Network Working Group Greg Vaudreuil Internet Draft Octel Network Services Expires in six months Glenn Parsons Obsoletes: RFC 1911 Nortel Technology September 9, 1996 Voice Profile for Internet Mail - version 2 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". To learn the current status of any Internet-Draft, please check the ``1id-abstracts.txt'' listing contained in the Internet-Drafts Shadow Directories on ftp.is.co.za (Africa), nic.nordu.net (Europe), munnari.oz.au (Pacific Rim), ds.internic.net (US East Coast), or ftp.isi.edu (US West Coast). Overview This document profiles Internet mail for voice messaging. It obsoletes RFC 1911 which describes version 1 of the profile. A list of changes from that document are noted in Appedix F. As well, Appendix G lists the open issues with this version of VPIM. Please send comments on this document to the EMA VPIM Work Group mailing list: Working Group Summary This profile was not reviewed by an active IETF working group. However, it has been reviewed by the VPIM Work Group of the Electronic Messaging Association (EMA). This work group, which has representatives from most major voice mail vendors, has held an interoperability demonstration between voice messaging vendors and received comments from traditional messaging vendors. Internet Draft VPIM v2 September 9, 1996 Table of Contents 1. ABSTRACT 4 2. SCOPE 5 2.1 Voice Messaging System Limitations 5 2.2 Design Goals 6 3. PROTOCOL RESTRICTIONS 7 4. VOICE MESSAGE INTERCHANGE FORMAT 8 4.1 Message Addressing Formats 8 4.2 Message Header Fields 10 4.3 Message Content Types 15 4.4 Forwarded Messages 20 5. MESSAGE TRANSPORT PROTOCOL 21 5.1 ESMTP Commands 21 5.2 ESMTP Keywords 23 5.3 ESMTP Parameters - MAIL FROM 24 5.4 ESMTP Parameters - RCPT TO 24 5.5 ESMTP - SMTP Downgrading 24 6. DIRECTORY ADDRESS RESOLUTION 25 7. IMAP 25 8. MANAGEMENT PROTOCOLS 25 8.1 Network Management 25 9. CONFORMANCE REQUIREMENTS 26 Vaudreuil, Parsons Expires 3/9/97 [Page 2] Internet Draft VPIM v2 September 9, 1996 10. REFERENCES 27 11. SECURITY CONSIDERATION 29 12. ACKNOWLEDGMENTS 29 13. AUTHORS' ADDRESSES 29 14. APPENDIX A - VPIM REQUIREMENTS SUMMARY 30 15. APPENDIX B - EXAMPLE VOICE MESSAGES 34 16. APPENDIX C - EXAMPLE ERROR VOICE PROCESSING ERROR CODES 37 17. APPENDIX D - AUDIO/32KADPCM CONTENT TYPE 38 18. APPENDIX E - IMAGE/TIFF CONTENT TYPE 39 18.1 References 39 18.2 TIFF Class F 39 19. APPENDIX F - CHANGE HISTORY: RFC 1911 TO THIS DOCUMENT 42 20. APPENDIX G -- OPEN ISSUES 43 Vaudreuil, Parsons Expires 3/9/97 [Page 3] Internet Draft VPIM v2 September 9, 1996 1. Abstract A class of special-purpose computers has evolved to provide voice messaging services. These machines generally interface to a telephone switch and provide call answering and voice messaging services. Traditionally, messages sent to a non-local machine are transported using analog networking protocols based on DTMF signaling and analog voice playback. As the demand for networking increases, there is a need for a standard high-quality digital protocol to connect these machines. The following document is a profile of the Internet standard MIME and ESMTP protocols for use as a digital voice messaging networking protocol. 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 intranets. This Internet Draft will be referred to as VPIM (Voice Profile for Internet Mail) in this document. This second version of VPIM is based on implementation experience and obsoletes RFC 1911 which describes version 1 of the profile. Vaudreuil, Parsons Expires 3/9/97 [Page 4] Internet Draft VPIM v2 September 9, 1996 2. Scope MIME is the Internet multipurpose, multimedia messaging standard. This document explicitly recognizes its capabilities and provides a mechanism for the exchange of various messaging technologies, highlighting voice and facsimile. This document specifies a restricted profile of the Internet multimedia messaging protocols for use between voice processing platforms. These platforms have historically been special-purpose computers and often do not have the same facilities normally associated with a traditional Internet Email-capable computer. As a result, VPIM also specifies additional functionality as it is needed. This profile is intended to specify the minimum common set of features to allow interworking between compliant systems. 2.1 Voice Messaging System Limitations The following are typical limitations of voice messaging platform which were considered in creating this baseline profile. 1) Text messages are not normally received and often cannot be displayed or viewed. They can often be processed only via text-to- speech or text-to-fax features not currently present in many of these machines. 2) Voice mail machines usually act as an integrated Message Transfer Agent, Message Store and User Agent. There is no relaying of messages and RFC 822 header fields may have limited use in the context of the limited messaging features currently deployed. 3) 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 gatewaying is not supported. In particular, storage of "CC" lists, "Received" lines, and "Message-ID" may be limited. 4) Internet-style distribution/exploder mailing lists are not typically supported. Voice mail machines often implement only local alias lists, with error-to-sender and reply-to-sender behavior. Reply-all capabilities using a CC list is not generally available. 5) Error reports must be machine-parsable so that helpful responses can be voiced to users whose only access mechanism is a telephone. 6) The voice mail systems generally limit address entry to 16 or fewer numeric characters, and normally do not support alphanumeric mailbox names. Alpha characters are not generally used for mailbox identification as they cannot be easily entered from a telephone terminal. Vaudreuil, Parsons Expires 3/9/97 [Page 5] Internet Draft VPIM v2 September 9, 1996 2.2 Design Goals 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 requirements for interoperability with current generation voice messaging systems. This goal is motivated by the desire to increase the accessibility to digital messaging by enabling the use of proven existing networking software for rapid development. This specification is intended for use on a TCP/IP network, however, it is possible to use the SMTP protocol suite over other transport protocols. The necessary protocol parameters for such use is outside the scope of this document. This profile is intended to be robust enough to be used in an environment such as the global Internet with installed base gateways which do not understand MIME, though typical use is expected to be within corporate intranets. Full functionality such, as reliable error messages and binary transport, will require careful selection of gateways (via MX records) to be used as VPIM forwarding agents. Nothing in this document precludes use of a general purpose MIME email packages to read and compose VPIM messages. While no special configuration is required to receive VPIM compliant messages, some may be required to originate compliant structures. It is expected that a VPIM messaging system will be managed by a system administrator who can perform TCP/IP network configuration. When using facsimile or multiple voice encodings, it is suggested that the system administrator maintain a list of the capabilities of the networked mail machines to reduce the sending of undeliverable messages due to lack of feature support. Configuration, implementation and management of this directory listing capabilities is a local matter. Vaudreuil, Parsons Expires 3/9/97 [Page 6] Internet Draft VPIM v2 September 9, 1996 3. Protocol Restrictions This protocol does not limit the number of recipients per message. Where possible, implementations should not restrict the number of recipients in a single message. It is recognized that no implementation supports unlimited recipients, and that the number of supported recipients may be quite low. However, ESMTP currently does not provide a mechanism for indicating the number of supported recipients. This protocol does not limit the maximum message length. Implementors should understand that some machines will be unable to accept excessively long messages. A mechanism is defined in the RFC 1425 SMTP service extensions to declare the maximum message size supported. The message size indicated in the ESMTP SIZE command is in bytes, not minutes or seconds. The number of bytes varies by voice encoding format and must include the MIME wrapper overhead. If the length must be known before sending, an approximate translation into minutes or seconds can be performed if the voice encoding is known. The following sections describe the restrictions and additions to Internet mail that are required to be compliant with this VPIM v2 profile. A table in Appendix A summarizes the details. Vaudreuil, Parsons Expires 3/9/97 [Page 7] Internet Draft VPIM v2 September 9, 1996 4. Voice Message Interchange Format The voice message interchange format is a profile of the Internet Mail Protocol Suite. As such, this document assumes an understanding of these specifications. Specifically, VPIM references components from the message format standard for Internet messages [RFC822], the Multipurpose Internet Message Extensions [MIME], the X.400 gateway specification [X.400], delivery status notification [DRPT][NOTIFY][STATUS], the message disposition notifications [MDN], and the electronic business card [DIRECTORY][VCARD]. 