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Versions: 00 01 02 03 RFC 1911

     Network Working Group                                Greg Vaudreuil
     Internet Draft                               Octel Network Services
     Expires: 11/5/1995                                      May 5, 1995
  
  
                             MIME/ESMTP Profile for
                                Voice Messaging
  
                         <draft-umig-mime-voice-03.txt>
  
     Changes From the previous version
  
     1) Message format profile and processing rules are more clearly
     separated.
  
     2) Much tutorial text was eliminated.  A basic familiarity with the
     SMTP/MIME protocols is now uniformly assumed.  Text describing the
     voice messaging environment remains to promote understanding between
     the traditional email community and the voice processing community.
  
     3) Text using the words "Recommended", "Required", "Optional" and
     "Discouraged" has been replaced with the more normal "Must", "Must
     Not", "Should", and "Should Not".
  
     Status of this Memo
  
     This document is an Internet Draft.  Internet Drafts are working
     documents of the Internet Engineering Task Force (IETF), its Areas,
     and its Working Groups.  Note that other groups may also distribute
     working documents as Internet Drafts.
  
     Internet Drafts are valid for a maximum of six months and may be
     updated, replaced, or obsoleted by other documents at any time.  It is
     inappropriate to use Internet Drafts as reference material or to cite
     them other than as a "work in progress".
  
  1. Abstract
  
     A class of special-purpose computers has evolved to provide voice
     messaging services.  These machines generally interface to a telephone
     switch and provide call answering and voice messaging services.
     Traditionally, messages sent to a non-local machine are transported
     using analog networking protocols based on DTMF signaling and analog
     voice playback.  As the demand for networking increases, there is a
     need for a standard high-quality digital protocol to connect these
     machines.  The following document is a profile of the Internet
     standard MIME and ESMTP protocols for use as a digital voice
     networking protocol.
  
     This profile is based on an earlier effort in the Audio Message
     Interchange Specification (AMIS) group to define a voice messaging
     protocol based on X.400 technology.  This protocol is intended to
     satisfy the user requirements statement from that earlier work with
     the industry standard ESMTP/MIME mail protocol infrastructures already
     used within corporate internets.  This profile will be called the
     voice profile in this document.
     Internet Draft         MIME Voice Profile               May 5, 1995
  
  
  2. Scope and Design Goals
  
     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 including
     voice and facsimile.
  
     This document specifies a profile of the TCP/IP multimedia messaging
     protocols for use by special-purpose voice processing platforms.
     These platforms have historically been special-purpose computers and
     often do not have facilities normally associated with a traditional
     Internet Email-capable computer.  This profile is intended to specify
     the minimum common set of features and functionally for conformant
     systems.
  
     The voice profile does not place limits on the use of additional media
     types or protocol options.  However, systems which are conformant to
     this profile should not send messages with features beyond this
     profile unless explicit per-destination configuration of these
     enhanced features is provided.  Such configuration information could
     be stored in a directory, though the implementation of this is a local
     matter.
  
     The following are typical restrictions of voice messaging platform
     which were considered in creating this baseline profile.
  
       1) Text messages are not normally received and often cannot be
       displayed or viewed.  They can often be processed only via advanced
       text-to-speech or text-to-fax features not currently present in
       these machines.
  
       2) Voice mail machines usually act as an integrated Message
       Transfer Agent and a User Agent.  The voice mail machine is
       responsible for final delivery, and there is no relaying of
       messages.  RFC 822 header fields may have limited use in the
       context of the simple messaging features currently deployed.
  
       3) VM message stores are generally not capable of preserving the
       full semantics of an Internet message.  As such, use of a voice
       mail machine for general message forwarding and gatewaying is not
       supported.  Storage of "Received" lines and "Message-ID" may be
       limited.
  
       4) Nothing in this document precludes use of a general purpose
       email gateway from providing these services.  However, severe
       performance degradation may result if the email gateway does not
       support the ESMTP options recommended by this document.
  
       5) Internet-style mailing lists are not generally supported.
       Distribution lists are implemented as local alias lists.
  
       6) There is generally no human operator.  Error reports must be
       machine-parsable so that helpful responses can be given to users
       whose only access mechanism is a telephone.
  
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       7) The system user names are often limited to 16 or fewer numeric
       characters.  Alpha characters are not generally used for mailbox
       identification as they cannot be easily entered from a telephone
       terminal.
  
     It is a goal of this effort to make as few restrictions and additions
     to the existing Internet mail protocols as possible while satisfying
     the user requirements for interoperability with current voice
     messaging systems.  This goal is motivated by the desire to increase
     the accessibility to digital messaging by enabling the use of proven
     existing networking software for rapid development.
  
     This specification is intended for use on a TCP/IP network, however,
     it is possible to use the SMTP protocol suite over other transport
     protocols.  The necessary protocol parameters for such use is outside
     the scope of this document.
  
