Network Working Group Greg Vaudreuil Internet Draft Lucent Technologies Expires in six months Glenn Parsons Obsoletes: RFC 2421 Nortel Networks July 12, 2000 Voice Profile for Internet Mail - version 2 <draft-ietf-vpim-vpimv2r2-00.txt> Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. This document is an Internet Draft. Internet Drafts are working documents of the Internet Engineering Task Force (IETF), its Areas, and its Working Groups. Note that other groups may also distribute working documents as Internet Drafts. Internet Drafts are valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet Drafts as reference material or to cite them other than as a "work in progress". To learn the current status of any Internet-Draft, please check the "1id-abstracts.txt" listing contained in the Internet-Drafts Shadow Directories on ftp.is.co.za (Africa), nic.nordu.net (Europe), munnari.oz.au (Pacific Rim), ds.internic.net (US East Coast), or ftp.isi.edu (US West Coast). Copyright Notice Copyright (C) The Internet Society (1999). All Rights Reserved. Internet Draft VPIM v2 July 12, 2000 Overview This document profiles Internet mail for voice messaging. It obsoletes RFC 2421 which describes version 2 of the profile with less precision. A list of changes from that document are noted in Appendix F. As well, Appendix A summarizes the protocol profiles of this version of VPIM. Note: Though this draft is `00', it is a revision of the Internet Draft issued as draft-ema-vpim-vpimv2r2-02.txt Please send comments on this document to the IETF VPIM mailing list: vpim@lists.neystadt.org Additional documents and background may be found on the VPIM web page: http://www.vpim.org Working Group Summary This document is a deliverable of the charter of the IETF VPIM BOF. This document is intended as a revision of VPIM v2 [RFC 2421] for the purposes of elevating its maturity status. No protocol changes should be made from RFC 2421 but this document is hoped to be a more precise profile. Vaudreuil, Parsons Expires January 12,2001 [Page 2]
Internet Draft VPIM v2 July 12, 2000 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............................................11 4.3 MIME Audio Content Descriptions..................................18 4.4 Voice Message Content Types......................................20 4.5 Return and Notification Messages.................................24 4.6 Forwarded Messages...............................................26 4.7 Reply Messages...................................................27 4.8 Notification Messages............................................27 5. MESSAGE TRANSPORT PROTOCOL ........................................28 5.1 ESMTP Commands...................................................28 5.2 ESMTP Keywords...................................................30 5.3 ESMTP Parameters - MAIL FROM.....................................31 5.4 ESMTP Parameters - RCPT TO.......................................32 5.5 ESMTP - SMTP Downgrading.........................................32 6. DIRECTORY ADDRESS RESOLUTION ......................................33 7. MANAGEMENT PROTOCOLS ..............................................33 7.1 Network Management...............................................33 8. CONFORMANCE REQUIREMENTS ..........................................34 9. SECURITY CONSIDERATIONS ...........................................35 9.1 General Directive................................................35 9.2 Threats and Problems.............................................35 9.3 Security Techniques..............................................36 10.REFERENCES ........................................................36 11.ACKNOWLEDGMENTS ...................................................39 12.COPYRIGHT NOTICE ..................................................39 13.AUTHORS' ADDRESSES ................................................40 14.APPENDIX A - VPIM REQUIREMENTS SUMMARY ............................41 15.APPENDIX B - EXAMPLE VOICE MESSAGES ...............................48 16.APPENDIX C - EXAMPLE ERROR VOICE PROCESSING ERROR CODES ...........53 17.APPENDIX D - EXAMPLE VOICE PROCESSING DISPOSITION TYPES ...........54 18.APPENDIX E - IANA REGISTRATIONS ...................................55 18.1 Voice Content-Disposition Parameter Definition .................55 19.APPENDIX F - CHANGE HISTORY: RFC 2421 (VPIM V2) TO THIS DOCUMENT ..56 Vaudreuil, Parsons Expires January 12,2001 [Page 3]
Internet Draft VPIM v2 July 12, 2000 1. Abstract Voice messaging evolved as telephone answering service into a full send, receive, and forward messaging paradigm with unique message features, semantics and usage patterns. Voice messaging was introduced on special purpose computers that interface to a telephone switch and provide call answering and voice messaging services. Traditionally, messages sent from one voice messaging system to another were transported using analog networking protocols based on DTMF signaling and analog voice playback. As the demand for networking increases, there was a need for a standard high-quality digital protocol to connect these machines. VPIM has successfully demonstrated its usefulness as this new standard. VPIM is widely implemented and is seeing deployment in early adopter customer networks. This document clarifies ambiguities found in the earlier specification and is consistent with implementation practice. The profile is referred to as VPIM (Voice Profile for Internet Mail) in this document. This second revision of the version 2 of obsoletes RFC 2421 that less precisely describes version 2 of the profile. Vaudreuil, Parsons Expires January 12,2001 [Page 4]
Internet Draft VPIM v2 July 12, 2000 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, primarily voice and facsimile. This document specifies a restricted profile of the Internet multimedia messaging protocols for use between voice processing server platforms. These platforms have historically been special- purpose computers and often do not have the same facilities normally associated with a traditional Internet Email-capable computer. As a result, VPIM also specifies additional functionality, as it is needed. This profile is intended to specify the minimum common set of features to allow interworking between 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 easily displayed or viewed. They can often be processed only via text-to-speech or text-to-fax features not currently present in many of these machines. 2) Voice mail machines usually act as an integrated Message Transfer Agent, Message Store and User Agent. There is typically no relaying of messages. RFC 822 header fields may have limited use in the context of the limited messaging features currently deployed. 3) Voice mail message stores are generally not capable of preserving the full semantics of an Internet message. As such, use of a voice mail machine for gatewaying is not supported. In particular, storage of recipient lists, "Received" lines, and "Message-ID" may be limited. 4) Internet-style distribution/exploder mailing lists are not typically supported. Voice mail machines often implement only local alias lists, with error-to-sender and reply-to-sender behavior. Reply-all capabilities using a CC list are not generally available. 5) Error reports must be machine-parsable so that helpful responses can be voiced to users whose only access mechanism is a telephone. 6) The voice mail systems generally limit address entry to 16 or fewer numeric characters, and normally do not support alphanumeric mailbox names. Alpha characters are not generally used for mailbox identification, as they cannot be easily entered from a telephone terminal. Vaudreuil, Parsons Expires January 12,2001 [Page 5]
Internet Draft VPIM v2 July 12, 2000 It should be noted that newer systems are based natively on SMTP/MIME and do not suffer these limitations. In particular, some systems may support media other than voice and fax. 2.2 Design Goals It is a goal of this profile to make as few restrictions and additions to the existing Internet mail protocols as possible while satisfying the requirements for interoperability with current generation voice messaging systems. This goal is motivated by the desire to increase the accessibility to digital messaging by enabling the use of proven existing networking software for rapid development. This specification is intended for use on a TCP/IP network; however, it is possible to use the SMTP protocol suite over other transport protocols. The necessary protocol parameters for such use 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 that do not understand MIME. Full functionality, such as reliable error messages and binary transport, will require careful selection of gateways (e.g., via MX records) to be used as VPIM forwarding agents. Nothing in this document precludes use of general purpose MIME email packages to read and compose VPIM messages. While no special configuration is required to receive VPIM 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 these directory-listing capabilities are local matters. Vaudreuil, Parsons Expires January 12,2001 [Page 6]
Internet Draft VPIM v2 July 12, 2000 3. Protocol Restrictions This protocol does not limit the number of recipients per message. Where possible, server implementations should not restrict the number of recipients in a single message. It is recognized that no implementation supports unlimited recipients, and that the number of supported recipients may be quite low. This protocol does not limit the maximum message length. Implementers should understand that some machines will be unable to accept excessively long messages. A mechanism is defined in the RFC 1425 SMTP service extensions to declare the maximum message size supported. The message size indicated in the ESMTP SIZE parameter is in bytes, not minutes or seconds. The number of bytes varies by voice encoding format and includes 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 protocols that are required to be compliant with this VPIM v2 profile. Though various SMTP, ESMTP and MIME features are described here, the implementer is referred to the relevant RFCs for complete details. The table in Appendix A summarizes the protocol details of this profile. The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [REQ]. Vaudreuil, Parsons Expires January 12,2001 [Page 7]