4.1 Message Addressing Formats RFC 822 addresses are based on the domain name system. This naming system has two components: the local part, used for username or mailbox identification; and the host part, used for global machine identification. 4.1.1 VPIM Addresses The local part of the address shall be a US-ASCII string uniquely identifying a mailbox on a destination system. For voice messaging, the local part is a printable string containing the mailbox ID of the originator or recipient. While alpha characters and long mailbox identifiers are permitted, most voice mail networks rely on numeric mailbox identifiers to retain compatibility with the limited 10 digit telephone keypad. The use of the domain naming system should be transparent to the user. It is the responsibility of the voice mail machine to lookup the fully-qualified domain name (FQDN) based on the address entered by the user (see Section 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, public telephone numbers will be noted according to the international numbering plan described in [E.164] and will be preceded by a `+'. 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@octel.com 2) mailbox number+extension - for use as a private numbering plan with extensions any number of digits, use of `+' as separator - e.g. 2722+111@octel.com 3) +international number - for international telephone numbers conforming to E.164 maximum of 15 digits - e.g. +16137637582@vm.nortel.ca Vaudreuil, Parsons Expires 3/9/97 [Page 8] Internet Draft VPIM v2 September 9, 1996 4) +international number+extension - for international telephone numbers conforming to E.164 maximum of 15 digits, with an extension (e.g. behind a PBX) that has a maximum of 15 digits. - e.g. +17035245550+230@ema.org 4.1.2 Special Addresses Special addresses are provided for compatibility with the conventions of Internet mail 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. 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. Loopback@domain A special mailbox name named "loopback" SHOULD be designated for loopback testing. If supported, all messages (including content) sent to this mailbox MUST be returned back to the address listed in the From: address as a new message. The originating address of the returned address MUST be "postmaster" to prevent mail loops. 4.1.3 Distribution Lists There are many ways to handle distribution list (DL) expansions and none are 'standard'. Simple alias is a behavior closest to what most voice mail systems do today and what is to be used with VPIM messages. That is: Reply to the originator - (Address in the RFC822 From field) Errors to the submitter - (Address in the MAIL FROM: field of the ESMTP exchange and the Return-Path: RFC 822 field) Some proprietary voice messaging protocols include only the recipient of the particular copy in the envelope and include no "headers" except date and per-message features. Most voice messaging systems do not provide for "Header Information" in their messaging queues and only include delivery information. As a result, recipient information MAY be in either the To or CC headers. Other recipients MAY optionally be included, however it is often not accurate enough for the reply-all capability. Vaudreuil, Parsons Expires 3/9/97 [Page 9] Internet Draft VPIM v2 September 9, 1996 4.2 Message Header Fields Internet messages contain a header information block. This header block contains information required to identify the sender, the list of recipients, the message send time, and other information intended for user presentation. Except for specialized gateway and mailing list cases, headers do not indicate delivery options for the transport of messages. Exploder lists are noted for modifying or adding to the headers of messages that pass through them. VPIM systems MUST be able to accept and ignore headers that are not defined here. The following header lines are permitted for use with VPIM voice messages: 4.2.1 From The originator's fully-qualified domain address (a mailbox address followed by the fully-qualified domain name). The user listed in this field should be presented in the voice message envelope as the originator of the message. Systems compliant with this profile SHOULD provide the text personal name of the sender in a quoted phrase if the name is available. To facilitate storage of the text name in a local dial-by-name cache directory, the first and last name names must be separable. Text names of persons in voice messages MUST be represented in the form "last, first, mi." and MUST be the same as found in the Vcard (section 4.3.4), if present. Text names of corporate or positional mailboxes MAY be provided as a simple string. From [822] Example: From: "User, Joe, S." <2145551212@mycompany.com> From: "Technical Support" <611@serviceprovider.com> If a From: address is present, it MAY be used to construct a reply message to the sender. Vaudreuil, Parsons Expires 3/9/97 [Page 10] Internet Draft VPIM v2 September 9, 1996 4.2.2 To The To header contains the recipient's fully-qualified domain address. There may be one or more To: fields in any message. Example: To: 2145551213@mycompany.com Systems compliant to this profile SHOULD provide a list of recipients only if all recipients can be provided. The To header MUST NOT be included in the message if the sending message transport agent (MTA) cannot resolve all the addresses in it, e.g. if an address is a DL alias for which the expansion is unknown (see section 4.1.3). If present, the addresses in the To header MAY be uses for a reply message to all primary recipients. 4.2.3 cc The cc header contains additional recipients' fully-qualified domain addresses. Many voice mail systems maintain only sufficient envelope information for message delivery and are not capable of storing or providing a complete list of recipients. Systems compliant to this profile SHOULD provide a list of recipients only if all disclosed recipients can be provided. The list of disclosed recipients does not include those sent via a blind copy. If not, systems SHOULD omit the CC headers to indicate that the full list of recipients is unknown. Example: cc: 2145551213@mycompany.com Systems compliant to this profile MAY discard the cc addresses of incoming messages as necessary. 