     This profile is intended to be robust enough to be used in an
     environment such as the global Internet with installed base gateways
     which do not understand MIME.  It is expected that a messaging system
     will be managed by a system administrator who can perform TCP/IP
     network configuration.  When using facsimile or multiple voice
     encodings, it is expected that the system administrator will maintain
     a list of the capabilities of the networked mail machines to reduce
     the sending of undeliverable messages due to lack of feature support.
     Configuration, implementation and management of this directory listing
     capabilities is a local matter.
  
     This specification is a profile of the relevant TCP/IP Internet
     protocols.  These technologies, as well as the specifications for the
     Internet mail protocols, are defined in the Request for Comment (RFC)
     document series.  That series documents the standards as well as the
     lore of the TCP/IP protocol suite.  This document should be read with
     the following RFC documents: RFC 821, Simple Mail Transfer Protocol;
     RFC 822, Standard for the format of ARPA Internet Messages; RFC 1521
     and RFC 1522, Multipurpose Internet Mail Extensions; RFC 1651, RFC
     1652, and RFC 1653, SMTP Service Extensions (ESMTP); and RFC 1034 and
     RFC 1035, Domain Name System. Where additional functionality is
     needed, it will be defined in this document or in an appendix.
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
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  3. Protocol Restrictions
  
     This protocol does not limit the number of recipients per message.
     Where possible, implementations should not restrict the number of
     recipients in a single message.  It is recognized that no
     implementation supports unlimited recipients, and that the number of
     supported recipients may be quite low.  However, ESMTP currently does
     not provide a mechanism for indicating the number of supported
     recipients.
  
     This protocol does not limit the maximum message length.  Implementors
     should understand that some machines will be unable to accept
     excessively long messages.  A mechanism is defined in the RFC 1425
     ESMTP extensions to declare the maximum message size supported.
  
     The message size indicated in the ESMTP SIZE command is in bytes, not
     minutes.  The number of bytes varies by voice encoding format and must
     include the MIME wrapper overhead.  If the length must be known before
     sending, an approximate translation into minutes can be performed if
     the voice encoding is known.
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
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  4. Voice Message Interexchange Format
  
     The voice message interchange format is a profile of the Internet
     Email Protocol Suite.  It requires components from the message format
     standard for Internet messages {RFC822], the Multipurpose Internet
     Message Extensions [MIME], the X.400 gateway specification [X.400],
     and the delivery report specifications [DRPT][STATUS].
  
  4.1 Message Addressing Formats
  
    The RFC 822 uses 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.
  
    The local part of the address shall be an ASCII string uniquely
    identifying a mailbox on a destination system.  For voice messaging,
    the local part is a printable string containing the mailbox ID of the
    originator or recipient.  Administration of this space is expected to
    conform to national or corporate private telephone numbering plans.
    While alpha characters and long mailbox identifiers are permitted,
    most voice mail networks rely on numeric mailbox identifiers to retain
    compatibility with the limited 10 digit telephone keypad.
  
    For example, a compliant message may contain the address
    2145551212@mycompany.com. It should be noted that while the example
    mailbox address is based on the North American Numbering Plan, any
    other corporate numbering plan can be used.  The use of the domain
    naming system should be transparent to the user.  It is the
    responsibility of the voice mail machine to lookup the fully-qualified
    domain name (FQDN) based on the address entered by the user.  The
    mapping of dialed address to final destination system is generally
    accomplished through implementation-specific means.
  
    Special addresses are provided for compatibility with the conventions
    of the Internet mail system and to facilitate testing.  These
    addresses do not use numeric local addresses, both to conform to
    current Internet practice and to avoid conflict with existing numeric
    addressing plans.  Some special addresses are 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 a individual
    implementation choice.
  
     Loopback@domain
  
     A special mailbox name named "loopback" SHOULD be designated for
     loopback testing.  If supported, all messages sent to this mailbox
     MUST be returned back to the address listed in the From: address as a
  
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     new message.  The originating address of the returned address MUST be
     "postmaster" to prevent mail loops.
  
     These two addresses are RESERVED so they do not conflict with any
     internal addressing plan.
  
  4.2 Message Header Fields
  
     Internet messages contain a header information block.  This header
     block contains information required to identify the sender, the list
     of recipients, the message send time, and other information intended
     for user presentation.  Except for specialized gateway and mailing
     list cases, headers do not indicate delivery options for the transport
     of messages.
  
     The following header lines are permitted for use with voice messages.
  
     From
  
     The originator's fully-qualified domain address (a mailbox address
     followed by the fully-qualified domain name).  The user listed in this
     field should be presented in the voice message envelope as the
     originator of the message.
  
     Systems conformant to this profile SHOULD provide the text personal
     name of the sender in a quoted phrase if available.  To facilitate
     storage of the text name in a local dial-by-name cache directory, the
     first and last name MUST be separable.  Text names in voice messages
     MUST be represented in the form "last, first, mi." From [822]
  
     Example:
  
       From: "User, Joe S." <2145551212@mycompany.com>
  
     To
  
     The TO header contains the recipient's fully-qualified domain address.
     There may be one or more To: fields in any message.
  
