

   SEND RULES

   A VPIM-compliant implementation SHOULD support the ability to request
   MDNs.  This is done via the use of the "Disposition-Notification-To:"
   header field as defined in [MDN].

   A VPIM-compliant implementation SHOULD support the ability to send
   MDNs, but these MDNs MUST conform to [REPORT] and [MDN].

   When sending an MDN, a VPIM-compliant implementation SHOULD provide a
   spoken message disposition in the "human-readable" body part of the
   MDN, but MAY provide a textual status.

   RECEIVE RULES

   A VPIM-compliant implementation SHOULD respond to an MDN request with
   an MDN response.

   A VPIM-compliant implementation MUST be able to receive MDNs that
   conform to [REPORT] and [MDN], if it is capable of requesting MDNs.
   If a VPIM-compliant implementation is capable of receiving MDNs, it
   MUST be able to receive a MDN whose "human-readable" body part
   contains a spoken message disposition phrase or a textual disposition
   description.  Though subsequent use of the phrase or text is a local
   implementation issue, the intent of the MDN MUST be presented to the
   end user.

4.8.  Forwarded Messages

   VPIM v2 explicitly supports the forwarding of voice and fax content
   with voice or fax annotation.  However, only the two constructs
   described below are acceptable in a VPIM message.  Since only the
   first (i.e., Message/RFC822) can be recognized as a forwarded message
   (or even multiple forwarded messages), it is RECOMMENDED that this
   construct be used whenever possible.





Vaudreuil & Parsons         Standards Track                    [Page 26]
^L
RFC 3801                         VPIMv2                        June 2004


   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



Vaudreuil & Parsons         Standards Track                    [Page 27]
^L
RFC 3801                         VPIMv2                        June 2004


   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]



Vaudreuil & Parsons         Standards Track                    [Page 28]
^L
RFC 3801                         VPIMv2                        June 2004


   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.








Vaudreuil & Parsons         Standards Track                    [Page 29]
^L
RFC 3801                         VPIMv2                        June 2004


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.




Vaudreuil & Parsons         Standards Track                    [Page 30]
^L
RFC 3801                         VPIMv2                        June 2004


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



Vaudreuil & Parsons         Standards Track                    [Page 31]
^L
RFC 3801                         VPIMv2                        June 2004


   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.






Vaudreuil & Parsons         Standards Track                    [Page 32]
^L
RFC 3801                         VPIMv2                        June 2004


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.





Vaudreuil & Parsons         Standards Track                    [Page 33]
^L
RFC 3801                         VPIMv2                        June 2004


   [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.






Vaudreuil & Parsons         Standards Track                    [Page 34]
^L
RFC 3801                         VPIMv2                        June 2004


   [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.




Vaudreuil & Parsons         Standards Track                    [Page 35]
^L
RFC 3801                         VPIMv2                        June 2004


   [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.





































Vaudreuil & Parsons         Standards Track                    [Page 36]
^L
RFC 3801                         VPIMv2                        June 2004


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













Vaudreuil & Parsons         Standards Track                    [Page 37]
^L
RFC 3801                         VPIMv2                        June 2004


                           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]
^L
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]
^L
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]
^L
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]
^L
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]
^L
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: +19725551212@vm1.mycompany.com
To: +16135551234@VM1.mycompany.com
From: "Parsons, Glenn" <12145551234@VM2.mycompany.com>
Date: Mon, 26 Aug 93 10:20:20 -0700 (CDT)
MIME-Version: 1.0  (Voice 2.0)
Content-type: Multipart/Voice-Message; Version=2.0;
     Boundary="MessageBoundary"
Content-Transfer-Encoding: 7bit
Message-ID: 123456789@VM2.mycompany.com
Sensitivity: Private
Importance: High



























Vaudreuil & Parsons         Standards Track                    [Page 43]
^L
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: +12145551212@vm1.mycompany.com
      From: "Vaudreuil, Greg" <+19725552345@VM2.mycompany.com>
      Date: Mon, 26 Aug 93 10:20:20 -0700 (CDT)
      MIME-Version: 1.0  (Voice 2.0)
      Content-type: Multipart/Voice-Message; Version=2.0;
        Boundary="MessageBoundary"
      Content-Transfer-Encoding: 7bit
      Message-ID: ABCD-123456789@VM2.mycompany.com