Internet Draft VPIM v2 July 12, 2000 4. Voice Message Interchange Format The voice message interchange format is a profile of the Internet Mail Protocol Suite. Any Internet Mail message containing the format defined in this section is referred to as a VPIM Message in this document. As a result, this document assumes an understanding of the Internet Mail specifications. Specifically, VPIM references components from the message format standard for Internet messages [RFC822], the Multipurpose Internet Message Extensions [MIME], the X.400 gateway specification [X.400], delivery status and message disposition notifications [REPORT][DSN][DRPT][STATUS][MDN], and the electronic business card [MIMEDIR][VCARD]. MIME, introduced in [MIME1], is a general-purpose message body format that is extensible to carry a wide range of body parts. It provides for encoding binary data so that it can be transported over the 7-bit text-oriented SMTP protocol. This transport encoding (denoted by the Content-Transfer-Encoding header field) is in addition to the audio encoding required to generate a binary object. MIME defines two transport-encoding mechanisms to transform binary data into a 7-bit representation, one designed for text-like data ("Quoted-Printable"), and one for arbitrary binary data ("Base64"). While Base64 is dramatically more efficient for audio data, either will work. Where binary transport is available, no transport encoding is needed, and the data can be labeled as "Binary". An implementation in compliance with this profile SHOULD send audio and/or facsimile data in binary form when binary message transport is available (see section 5). When binary transport is not available, implementations MUST encode the audio and/or facsimile data as Base64. 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 in a transfer encoding that cannot be rendered to the user, an appropriate negative delivery status notification MUST be sent. 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. Vaudreuil, Parsons Expires January 12,2001 [Page 8]
Internet Draft VPIM v2 July 12, 2000 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. As a result, some voice messaging systems may only be able to handle a numeric local part. The reception of alphanumeric local parts on these systems may result in the address being mapped to some locally unique (but confusing to the recipient) number or, in the worst case the address could be deleted making the message un-replyable. Additionally, it may be difficult to create messages on these systems with an alphanumeric local part without complex key sequences or some form of directory lookup (see 6). The use of the domain 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 6). In the absence of a global directory, specification of the local part is expected to conform to international or private telephone numbering plans. It is likely that private numbering plans will prevail and these are left for local definition. However, it is RECOMMENDED that public telephone numbers be noted according to the international numbering plan described in [E.164]. The indication that the local part is a public telephone number is given by a preceding `+' (the `+' would not be entered from a telephone keypad, it is added by the system as a flag). Since the primary information in the numeric scheme is contained by the digits, other character separators (e.g. `-') may be ignored (i.e. to allow parsing of the numeric local mailbox) or may be used to recognize distinct portions of the telephone number (e.g. country code). The specification of the local part of a VPIM address can be split into the four groups described below: 1) mailbox number - for use as a private numbering plan (any number of digits) - e.g. 2722@lucent.com 2) mailbox number+extension - for use as a private numbering plan with extensions any number of digits, use of `+' as separator - e.g. 2722+111@Lucent.com 3) +international number - for international telephone numbers conforming to E.164 maximum of 15 digits - e.g. +16137637582@vm.nortel.ca Vaudreuil, Parsons Expires January 12,2001 [Page 9]
Internet Draft VPIM v2 July 12, 2000 4) +international number+extension - for international telephone numbers conforming to E.164 maximum of 15 digits, with an extension (e.g. behind a PBX) that has a maximum of 15 digits. - e.g. +17035245550+230@ema.org Note that this address format is designed to be compatible with current usage within the voice messaging industry. It is not compatible with the addressing formats of RFC s 2303-2304. It is expected that as telephony services become more widespread on the Internet, these addressing formats will converge. 4.1.2 Special Addresses Special addresses are provided for compatibility with the conventions of Internet mail. These addresses do not use numeric local addresses, both to conform to current Internet practice and to avoid conflict with existing numeric addressing plans. Two special addresses are RESERVED for use as follows: postmaster@domain By convention, a special mailbox named "postmaster" MUST exist on all systems. This address is used for diagnostics and should be checked regularly by the system manager. This mailbox is particularly likely to receive text messages, which is not normal on a voice-processing platform. The specific handling of these messages is an individual implementation choice. non-mail-user@domain If a reply to a message is not possible, such as a telephone- answering message, then the special address "non-mail-user" SHOULD be used as the originator's address. Any text name such as "Telephone Answering", or the telephone number if it is available, is permitted. This special address is used as a token to indicate an unreachable originator. For compatibility with the installed base of mail user agents, implementations that generate this special address MUST send a negative delivery status notification (DSN) for reply messages sent to the undeliverable address. The status code for such NDN's is 5.1.1 "Mailbox does not exist". Example: From: Telephone Answering <non-mail-user@mycompany.com> 4.1.3 Distribution Lists There are many ways to handle distribution list (DL) expansions and none are 'standard'. 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: Vaudreuil, Parsons Expires January 12,2001 [Page 10]
Internet Draft VPIM v2 July 12, 2000 Reply to the originator - (Address in the RFC822 Reply-to or From field) Errors to the submitter - (Address in the MAIL FROM: field of the ESMTP exchange 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 "header fields" except date and per-message features. Most voice messaging systems do not provide for "Header Information" in their messaging queues and only include delivery information. As a result, recipient information MAY be in either the To or CC header fields. If all recipients cannot be presented then the recipient header fields SHOULD be omitted to indicate that an accurate list of recipients (e.g. for use with a reply-all capability) is not known. 4.2 Message Header Fields Internet messages contain a header information block. This header block contains information required to identify the sender, the list of recipients, the message send time, and other information intended for user presentation. Except for specialized gateway and mailing list cases, header fields do not indicate delivery options for the transport of messages. Distribution list processors are noted for modifying or adding to the header fields of messages that pass through them. VPIM systems MUST be able to accept and ignore header fields that are not defined here. The following header lines are permitted for use with VPIM voice messages: 4.2.1 From SEND RULES The originator's fully qualified domain address (a mailbox address followed by the fully qualified domain name) MUST be present. Systems compliant with this profile SHOULD provide the text personal name of the voice message originator in a quoted phrase, if the name is available. Text names of corporate or positional mailboxes MAY be provided as a simple string. From [RFC822] Example: From: "Joe S. User" <12145551212@mycompany.com> From: Technical Support <611@serviceprovider.com> From: Non-mail-user@myserver.mycompany.com Vaudreuil, Parsons Expires January 12,2001 [Page 11]
Internet Draft VPIM v2 July 12, 2000 Voice mail machines may not be able to support separate attributes for the "From:" and "Reply-To:" header fields and the SMTP MAIL FROM, VPIM-conforming systems SHOULD set these values to the same address. Use of addresses different than those present in the "From:" header field address may result in unanticipated behavior. RECEPTION RULES The user listed in the from field should be presented in the voice message envelope of the voice messaging system as the originator of the message. The "From:" address SHOULD be used for replies (see 4.7). However, if the "From:" address contains <non-mail- user@domain>, the user SHOULD NOT be offered the option to reply, nor should notifications be sent to this address. 4.2.2 To The "To:" field contains the recipient's fully-qualified domain address. Example: To: +12145551213@mycompany.com SEND RULES There MAY be one or more "To:" fields in any message. Systems SHOULD provide a list of recipients only if all recipients are available. Systems such as gateways from protocols which do not indicate the complete list of recipients SHOULD provide a "To:" line. Because these systems cannot accurately enumerate all recipients in the "To:" headers, no recipients should be enumerated. RECEPTION RULES Systems compliant to this profile MAY discard the addresses in the "To:" fields if they are unable to store the information. This would, of course, make a reply-to-all capability impossible. If present, the addresses in the "To:" field MAY be used for a reply message to all recipients. 4.2.3 Cc The "Cc:" field contains additional recipients' fully qualified domain addresses. Many voice mail systems maintain only sufficient envelope information for message delivery and are not capable of storing or providing a complete list of additional recipients. SEND RULES Vaudreuil, Parsons Expires January 12,2001 [Page 12]