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 header contains the date, time, and time zone in which the message was sent by the originator. The time zone SHOULD be represented in a four-digit time zone offset, such as -0600 for North American Eastern Standard Time. This may be supplemented by a time zone name in parentheses, e.g., "-0800 (PDT)". Compliant implementations SHOULD be able to convert RFC 822 date and time stamps into local time. Example: Date: Wed, 28 Jul 96 10:08:49 -0900 (PST) The sending system MUST report the time the message was sent. From [822] Vaudreuil, Parsons Expires 3/9/97 [Page 11] Internet Draft VPIM v2 September 9, 1996 4.2.5 Sender The Sender header contains the actual address of the originator if the message is sent by an agent on behalf of the author indicated in the From: field and MAY be present in a VPIM message. While it may not be possible to save this information in some voice mail machines, discarding this information or the ESMTP MAIL FROM address will make it difficult to send an error message to the proper destination. From [822] 4.2.6 Message-id The Message-id header contains a unique per-message identifier. A unique message-id MUST be generated for each message sent from a compliant implementation. The message-id is not required to be stored on the receiving system. This identifier MAY be used for tracking, auditing, and returning read-receipt reports. From [822] Example: Message-id: <12345678@mycompany.com> 4.2.7 Received The Received header contains trace information added to the beginning of a RFC 822 message by MTAs. This is the only header permitted to be added by an MTA. Information in this header is useful for debugging when using an US-ASCII message reader or a header parsing tool. A compliant system MUST add Received headers when acting as a gateway and MUST NOT remove any. These headers MAY be ignored or deleted when the message is received at the final destination. From [822] 4.2.8 MIME Version The MIME-Version header indicates that the message conforms to the MIME message format specification. Systems compliant with this specification MUST include a comment with the words "(Voice 2.0)". RFC 1911 defines an earlier version of this profile and uses the token (Voice 1.0). From [MIME][VPIM1] Example: MIME-Version: 1.0 (Voice 2.0) Vaudreuil, Parsons Expires 3/9/97 [Page 12] Internet Draft VPIM v2 September 9, 1996 4.2.9 Content-Type The content-type header declares the type of content enclosed in the message. One of the allowable contents is multipart/mixed, a mechanism for bundling several message components into a single message. The allowable contents are detaileded in the section 4.3 of this document. From [MIME] 4.2.10 Content-Transfer-Encoding Because Internet mail was initially specified to carry only 7-bit US- ASCII text, it may be necessary to encode voice and fax data into a representation suitable for that environment. The content-transfer- encoding header describes this transformation if it is needed. Compliant implementations MUST recognize and decode the standard encodings, "Binary", "7bit, "8bit", "Base64" and "Quoted-Printable". The allowable content-transfer-encodings are specified in section 4.3. From [MIME] 4.2.11 Sensitivity The sensitivity header, if present, indicates the requested privacy level. The case-insensitive values "Personal" and "Private" are specified. If no privacy is requested, this field is omitted. If a sensitivity header is present in the message, a compliant system MUST prohibit the recipient from forwarding this message to any other user. A compliant system, however, SHOULD allow the user to reply to a sensitive message, but SHOULD NOT include the original message content. The sensitivity of the reply message MAY be set by the user. If the receiving system does not support privacy and the sensitivity is one of "Personal" or "Private", the message MUST be returned to the sender with an appropriate error code indicating that privacy could not be assured and that the message was not delivered. A non-delivery notification to a private message need not be tagged private since it will be sent to the originator. From: [X.400] 4.2.12 Importance Indicates the requested priority to be given by the receiving system. The case-insensitive values "low", "normal" and "high" are specified. If no special importance is requested, this header may be omitted and the value assumed to be "normal". Compliant implementations MAY use this header to indicate the importance of a message and may order messages in a recipient's mailbox. From: [X400] Vaudreuil, Parsons Expires 3/9/97 [Page 13] Internet-Draft VPIM v2 September 9, 1996 4.2.13 Subject The subject field is often provided by email systems but is not widely supported on Voice Mail platforms. For compatibility with text based mailbox interfaces, a text subject field SHOULD be generated by a compliant implementation but MAY be discarded if present by a receiving system. From [822] It is recommended that voice messaging systems that do not support any text user interfaces (e.g. access only by a telephone) insert a generic subject header of "VPIM Message" for the benefit of text enabled recipients. Vaudreuil, Parsons Expires 3/9/97 [Page 14] Internet Draft VPIM v2 September 9, 1996 4.3 Message Content Types MIME, introduced in [MIME], is a general-purpose message body format that is extensible to carry a wide range of body parts. It provides for encoding binary data so that it can be transported over the 7-bit text-oriented SMTP protocol. This transport encoding is in addition to the audio encoding required to generate a binary object. MIME defines two transport encoding mechanisms to transform binary data into a 7 bit representation, one designed for text-like data ("Quoted-Printable"), and one for arbitrary binary data ("Base64"). While Base64 is dramatically more efficient for audio data, both will work. Where binary transport is available, no transport encoding is needed, and the data can be labeled as "Binary". An implementation in compliance with this profile SHOULD send audio and/or facsimile data in binary form when binary message transport is available. When binary transport is not available, implementations MUST encode the audio and/or facsimile data as Base64. The detection and decoding of "Quoted-Printable", "7bit", and "8bit" MUST be supported in order to meet MIME requirements and to preserve interoperability with the fullest range of possible devices. However, if a content is received that cannot be rendered to the user, an appropriate non-delivery notifcation MUST be sent. The content types described in this section are identified for use with this profile. Each of these contents can be sent individually in a VPIM message or wrapped in a multipart/mixed to form a more complex structure (several examples are given in Appendix B). When mulitple contents are present, they SHOULD be presented to the user in the order that they appear in the message. 4.3.1 Text/Plain MIME requires support of the basic Text/Plain content type. This content type has limited applicability within the voice messaging environment. Compliant implementations SHOULD NOT send the Text/Plain content-type and SHOULD only send this content if the recipient system is known to support it. Compliant implementations MUST accept Text/Plain messages, however, specific handling is left as an implementation decision. From [MIME] There are several mechanisms that can be used to support text on voice messaging systems including text-to-speech and text-to-fax conversions. If no rendering of the text is possible (i.e. it is not possible to determine if the text is a critical part of the message), the entire message MUST be non-delivered and returned to the sender with a media-unsupported error code. Vaudreuil, Parsons Expires 3/9/97 [Page 15] Internet Draft VPIM v2 September 9, 1996 4.3.2 Multipart/Mixed MIME provides the facilities for enclosing several body parts in a single message. Multipart/Mixed SHOULD be used for sending multi- segment voice messages, that is, to preserve across the network the distinction between an annotation and a forwarded message, or between a spoken subject and the voice message. Compliant systems MUST accept multipart/mixed body parts. Systems MAY collapse such a multi-segment voice or fax message into a single segment if multi-segment messages are not supported on the receiving machine. From [MIME] While any valid MIME body header MAY be used, the following header has specific semantics when included with this body part: 4.3.2.1 Content-Description: This field SHOULD be present to allow the text identification of this body part as being a VPIM message. This is particulary useful for identification when using a simple MIME mail package. If there are multiple multipart/mixed bodies present, then this header MUST be present to allow differentiation. It is recommended that the value `VPIM Message' be used to identify content compliant with this document. 