     Systems conformant to this profile SHOULD provide the text personal
     name of the recipient, if known, in a quoted phrase.  The name MUST be
     in the form "last, first, mi." From [822]
  
     Example:
  
       To: "User, Sam S." <2145551213@mycompany.com>
  
     Cc
  
     The CC header contains additional recipients' fully-qualified domain
     addresses. Many voice mail systems are not capable of storing or
     reporting the full list of recipients to the receiver.
  
  
  
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     Systems conformant to this profile SHOULD provide the text personal
     name of the recipient, if known, in a quoted phrase.  The name MUST be
     in the form "last, first, mi." From [822]
  
     Example:
  
       To: "User, Sam S." <2145551213@mycompany.com>
  
     Systems conformant to this profile may discard the CC list of incoming
     messages as necessary.  Systems conformant to this profile should
     provide a complete list of recipients when possible.
  
     Date
  
     The Date header contains the date, time, and time zone in which the
     message was sent by the originator.  Conforming implementations SHOULD
     be able to convert RFC 822 date and time stamps into local time.
  
     Example:
  
       Date: Wed, 28 Jul 93 10:08:49 PST
  
     The sending system MUST report the time the message was sent. From
     [822]
  
     Sender
  
     The Sender header contains the actual address of the originator if the
     message is sent by an agent on behalf of the author indicated in the
     From: field.  Support for this field cannot be assumed when talking to
     a voice system and SHOULD NOT be generated by a conforming
     implementation.
  
     The Sender field often contains the name of an Internet-style mailing
     list administrator and is the destination address for reporting errors
     if the ESMTP MAIL FROM address is not available.
  
     While it may not be possible to save this information in some voice
     mail machines, discarding this information or the ESMTP MAIL FROM
     address will make it difficult to send an error message to the proper
     destination. From [822]
  
     Message-id
  
     The Message-id header contains a unique per-message identifier.  A
     unique message-id MUST be generated for each message sent from a
     conforming implementation.
  
     The message-id is not required to be stored on the receiving system.
     This identifier MAY be used for tracking, auditing, and returning
     read-receipt reports.  From [822]
  
     Example:
  
  
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       Message-id: <12345678@mycompany.com>
  
     Received
  
     The Received header contains trace information added to the beginning
     of a RFC 822 message by message transport agents (MTA).  This is the
     only header permitted to be added by an MTA.  Information in this
     header is useful for debugging when using an ASCII message reader or a
     header parsing tool.
  
     A conforming system MUST add Received headers when acting as a gateway
     and must not remove them.  These headers MAY be ignored or deleted
     when the message is received at the final destination. From [822]
  
     MIME Version
  
     The MIME-Version header indicates that the message is conformant to
     the MIME message format specification. Systems conformant to the voice
     messaging profile MUST include a comment with the words "(Voice 1.0)".
     From [MIME]
  
     Example:
  
       MIME-Version: 1.0 (Voice 1.0)
  
     Content-Type
  
     The content-type header declares the type of content enclosed in the
     message.  One of the allowable contents is multipart, a mechanism for
     bundling several message components into a single message.  The
     allowable contents are specified in the next section of this document.
     From [MIME]
  
     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.
     Conformant implementations MUST recognize and decode the standard
     encodings, "Binary", "7bit, "8bit", "Base-64" and "Quoted-Printable".
     The allowable content-transfer-encodings are specified in the next
     section of this document.  From [MIME]
  
     Sensitivity
  
     The Sensitivity header, if present, indicates the requested privacy
     level.  The case-insensitive values "Personal" and "Private" are
     specified. If no privacy is requested, this field is omitted.
  
     If a Sensitivity header is present in the message, a conformant system
     MUST prohibit the recipient from forwarding this message to any other
     user.  If the receiving system does not support privacy and the
     sensitivity is one of "Personal" or "Private", the message MUST be
  
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     returned to the sender with an appropriate error code indicating that
     privacy could not be assured and that the message was not delivered.
  
     Importance
  
     Indicates the requested priority to be given by the receiving system.
     The case-insensitive values "low", "normal" and "high" are specified.
     If no special importance is requested, this header may be omitted and
     the value assumed to be "normal".
  
     Conformant implementations MAY use this header to indicate the
     importance of a message and may order messages in a recipient's
     mailbox. From: [X400]
  
     Subject
  
     The subject field is often provided by email systems but is not widely
     supported on Voice Mail platforms. This field MAY be generated by a
     conforming implementation and may be discarded if present by a
     receiving system.
  
  4.3 Message Content Types
  
     MIME is a general-purpose message body format that is extensible to
     carry a wide range of body parts.  The basic protocol is described in
     [MIME]. MIME also provides for encoding binary data so that it can be
     transported over the 7-bit text-oriented SMTP protocol.  This
     transport encoding is independent of the audio encoding designed 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 ("Base-64").
     While Base-64 is dramatically more efficient for audio data, both will
     work.  Where binary transport is available, no transport encoding is
     needed, and the data can be labeled as "Binary".
  
     An implementation in conformance with this profile SHOULD send audio
     data in binary form when binary message transport is available.  When
     binary transport is not available, implementations MUST encode the
     message as Base-64.  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.
  
     The following content types are identified for use with this profile.
     Note that each of these contents can be sent individually in a message
     or wrapped in a multipart message to send multi-segment messages.
  