Internet Draft VPIM v2 July 12, 2000 Conforming implementations MAY send "Cc:" lists if all recipients are known at the time of origination . The list of disclosed recipients MUST not include undisclosed recipients (ie., those sent via a blind copy). If not, systems SHOULD omit the "Cc:" fields to indicate that the full list of recipients is unknown or otherwise unavailable. Example: Cc: +12145551213@mycompany.com RECEPTION RULES Systems compliant to this profile MAY add all the addresses in the "Cc:" field to the "To:" field, others MAY discard the addresses in the "Cc:" fields. If a list of "Cc:" addresses is present, these addresses MAY be used for a reply message to all recipients. 4.2.4 Date The "Date:" field MUST be present and contains the date, time, and time zone in which the message was sent by the originator. SEND RULES The time zone MUST be present and SHOULD be represented in a four- digit time zone offset, such as -0500 for North American Eastern Standard Time. This MAY be supplemented by a time zone name in parentheses, e.g., "-0900 (PDT)". Compliant implementations SHOULD be able to convert [RFC822] date and time stamps into local time. If the VPIM sender is relaying a message from a system that does not provide a time stamp, the time of arrival at the gateway system SHOULD be used as the date. Example: Date: Wed, 28 Jul 96 10:08:49 -0800 (PST) RECEPTION RULES The sending system MUST report the time the message was sent. From [RFC822] 4.2.5 Sender SEND RULES The "Sender:" field contains the actual address of the originator if an agent on behalf of the author indicated in the "From:" field sends the message. This header field MAY be sent by VPIM-conforming systems. Vaudreuil, Parsons Expires January 12,2001 [Page 13]
Internet Draft VPIM v2 July 12, 2000 RECEPTION RULES If the address in the "Sender:" field cannot be preserved in the recipient's message queues or in the next-hop protocol from a gateway, the field MAY be silently discarded. 4.2.6 Return-Path The "Return-path:" field is added by the final delivering SMTP server. If present, it contains the address from the MAIL FROM parameter of the ESMTP exchange (see 5.1.2). Any error messages resulting from the delivery failure MUST be sent to this address. Note that if the "Return-path:" is null ("<>"), e.g. no path, loop prevention or confidential, delivery status and message disposition notifications MUST NOT be sent. SEND RULES The originator system MUST not add this header. RECEPTION RULES If the receiving system is incapable of storing the return path to be used for subsequent delivery errors, the receiving system must otherwise ensure that further delivery errors don't happen. Systems that do not support the return path MUST ensure that at the time the message is acknowledged, the message is delivered to the recipient's ultimate mailbox. Non-Delivery notifications should not be sent after that final delivery. 4.2.7 Message-id The "Message-Id:" field contains a unique per-message identifier. SEND RULES A unique message-id MUST be generated for each message sent from a VPIM-compliant implementation. Example: Message-Id: <12345678@mycompany.com> RECEPTION RULES The message id is not required to be stored on the receiving system. This identifier MAY be used for tracking, auditing, and returning receipt notification reports. From [RFC822] Vaudreuil, Parsons Expires January 12,2001 [Page 14]
Internet Draft VPIM v2 July 12, 2000 4.2.8 Reply-To If present, the "Reply-to:" header provides a preferred address to which reply messages should be sent (see 4.7). Typically, voice mail systems can only support one originator of a message so it is likely that this field will be ignored by the receiving system. From [RFC822] SEND RULES A compliant system SHOULD NOT send a Reply-To header. RECEPTION RULES If a "reply-to:" field is present, a reply-to sender message MAY be sent to the address specified (that is, in lieu of the address in the "From:" field). If only one address of the originator is supported in the message store or in the next-hop protocol from a multi-protocol gateway, the address in the "From:" field MUST be used and the "Reply-To:" field MAY be silently discarded. 4.2.9 Received The "Received:" field contains trace information added to the beginning of a RFC 822 message by MTAs. This is the only field that may be added by an MTA. Information in this header is useful for debugging when using an US-ASCII message reader or a header-parsing tool. From [RFC822] SEND RULES A VPIM-compliant system MUST add a "Received:" field. When acting as a gateway, information about the system translated from SHOULD be included. RECEPTION RULES A VPIM-compliant system SHOULD NOT remove any "Received:" fields when relaying messages to other MTAs or gateways. These header fields MAY be ignored or deleted when the message is received at the final destination. 4.2.10 MIME Version The "MIME-Version:" field indicates that the message conforms to [MIME]. Systems compliant with this specification SHOULD include a comment with the words "(Voice 2.0)". [VPIM1] defines an earlier version of this profile and uses the token (Voice 1.0). Example: MIME-Version: 1.0 (Voice 2.0) Vaudreuil, Parsons Expires January 12,2001 [Page 15]
Internet Draft VPIM v2 July 12, 2000 This identifier is intended for information only and SHOULD NOT be used to semantically identify the message as being a VPIM message. Instead, the presence of the content defined in [V-MSG] SHOULD be used if identification is necessary. 4.2.11 Content-Type The content-type header declares the type of content enclosed in the message. The typical top level content in a VPIM Message SHOULD be multipart/voice-message. The allowable contents are detailed starting in section 4.4 of this document. From [MIME2] 4.2.12 Content-Transfer-Encoding Because Internet mail was initially specified to carry only 7-bit US- ASCII text, it may be necessary to encode voice and fax data into a representation suitable for that environment. The content-transfer- encoding header describes this transformation if it is needed. Compliant implementations MUST recognize and decode the standard encodings, "Binary", "7bit, "8bit", "Base64" and "Quoted-Printable". From [MIME1] 4.2.13 Sensitivity The "Sensitivity:" field, if present, indicates the requested privacy level. The case-insensitive values "Personal", "Private", and "Normal" are specified. If no privacy is requested, this field is omitted. SEND RULES A VPIM-compliant implementations MAY include this header to indicate the sensitivity of a message. If the message is of "Normal" sensitivity, this field SHOULD be omitted. From: [X.400] RECEPTION RULES If a "Sensitivity:" field with a value of "Personal" or "Private" 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 responder to reply to a sensitive message, but SHOULD NOT include the original message content. The responder MAY set the sensitivity of the reply message. If the receiving system does not support privacy and the sensitivity is one of "Personal" or "Private", a negative delivery status notification MUST be sent to the originator with the appropriate status code (X.Y.Z) indicating that privacy could not be assured. The message contents SHOULD be returned to the sender to allow for a voice context with the notification. A non-delivery notification to a private message SHOULD NOT be tagged private since it will be sent to the originator. From: [X.400] Vaudreuil, Parsons Expires January 12,2001 [Page 16]
Internet Draft VPIM v2 July 12, 2000 A message with no privacy explicitly noted (ie., no header) or with _ Normal_ sensitivity has no special treatment. 4.2.14 Importance Indicates the requested importance to be given by the receiving system. The case-insensitive values "low", "normal" and "high" are specified. If no special importance is requested, this header may be omitted and the value of the absent header assumed to be "normal". From: [X.400] SEND RULES Compliant implementations MAY include this header to indicate the importance of a message RECEPTION RULES If the receiving system does not support importance, the attribute may be silently dropped. If the attribute is supported, it can be used for various user interface purposes including the ordering messages within a mailbox or trigging notification devices such as pagers. 4.2.15 Subject The subject field is often provided by email systems but is not widely supported on Voice Mail platforms. From [RFC822] SEND RULES For compatibility with text based mailbox interfaces, a text subject field SHOULD be generated by a compliant implementation. It is recommended that voice-messaging systems that do not support any text user interfaces (e.g. access only by a telephone) insert a generic subject header of "VPIM Message" or _ Voice Message_ for the benefit of GUI enabled recipients. RECEPTION RULES It is anticipated that many voice-only systems will be incapable of storing the subject line. The subject MAY be discarded if present by a receiving system. 4.2.16 Disposition-Notification-To This header MAY be present to indicate that the sender is requesting a receipt notification from the receiving user agent. The user agent typically sends this message disposition notification (MDN) after the user has listened to the message and consented to an MDN being sent Example: Vaudreuil, Parsons Expires January 12,2001 [Page 17]
Internet Draft VPIM v2 July 12, 2000 Disposition-notification-to: +12145551213@mycompany.com SEND RULES VPIM-compliant implementations MAY include this header to request a disposition indication such as a listen confirmation. RECEPTION RULES The presence of a "Disposition-notification-to:" header in a message is merely a request for an MDN described in 4.5.3. The recipients' system is always free to silently ignore such a request so this header does not burden any system that does not support it. From [MDN]. 4.2.17 Disposition-Notification-Options This header MAY be present to define future extension parameters for an MDN requested by the presence of the header in the previous section. SEND RULES No "Disposition-notification-options:" are defined that are useful for voice messaging. Sending systems SHOULD NOT request disposition notification options by sending a disposition-notification-options header. RECEPTION RULES Currently no parameters are defined by this document or by [MDN]. However for forward compatibility with future extensions, this header MUST be processed if present, if MDNs are supported. If it contains a extension parameter that is required for proper MDN generation (noted with "=required"), then an MDN MUST NOT be sent if the parameter is not understood. See [MDN] for complete details. Example: Disposition-notification-options: whizzbang=required,foo 4.3 MIME Audio Content Descriptions 4.3.1 Content-Description: This field MAY be present to facilitate the text identification of these body parts in simple email readers. Any values may be used, though it may be useful to use values similar to those for Content- Disposition. Example: Vaudreuil, Parsons Expires January 12,2001 [Page 18]