4.3.3 Message/RFC822 MIME requires support of the Message/RFC822 message encapsulation body part. This body part is used within a multipart/mixed message to forward complete messages (see section 4.4) or to reply with original content. From [MIME] 4.3.4 Application/Directory The spoken name and the spelled name of the message sender SHOULD be sent with each message in an Application/Directory content type [DIRECTORY]. If included in a message, the Versit VCARD profile MUST be used [VCARD] and MUST specify at least the following attributes: TEL - telephone number (various types, typically VOICE) EMAIL - email address (various types, typically INTERNET) The following attributes SHOULD be specified: N - Family Name, Given Name, Additional Names, Honorific Prefixes, and Suffixes (all present components in the From text name MUST match) ROLE - alternative to `N' attribute when sender is a corporate or positional mailbox SOUND - sound data (various types, typically 32KADPCM) REV - Revision of Vcard in ISO 8601 date format The content MAY use the other types (e.g. capabilities) as defined in [VCARD]. Vaudreuil, Parsons Expires 3/9/97 [Page 16] Internet Draft VPIM v2 September 9, 1996 The spoken name SHOULD be denoted by a content ID pointing to an audio/* content elsewhere in the VPIM message. Alternatively, the spoken name MAY be included inline in the "SOUND" type using a Base64 encoding of typically 32KADPCM. However, it MUST NOT be denoted using an URL. For the Vcard to be identified as the sender's, it MUST include the EMAIL token 'VPIM' and match the address in the From: header. The Name, if present, SHOULD NOT be used for comparison since the Vcard has more components. There MUST only be one Vcard per VPIM message. If more than one is present it is an error condition, all Vcards not associated with with the sender may be discarded. Example: BEGIN: vCard N: Parsons;Glenn ORG: Nortel Technology TEL;TYPE=VOICE,MSG,WORK: +1-613-763-7582 EMAIL;TYPE=INTERNET: glenn.parsons@nortel.ca EMAIL;TYPE=INTERNET,VPIM: 6137637582@vm.nortel.ca SOUND;TYPE=32KADPCM;ENCODE=BASE64;VALUE=INLINE: iIiIiIjMzN3czdze3s7d7fwfHhcvESJVe/4yEhLz8/FOQjVFRERCESL/zqrq (This is the Spoken Name audio data) 3Or/zrPCzxv43u3L7buR3b0 AAEAAAAIAAAAFQEDAAEAAAABAAAAFgEEAAEAAACqCAAAFwEEAAEAAAD1uQEA GgEFAAEAAAAIugEAGwEFAAEAAAAQugEAJAEEAAEAAAAEAAAAAAAAAA== REV: 19960831T103310Z END: vCard Vaudreuil, Parsons Expires 3/9/97 [Page 17] Internet Draft VPIM v2 September 9, 1996 4.3.5 Audio/32KADPCM CCITT Recommendation G.726 [G726] describes the algorithm recommended for conversion of a 64 kbit/s A-law or u-law PCM channel to and from a 32 kbit/s channel (this is the same algorithm as the deprecated G.721). The conversion is applied to the PCM stream using an Adaptive Differential Pulse Code Modulation (ADPCM) transcoding technique. An implementation compliant to this profile MUST use Audio/32KADPCM by default for voice. Typically this body contains several minutes of message content, however if used for spoken name or subject the content should be considerably shorter (i.e. about 10 and 20 seconds respectively). While any valid MIME body header MAY be used, several headers have the following semantics when included with this body part: 4.3.5.1 Content-Description: This field SHOULD be present to allow the parsable text identification of these body parts. If more than one Audio/32KADPCM body occurs within a single multipart/mixed, then this header MUST be present to allow differentiation. It is recommended that the following text values be used as appropriate: Voice Message - the primary voice message, 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 4.3.5.2 Content-Duration: This field MAY be present to allow the specification of the length of the bodypart in seconds. The use of this field on reception is a local implementation issue. The formal BNF for this header is: duration := "Content-Duration" ":" 1*6DIGIT "seconds" Example: Content-Duration: 33 seconds 4.3.5.3 Content-Language: This field MAY be present to allow the specification of the spoken language of the bodypart. The encoding is defined in [LANG] (e.g. EN-UK for UK English). The use of this field on reception is a local implementation issue. Vaudreuil, Parsons Expires 3/9/97 [Page 18] Internet Draft VPIM v2 September 9, 1996 4.3.6 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 voice 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 compliant implementation MAY use any other encoding with explicit per-destination configuration. 4.3.7 Image/TIFF All implementations MUST generate and read TIFF-F [TIFF][S100] compatible facsimile contents. The tags that MUST be supported by systems complying to this recommendation are described in the Enterprise Computer Telephony Forum's S.100 API specification [S100]. The TIFF-F content, originally from [TPC.INT] has been refined to reflect this common practice, and is summarized in Appendix E for completeness. 4.3.8 Multipart/report An implementation MAY send this fax content in VPIM messages and MUST be able to recognize it in received messages. If a fax message is received that cannot be rendered to the user, then the system MUST non-deliver the entire message with a media not supported error. Multipart/Report The Multipart/Report is used for enclosing a Message/Notification and Message/Disposition-notification body parts and any returned message content. Compliant implementations MUST use the Multipart/Report construct when returning messages, sending warnings, or issuing read receipts. Compliant implementations MUST recognize and decode the Multipart/Report content type. From [REPORT] 4.3.9 Message/Notification This MIME body part is used for sending machine-parsable delivery status notifications. Compliant implementations must use the Message/Notification construct when returning messages or sending warnings. Compliant implementations must recognize and decode the Message/Notification content type and present the reason for failure to the user. From [NOTIFY] 4.3.10 Message/Disposition-notification This MIME body part is used for sending machine-parsable read-receipt and extended-absence status notifications. Compliant implementations must use the Message/Disposition-notification construct when sending post-delivery message status notifications. Compliant implementations must recognize and decode the Message/Disposition-notification content type and present the reason for failure to the user. From [MDN] Vaudreuil, Parsons Expires 3/9/97 [Page 19] Internet Draft VPIM v2 September 9, 1996 4.4 Forwarded Messages VPIM version 2 explicitly supports the forwarding of voice and fax content with voice or fax annotation. Forwarded VPIM messages SHOULD be sent as a multipart/mixed with the entire original message enclosed in a message/rfc822 content type and the annotation as a separate Audio/* body part. In the event that the RFC822 headers are not available for the forwarded content, simulated headers with information as available SHOULD be constructed to indicate the original sending timestamp, and the original sender as indicated in the "From" line. The message/rfc822 content MUST include at least the MIME-Version: 1.0 (Voice 2.0), the MIME content type and MIME content-encoding header as necessary. In the event that forwarding information is lost through concatenation of the original message and the forwarding annotation, such as must be done in an AMIS to VPIM gateway, the entire content MAY be sent as a single Audio/* segment without including any forwarding semantics. Vaudreuil, Parsons Expires 3/9/97 [Page 20] Internet Draft VPIM v2 September 9, 1996 5. Message Transport Protocol Messages are transported between voice mail machines using the Internet Extended Simple Mail Transfer Protocol (ESMTP). All information required for proper delivery of the message is included in the ESMTP dialog. This information, including the sender and recipient addresses, is commonly referred to as the message "envelope". This information is equivalent to the message control block in many analog voice networking protocols. ESMTP is a general-purpose messaging protocol, designed both to send mail and to allow terminal console messaging. Simple Mail Transport Protocol (SMTP) was originally created for the exchange of US-ASCII 7- bit text messages. Binary and 8-bit text messages have traditionally been transported by encoding the messages into a 7-bit text-like form. [ESMTP] formalized an extension mechanism for SMTP, and subsequent RFCs have defined 8-bit text networking, command streaming, binary networking, and extensions to permit the declaration of message size for the efficient transmission of large messages such as multi-minute voice mail. The following sections list ESMTP commands, keywords, and parameters that are required and those that are optional. 