Vaudreuil & Parsons         Standards Track                    [Page 44]
^L
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: part3@VM2-4321

      glslfdslsertiflkTfpgkTportrpkTpfgTpoiTpdadasssdasddasdasd
      (This is a sample of the base-64 Spoken Name data)
      fgdhgd dlkgpokpeowrit09==

      --MessageBoundary
      Content-type: Audio/32KADPCM
      Content-Description: Forwarded Message Annotation
      Content-Disposition: inline; voice=Voice-Message
      Content-Transfer-Encoding: Base64

      glslfdslsertiflkTfpgkTportrpkTpfgTpoiTpdadasssdasddasdasd
      (This is the voiced introductory remarks encoded in base64)
      jrgoij3o45itj09fiuvdkjgWlakgQ93ijkpokfpgokQ90gQ5tkjpokfgW
      dlkgpokpeowrit09==






























Vaudreuil & Parsons         Standards Track                    [Page 45]
^L
RFC 3801                         VPIMv2                        June 2004


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

      To: +19725552345@VM2.mycompany.com
      From: "Parsons, Glenn, W." <+16135551234@VM1.mycompany.com>
      Date: Mon, 26 Aug 93 8:23:10 -0500 (EST)
      Content-type: Multipart/Voice-Message; Version=2.0;
        Boundary="MessageBoundary2"
      Content-Transfer-Encoding: 7bit
      MIME-Version: 1.0  (Voice 2.0)

      --MessageBoundary2
      Content-type: Audio/32KADPCM
      Content-Transfer-Encoding: Base64
      Content-Disposition: inline; voice=Originator-Spoken-Name
      Content-Language: en-US
      Content-ID: part6@VM2-4321

      glslfdslsertiflkTfpgkTportrpkTpfgTpoiTpdadasssdasddasdasd
      (This is a sample of the base-64 Spoken Name data) fgdhgd
       dlkgpokpeowrit09==

      --MessageBoundary2
      Content-type: Audio/32KADPCM
      Content-Disposition: inline; voice=Voice-Message
      Content-Transfer-Encoding: Base64

      glslfdslsertiflkTfpgkTportrpkTpfgTpoiTpdadasssdasddasdasd
      (This is the original message audio data) fgwersdfmniwrjj
      jrgoij3o45itj09fiuvdkjgWlakgQ93ijkpokfpgokQ90gQ5tkjpokfgW
      dlkgpokpeowrit09==

      --MessageBoundary2--

      --MessageBoundary--















Vaudreuil & Parsons         Standards Track                    [Page 46]
^L
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 <MAILER-DAEMON@vm.company.com>
      Message-ID: <199407072116.RAA14128@vm1.company.com>
      Subject: Returned voice message
      To: 2175552345@VM2.mycompany.com
      MIME-Version: 1.0
      Content-Type: multipart/report; report-type=delivery-status;
        boundary="RAA14128.773615765/VM1.COMPANY.COM"

      --RAA14128.773615765/VM1.COMPANY.COM
      Content-type: Audio/32KADPCM
      Content-Description: Spoken Delivery Status Notification
      Content-Disposition: inline; voice= Voice-Message-Notification
      Content-Transfer-Encoding: Base64

      glslfdslsertiflkTfpgkTportrpkTpfgTpoiTpdadadffsssddasdasd
      (This is a voiced description of the error in base64)
      jrgoij3o45itj09fiuvdkjgWlakgQ93ijkpokfpgokQ90gdffkjpokfgW
      dlkgpokpeowrit09==

      --RAA14128.773615765/VM1.COMPANY.COM
      Content-type: Message/Delivery-Status

      Reporting-MTA: dns; vm1.company.com

      Original-Recipient: rfc822; 2145551234@VM1.mycompany.com
      Final-Recipient: rfc822; 2145551234@VM1.mycompany.com
      Action: failed
      Status: 5.1.1 (User does not exist)
      Diagnostic-Code: smtp; 550 Mailbox not found
      Last-Attempt-Date: Thu, 7 Jul 1994 17:15:49 -0400

















Vaudreuil & Parsons         Standards Track                    [Page 47]
^L
RFC 3801                         VPIMv2                        June 2004