Internet Draft VPIM v2 July 12, 2000 Content-Description: Big Telco Voice Message 4.3.2 Content-Disposition: This field MUST be present to allow the parsable identification of body parts within a VPIM voice message. This is especially useful if, as is typical, more than one Audio/* body occurs within a single level (e.g. multipart/voice-message). Since a VPIM voice message is intended to be automatically played upon display of the message, in the order in which the audio contents occur, the audio contents must always be of type inline. However, it is still useful to include a filename value, so this should be present if this information is available. From [DISP] In order to distinguish between the various types of audio contents in a VPIM voice message a new disposition parameter "voice" is defined with the parameter values below to be used as appropriate Voice-Message - the primary voice message, Voice-Message-Notification - a spoken delivery notification or spoken disposition notification, Originator-Spoken-Name - the spoken name of the originator, Recipient-Spoken-Name - the spoken name of the recipient(s) if available to the originator Spoken-Subject- the spoken subject of the message, typically spoken by the originator Note that there SHOULD only be one instance of each of these types of audio contents per message level. Additional instances of a given type (i.e., parameter value) may occur within an attached forwarded voice message. Implementations that do not understand the "voice" parameter (or the Content-Disposition header) can safely ignore it, and will present the audio bodyparts in order (but will not be able to distinguish between them). 4.3.3 Content-Duration: This field MAY be present to allow the specification of the length of the audio bodypart in seconds. The use of this field on reception is a local implementation issue. From [DUR] Example: Content-Duration: 33 4.3.4 Content-Language: This field MAY be present to allow the specification of the spoken language of the audio bodypart. The encoding is defined in [LANG]. The use of this field on reception is a local implementation issue. Vaudreuil, Parsons Expires January 12,2001 [Page 19]
Internet Draft VPIM v2 July 12, 2000 Example for UK English: Content-Language: en-UK 4.4 Voice Message Content Types The content types described in this section are identified for use within the multipart/voice-message content. This content is referred to as a `VPIM voice message' in this document and is the fundamental part of a `VPIM message'. Only the contents profiled subsequently (and occasionally those in 4.5) can be sent within a VPIM voice message construct (i.e., the multipart/voice-message content type) to form a simple or a more complex structure (several examples are given in Appendix B). The presence of other contents within a VPIM voice message is not permitted. Conforming implementations SHOULD NOT create a message containing prohibited contents. In the spirit of liberal acceptance, a conforming implementation MAY accept and render prohibited content. unable to accept or render prohibited contents MAY discard the contents as necessary to deliver the voice content. When multiple contents are present within the multipart/voice-message, they SHOULD be presented to the user in the order that they appear in the message. Some deployed implementations based on a common interpretation of the original VPIM v2 specification reject messages with prohibited content rather than discard the unsupported contents. For interoperability with these systems, it is especially important that prohibited contents not be sent within a multipart/voice message. 4.4.1 Multipart/Voice-Message This MIME multipart structure provides a mechanism for packaging a voice message into one container that is tagged as VPIM v2 compliant. SEND RULES The Multipart/Voice-Message content-type MUST only contain the profiled media and content types specified in this section (i.e. audio/*, image/*, message/rfc822 and text/directory). The most common will be: spoken name, spoken subject, the message itself, and an attached fax. Forwarded messages are created by simply using the message/rfc822 construct. Conformant implementations MUST send the multipart/voice-message in a VPIM message. In most cases, this Multipart/Voice-Message content will be the top level (i.e. in the Content-Type header). RECEPTION RULES Vaudreuil, Parsons Expires January 12,2001 [Page 20]
Internet Draft VPIM v2 July 12, 2000 Conformant implementations MUST recognize the Multipart/Voice-Message content (whether it is a top-level content or below a multipart/mixed) and be able to separate the contents (e.g. spoken name or spoken subject). The semantic of multipart/Voice-Message (defined in [V-MSG]) is identical to multipart/mixed and may be interpreted as that by systems that do not recognize this content-type. 4.4.2 Message/RFC822 SEND RULES MIME requires support of the Message/RFC822 message encapsulation body part. This body part SHOULD be used within a multipart/voice- message to forward complete messages (see 4.6) or to reply with original content (see 4.7). From [MIME2] RECEPTION RULES The receiving system SHOULD treat this attachment as a forwarded message. The receiving system may flatten the forwarding structure (i.e., remove this construct to leave multiple voice contents or even concatenate the voice contents to fit in a recipient's mailbox) if necessary. 4.4.3 Text/Directory SEND RULES This content was profiled in the original specification of VPIM v2 as a means of transporting contact information from the sender to the recipient. This usage did not find widespread adoption and is no longer a feature of VPIM V2. Conforming implementations SHOULD NOT send the text/directory content type. RECEPTION RULES For compatibility with an earlier specification of VPIM v2, the Text/Directory content type MUST be accepted by a conforming implementation, but need not be stored, processed, or rendered to the recipient. 4.4.4 Audio/32KADPCM SEND RULES Vaudreuil, Parsons Expires January 12,2001 [Page 21]
Internet Draft VPIM v2 July 12, 2000 An implementation compliant to this profile MUST send Audio/32KADPCM by default for voice [ADPCM]. This encoding is a moderately compressed encoding with a data rate of 32 kbits/second using moderate processing resources. Typically this body contains several minutes of message content, however if used for spoken name or subject the content should be considerably shorter (i.e. about 5 and 20 seconds respectively). RECEPTION RULES Receivers MUST be able to accept and decode Audio/32KADPCM. If an implementation can only handle one voice body, then multiple voice bodies (if present) SHOULD be concatenated, and SHOULD NOT be discarded. It is RECOMMENDED that this be done in the same order as they were sent. 4.4.5 Image/Tiff A common image encoding for facsimile, known as TIFF-F, is a derivative of the Tag Image File Format (TIFF) and is described in several documents. For the purposes of VPIM, the F Profile of TIFF for Facsimile (TIFF-F) is defined in [TIFF-F] and the image/tiff MIME content type is defined in [TIFFREG]. While there are several formats of TIFF, only TIFF-F is profiled for use within a VPIM voice message. Further, since the TIFF-F file format is used in a store- and-forward mode with VPIM, the image MUST be encoded so that there is only one image strip per facsimile page. SEND RULES All VPIM implementations that support facsimile MUST generate TIFF-F compatible facsimile contents in the image/tiff; application=faxbw sub-type encoding by default. If the VPIM message is a voice annotated fax, the implementation SHOULD send this fax content in multipart/voice-message. If the message is a simple fax, an implementation may send it without using the multipart/voice-message to be more compatible with fax only (RFC 2305) implementations. While any valid MIME body header MAY be used (e.g., Content- Disposition to indicate the filename), none are specified to have special semantics for VPIM and MAY be ignored. Note that the content type parameter application=faxbw MUST be included in outbound messages. RECEPTION RULES Inbound messages in the multipart/voice-message with or without the application parameter MUST be rendered to the user. If the rendering software encounters an error in the file format, some form of negative delivery status notification SHOULD be sent to the originator. Vaudreuil, Parsons Expires January 12,2001 [Page 22]
Internet Draft VPIM v2 July 12, 2000 Not all VPIM systems support fax, but all SHOULD accept it. Those that do MUST support it within the multipart/voice-message and MAY support it outside of the multipart/voice-message. Within a multipart/voice-message, a receiving system that cannot render fax content SHOULD accept the voice content of a VPIM message and discard the fax content. Outside a multipart/voice-message, a recipient system MAY reject (with appropriate NDN) the entire message if it cannot handle the fax attachments. Some deployed implementations based on a common interpretation of the original VPIM V2 specification reject messages with fax content within the multipart/voice-message rather than discard the unsupported contents. These systems will return the message to the sender with a NDN indicating lack of support for fax. 4.4.6 Proprietary Voice or Fax Formats Use of any other encoding except the required codecs reduces interoperability in the absence of explicit knowledge about the capabilities of the recipient. A compliant implementation MAY use any other encoding provided a unique identifier is registered with the IANA prior to use (see [MIME4]). The voice encodings should be registered as sub-types of Audio. The fax encodings should be registered as sub-types of Image. SEND RULES Proprietary voice encoding formats or other standard formats MAY be sent under this profile only if the sender has a reasonable expectation that the recipient will accept the encoding. In practice, this requires explicit per-destination configuration information maintained either in a directory, personal address book, or gateway configuration tables. RECEPTION RULES Systems MAY accept other audio/* or image/* content types if they can decode them. Systems which receive audio/* or image/* content types which they are unable to decode MUST return the message to the originator with an NDN indicating media not supported. 4.4.7 Multipart/Mixed SEND RULES A VPIM voice message MAY be included within a message with a multipart/mixed top level content type. Typically, this would only be used when mixing non-voice or fax contents with a voice message. RECEPTION RULES Vaudreuil, Parsons Expires January 12,2001 [Page 23]