5.1 ESMTP Commands 5.1.1 HELO Base SMTP greeting and identification of sender. This command is not to be sent by compliant systems unless the more-capable EHLO command is not accepted. It is included for compatibility with general SMTP implementations. Compliant implementations MUST implement the HELO command for backward compatibility but SHOULD NOT send it unless EHLO is not supported. From [SMTP] 5.1.2 MAIL FROM (REQUIRED) Originating mailbox. This address contains the mailbox to which errors should be sent. This address may not be the same as the message sender listed in the message header fields if the message was received from a gateway or sent to an Internet-style mailing list. Compliant implementations MUST implement the extended MAIL FROM command. From [SMTP, ESMTP] 5.1.3 RCPT TO Recipient's mailbox. This field contains only the addresses to which the message should be delivered for this transaction. In the event that multiple transport connections to multiple destination machines are required for the same message, this list may not match the list of recipients in the message header. Compliant implementations MUST implement the extended RCPT TO command. From [SMTP, ESMTP] Vaudreuil, Parsons Expires 3/9/97 [Page 21] Internet Draft VPIM v2 September 9, 1996 5.1.4 DATA Initiates the transfer of message data. Support for this command is required in the event the binary mode command BDAT is not supported by the remote system. Compliant implementations MUST implement the SMTP DATA command for backwards compatibility. From [SMTP] 5.1.5 TURN Requests a change-of-roles, that is, the client that opened the connection offers to assume the role of server for any mail the remote machine may wish to send. Because SMTP is not an authenticated protocol, the TURN command presents an opportunity to improperly fetch mail queued for another destination. Compliant implementations SHOULD NOT implement the TURN command. From [SMTP] 5.1.6 QUIT Requests that the connection be closed. If accepted, the remote machine will reset and close the connection. Compliant implementations MUST implement the QUIT command. From [SMTP] 5.1.7 RSET Resets the connection to its initial state. Compliant implementations MUST implement the RSET command. From [SMTP] 5.1.8 VRFY Requests verification that this node can reach the listed recipient. While this functionality is also included in the RCPT TO command, VRFY allows the query without beginning a mail transfer transaction. This command is useful for debugging and tracing problems. Compliant implementations MAY implement the VRFY command. From [SMTP] (Note that the implementation of VRFY may simplify the guessing of a recipient's mailbox or automated sweeps for valid mailbox addresses, resulting in a possible reduction in privacy. Various implementation techniques may be used to reduce the threat, such as limiting the number of queries per session.) From [SMTP] 5.1.9 EHLO The enhanced mail greeting that enables a server to announce support for extended messaging options. The extended messaging modes are discussed in subsequent sections of this document. Compliant implementations MUST implement the ESMTP command and return the capabilities indicated later in this memo. From [ESMTP] Vaudreuil, Parsons Expires 3/9/97 [Page 22] Internet Draft VPIM v2 September 9, 1996 5.1.10 BDAT The BDAT command provides a higher efficiency alternative to the earlier DATA command, especially for voice. The BDAT command provides for native binary transport of messages. Compliant implementations SHOULD support binary transport using the BDAT command.[BINARY] 5.2 ESMTP Keywords The following ESMTP keywords indicate extended features useful for voice messaging. 5.2.1 PIPELINING The "PIPELINING" keyword indicates ability of the receiving server to accept pipelined commands. Pipelining commands dramatically improves performance by reducing the number of round-trip packet exchanges and makes it possible to validate all recipient addresses in one operation. Compliant implementations SHOULD support the command pipelining indicated by this parameter. From [PIPE] 5.2.2 SIZE The "SIZE" keyword provides a mechanism by which the SMTP server can indicate the maximum size message supported. Compliant implementations MUST provide the size capability and SHOULD honor any size limitations when sending. From [SIZE] 5.2.3 CHUNKING The "CHUNKING" keyword indicates that the receiver will support the high-performance binary transport mode. Note that CHUNKING can be used with any message format and does not imply support for binary encoded messages. Compliant implementations SHOULD support binary transport indicated by this capability. From [BINARY] 5.2.4 BINARYMIME The "BINARYMIME" keyword indicates that the SMTP server can accept binary encoded MIME messages. Compliant implementations SHOULD support binary transport indicated by this capability. From [BINARY] 5.2.5 NOTIFY The "NOTIFY" keyword indicates that the SMTP server will accept explicit delivery status notification requests. Compliant implementations MUST support the delivery notification extensions in [DSN]. Vaudreuil, Parsons Expires 3/9/97 [Page 23] Internet Draft VPIM v2 September 9, 1996 5.2.6 ENHANCEDSTATUSCODES The "EHNAHCEDSTATUSCODES" keyword indicates that an SMTP server augments its responses with the enhanced mail system status codes [CODES]. These codes can then be used to provide more informative explanations of error conditions, especially in the context of the delivery status notifications format defined in [NOTARY]. Compliant implementations SHOULD support this capability. From [STATUS] 5.3 ESMTP Parameters - MAIL FROM 5.3.1 BINARYMIME The current message is a binary encoded MIME messages. Compliant implementations SHOULD support binary transport indicated by this parameter. From [BINARY] 5.4 ESMTP Parameters - RCPT TO 5.4.1 NOTIFY The NOTIFY parameter indicates the conditions under which a delivery report should be sent. Compliant implementations MUST honor this request. From [DSN] 5.4.2 RET The RET parameter indicates whether the content of the message should be returned. Compliant systems SHOULD honor a request for returned content. From [DSN] 5.5 ESMTP - SMTP Downgrading To ensure a consistant level of service across an intranet or the global Internet, it is essential that VPIM compliant ESMTP be supported at all hops between a VPIM originating system and the recipient system. Unfortunately, in the situation where a `downgrade' is unavoidable the expected result is not defined. However, it is recommended that the downgrading system should continue to attempt to deliver the message via SMTP, but MUST send a delivery notification to the originator indicating that the message left an ESMTP host and was sent (unreliably) via SMTP. Vaudreuil, Parsons Expires 3/9/97 [Page 24] Internet Draft VPIM v2 September 9, 1996 6. Directory Address Resolution It is the responsibility of a VPIM system to lookup the fully- qualified domain name (FQDN) based on the address entered by the user (if the entered address is not already a FQDN). This would typically be an issue on systems that offered only a telephone user interface. The mapping of the dialed target number to a routable address allowing delivery to the destination system can be accomplished through implementation-specific means. An implementations may wish to populate local directories with address information extracted from received messages. It is mandated that only address information from Vcard attachments to VPIM messages be used to populate such a directory when the Vcard is available. Stripping addresses from the headers of VPIM messages SHOULD NOT be used to populate directories as it only provides partial data. Alternatively, bilateral agreements could be made to allow the bulk transfer of Vcards between systems. 