      --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" <22722@vm.company.com>
Message-ID: <199407072116.RAA14128@exchange.company.com>
Subject: Voice message played
To: 2175552345@VM2.mycompany.com
MIME-Version: 1.0
Content-Type: multipart/report;
        Report-type=disposition-notification;
        Boundary="RAA14128.773615765/EXCHANGE.COMPANY.COM"

--RAA14128.773615765/EXCHANGE.COMPANY.COM
Content-type: Audio/32KADPCM
Content-Description: Spoken Disposition Notification
Content-Disposition: inline; voice= Voice-Message-Notification
Content-Transfer-Encoding: Base64

glslfdslsertiflkTfpgkTportrpkTpfgTpoiTpdadadffsssddasdasd
(Voiced description of the disposition action in base64)
jrgoij3o45itj09fiuvdkjgWlakgQ93ijkpokfpgokQ90gdffkjpokfgW
dlkgpokpeowrit09==

--RAA14128.773615765/EXCHANGE.COMPANY.COM
Content-type: Message/Disposition-Notification

Reporting-UA: gregs-laptop.dallas.company.com (Unified FooMail 3.0)

Original-Recipient: rfc822;22722@vm.company.com
Final-Recipient: rfc822;Greg.Vaudreuil@foomail.company.com
Original-Message-ID: <199509192301.12345@vm2.mycompany.com>
Disposition: manual-action/MDN-sent-automatically; displayed

--RAA14128.773615765/EXCHANGE.COMPANY.COM
Content-type: Message/RFC822

[original VPIM message goes here]

--RAA14128.773615765/EXCHANGE.COMPANY.COM--



Vaudreuil & Parsons         Standards Track                    [Page 48]
^L
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




Vaudreuil & Parsons         Standards Track                    [Page 49]
^L
RFC 3801                         VPIMv2                        June 2004


      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.











Vaudreuil & Parsons         Standards Track                    [Page 50]
^L
RFC 3801                         VPIMv2                        June 2004


16.1.  Voice Content-Disposition Parameter Definition

   To: IANA@IANA.ORG

   Subject: Registration of new Content-Disposition parameter

   Content-Disposition parameter name: voice

   Allowable values for this parameter:

         Voice-Message - the primary voice message,
         Voice-Message-Notification - a spoken delivery notification
           or spoken disposition notification,
         Originator-Spoken-Name - the spoken name of the originator,
         Recipient-Spoken-Name - the spoken name of the recipient if
           available to the originator and present if there is ONLY one
           recipient,
         Spoken-Subject- the spoken subject of the message, typically
           spoken by the originator

   Description:

   In order to distinguish between the various types of audio contents
   in a VPIM voice message a new disposition parameter "voice" is
   defined with the preceding values to be used as appropriate.  Note
   that there SHOULD only be one instance of each of these types of
   audio contents per message level.  Additional instances of a given
   type (i.e., parameter value) may occur within an attached forwarded
   voice message.

16.2.  Multipart/Voice-Message MIME Media Type Definition

   To: ietf-types@iana.org
   Subject: Registration of MIME media type
            Multipart/voice-message

   MIME media type name: multipart

   MIME subtype name: voice-message

   Required parameters: boundary, version

      The use of boundary is defined in [MIME2]








Vaudreuil & Parsons         Standards Track                    [Page 51]
^L
RFC 3801                         VPIMv2                        June 2004


      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
      gparsons@nortelnetworks.com

      Gregory M. Vaudreuil
      gregv@ieee.org

   Intended usage: COMMON




Vaudreuil & Parsons         Standards Track                    [Page 52]
^L
RFC 3801                         VPIMv2                        June 2004


   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.





Vaudreuil & Parsons         Standards Track                    [Page 53]
^L
RFC 3801                         VPIMv2                        June 2004


18.  Authors' Addresses

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

   EMail: gregv@ieee.org


   Glenn W. Parsons
   Nortel Networks
   P.O. Box 3511, Station C
   Ottawa, ON  K1Y 4H7
   Canada

   Phone: +1-613-763-7582
   Fax: +1-613-763-2697
   EMail: GParsons@NortelNetworks.com































Vaudreuil & Parsons         Standards Track                    [Page 54]
^L
RFC 3801                         VPIMv2                        June 2004


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-
   ipr@ietf.org.

Acknowledgement

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









Vaudreuil & Parsons         Standards Track                    [Page 55]
^L