Internet Draft VPIM v2 July 12, 2000 Such a message is not itself a VPIM message and the handling of such a construct is outside the scope of the VPIM profile. However, an the spirit of liberal acceptance, a conforming implementation MAY accept and render a VPIM voice message contained in a multipart/mixed. 4.4.8 Text/Plain MIME requires support of the basic Text/Plain content type. This content type has limited applicability within the voice-messaging environment. However, because VPIM is a MIME profile, MIME requirements should be met. SEND RULES Compliant VPIM implementations SHOULD NOT send the Text/Plain content-type. It should be understood that the textual information is not considered a primary media within multipart/voice-message and may be discarded (or rejected) by a receiving system. RECEIVE RULES Within a multipart/voice message, the text/plain content type MAY be dropped from the message if necessary to deliver the audio components. The recipient SHOULD NOT reject the entire message if the text component cannot be accepted or rendered. Outside a Multipart/Voice-message, compliant implementations MUST accept Text/Plain messages, however, specific handling is left as an implementation decision. From [MIME2] There are several mechanisms that can be used to support text (once accepted) on voice messaging systems including text-to-speech and text-to-fax conversions. If no rendering of the text is possible and no indication of its presence can be given to the recipient, the entire message MUST be returned to the sender with a negative delivery status notification and a media-unsupported status code. 4.5 Return and Notification Messages VPIM delivery status notification messages (4.5.2) MUST be sent to the originator of the message when any form of non-delivery of the subject message or its components occurs. These error messages MUST be sent to the address in the Mail From (5.1.2) if available (same as the return path (4.2.6) if present), otherwise, the From (4.2.1) address may be used. VPIM Receipt Notification messages (4.5.3) SHOULD be sent to the sender specified in the Disposition-Notification-To header field (4.2.16). The MDN SHOULD be sent after the message has been Vaudreuil, Parsons Expires January 12,2001 [Page 24]
Internet Draft VPIM v2 July 12, 2000 presented to the recipient or if the message has somehow been disposed of without being presented to the recipient (e.g. if it were deleted before playing it). VPIM Notification messages may be positive or negative, and can indicate delivery at the server or receipt by the client. However, the notification MUST be contained in a multipart/report container (4.5.1) and SHOULD contain a spoken error message. 4.5.1 Multipart/Report The Multipart/Report is used for enclosing human-readable and machine parsable notification (e.g. Message/delivery-status) body parts and any returned message content. The multipart/report content-type is used to deliver both delivery status reports indicating transport success or failure and message disposition notifications to indicate post-delivery events such as receipt notification. SEND RULES Compliant implementations MUST use the Multipart/Report construct. From [REPORT] Multipart/Report messages from VPIM implementations SHOULD include the human-readable description of the error as a spoken audio/* content (this speech MAY be made available to the notification recipient). As well, VPIM implementations MAY generate Multipart/Report messages that encode the human-readable description of the error as text. Note that per [DSN] the human-readable part MUST always be present. RECEPTION RULES Compliant implementations MUST recognize and decode the Multipart/Report content type and its components in order to present the report to the user. As well, implementers MUST be able to handle the human readable description of the error as text or audio. 4.5.2 Message/Delivery-status This MIME body part is used for sending machine-parsable delivery status notifications. SEND RULES Compliant implementations MUST use the Message/delivery-status construct when returning messages or sending warnings. RECEPTION RULES Vaudreuil, Parsons Expires January 12,2001 [Page 25]
Internet Draft VPIM v2 July 12, 2000 Compliant implementations MUST recognize and decode the Message/delivery-status content type and present the reason for failure to the sender of the message. From [DSN] 4.5.3 Message/Disposition-notification This MIME body part is used for sending machine-parsable read-receipt message disposition notifications. SEND RULES Conforming implementations SHOULD use the Message/Disposition- notification construct when sending post-delivery message status notifications. These MDNs, however, MUST only be sent in response to the presence of the Disposition-notification-to header described in 4.2.16. RECEPTION RULES Conforming implementations should recognize and decode the Message/Disposition-notification content type and present the notification to the user. From [MDN] 4.6 Forwarded Messages VPIM version 2 explicitly supports the forwarding of voice and fax content with voice or fax annotation. However, only the two constructs described below are acceptable in a VPIM message. Since only the first (i.e. message/rfc822) can be recognized as a forwarded message (or even multiple forwarded messages), it is RECOMMENDED that this construct be used whenever possible. Forwarded VPIM messages SHOULD be sent as a multipart/voice-message with the entire original message enclosed in a message/rfc822 content type and the annotation as a separate Audio/* or image/* body part. If the RFC822 header fields are not available for the forwarded content, simulated header fields with available information SHOULD be constructed to indicate the original sending timestamp, and the original sender as indicated in the "From" line. However, note that at least one of "From", "Subject", or "Date" MUST be present. As well, the message/rfc822 content MUST include at least the "MIME- Version", and "Content-Type" header fields. From [MIME2] In the event that forwarding information is lost, the entire audio content MAY be sent as a single Audio/* segment without including any forwarding semantics. An example of this loss is an AMIS message being forwarded through an AMIS-to-VPIM gateway. Vaudreuil, Parsons Expires January 12,2001 [Page 26]
Internet Draft VPIM v2 July 12, 2000 4.7 Reply Messages Replies to VPIM messages (and Internet mail messages) are addressed to the address noted in the reply-to header (see 4.2.8) if it is present, else the From address (see 4.2.1) is used. RECEPTION RULES Support of multiple originator header fields is often not possible on voice messaging systems, so it may be necessary to choose only one when gatewaying a VPIM message to another voice message system. However, implementers should note that this may make it impossible to send error messages and replies to their proper destinations. In some cases, a reply message is not possible, such as with a message created by telephone answering (i.e. classic voice mail). In this case, the From field MUST contain the special address non-mail- user@domain (see 4.1.2). A null ESMTP MAIL FROM address SHOULD also be used in this case (see 5.1.2). A receiving VPIM system SHOULD NOT offer the user the option to reply to this kind of message. 4.8 Notification Messages VPIM delivery status notification messages (4.5.2) MUST be sent to the originator of the message when any form of non-delivery of the subject message or its components occurs. These error messages must be sent to the Mail From (5.1.2) if available (same as the return path (4.2.6) if present), otherwise, the From (4.2.1) address may be used. VPIM Receipt Notification messages (4.5.3) should be sent to the sender specified in the Disposition-Notification-To header field (4.2.16), only after the message has been presented to the recipient or if the message has somehow been disposed of without being presented to the recipient (e.g. if it were deleted before playing it). VPIM Notification messages may be positive or negative, and can indicate delivery at the server or receipt by the client. However, the notification MUST be contained in a multipart/report container (4.5.1) and SHOULD contain a spoken error message. If a VPIM system receives a message with contents that are not understood (see 4.4), its handling is a local matter. A delivery status notification SHOULD be generated if the message could not be delivered because of unknown contents (e.g., on traditional voice processing systems). In some cases, the message may be delivered (with a positive DSN sent) to a mailbox before the determination of rendering can be made. Vaudreuil, Parsons Expires January 12,2001 [Page 27]
Internet Draft VPIM v2 July 12, 2000 5. Message Transport Protocol Messages are transported between voice mail machines using the Internet Extended Simple Mail Transfer Protocol (ESMTP). All information required for proper delivery of the message is included in the ESMTP dialog. This information, including the sender and recipient addresses, is commonly referred to as the message "envelope". This information is equivalent to the message control block in many analog voice messaging protocols. ESMTP is a general-purpose messaging protocol, designed both to send mail and to allow terminal console messaging. Simple Mail Transport Protocol (SMTP) was originally created for the exchange of US-ASCII 7-bit text messages. Binary and 8-bit text messages have traditionally been transported by encoding the messages into a 7-bit text-like form. [ESMTP] formalized an extension mechanism for SMTP, and subsequent RFCs have defined 8-bit text networking, command streaming, binary networking, and extensions to permit the declaration of message size for the efficient transmission of large messages such as multi-minute voice mail. The following sections list ESMTP commands, keywords, and parameters that are required and those that are optional for conformance to this profile. 5.1 ESMTP Commands 5.1.1 HELO Base SMTP greeting and identification of sender. SEND RULES This command SHOULD not be sent by compliant systems unless the more- capable EHLO command is not accepted. It is included for compatibility with general SMTP implementations. RECEPTION RULES Compliant servers MUST implement the HELO command for backward compatibility. From [SMTP] 5.1.2 MAIL FROM Originating mailbox. This address contains the mailbox to which errors should be sent. SEND RULES Vaudreuil, Parsons Expires January 12,2001 [Page 28]