7. IMAP The use of client/server desktop mailbox protocols like IMAP or POP to retrieve VPIM messages from a IMAP or POP message store is possible without any special modifications to this VPIM specification. Email clients (and web browsers) typically have a table for mapping from MIME type to displaying application. The audio/*, image/tiff and application/directory contents can be configured so that they invoke the correct player/recorder for rendering. In addition with IMAP clients, the first multipart/mixed content (if present) will not appear since it is generic. The user instead will be presented with a message that has (for example) audio and image contents. 8. Management Protocols The Internet protocols provide a mechanism for the management of messaging systems, from the management of the physical network through the management of the message queues. SNMP should be supported on a compliant message machine. 8.1 Network Management The digital interface to the VM and the TCP/IP protocols SHOULD be managed. MIB II SHOULD be implemented to provide basic statistics and reporting of TCP and IP protocol performance. [MIB II] Authors Note: Last time I checked, MADMAN was being rewritten for submission again as proposed standard. Without a profile, I don't think we should require this. Fine. Do you still want to require MIB II? Vaudreuil, Parsons Expires 3/9/97 [Page 25] Internet Draft VPIM v2 September 9, 1996 9. Conformance Requirements In order to claim conformance to this document and be called `VPIM compliant', a voice messaging system must implement all mandatory features of this profile in each of three areas: Content, Transport, and Notifications. In addition, systems which conform to this profile must 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 currently a local matter. It is also possible, though not encouraged, to claim conformance to only specific areas (e.g. VPIM content compliant) of this profile. The delineation of these areas is as follows: Content - Section 4.24, except REPORT, NOTIFY & MDN, and Section 6 Transport - Section 5 except NOTIFY & RET, and Section 8 Notifications - REPORT, NOTIFY & MDN from Section 4, NOTIFY & RET from Section 5 and all notification requirements. A summary of compliance requirements is contained in Appendix A. Vaudreuil, Parsons Expires 3/9/97 [Page 26] Internet Draft VPIM v2 September 9, 1996 10. References [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 [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. [X.400] Hardcastle-Kille, S., "Mapping between X.400(1988) / ISO 10021 and RFC 822", RFC 1327, May 1992. [PIPE] Freed, N., Cargille, A., "SMTP Service Extension for Command Pipelining" RFC 1854, October 1995. [ESMTP] Klensin, J., Freed, N., Rose, M., Stefferud, E., and D. Crocker, "SMTP Service Extensions" RFC 1869, United Nations University, Innosoft International, Inc., Dover Beach Consulting, Inc., Network Management Associates, Inc., The Branch Office, November 1995. [SIZE] Klensin, J, Freed, N., Moore, K, "SMTP Service Extensions for Message Size Declaration" RFC 1870, United Nations University, Innosoft International, Inc., November 1995. [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", RFC 1830, October 1995. [NOTIFY] Moore, K., Vaudreuil, G., "An Extensible Message Format for Delivery Status Notifications", RFC 1894, 01/15/1996. [REPORT] Vaudreuil, G., "The Multipart/Report Content Type for the Reporting of Mail System Administrative Messages", RFC 1892, 01/15/1996. Vaudreuil, Parsons Expires 3/9/97 [Page 27] Internet Draft VPIM v2 September 9, 1996 [DSN] Moore, K. "SMTP Service Extensions for Delivery Status Notifications", RFC 1891, 01/15/1996 [CODES] Vaudreuil, G. "Enhanced Mail System Status Codes", RFC 1893, 01/15/1996. [STATUS] Freed, N. "SMTP Service Extension for Returning Enhanced Error Codes", Internet-Draft , July 1996. [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). [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. [RELATED] Levinson, E., "The MIME Multipart/Related Content-Type", RFC 1872, Dec 1995 [MDN] Fajman, Roger, "An Extensible Message Format for Message Disposition Notifications" [DIRECTORY] Howes, Tim, Smith, Mark, A MIME Content-Type for Directory Information" [VCARD] Dawson, Frank, Howes, Tim, "An Application/Directory MIME Content-Type Electronic Business Card Profile" [LANG] Alvestrand,H., "Tags for the Identification of Languages", RFC 1766, Mar 1995 [TPC.INT] C. Malamud, M. Rose, "Principles of Operation for the TPC.INT Subdomain: Remote Printing -- Technical Procedures", RFC 1528, 10/06/1993 [VPIM1] Vaudreuil, Greg, "Voice Profile for Internet Mail", RFC 1911, Feb 1996. [TIFF] Adobe Developers Association, TIFF (TM) Revision 6.0 - Final, June 3, 1992. [S100] Enterprise Computer Telephony Forum, S.100 Revision 1.0 - Media Services "C" Language - Application Programming Interfaces, February 1996. Vaudreuil, Parsons Expires 3/9/97 [Page 28] Internet Draft VPIM v2 September 9, 1996 11. 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. Further, the profile specified in this document does not in any way preclude the use of any Internet mail security protocol to encrypt, authenticate, or non-repudiate the messages. 12. Acknowledgments The authors would like to offer a special thanks to the Electronic Messaging Association, especially the members of the Voice Messaging Committee, for their support of the VPIM specification and the efforts they have made to ensure its success. 13. Authors' Addresses Glenn W. Parsons Nortel Technology P.O. Box 3511, Station C Ottawa, ON K1Y 4H7 Canada Phone: +1-613-763-7582 Fax: +1-613-763-8385 Glenn.Parsons@Nortel.ca Gregory M. Vaudreuil Octel Network Services 17080 Dallas Parkway Dallas, TX 75248-1905 United States Phone/Fax: +1-214-733-2722 Greg.Vaudreuil@Octel.Com Vaudreuil, Parsons Expires 3/9/97 [Page 29] Internet Draft VPIM v2 September 9, 1996 14. Appendix A - VPIM Requirements Summary The following table summarizes the profile of VPIM version 2 detailed in this document. For complete explanations of each feature it is recommended to read the accompanying text. The conformance table is separated into various columns: Feature - name of protocol feature Section - reference section in main text of this document Area - conformance area to which each feature applies: C - content T - transport N - notifications Status - whether the feature is mandatory, optional, or prohibited. There are three different degrees of optional used in this table: Must - mandatory Should - encouraged optional May - optional Should not - discouraged optional Must not - prohibited Footnote - special comment about conformance for a particular feature Vaudreuil, Parsons Expires 3/9/97 [Page 30] Internet Draft VPIM v2 September 9, 1996 VPIM version 2 Conformance | | | | |S| | | | | | | |H| |F | | | | | |O|M|o | | | |S| |U|U|o | | | |H| |L|S|t | |A|M|O| |D|T|n | |R|U|U|M| | |o | |E|S|L|A|N|N|t | |A|T|D|Y|O|O|t FEATURE |SECTION | | | | |T|T|e -------------------------------------------|----------|-|-|-|-|-|-|- | | | | | | | | Message Addressing Formats: | | | | | | | | Use DNS host names |4.1 |C|x| | | | | Use only numbers in mailbox IDs |4.1.1 |C| |x| | | | Use alpha-numeric mailbox IDs |4.1.1 |C| | |x| | | Support of postmaster@domain |4.1.2 |C|x| | | | | Support of loopback@domain |4.1.2 |C| |x| | | | Support of distribution lists |4.1.3 |C| |x| | | | | | | | | | | | Message Header Fields: | | | | | | | | Encoding outbound messages | | | | | | | | From |4.2.1 |C|x| | | | | Addition of text name |4.2.1 |C| |x| | | | To |4.2.2 |C|x| | | | |1 cc |4.2.3 |C| |x| | | |1 Date |4.2.4 |C|x| | | | | Sender |4.2.5 |C| | | |x| | Message-id |4.2.6 |C|x| | | | | Received |4.2.7 |C|x| | | | | MIME Version: 1.0 (Voice 2.0) |4.2.8 |C|x| | | | | Content-Type |4.2.9 |C|x| | | | | Content-Transfer-Encoding |4.2.10 |C|x| | | | | Sensitivity |4.2.11 |C| | |x| | | Importance |4.2.12 |C| | |x| | | Subject |4.2.13 |C| |x| | | | | | | | | | | | Detection & Decoding inbound messages | | | | | | | | From |4.2.1 |C|x| | | | | Utilize 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| | Message ID |4.2.6 |C|x| | | | | Received |4.2.7 |C| | |x| | | MIME Version: 1.0 (Voice 2.0) |4.2.8 |C|x| | | | | Content Type |4.2.9 |C|x| | | | | Content-Transfer-Encoding |4.2.10 |C|x| | | | | Sensitivity |4.2.11 |C|x| | | | |2 Importance |4.2.12 |C| | |x| | | Subject |4.2.13 |C| | |x| | | Vaudreuil, Parsons Expires 3/9/97 [Page 31] Internet Draft VPIM v2 September 9, 1996 Message Content Encoding: | | | | | | | | Encoding outbound audio/fax contents | | | | | | | | 7BITMIME |4.3 |C| | | | |x| 8BITMIME |4.3 |C| | | | |x| Quoted