     Message/RFC822
  
     MIME requires support of the Message/RFC822 message encapsulation body
     part.  This body part is used in the Internet to forward complete
     messages within a multipart/mixed message.  Processing of this body
  
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     part entails trivial processing to decapsulate/encapsulate the
     message.  Systems conformant to this profile SHOULD NOT send this body
     part but MUST accept if in conformance with basic MIME.  Specific
     handling depends on the platform, and interpretation of this content-
     type is left as an implementation decision. From [MIME]
  
     Text/Plain
  
     MIME requires support of the basic Text/Plain content type.  This
     content type has no applicability within the voice messaging
     environment.  Conformant implementations MUST NOT send the Text/Plain
     content-type.  Conformant implementations MUST accept Text/Plain
     messages, however, specific handling is left as an implementation
     decision.  One option is to return the message to the sender with a
     media-unsupported error code.  From [MIME]
  
     Multipart/Mixed
  
     MIME provides the facilities for enclosing several body parts in a
     single message. Multipart/Mixed MAY be used for sending multi-segment
     voice messages, that is, to preserve across the network the
     distinction between an annotation and a forwarded message.  Conformant
     systems MUST accept multipart/mixed body parts.  Systems MAY to
     collapse such a multi-segment message into a single segment if multi-
     segment messages are not supported on the receiving machine.  From
     [MIME]
  
     Message/Notification
  
     This MIME body part is used for sending machine-parsable delivery
     status notifications.  Conformant implementations must use the
     Message/Notification construct when returning messages or sending
     warnings.  Conformant implementations must recognize and decode the
     Message/Notification content type and present the reason for failure
     to the user.  From [NOTIFY]
  
     Multipart/Report
  
     The Multipart/Report is used for enclosing a Message/Notification body
     part and any returned message content.  This body type is a companion
     to Message/Notification.  Conformant implementations must use the
     Multipart/Report construct when returning messages or sending
     warnings.  Conformant implementations must recognize and decode the
     Multipart/Report content type.  From [REPORT]
  
     Audio/32KADPCM
  
     CCITT Recommendation G.721 [G721] describes the algorithm recommended
     for conversion of a 64 KB/s A-law or u-law PCM channel to and from a
     32 KB/s channel.  The conversion is applied to the PCM stream using an
     Adaptive Differential Pulse Code Modulation (ADPCM) transcoding
     technique. This algorithm will be registered with the IANA for MIME
     use under the name Audio/32KADPCM.
  
  
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     An implementation conformant to this profile MUST use Audio/32KADPCM
     by default.
  
     Proprietary Voice Formats
  
     Proprietary voice encoding formats or other standard formats may be
     supported under this profile provided a unique identifier is
     registered with the IANA prior to use.  These encodings should be
     registered as sub-types of Audio.
  
     Use of any other encoding except Audio/32KADPCM reduces
     interoperability in the absence of explicit manual system
     configuration.  A conformant implementation MAY use any other encoding
     with explicit per-destination configuration.
  
     Multipart/Voice-Message
  
     This new MIME multipart structure provides a mechanism for packaging
     the senders spoken name, a spoken subject and, the message.  The
     multipart provides for the packaging of three segments, the first is
     the spoken name, the second is a spoken subject, and the third is the
     message itself.  Forwarded messages can be created by simply nesting
     multipart content-types (this is also possible with Multipart/Mixed if
     spoken name or spoken subject is not present).  This type is defined
     in an appendix to this document.
  
     Conforming implementations MUST send the Multipart/Voice-Message if a
     spoken name or spoken subject is available.  Conforming
     implementations SHOULD recognize the Multipart/Voice-Message and
     separate the spoken name or spoken subject.
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
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  5. Message Transport Protocol
  
     Messages are transported between voice mail machines using the
     Internet Extended Simple Mail Transfer Protocol (ESMTP).  All
     information required for proper delivery of the message is included in
     the ESMTP dialog.  This information, including the sender and
     recipient addresses, is commonly referred to as the message
     "envelope".  This information is equivalent to the message control
     block in many analog voice networking protocols.
  
     ESMTP is a general-purpose messaging protocol, designed both to send
     mail and to allow terminal console messaging.  Simple Mail Transport
     Protocol (SMTP) was originally created for the exchange of US-ASCII 7-
     bit text messages.  Binary and 8-bit text messages have traditionally
     been transported by encoding the messages into a 7-bit text-like form.
     [ESMTP] was recently published and formalized an extension mechanism
     for SMTP, and subsequent RFCs have defined 8-bit text networking,
     binary networking, and extensions to permit the declaration of message
     size for the efficient transmission of large messages such as multi-
     minute voice mail.
  
     A command streaming extension for high performance message
     transmission has been defined.  [PIPE] This extension reduces the
     number of round-trip packet exchanges and makes it possible to
     validate all recipient addresses in one operation.  This extension is
     optional but recommended.
  
     The following sections list ESMTP commands, keywords, and parameters
     that are required and those that are optional.
  