Internet Draft VPIM v2 July 12, 2000 VPIM implementations SHOULD use the same address in the MAIL FROM command as is used in the From header field. This address is not necessarily 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. From [SMTP, ESMTP] RECEPTION RULES The MAIL FROM address SHOULD be stored in the local message store for the purposes of generating a delivery status notification to the originator. The address indicated in the MAIL FROM command SHOULD be passed as a local system parameter or placed in a Return-Path: line inserted at the beginning of a VPIM message. From [HOSTREQ] Since delivery status notifications MUST be sent to the MAIL FROM address, the use of the null address ("<>") is often used to prevent looping of messages. This null address MAY be used to note that a particular message has no return path (e.g. a telephone answer message). From [SMTP] 5.1.3 RCPT TO The parameter to this command contains only the address to which the message should be delivered for this transaction. It is the set of addresses in one or more RCPT TO commands that are used for mail routing. From [SMTP, ESMTP] Note: In the event that multiple transport connections to multiple destination machines are required for the same message, the set of addresses in a given transport connection may not match the list of recipients in the message header fields. 5.1.4 DATA Initiates the transfer of message data. Support for this command is required. Compliant implementations MUST implement the SMTP DATA command for backward 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] Vaudreuil, Parsons Expires January 12,2001 [Page 29]
Internet Draft VPIM v2 July 12, 2000 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 section 5. From [ESMTP] 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 new commands before issuing a response to the previous command. 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 keyword. From [PIPE] Vaudreuil, Parsons Expires January 12,2001 [Page 30]
Internet Draft VPIM v2 July 12, 2000 5.2.2 SIZE The "SIZE" keyword provides a mechanism by which the SMTP server can indicate the maximum size message supported. Compliant servers MUST provide size extension to indicate the maximum size message that can be accepted. Clients SHOULD NOT send messages larger than the size indicated by the server. Clients SHOULD advertise SIZE= when sending messages to servers that indicate support for the SIZE extension. 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 MAY 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 MAY support binary transport indicated by this capability. Note that support for this feature requires support of CHUNKING. From [BINARY] 5.2.5 DSN The "DSN" keyword indicates that the SMTP server will accept explicit delivery status notification requests. Compliant implementations MUST support the delivery notification extensions in [DRPT]. 5.2.6 ENHANCEDSTATUSCODES The "ENHANCEDSTATUSCODES" 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 notification format defined in [DSN]. 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] Vaudreuil, Parsons Expires January 12,2001 [Page 31]
Internet Draft VPIM v2 July 12, 2000 5.3.2 RET The RET parameter indicates whether the content of the message should be returned. Compliant systems SHOULD honor a request for returned content. From [DRPT] 5.3.3 ENVID The ENVID keyword of the SMTP MAIL command is used to specify an "envelope identifier" to be transmitted along with the message and included in any DSNs issued for any of the recipients named in this SMTP transaction. The purpose of the envelope identifier is to allow the sender of a message to identify the transaction for which the DSN was issued. Compliant implementations MAY use this parameter. From [DRPT] 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 [DRPT] 5.4.2 ORCPT The ORCPT keyword of the RCPT command is used to specify an "original" recipient address that corresponds to the actual recipient to which the message is to be delivered. If the ORCPT esmtp-keyword is used, it MUST have an associated esmtp-value, which consists of the original recipient address. Compliant implementations MAY use this parameter. From [DRPT] 5.5 ESMTP - SMTP Downgrading The ESMTP extensions suggested or required for conformance to VPIM fall into two categories. The first category includes features that increase the efficiency of the transport system such as SIZE, BINARYMIME, and PIPELINING. In the event of a downgrade to a less functional transport system, these features can be dropped with no functional change to the sender or recipient. Vaudreuil, Parsons Expires January 12,2001 [Page 32]
Internet Draft VPIM v2 July 12, 2000 The second category of features is transport extensions in support of new functions. DSN and EnhancedStatusCodes provide essential improvements in the handling of delivery status notifications to bring email to the level of reliability expected of Voice Mail. To ensure a consistent level of service across an intranet or the global Internet, it is essential that VPIM compliant ESMTP support the ESMTP DSN extension at all hops between a VPIM originating system and the recipient system. In the situation where a `downgrade' is unavoidable a relay hop may be forced (by the next hop) to forward a VPIM message without the ESMTP request for positive delivery status notification. It is RECOMMENDED that the downgrading system should continue to attempt to deliver the message, but MUST send an appropriate delivery notification to the originator, e.g. the message left an ESMTP host and was sent (unreliably) via SMTP. 6. Directory Address Resolution It is the responsibility of a VPIM system to provide the fully- qualified domain name (FQDN) of the recipient based on the address entered by the user (if the entered address is not already a FQDN). This would typically be an issue on systems that offered only a telephone user interface. The mapping of the dialed target number to a routable FQDN address allowing delivery to the destination system can be accomplished through implementation-specific means. To facilitate a local cache, an implementation may wish to populate local directories with the first and last names, as well as the senders spoken name information extracted from received messages. Addresses or names parsed from the header fields of VPIM messages MAY be used to populate directories. 7. Management Protocols The Internet protocols provide a mechanism for the management of messaging systems, from the management of the physical network through the management of the message queues. SNMP should be supported on a compliant message machine. 7.1 Network Management The digital interface to the VM and the TCP/IP protocols MAY be managed. MIB II MAY be implemented to provide basic statistics and reporting of TCP and IP protocol performance. [MIB II] Vaudreuil, Parsons Expires January 12,2001 [Page 33]
Internet Draft VPIM v2 July 12, 2000 8. Conformance Requirements VPIM is a messaging application that must be supported in several environments and be supported on differing devices. These environments include traditional voice processing systems, desktop voice messaging systems, store and forward relays, and protocol translation gateways. In order to accommodate all environments, this document defines two areas of conformance: transport and content. Transport conformant systems will pass VPIM messages in a store and forward manner with assured delivery notifications and without the loss of information. It is expected that most store and forward Internet mail based messaging systems will be VPIM transport compliant. Content conformant systems will generate and interpret VPIM messages. Conformance in the generation of VPIM messages indicates that the restrictions of this profile are honored. Only contents specified in this profile or extensions agreed to by bilateral agreement may be sent. Conformance in the interpretation of VPIM messages indicates that all VPIM content types and constructs can be received; that all mandatory VPIM content types can be decoded and presented to the recipient in an appropriate manner; and that any unrenderable contents result in the appropriate notification. A summary of the compliance requirements is contained in Appendix A. VPIM end systems are expected to be both transport and content conformant. They should generate conforming content, reliably send it to the next hop system, receive a message, decode the message and present it to the user. Voice messaging systems and protocol conversion gateways are considered end systems. Relay systems are expected to be transport compliant in order to receive and send conforming messages. However, they must also create VPIM conforming delivery status notifications in the event of delivery problems. Desktop Email clients that support VPIM and are expected to be content conformant. Desktop email clients use various protocols and API's for exchanging messages with the local message store and message transport system. While these clients may benefit from VPIM transport capabilities, specific client-server requirements are out- of-scope for this document. Vaudreuil, Parsons Expires January 12,2001 [Page 34]