Printable |4.3 |C| | | | |x| Base64 |4.3 |C|x| | | | |3 Binary |4.3 |C| |x| | | |4 Detection & decoding inbound messages | | | | | | | | 7BITMIME |4.3 |C|x| | | | | 8BITMIME |4.3 |C|x| | | | | Quoted Printable |4.3 |C|x| | | | | Base64 |4.3 |C|x| | | | | Binary |4.3 |C|x| | | | |4 | | | | | | | | Message Content Types: | | | | | | | | Inclusion in outbound messages | | | | | | | | Text/plain |4.3.1 |C| | | |x| | Multipart/Mixed |4.3.2 |C| |x| | | | Content-Description |4.3.2.1 |C| |x| | | |5 Message/RFC822 |4.3.3 |C| | |x| | | Application/Directory |4.3.4 |C| |x| | | | Audio/32KADPCM |4.3.5 |C|x| | | | | Content-Description |4.3.5.1 |C| |x| | | |5 Content-Duration |4.3.5.2 |C| | |x| | | Content-Langauge |4.3.5.3 |C| | |x| | | Audio/* (other encodings) |4.3.6 |C| | |x| | | Image/TIFF |4.3.7 |C|x| | | | | Multipart/Report |4.3.8 |N|x| | | | | Message/Notification |4.3.9 |N|x| | | | | Message/Disposition-notification |4.3.10 |N|x| | | | | Detection & decoding in inbound messages | | | | | | | | Text/plain |4.3.1 |C|x| | | | |6 Multipart/Mixed |4.3.2 |C|x| | | | | Content-Description |4.3.2.1 |C| | |x| | | Message/RFC822 |4.3.3 |C|x| | | | | Application/Directory |4.3.4 |C| |x| | | | Audio/32KADPCM |4.3.5 |C|x| | | | | Content-Description |4.3.5.1 |C| |x| | | | Content-Duration |4.3.5.2 |C| | |x| | | Content-Langauge |4.3.5.3 |C| | |x| | | Audio/* (other encodings) |4.3.6 |C| | |x| | | Image/TIFF |4.3.7 |C|x| | | | |6 Multipart/Report |4.3.8 |N|x| | | | | Message/Notification |4.3.9 |N|x| | | | | Message/Disposition-notification |4.3.10 |N|x| | | | | Forwarded Messages | | | | | | | | use Message/RFC822 construct |4.4 |C| |x| | | | simulate headers if none available |4.4 |C| |x| | | | Vaudreuil, Parsons Expires 3/9/97 [Page 32] Internet Draft VPIM v2 September 9, 1996 | | | | | | | | Message Transport Protocol: | | | | | | | | ESMTP Commands | | | | | | | | HELO |5.1.1 |T|x| | | | | MAIL FROM |5.1.2 |T|x| | | | | RCPT TO |5.1.3 |T|x| | | | | DATA |5.1.4 |T|x| | | | | TURN |5.1.5 |T| | | | |x| QUIT |5.1.6 |T|x| | | | | RSET |5.1.7 |T|x| | | | | VRFY |5.1.8 |T| | |x| | | EHLO |5.1.9 |T|x| | | | | BDAT |5.1.10 |T| |x| | | |4 ESMTP Keywords & Parameters | | | | | | | | PIPELINING |5.2.1 |T| |x| | | | SIZE |5.2.2 |T|x| | | | | CHUNKING |5.2.3 |T| |x| | | | BINARYMIME |5.2.4,5.3.1|T| |x| | | | NOTIFY |5.2.5,5.4.1|N|x| | | | | ENHANCEDSTATUSCODES |5.2.6 |T| |x| | | | RET |5.4.2 |N| |x| | | | ESMTP-SMTP Downgrading | | | | | | | | send delivery report upon downgrade |5.5 |N|x| | | | | | | | | | | | | Directory Address Resolution | | | | | | | | provide facility to resolve addresses |6 |C| |x| | | | use Vcards to populate local directory |6 |C|x| | | | | use headers to populate local directory |6 |C| | | |x| | | | | | | | | | Management Protocols: | | | | | | | | Network management |8.1 |T| |x| | | | -------------------------------------------|----------|-|-|-|-|-|-|- 1. MUST NOT include if all recipients are not known or resolvable. 2. If a sensitive message is received by a system that does not support sensitivity, then it MUST be returned to the originator with an appropriate error notification. Also, a received sensitive message MUST NOT be forwarded to anyone. 3. When binary transport is not available 4. When binary transport is available 5. If multiple contents are present in a message, this header MUST be present 6. If the content cannot be presented in some form, the entire message MUST be non-delivered. Vaudreuil, Parsons Expires 3/9/97 [Page 33] Internet Draft VPIM v2 September 9, 1996 15. Appendix B - Example Voice Messages 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: 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 2.0) Content-type: Multipart/Mixed; Boundary="MessageBoundary" Content-Transfer-Encoding: 7bit Message-ID: VM2.mycompany.com-123456789 Sensitivity: Private Importance: High --MessageBoundary Content-type: Audio/32KADPCM Content-Transfer-Encoding: Base64 Content-Description: Originator Spoken Name Content-Language: EN-US Content-ID: part1@VM2-4321 glslfdslsertiflkTfpgkTportrpkTpfgTpoiTpdadasssdasddasdasd (This is a sample of the base-64 Spoken Name data) fgdhgd dlkgpokpeowrit09== --MessageBoundary Content-type: Audio/32KADPCM Content-Transfer-Encoding: Base64 Content-Description: VPIM Message Content-Duration: 25 seconds iIiIiIjMzN3czdze3s7d7fwfHhcvESJVe/4yEhLz8/FOQjVFRERCESL/zqrq (This is a sample of the base64 message data) zb8tFdLTQt1PXj u7wjOyRhws+krdns7Rju0t4tLF7cE0K0MxOTOnRW/Pn30c8uHi9== --MessageBoundary Content-type: Application/Directory Content-Transfer-Encoding: 7bit BEGIN: Vcard N: Vaudreuil;Greg;;Mr.; EMAIL;TYPE=INTERNET: 2175552345@VM2.mycompany.com TEL: +1-217-555-2345 SOUND;TYPE=32KADPCM;ENCODE=BASE64;VALUE=CID: REV: 19951031T222710Z END: Vcard --MessageBoundary-- Vaudreuil, Parsons Expires 3/9/97 [Page 34] Internet Draft VPIM v2 September 9, 1996 The following message is a forwarded single segment voice. To: 2145551212@vm1.mycompany.com From: "Vaudreuil, Greg" <2175552345@VM2.mycompany.com> Date: Mon, 26 Aug 93 10:20:20 CST MIME-Version: 1.0 (Voice 2.0) Content-type: Multipart/Mixed; Boundary="MessageBoundary" Content-Transfer-Encoding: 7bit Message-ID: VM2.mycompany.com-123456789 --MessageBoundary Content-type: Audio/32KADPCM Content-Description: VPIM Message Content-Transfer-Encoding: Base64 glslfdslsertiflkTfpgkTportrpkTpfgTpoiTpdadasssdasddasdasd (This is the voiced introductory remarks encoded in base64) jrgoij3o45itj09fiuvdkjgWlakgQ93ijkpokfpgokQ90gQ5tkjpokfgW dlkgpokpeowrit09== --MessageBoundary Content-type: Message/RFC822 Content-Transfer-Encoding: 7bit To: 2175552345@VM2.mycompany.com From: "Parsons, Glenn, W." <2145551234@VM1.mycompany.com> From: Date: Mon, 26 Aug 93 8:23:10 EST MIME-Version: 1.0 (Voice 2.0) Content-type: Audio/32KADPCM Content-Description: VPIM Message Content-Transfer-Encoding: Base64 glslfdslsertiflkTfpgkTportrpkTpfgTpoiTpdadasssdasddasdasd (This is the original message audio data) fgwersdfmniwrjj jrgoij3o45itj09fiuvdkjgWlakgQ93ijkpokfpgokQ90gQ5tkjpokfgW dlkgpokpeowrit09== --MessageBoundary Content-type: Application/Directory Content-Transfer-Encoding: 7bit BEGIN: Vcard N: Vaudreuil;Greg;;Mr.; SOUND;TYPE=32kbADPCM;ENCODE=BASE64;VALUE=INLINE: glslfdslsertiflkTfpgkTportrpkTpfgTpoiTpdadasssdasddasdasd (This is the Spoken Name audio data) fgwersdfmniwrjjedfsa jrgoij3o45itj09fiuvdkjgWlakgQ93ijkpokfpgokQ90gQ5tkjpokfgW dlkgpokpeowrit09== REV: 19951031T222710Z END: Vcard --MessageBoundary- Vaudreuil, Parsons Expires 3/9/97 [Page 35] Internet Draft VPIM v2 September 9, 1996 The following example is for a message returned to the sender by a VPIM gateway at VM1.company.com for a mailbox which does not exist. Date: Thu, 7 Jul 1994 17:16:05 -0400 From: Mail Delivery Subsystem Message-Id: <199407072116.RAA14128@vm1.company.com> Subject: Returned voice message To: 2175552345@VM2.mycompany.com MIME-Version: 1.0 (Voice 2.0) Content-Type: multipart/report; report-type=delivery-status; boundary="RAA14128.773615765/VM1.COMPANY.COM" --RAA14128.773615765/VM1.COMPANY.COM Content-type: Audio/32KADPCM Content-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 Diagnostic-Code: smtp; 550 Mailbox not found Last-Attempt-Date: Thu, 7 Jul 1994 17:15:49 -0400 --RAA14128.773615765/VM1.COMPANY.COM content-type: message/rfc822 [original VPIM message goes here] --RAA14128.773615765/VM1.COMPANY.COM-- Vaudreuil, Parsons Expires 3/9/97 [Page 36] Internet Draft VPIM v2 September 9, 1996 16. Appendix C - Example Error Voice Processing Error Codes Error condition RFC 1893 Error codes and recommended comments Analog delivery failed because remote system is busy 4.4.0 Persistent connection - other Analog delivery failed because remote system is ring-no-answer 4.4.1 Persistent protocol - no answer from host Remote system did not answer "D" in response to "C" at connect time 5.5.5 Permanent protocol - wrong version Mailbox does not exist 5.1.1 Permanent mailbox - does not exist Mailbox full or over quota 4.2.2 Persistent mailbox - is full Disk full 4.3.1 Persistent system - is full Command out of sequence 5.5.1 Permanent protocol - error Frame Error 5.5.2 Permanent protocol - syntax error Mailbox does not support FAX 5.6.1 Permanent media - not capable Mailbox does not support TEXT 5.6.1 Permanent media - not capable Sender is not authorized 5.7.1 Permanent security - sender not