  5.1 ESMTP Commands
  
     HELO
  
     Base SMTP greeting and identification of sender.  This command is not
     to be sent by conforming systems unless the more-capable EHLO command
     is not accepted.  It is included for compatibility with general SMTP
     implementations. Conforming implementations MUST implement the HELO
     command for backward compatibility but SHOULD NOT send it unless EHLO
     is not supported.  From [SMTP]
  
     MAIL FROM (REQUIRED)
  
     Originating mailbox.  This address contains the mailbox to which
     errors should be sent.  This address may not be the same as the
     message sender listed in the message header fields if the message was
     received from a gateway or sent to an Internet-style mailing list.
     Conforming implementations MUST implement the extended MAIL FROM
     command.  From [SMTP, ESMTP]
  
     RCPT TO
  
     Recipient's mailbox.  This field contains only the addresses to which
     the message should be delivered for this transaction.  In the event
  
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     that multiple transport connections to multiple destination machines
     are required for the same message, this list may not match the list of
     recipients in the message header. Conforming implementations MUST
     implement the extended RCPT TO command.  From [SMTP, ESMTP]
  
     DATA
  
     Initiates the transfer of message data.  Support for this command is
     required in the event the binary mode command BDAT is not supported by
     the remote system.  Conforming implementations MUST implement the SMTP
     DATA command for backwards compatibility.  From [SMTP]
  
     TURN
  
     Requests a change-of-roles, that is, the client that opened the
     connection offers to assume the role of server for any mail the remote
     machine may wish to send.  Because SMTP is not an authenticated
     protocol, the TURN command presents an opportunity to improperly fetch
     mail queued for another destination.  Conforming implementations
     SHOULD NOT implement the TURN command.  From [SMTP]
  
     QUIT
  
     Requests that the connection be closed.  If accepted, the remote
     machine will reset and close the connection.  Conforming
     implementations MUST implement the QUIT command.  From [SMTP]
  
     RSET
  
     Resets the connection to its initial state.  Conforming
     implementations MUST implement the RSET command. From [SMTP]
  
     VRFY
  
     Requests verification that this node can reach the listed recipient.
     While this functionality is also included in the RCPT TO command, VRFY
     allows the query without beginning a mail transfer transaction.  This
     command is useful for debugging and tracing problems.  Conforming
     implementations MAY implement the VRFY command.  From [SMTP]
  
     (Note that the implementation of VRFY may simplify the guessing of a
     recipient's mailbox or automated sweeps for valid mailbox addresses,
     resulting in a possible reduction in privacy.  Various implementation
     techniques may be used to reduce the threat, such as limiting the
     number of queries per session.)  From [SMTP]
  
     EHLO
  
     The enhanced mail greeting that enables a server to announce support
     for extended messaging options.  The extended messaging modes are
     discussed in a later section of this document.  Conformant
     implementations MUST implement the ESMTP command and return the
     capabilities indicated later in this memo.  From [ESMTP]
  
  
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     BDAT
  
     The BDAT command provides a higher efficiency alternative to the
     earlier DATA command, especially for voice. The BDAT command provides
     for native binary transport.  Because voice messages are large binary
     objects otherwise subject to BASE-64 encoding, BDAT will result in a
     substantial improvement in transmission efficiency over DATA.
     Conformant implementations SHOULD support binary transport using the
     BDAT command.[BINARY]
  
  5.2 ESMTP Capabilities
  
    The following ESMTP keywords indicate extended features useful for
    voice messaging.
  
     PIPELINING
  
     The "PIPELINING" keyword indicates ability of the receiving SMTP to
     accept pipelined commands.  Pipelining commands dramatically improves
     the protocol performance over wide area networks.  Conformant
     implementations SHOULD support the command pipelining indicated by
     this parameter.  From [PIPE]
  
     SIZE
  
     The "SIZE" keyword provides a mechanism by which the receiving SMTP
     can indicate the maximum size message supported.  Conformant
     implementations MUST provide the size capability and SHOULD honor any
     size limitations when sending. From [SIZE]
  
     CHUNKING
  
     The "CHUNKING" keyword indicates that the receiver will support the
     high-performance binary transport mode.  Note that CHUNKING can be
     used with any message format and does not imply support for binary
     encoded messages. Conformant implementations SHOULD support binary
     transport indicated by this capability.  From [BINARY]
  
     BINARYMIME
  
     The "BINARYMIME" keyword indicates that the receiver SMTP can accept
     binary encoded MIME messages. Conformant implementations should
     support binary transport indicated by this capability.  From [BINARY]
  
     NOTIFY
  
     The "NOTIFY" keyword indicates that the receiver SMTP will accept
     explicit delivery status notification requests.  Conformant
     implementations MUST support the delivery notification extensions in
     [DSN].
  