Internet Draft VPIM v2 July 12, 2000 9. Security Considerations 9.1 General Directive This document is a profile of existing Internet mail protocols. To maintain interoperability with Internet mail, any security to be provided should be part of the Internet security infrastructure, rather than a new mechanism or some other mechanism outside of the Internet infrastructure. 9.2 Threats and Problems Both Internet mail and voice messaging have their own set of threats and countermeasures. As such, this specification does not create any security issues not already existing in the profiled Internet mail and voice mail protocols themselves. This section attends only to the set of additional threats that ensue from integrating the two services. 9.2.1 Spoofed sender The actual sender of the voice message might not be the same as that specified in the Sender or From header fields of the message content header fields or the MAIL FROM address from the SMTP envelope. In a tightly constrained environment, sufficient physical and software controls may be able to ensure prevention of this problem. In addition, the recognition of the sender's voice may provide confidence of the sender's identity irrespective of that specified in Sender or From. It should be recognized that SMTP implementations do not provide inherent authentication of the senders of messages, nor are sites under obligation to provide such authentication. 9.2.2 Unsolicited voice mail Assigning an Internet mail address to a voice mailbox opens the possibility of receiving unsolicited messages (either text or voice mail). Traditionally voice mail systems operated in closed environments and were not susceptible to unknown senders. Voice mail users have a higher expectation of mailbox privacy and may consider such messages as a security breach. Many Internet mail systems are choosing to block all messages from unknown sources in an attempt to curb this problem. 9.2.3 Message disclosure Users of voice messaging systems have an expectation of a level of message privacy that is higher than the level provided by Internet mail without security enhancements. This expectation of privacy by users SHOULD be preserved as much as possible. Vaudreuil, Parsons Expires January 12,2001 [Page 35]
Internet Draft VPIM v2 July 12, 2000 9.3 Security Techniques Sufficient physical and software control may be acceptable in constrained environments. Further, the profile specified in this document does not in any way preclude the use of any Internet object or channel security protocol to encrypt, authenticate, or non- repudiate the messages. 10. References [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. [ADPCM] G. Vaudreuil and G. Parsons, "Toll Quality Voice - 32 kbit/s ADPCM: MIME Sub-type Registration", RFC 2422, September 1998. [AMIS-A] Audio Messaging Interchange Specifications (AMIS) - Analog Protocol Version 1, Issue 2, February 1992. [AMIS-D] Audio Messaging Interchange Specifications (AMIS) - Digital Protocol Version 1, Issue 3 August 1993. [BINARY] Vaudreuil, G., "SMTP Service Extensions for Transmission of Large and Binary MIME Messages", RFC 1830, October 1995. [CODES] Vaudreuil, G. "Enhanced Mail System Status Codes", RFC 1893, 01/15/1996. [MIMEDIR] F. Dawson, T. Howes, & M. Smith, "A MIME Content-Type for Directory Information", RFC 2425 September 1998 [DISP] R. Troost and S. Dorner, Communicating Presentation Information in Internet Messages: The Content-Disposition Header, RFC 2183, August 1997 [DNS1] Mockapetris, P., "Domain names - implementation and specification", RFC1035, Nov 1987. [DNS2] Mockapetris, P., "Domain names - concepts and facilities", RFC 1034, Nov 1987. [DRPT] Moore, K. "SMTP Service Extensions for Delivery Status Notifications", RFC 1891, 01/15/1996 [DSN] Moore, K., Vaudreuil, G., "An Extensible Message Format for Delivery Status Notifications", RFC 1894, 01/15/1996. [DUR] G. Parsons and G. Vaudreuil, "Content Duration MIME Header Definition", RFC 2424, September 1998. Vaudreuil, Parsons Expires January 12,2001 [Page 36]
Internet Draft VPIM v2 July 12, 2000 [E164] CCITT Recommendation E.164 (1991), Telephone Network and ISDN Operation, Numbering, Routing and Mobile Service - Numbering Plan for the ISDN Era. [ESMTP] Klensin, J., Freed, N., Rose, M., Stefferud, E., and D. Crocker, "SMTP Service Extensions" RFC 1869, United Nations University, Innosoft International, Inc., Dover Beach Consulting, Inc., Network Management Associates, Inc., The Branch Office, November 1995. [G726] CCITT Recommendation G.726 (1990), General Aspects of Digital Transmission Systems, Terminal Equipment - 40, 32, 24,16 kbit/s Adaptive Differential Pulse Code Modulation (ADPCM). [HOSTREQ] Braden, R., "Requirements for Internet Hosts -- Application and Support", STD 3, RFC 1123, October 1989. [LANG] Alvestrand,H., "Tags for the Identification of Languages", RFC 1766, Mar 1995 [MDN] Fajman, Roger, "An Extensible Message Format for Message Disposition Notifications" RFC 2298, March 1998 [MIB II] M. Rose, "Management Information Base for Network Management of TCP/IP-based internets: MIB-II", RFC 1158, May 1990. [MIME1] N. Freed and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies", RFC 2045, Innosoft, First Virtual, Nov 1996. [MIME2] N. Freed and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types ", RFC 2046, Innosoft, First Virtual, Nov 1996. [MIME3] K. Moore, "Multipurpose Internet Mail Extensions (MIME) Part Three: Message Header Extensions for Non-ASCII Text ", RFC 2047, University of Tennessee, Nov 1996. [MIME4] N. Freed, J. Klensin and J. Postel, "Multipurpose Internet Mail Extensions (MIME) Part Four: Registration Procedures", RFC 2048, Innosoft, MCI, ISI, Nov 1996. [MIME5] N. Freed and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part Five: Conformance Criteria and Examples ", RFC 2049, Innosoft, First Virtual, Nov 1996. [PIPE] Freed, N., Cargille, A., "SMTP Service Extension for Command Pipelining" RFC 1854, October 1995. [REPORT] Vaudreuil, G., "The Multipart/Report Content Type for the Reporting of Mail System Administrative Messages", RFC 1892, 01/15/1996. Vaudreuil, Parsons Expires January 12,2001 [Page 37]
Internet Draft VPIM v2 July 12, 2000 [REQ] S. Bradner, "Key words for use in RFCs to Indicate Requirement Levels", RFC 2119, March 1997. [RFC822] Crocker, D., "Standard for the Format of ARPA Internet Text Messages", STD 11, RFC 822, UDEL, August 1982. [SIZE] Klensin, J, Freed, N., Moore, K, "SMTP Service Extensions for Message Size Declaration" RFC 1870, United Nations University, Innosoft International, Inc., November 1995. [SMTP] Postel, J., "Simple Mail Transfer Protocol", STD 10, RFC 821, USC/Information Sciences Institute, August 1982. [STATUS] Freed, N. "SMTP Service Extension for Returning Enhanced Error Codes", RFC 2034, 10/30/1996. [TIFF-F] G. Parsons and J. Rafferty, "Tag Image File Format: Application F", RFC 2306 , March 1998. [TIFFREG] G. Parsons, J. Rafferty & S. Zilles, "Tag Image File Format: image/tiff - MIME sub-type registraion", RFC 2302, March 1998. [V-MSG] G. Vaudreuil and G. Parsons, "VPIM Voice Message MIME Sub-type Registration", RFC 2423, September 1998. [VCARD] Dawson, Frank, Howes, Tim, "vCard MIME Directory Profile" RFC 2426, September 1998. [VPIM1] Vaudreuil, Greg, "Voice Profile for Internet Mail", RFC 1911, Feb 1996. [VPIM2] Vaudreuil, Greg, Parsons, Glenn, "Voice Profile for Internet Mail, Version 2", RFC 2421, September 1998. [X.400] CCITT/ISO, "CCITT Recommendations X.400/ ISO/IEC 10021-1, Message Handling: System and Service Overview", Dec 1988. Vaudreuil, Parsons Expires January 12,2001 [Page 38]
Internet Draft VPIM v2 July 12, 2000 11. Acknowledgments The authors would like to offer a special thanks to the Electronic Messaging Association (EMA), especially the members of the Voice Messaging Committee and the VPIM Work Group, for their support of the VPIM specification and the efforts they have made to ensure its success. The EMA hosts the VPIM web page at http://www.ema.org/vpim. 12. Copyright Notice "Copyright (C) The Internet Society (2000). All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns. This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE." Vaudreuil, Parsons Expires January 12,2001 [Page 39]
Internet Draft VPIM v2 July 12, 2000 13. Authors' Addresses Glenn W. Parsons Nortel Networks P.O. Box 3511, Station C Ottawa, ON K1Y 4H7 Canada Phone: +1-613-763-7582 Fax: +1-613-763-4461 GParsons@NortelNetworks.com Gregory M. Vaudreuil Lucent Technologies 7291 Williamson Rd Dallas, TX 75214 United States Phone/Fax: +1-972-733-2722 GregV@ieee.org Vaudreuil, Parsons Expires January 12,2001 [Page 40]
Internet Draft VPIM v2 July 12, 2000 14. Appendix A - VPIM Requirements Summary The following table summarizes the profile of VPIM version 2 detailed in this document. Since in many cases it is not possible to simplify the qualifications for supporting each feature this appendix is informative. The reader is recommended to read the complete explanation of each feature in the referenced section. The text in the previous sections shall be deemed authoritative if any item in this table is ambiguous. The conformance table is separated into various columns: Feature - name of protocol feature (note that the indenting indicates a hierarchy of conformance, i.e. the conformance of a lower feature is only relevant if there is conformance to the higher feature) Section - reference section in main text of this document Area - conformance area to which each feature applies: C - content T - transport Status - whether the feature is mandatory, optional, or prohibited. The key words used in this table are to be interpreted as described in [REQ], though the following list gives a quick overview of the different degrees of feature conformance: Must - mandatory Should - required in the absence of a compelling need to omit. May - optional Should not - prohibited in the absence of a compelling need. Must not - prohibited Footnote - special comment about conformance for a particular feature Vaudreuil, Parsons Expires January 12,2001 [Page 41]
Internet Draft VPIM v2 July 12, 2000 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 non-mail-user@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| | | Return-Path |4.2.6 |C| | | |x| | Message-id |4.2.7 |C|x| | | | | Reply-To |4.2.8 |C| | | |x| | Received |4.2.9 |C|x| | | | | MIME Version: 1.0 (Voice 2.0) |4.2.10 |C| |x| | | | Content-Type |4.2.11 |C|x| | | | | Content-Transfer-Encoding |4.2.12 |C|x| | | | | Sensitivity |4.2.13 |C| | |x| | | Importance |4.2.14 |C| | |x| | | Subject |4.2.15 |C| |x| | | | Disposition-notification-to |4.2.16 |C| | |x| | | Disposition-notification-options |4.2.17 |C| | |x| | | Other Headers |4.2 |C| | |x| | | | | | | | | | | Vaudreuil, Parsons Expires January 12,2001 [Page 42]