authorized Message marked private, but system is not private capable 5.3.3 Permanent system - not private capable Vaudreuil, Parsons Expires 3/9/97 [Page 37] Internet Draft VPIM v2 September 9, 1996 17. Appendix D - 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. ITU-T Recommendation G.726 [G726] (was G.721) describes the algorithm recommended for conversion of a single 64 kbit/s A-law or mu-law PCM channel encoded at 8000 samples/sec to and from a 32 kbit/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 as part of the audio data. The 4-bit code words of the G.726 encoding MUST be packed into octets/bytes as follows: the first code word is placed in the four least significant bits of the first octet, with the least significant bit of the code word in the least significant bit of the octet; the second code word is placed in the four most significant bits of the first octet, with the most significant bit of the code word in the most significant bit of the octet. Subsequent pairs of the code words shall be packed in the same way into successive octets, with the first code word of each pair placed in the least significant four bits of the octet. It is prefered that the voice sample be extended with silence such that the encoded value comprises an even number of code words. However, if the voice sample comprises an odd number of code words, then the last code word shall be discarded. In the context of VPIM, the Content-Description header SHOULD be used to describe the contents of the audio body. The header must be able to be parsed to find these identifiying phrases: Voice Message, Originator Spoken Name, Recipient Spoken Name, or Spoken Subject. Other headers may be used with their defined semantics. Vaudreuil, Parsons Expires 3/9/97 [Page 38] Internet Draft VPIM v2 September 9, 1996 18. Appendix E - image/TIFF Content Type Mime type name: image Mime Sub-Type name: TIFF Required Parameters: None Optional Parameters: None Encoding Considerations: Any encoding necessary for transport may be used. 18.1 References TIFF (Tag Image File Format) is defined in: TIFF (TM) Revision 6.0 - Final - Adobe Developers Association Adobe Systems Incorporated 1585 Charleston Road P.O. Box 7900 Mountain View, CA 94039-7900 A copy of this specification can be found in: ftp://ftp.adobe.com/pub/adobe/DeveloperSupport/TechNotes/PDFfiles TIFF Class F has previously never been documented in a detailed fashion. However, it is clearly defined in Section 10.7.4 Spatial Media of: Enterprise Computer Telephony Forum S.100 Revision 1.0 Media Services "C" Language Application Programming Interfaces THE ECT Forum 303 Vintage Park Drive Foster City, CA 94404-1138 A copy of this specification can be found in: http://www.ectf.org/ectf_s100.html 18.2 TIFF Class F The essential parts of the ECTF S.100 definition are repeated here: The default TIFF tags which apply for reading (sending) and writing (receiving) are described in the sections below entitled TIFF Reader and TIFF Writer. The TIFF requirements below are broken into two sections, specifying the requirements for all TIFF reader implementations (Used for sending a FAX) and TIFF writer implementations (Used to receive a fax) that will be supported for use. Vaudreuil, Parsons Expires 3/9/97 [Page 39] Internet Draft VPIM v2 September 9, 1996 18.2.1 TIFF Reader All implementations must be able to read (send) TIFF files meeting the requirements below. Image data must not have any coding errors. Implementations may also read any other formats as long as available formats can be disclosed to applications at run time. ByteOrder: MM,II (Either byte order is allowed) These tags shown below must be readable. If not present, reader must use default shown: TIFF Reader Tags Tag | Legal | Default |Comment ------------------|-------------|--------------|---------------------- BitsPerSample | 1 | 1 |one bit per sample CleanFaxData | 0 | 0 |data has no errors Compression | 3 | 3 |T.4 bi-level encoding, | | | MH FillOrder | 2,1 | 2 |LSB first or MSB first ImageWidth | 1728 | 1728 | ImageLength | >0 | |required NewSubFileType | 2 | 2 |single page of | | |multipage file Orientation | 1 | 1 |1st row=top left, | | | 1st col=top PageNumber | X/X | 0/1 |pg/tot, 0 base, | | | tot in 1st IFD PhotometricInterp | 0 | 0 |0 is white ResolutionUnit | 2 | 2 |inches RowsPerStrip |=ImageLength |=ImageLength | SamplesPerPixel | 1 | 1 |one sample per pixel StripByteCounts | >0 | |required StripOffsets | >0 | |required T4Options | 4 | 4 |MH, byte aligned EOL Xresolution | 204,200,77 | 204 | Yresolution | 196,98,100, | 196 | | 200,77,38.5 | | ------------------|-------------|--------------|---------------------- Other tags may be present, but must be of the sort that can be ignored safely by implementations (i.e. purely informational). Vaudreuil, Parsons Expires 3/9/97 [Page 40] Internet Draft VPIM v2 September 9, 1996 18.2.2 TIFF Writer For fax writing (receiving), implementations are required to use the following TIFF format as a default. Image data must not have any coding errors. Implementations may write other formats as long as applications have selected from among those formats at run time. TIFF Writer Tags Tag | Legal Values | Comment ------------------|----------------|---------------------------------- ByteOrder | II | BitsPerSample | 1 | one bit per sample Compression | 3 | T.4 bi-level encoding, MH FillOrder | 2 | LSB first ImageWidth | 1728 | ImageLength | > 0 | NewSubFileType | 2 | single page of multi-page file PageNumber | X/X | pg/tot, 0 base, tot in 1st IFD PhotometricInterp | 0 | 0 is white ResolutionUnit | 2 | inches RowsPerStrip | >0 | must be same as ImageLength SamplesPerPixel | 1 | one sample per pixel StripByteCounts | >0 | as appropriate StripOffsets | >0 | as appropriate T4Options | 4 | MH, byte aligned EOL Xresolution | 204,200,77 | Yresolution | 196,98,100, | | 200,77,38.5 | ------------------|----------------|---------------------------------- Tags that are optional, but if present must contain the values as shown: Optional TIFF Writer Tags Tag | Legal Values | Comment ----------------|----------------|------------------------------------ CleanFaxData | 0 | data doesn't contain bad scan lines Orientation | 1 | 1st row = top left, 1st col = top ----------------|----------------|------------------------------------ Other tags may be present, but must be of the sort that can be ignored safely by applications (i.e. purely for information). Recommended informational tags are: Software, Datetime, BadFaxLines, ConsecutiveBadFaxLines Vaudreuil, Parsons Expires 3/9/97 [Page 41] Internet Draft VPIM v2 September 9, 1996 19. Appendix F - Change History: RFC 1911 to this Document This update is based on the experience of a proof of concept demonstration of VPIM at EMA'96 in April 1996. This version of the profile is significantly different from the previous. These changes are detailed below: 1. General - Various editorial updates to improve readability - Changed the Voice version to 2.0 - Added Table of Contents and more examples - Refined audio/32KADPCM (nibble order) and image/TIFF (tag defaults) definitions 2. Content - Deprecated multipart/voice-message content because of the removal of positional dependence of contents and the desire to interoperate with minimal MIME implementationsde - Explicitly defined the forwarding model using message/RFC822 - Eliminated the text name in the "To" and "CC" headers. Edited the conformance to require last-name, first-name only for persons - Described handling of private messages - Profiled the Vcard in the application/directory body part for transport of directory information on the originator - Added support for facsimile using the refined image/TIFF content - Loosened text restriction - Added suggested addressing formats - Added additional details on delivery notifications 3. Transport - Moved Binary support to optional - Added ESMTP keyword for Return of Status codes 4. Compliance - Added an explicit section on conformance allowing conformance to all or any of three conformance areas - Improved conformance table Vaudreuil, Parsons Expires 3/9/97 [Page 42] Internet Draft VPIM v2 September 9, 1996 20. Appendix G -- Open Issues 1) Finalize changes appendix 2) Sufficient examples 3) Must date be included at an AMIS to VPIM gateway? Vaudreuil, Parsons Expires 3/9/97 [Page 43]