  5.3 ESMTP Parameters - MAIL FROM
  
     BINARYMIME
  
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     The current message is a binary encoded MIME messages.  Conformant
     implementations SHOULD support binary transport indicated by this
     parameter.  From [BINARY]
  
  5.4 ESMTP Parameters - RCPT TO
  
     NOTIFY
  
     The NOTIFY parameter indicates the conditions under which a delivery
     report SHOULD be sent. Conformant implementations must honor this
     request.  From [DSN]
  
     RET
  
     The RET parameter indicates whether the content of the message should
     be returned.  Conformant systems SHOULD honor a request for returned
     content. From [DSN]
  
  6. Management Protocols
  
     The Internet protocols provide a mechanism for the management of
     messaging systems, from the management of the physical network through
     the management of the message queues.  SNMP should be supported on a
     compliant message machine.
  
  6.1 Network Management
  
     The digital interface to the VM and the TCP/IP protocols SHOULD be
     managed.  MIB II SHOULD be implemented to provide basic statistics and
     reporting of TCP and IP protocol performance. [MIB II]
  
  6.2 Directory and Message Management
  
     Conformant systems SHOULD provide for the management of message
     traffic and queue monitoring based on the Message and Directory MIB.
     [MADMAN]
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
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  7. References
  
  [MIME]    Borenstein, N., and N. Freed, "Multipurpose Internet Mail
      Extensions", RFC 1521, Bellcore, Innosoft, Sept 1993.
  
  [MSG822]  Crocker, D., "Standard for the Format of ARPA Internet Text
      Messages", STD 11, RFC 822, UDEL, August 1982.
  
  [X400]    Hardcastle-Kille, S., "Mapping between X.400(1988) / ISO 10021
      and RFC 822", RFC 1327, May 1992.
  
  [PIPE]    Freed, N., Klensin, J., "SMTP Service Extension for Command
      Pipelining" Internet Draft <draft-ietf-mailext-pipelining-02.txt>
  
  [ESMTP]   Klensin, J., Freed, N., Rose, M., Stefferud, E., and D.
      Crocker, "SMTP Service Extensions" RFC 1651, United Nations
      University, Innosoft International, Inc., Dover Beach Consulting,
      Inc., Network Management Associates, Inc., The Branch Office,
      February 1993.
  
  [SIZE]    Klensin, J, Freed, N., Moore, K, "SMTP Service Extensions for
      Message Size Declaration" RFC 1653,  United Nations University,
      Innosoft International, Inc., Inc., February 1993. February 1993.
  
  [8BIT]    Klensin, J., Freed, N., Rose, M., Stefferud, E., D. Crocker,
      "SMTP Service Extension for 8bit-MIMEtransport" RFC 1426, United
      Nations University, Innosoft International, Inc., Dover Beach
      Consulting, Inc., Network Management Associates, Inc., The Branch
      Office, February 1993.
  
  [DNS1]    Mockapetris, P., "Domain names - implementation and
      specification", RFC1035, Nov 1987.
  
  [DNS2]    Mockapetris, P., "Domain names - concepts and facilities", RFC
      1034, Nov 1987.
  
  [SMTP]    Postel, J., "Simple Mail Transfer Protocol", STD 10, RFC 821,
      USC/Information Sciences Institute, August 1982.
  
  [BINARY]  Vaudreuil, G., "SMTP Service Extensions for Transmission of
      Large and Binary MIME Messages", Internet Draft <draft-ietf-mailext-
      binary-06.txt>
  
  [NOTIFY]  Vaudreuil, G., Moore, K., "An Extensible Message Format for
      Delivery Status Notifications", Internet Draft <draft-ietf-notary-
      mime-delivery-02-txt>
  
  [REPORT]  Vaudreuil, G., "Multipart/Report", Internet-Draft, <draft-
      ietf-notary-mime-report-04.txt>
  
  [DSN]     Moore, K. "SMTP Service Extensions for Delivery Status
      Notifications", Internet Draft <draft-ietf-notary-smtp-drpt-03.txt>.
  
  
  
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  [G721]    CCITT Recommendation G.700-G.795 (1988), General Aspects of
      Digital Transmission Systems, Terminal Equipment.  Blue Book.
  
  [MADMAN]  N. Freed, S. Kille, "Mail Monitoring MIB", RFC 1566, Jan 1994.
  
  [MIB II]  M. Rose, "Management Information Base for Network Management
      of TCP/IP-based internets:  MIB-II", RFC 1158, May 1990.
  
  8. Security Consideration
  
     This document is a profile of existing Internet mail protocols.  As
     such, it does not create any security issues not already existing in
     the profiled Internet mail protocols themselves.
  
  9. Acknowledgments
  
     The author would like to offer special thanks to Glenn Parsons/BNR for
     his extensive review, helpful suggestions, and extensive editing
     including the requirements matrix.
  
  10. Author's Address
  
     Gregory M. Vaudreuil
     Octel Network Services
     17080 Dallas Parkway
     Dallas, TX 75248-1905
     Phone/Fax: +1-214-733-2722
     Greg.Vaudreuil@Octel.Com
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
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  11. Appendix - MIME/ESMTP Voice Profile Requirements Summary
  
                                               |          | | | |S| |
                                               |          | | | |H| |F
                                               |          | | | |O|M|o
                                               |          | |S| |U|U|o
                                               |          | |H| |L|S|t
                                               |          |M|O| |D|T|n
                                               |          |U|U|M| | |o
                                               |          |S|L|A|N|N|t
                                               |          |T|D|Y|O|O|t
    FEATURE                                    |SECTION   | | | |T|T|e
    -------------------------------------------|----------|-|-|-|-|-|-
                                               |          | | | | | |
    Message Addressing Formats:                |          | | | | | |
      Use DNS host names                       |4.1       |x| | | | |
      Use only numbers in mailbox IDs          |4.1       | |x| | | |
      Use alpha-numeric mailbox IDs            |4.1       | | |x| | |
      Support of postmaster@domain             |4.1       | |x| | | |
      Support of loopback@domain               |4.1       | |x| | | |
                                               |          | | | | | |
    Message Header Fields:                     |          | | | | | |
      Encoding outbound messages               |          | | | | | |
        From                                   |4.2       |x| | | | |
          Addition of text personal name       |4.2       | |x| | | |
        To                                     |4.2       |x| | | | |
          Addition of text personal name       |4.2       | |x| | | |
        CC                                     |4.2       | | |x| | |
        Date                                   |4.2       |x| | | | |
        Sender                                 |4.2       | | | |x| |
        Message-id                             |4.2       | |x| | | |
        Received                               |4.2       |x| | | | |
        MIME Version: 1.0 (Voice 1.0)          |4.2       |x| | | | |
        Content-Type                           |4.2       |x| | | | |
        Content-Transfer-Encoding              |4.2       |x| | | | |
        Sensitivity                            |4.2       | | |x| | |
        Importance                             |4.2       | | |x| | |
        Subject                                |4.2       | | |x| | |
      Detection & Decoding inbound messages    |          | | | | | |
        From                                   |4.2       |x| | | | |
          Utilize text personal name           |4.2       | |x| | | |
        To                                     |4.2       |x| | | | |
          Utilize text personal name           |4.2       | | |x| | |
        CC                                     |4.2       | | |x| | |
          Utilize text personal name           |4.2       | | |x| | |
        Date                                   |4.2       |x| | | | |
          Conversion of Date to local time     |4.2       | |x| | | |
        Sender                                 |4.2       | | | |x| |
        Message ID                             |4.2       |x| | | | |
        Received                               |4.2       | |x| | | |
        MIME Version: 1.0 (Voice 1.0)          |4.2       |x| | | | |
        Content Type                           |4.2       |x| | | | |
        Content-Transfer-Encoding              |4.2       |x| | | | |
        Sensitivity                            |4.2       |x| | | | |1
  
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        Importance                             |4.2       | | |x| | |
        Subject                                |4.2       | | |x| | |
                                               |          | | | | | |
    Binary Content Encoding:                   |          | | | | | |
      Encoding outbound messages               |          | | | | | |
        7BITMIME                               |4.3       | | | | |x|
        8BITMIME                               |4.3       | | | | |x|
        Quoted Printable                       |4.3       | | | | |x|
        Base-64                                |4.3       |x| | | | |2
        Binary                                 |4.3       |x| | | | |3
      Detection & decoding inbound messages    |          | | | | | |
        7BITMIME                               |4.3       |x| | | | |
        8BITMIME                               |4.3       |x| | | | |
        Quoted Printable                       |4.3       |x| | | | |
        Base-64                                |4.3       |x| | | | |
        Binary                                 |4.3       |x| | | | |
                                               |          | | | | | |
    Message Content Types:                     |          | | | | | |
      Inclusion in outbound messages           |          | | | | | |
        Message/RFC822                         |4.3       | | | |x| |
        Text/plain                             |4.3       | | | | |x|
        Multipart/Mixed                        |4.3       | | |x| | |
        Message/Notification                   |4.3       |x| | | | |
        Multipart/Report                       |4.3       |x| | | | |
        Audio/32KADPCM                         |4.3       |x| | | | |
        Audio/* (proprietary encodings)        |4.3       | | |x| | |
        Multipart/Voice-Message                |4.3       |X| | | | |
      Detection & decoding in inbound messages |          | | | | | |
        Message/RFC822                         |4.3       |x| | | | |
        Text/plain                             |4.3       |x| | | | |
        Multipart/Mixed                        |4.3       |x| | | | |
        Message/Notification                   |4.3       |x| | | | |
        Multipart/Report                       |4.3       |x| | | | |
        Audio/32KADPCM                         |4.3       |x| | | | |
        Audio/* (proprietary encodings)        |4.3       | | |x| | |
        Multipart/Voice-Message                |4.3       |X| | | | |
                                               |          | | | | | |
    Message Transport Protocol:                |          | | | | | |
      ESMTP Commands                           |          | | | | | |
        HELO                                   |5.1       |x| | | | |
        MAIL FROM                              |5.1       |x| | | | |
        RCPT TO                                |5.1       |x| | | | |
        DATA                                   |5.1       |x| | | | |
        TURN                                   |5.1       | | | | |x|
        QUIT                                   |5.1       |x| | | | |
        RSET                                   |5.1       |x| | | | |
        VRFY                                   |5.1       | | |x| | |
        EHLO                                   |5.1       |x| | | | |
        BDAT                                   |5.1       | |x| | | |3
      ESMTP Keywords                           |          | | | | | |
        STREAMING                              |5.2       | |x| | | |
        SIZE                                   |5.2       |x| | | | |
        CHUNKING                               |5.2       | |x| | | |
        BINARYMIME                             |5.2       | |x| | | |
  
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        NOTIFY                                 |5.2       |x| | | | |
                                               |          | | | | | |
    Management Protocols:                      |          | | | | | |
      Network management                       |6.1       | |x| | | |
      Monitoring queues                        |6.2       | |x| | | |
    -------------------------------------------|----------|-|-|-|-|-|-
  
     1.  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.
     2.  When binary transport is not available
     3.  When binary transport is available
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
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  12. Appendix - Example Voice Message
  
     The following message is a full-featured, all-options-enabled message
     addressed to two recipients. The message includes the sender's spoken
     name and a short speech segment.  The message is marked as important
     and private.
  
     To: 2145551212@vm1.mycompany.com
     To: "Parsons, Glenn, W." 2145551234@VM1.mycompany.com
     From: "Vaudreuil, Greg" 2175552345@VM2.mycompany.com
     Date: Mon, 26 Aug 93 10:20:20 CST
     MIME-Version: 1.0  (Voice 1.0)
     Content-type: Multipart/Voice-Message; Boundary = "MessageBoundary"
     Content-Transfer-Encoding: 7bit
     Message-ID: VM2.mycompany.com-123456789
     Sensitivity: Private
     Importance: High
  
     --MessageBoundary
     Content-type: Audio/32KADPCM
     Content-Transfer-Encoding: Base-64
  
     glslfdslsertiflkTfpgkTportrpkTpfgTpoiTpdadasssdasddasdasd
     (This is a sample of the base-64 Spoken Name data) fgdhgd
     jrgoij3o45itj09fiuvdkjgWlakgQ93ijkpokfpgokQ90gQ5tkjpokfgW
     dlkgpokpeowrit09==
  
     --MessageBoundary
     Content-type: Audio/32KADPCM
     Content-Transfer-Encoding: Base-64
  
     glslfdslsertiflkTfpgkTportrpkTpfgTpoiTpdadasssdasddasdasd
     (This is a sample of the base-64 Spoken Subject data) fgdhgd
     jrgoij3o45itj09fiuvdkjgWlakgQ93ijkpokfpgokQ90gQ5tkjpokfgW
     dlkgpokpeowrit09==
  
     --MessageBoundary
     Content-type: Audio/32KADPCM
     Content-Transfer-Encoding: Base-64
  
     glslfdslsertiflkTfpgkTportrpkTpfgTpoiTpdadasssdasddasdasd
     (This is a sample of the base-64 message data) fgdhgdfwgd
     jrgoij3o45itj09fiuvdkjgWlakgQ93ijkpokfpgokQ90gQ5tkjpokfgW
     dlkgpokpeowrit09==
  
     --MessageBoundary--
  
  
  
  
  
  
  
  
  
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     13. Appendix - Audio/32KADPCM Content Type
  
     Mime type name: Audio
     Mime Sub-Type name: 32KADPCM
     Required Parameters: None
     Optional Parameters: None
     Encoding Considerations: Any encoding necessary for transport may be
     used.
  
     CCITT Recommendation G.721 [G721] describes the algorithm recommended
     for conversion of a 64 KB/s A-law or u-law PCM channel to and from a
     32 KB/s channel.  The conversion is applied to the PCM stream using an
     Adaptive Differential Pulse Code Modulation (ADPCM) transcoding
     technique.
  
     No header information shall be included before the audio data. When
     this subtype is present, a sample rate of 8000 Hz and a single channel
     is assumed.
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
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     13.    Appendix - Multipart/Voice-Message
  
     Mime type name: Multipart
     Mime Sub-Type name: Voice-Message
     Required Parameters: Boundary
     Optional Parameters: None
     Encoding Considerations: Binary of 7 bit are sufficient.  Base-64 and
     Quoted-Printable are prohibited on multipart content-types.
  
     The syntax of a Multipart/Voice-Message  is identical to the
     Multipart/Mixed content type.  The Voice-Message content-type contains
     three body parts.  The first is an audio segment containing the spoken
     name of the originator, the second is an audio segment containing a
     spoken subject, and the third is the voice message itself.  Forwarded
     voice messages can be created by simply nesting multipart content
     types.
  
     The spoken name segment shall contain the name of the message sender
     in the voice of the sender.  The length of the spoken name segment
     must not exceed 12 seconds.  If no spoken name is available, the
     segment must still be present but may be empty.
  
     The spoken subject segment shall contain the subject of the message
     sender in the voice of the sender.  The length of the spoken subject
     segment must not exceed 20 seconds.  If no spoken subject segment is
     available, the segment must still be present but may be empty.
  
     The voice message body part may contain any arbitrary content
     including a multipart/mixed collections of body parts, though will
     typically be an audio segment.
  
     The default handling of the Multipart/Voice-Message  shall be to voice
     the spoken-name segment and then the spoken-subject prior to
     displaying or voicing the remainder of the message.
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
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