Internet Draft VPIM v2 July 12, 2000 | | | | |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 -------------------------------------------|----------|-|-|-|-|-|-|- Detection & Decoding inbound messages | | | | | | | | From |4.2.1 |C|x| | | | | Present text personal name |4.2.1 |C| | |x| | | To |4.2.2 |C|x| | | | | cc |4.2.3 |C| | |x| | | Date |4.2.4 |C|x| | | | | Conversion of Date to local time |4.2.4 |C| |x| | | | Sender |4.2.5 |C| | |x| | | Return-Path |4.2.6 |C| |x| | | | Message ID |4.2.7 |C|x| | | | | Reply-To |4.2.8 |C| | |x| | | Received |4.2.9 |C| | |x| | | MIME Version: 1.0 (Voice 2.0) |4.2.10 |C| |x| | | | Content Type |4.2.11 |C|x| | | | | Content-Transfer-Encoding |4.2.12 |C|x| | | | | Sensitivity |4.2.13 |C|x| | | | |2 Importance |4.2.14 |C| | |x| | | Subject |4.2.15 |C| | |x| | | Disposition-notification-to |4.2.16 |C| | |x| | | Disposition-notification-options |4.2.17 |C| | | |x| | Other Headers |4.2 |C|x| | | | |3 | | | | | | | | Message Content Encoding: | | | | | | | | Encoding outbound audio/fax contents | | | | | | | | 7BIT |4 |C| | | | |x| 8BIT |4 |C| | | | |x| Quoted Printable |4 |C| | | | |x| Base64 |4 |C|x| | | | |4 Binary |4 |C| |x| | | |5 Detection & decoding inbound messages | | | | | | | | 7BIT |4 |C|x| | | | | 8BIT |4 |C|x| | | | | Quoted Printable |4 |C|x| | | | | Base64 |4 |C|x| | | | | Binary |4 |C|x| | | | |5 | | | | | | | | Vaudreuil, Parsons Expires January 12,2001 [Page 43]
Internet Draft VPIM v2 July 12, 2000 | | | | |S| | | | | | | |H| |F | | | | | |O|M|o | | | |S| |U|U|o | | | |H| |L|S|t | |A|M|O| |D|T|n | |R|U|U|M| | |o | |E|S|L|A|N|N|t | |A|T|D|Y|O|O|t FEATURE |SECTION | | | | |T|T|e -------------------------------------------|----------|-|-|-|-|-|-|- Message Content Types: | | | | | | | | Inclusion in outbound messages | | | | | | | | Multipart/Voice-Message |4.4.1 |C|x| | | | | Message/RFC822 |4.4.2 |C| | |x| | | Audio/32KADPCM |4.4.4 |C|x| | | | | Content-Description |4.3.1 |C| | |x| | | Content-Disposition |4.3.2 |C|x| | | | | Content-Duration |4.3.3 |C| | |x| | | Content-Language |4.3.4 |C| | |x| | | Image/tiff; application=faxbw |4.4.5 |C| | |x| | | Audio/* or Image/* (other encodings) |4.4.6 |C| | |x| | | Other contents |4.4 |C| | | | |x| Multipart/Mixed |4.4.7 |C| | |x| | | Text/plain |4.4.8 |C| | | |x| | Multipart/Report |4.5.1 |C|x| | | | | human-readable part is voice |4.5.1 |C| |x| | | | human-readable part is text |4.5.1 |C| | |x| | | Message/delivery-status |4.5.2 |C|x| | | | | Message/disposition-notification |4.5.3 |C| |x| | | | Other contents |4.4 |C| | |x| | |6 | | | | | | | | Detection & decoding in inbound messages | | | | | | | | Multipart/Voice-Message |4.4.1 |C|x| | | | | Message/RFC822 |4.4.2 |C|x| | | | | Text/Directory |4.4.3 |C|x| | | | | Audio/32KADPCM |4.4.4 |C|x| | | | | Content-Description |4.3.1 |C| | |x| | | Content-Disposition |4.3.2 |C| |x| | | | Content-Duration |4.3.3 |C| | |x| | | Content-Langauge |4.3.4 |C| | |x| | | Image/tiff; application=faxbw |4.4.5 |C| |x| | | |7 Audio/* or Image/* (other encodings) |4.4.6 |C| | |x| | | Other contents |4.4 |C| | | |x| | Multipart/Mixed |4.4.7 |C|x| | | | | Text/plain |4.4.8 |C|x| | | | | send NDN if unable to render |4.4.8 |C|x| | | | | Vaudreuil, Parsons Expires January 12,2001 [Page 44]
Internet Draft VPIM v2 July 12, 2000 | | | | | |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 ------------------------------------------|-----------|-|-|-|-|-|-|- | | | | | | | | Multipart/Report |4.5.1 |C|x| | | | | human-readable part is voice |4.5.1 |C| |x| | | | human-readable part is text |4.5.1 |C|x| | | | | Message/delivery-status |4.5.2 |C|x| | | | | Message/disposition-notification |4.5.3 |C| |x| | | | Other contents |4.4 |C| | |x| | |6 send NDN if unable to render |4.4 |C| |x| | | | | | | | | | | | Forwarded Messages | | | | | | | | use Message/RFC822 construct |4.6 |C| |x| | | | simulate headers if none available |4.6 |C| |x| | | | | | | | | | | | Reply Messages | | | | | | | | send to Reply-to, else From address |4.7 |C|x| | | | | send to non-mail-user |4.7 |C| | | |x| | | | | | | | | | Notifications | | | | | | | | use multipart/report format |4.8 |C|x| | | | | always send error on non-delivery |4.8 |C| |x| | | | | | | | | | | | Message Transport Protocol: | | | | | | | | ESMTP Commands | | | | | | | | HELO |5.1.1 |T|x| | | | | MAIL FROM |5.1.2 |T|x| | | | | support null address |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| | |5 Vaudreuil, Parsons Expires January 12,2001 [Page 45]
Internet Draft VPIM v2 July 12, 2000 | | | | |S| | | | | | | |H| |F | | | | | |O|M|o | | | |S| |U|U|o | | | |H| |L|S|t | |A|M|O| |D|T|n | |R|U|U|M| | |o | |E|S|L|A|N|N|t | |A|T|D|Y|O|O|t FEATURE |SECTION | | | | |T|T|e -------------------------------------------|----------|-|-|-|-|-|-|- | | | | | | | | ESMTP Keywords & Parameters | | | | | | | | 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| | | DSN |5.2.5 |T|x| | | | | ENHANCEDSTATUSCODES |5.2.6 |T| |x| | | | RET |5.3.2 |T| |x| | | | ENVID |5.3.3 |T| | |x| | | NOTIFY |5.4.1 |T|x| | | | | ORCPT |5.4.2 |T| | |x| | | | | | | | | | | ESMTP-SMTP Downgrading | | | | | | | | send delivery report upon downgrade |5.5 |T|x| | | | | | | | | | | | | Directory Address Resolution | | | | | | | | provide facility to resolve addresses |6 |C| |x| | | | use headers to populate local directory |6 |C| | |x| | | | | | | | | | | Management Protocols: | | | | | | | | Network management |7.1 |T| | |x| | | -------------------------------------------|----------|-|-|-|-|-|-|- Footnotes: 1. SHOULD leave blank if all recipients are not known or resolvable. 2. If a sensitive message is received by a system that does not support sensitivity, then it MUST be returned to the originator with an appropriate error notification. Also, a received sensitive message MUST NOT be forwarded to anyone. 3. If the additional header fields are not understood they MAY be ignored 4. When binary transport is not available 5. When binary transport is available 6. Other un-profiled contents must only be sent by bilateral agreement. 7. If the content cannot be presented or acknowledged in some form, the entire message MUST be returned with a negative delivery status notification. Vaudreuil, Parsons Expires January 12,2001 [Page 46]
Internet Draft VPIM v2 July 12, 2000 8. When the vCard is present in a message Vaudreuil, Parsons Expires January 12,2001 [Page 47]
Internet Draft VPIM v2 July 12, 2000 15. Appendix B - Example Voice Messages The following message is a full-featured message addressed to two recipients. The message includes the sender's spoken name, spoken subject and a short speech segment. The message is marked as important and private. To: +19725551212@vm1.mycompany.com To: +16135551234@VM1.mycompany.com From: "Parsons, Glenn" <12145551234@VM2.mycompany.com> Date: Mon, 26 Aug 93 10:20:20 -0700 (CDT) MIME-Version: 1.0 (Voice 2.0) Content-type: Multipart/Voice-Message; Version=2.0; Boundary="MessageBoundary" Content-Transfer-Encoding: 7bit Message-ID: 123456789@VM2.mycompany.com Sensitivity: Private Importance: High --MessageBoundary Content-type: Audio/32KADPCM Content-Transfer-Encoding: Base64 Content-Disposition: inline; voice=Originator-Spoken-Name Content-Language: en-US Content-ID: part1@VM2-4321 glslfdslsertiflkTfpgkTportrpkTpfgTpoiTpdadasssdasddasdasd (This is a sample of the base-64 Spoken Name data) fgdhgddlkgpokpeowrit09== --MessageBoundary Content-type: Audio/32KADPCM Content-Transfer-Encoding: Base64 Content-Disposition: inline; voice=Spoken-Subject Content-Language: en-US Content-ID: part2@VM2-4321 glslfdslsertiflkTfpgkTportrpkTpfgTpoiTpdadasssdasddasdasd (This is a sample of the base-64 Spoken Subject data) fgdhgddlkgpokpeowrit09== --MessageBoundary Content-type: Audio/32KADPCM Content-Transfer-Encoding: Base64 Content-Description: Brand X Voice Message Content-Disposition: inline; voice=Voice-Message; filename=msg1.726 Content-Duration: 25 iIiIiIjMzN3czdze3s7d7fwfHhcvESJVe/4yEhLz8/FOQjVFRERCESL/zqrq (This is a sample of the base64 message data) zb8tFdLTQt1PXj u7wjOyRhws+krdns7Rju0t4tLF7cE0K0MxOTOnRW/Pn30c8uHi9== Vaudreuil, Parsons Expires January 12,2001 [Page 48]
Internet Draft VPIM v2 July 12, 2000 --MessageBoundary_ The following message is a forwarded single segment voice. Both the forwarded message and the forwarding message contain the senders spoken names. To: +12145551212@vm1.mycompany.com From: "Vaudreuil, Greg" <+19725552345@VM2.mycompany.com> Date: Mon, 26 Aug 93 10:20:20 -0700 (CDT) MIME-Version: 1.0 (Voice 2.0) Content-type: Multipart/Voice-Message; Version=2.0; Boundary="MessageBoundary" Content-Transfer-Encoding: 7bit Message-ID: ABCD-123456789@VM2.mycompany.com --MessageBoundary Content-type: Audio/32KADPCM Content-Transfer-Encoding: Base64 Content-Disposition: inline; voice=Originator-Spoken-Name Content-Language: en-US Content-ID: part3@VM2-4321 glslfdslsertiflkTfpgkTportrpkTpfgTpoiTpdadasssdasddasdasd (This is a sample of the base-64 Spoken Name data) fgdhgd dlkgpokpeowrit09== --MessageBoundary Content-type: Audio/32KADPCM Content-Description: Forwarded Message Annotation Content-Disposition: inline; voice=Voice-Message Content-Transfer-Encoding: Base64 glslfdslsertiflkTfpgkTportrpkTpfgTpoiTpdadasssdasddasdasd (This is the voiced introductory remarks encoded in base64) jrgoij3o45itj09fiuvdkjgWlakgQ93ijkpokfpgokQ90gQ5tkjpokfgW dlkgpokpeowrit09== --MessageBoundary Content-type: Message/RFC822 Content-Transfer-Encoding: 7bit To: +19725552345@VM2.mycompany.com From: "Parsons, Glenn, W." <+16135551234@VM1.mycompany.com> Date: Mon, 26 Aug 93 8:23:10 -0500 (EST) Content-type: Multipart/Voice-Message; Version=2.0; Boundary="MessageBoundary2" Content-Transfer-Encoding: 7bit MIME-Version: 1.0 (Voice 2.0) Vaudreuil, Parsons Expires January 12,2001 [Page 49]
Internet Draft VPIM v2 July 12, 2000 --MessageBoundary2 Content-type: Audio/32KADPCM Content-Transfer-Encoding: Base64 Content-Disposition: inline; voice=Originator-Spoken-Name Content-Language: en-US Content-ID: part6@VM2-4321 glslfdslsertiflkTfpgkTportrpkTpfgTpoiTpdadasssdasddasdasd (This is a sample of the base-64 Spoken Name data) fgdhgd dlkgpokpeowrit09== --MessageBoundary2 Content-type: Audio/32KADPCM Content-Disposition: inline; voice=Voice-Message Content-Transfer-Encoding: Base64 glslfdslsertiflkTfpgkTportrpkTpfgTpoiTpdadasssdasddasdasd (This is the original message audio data) fgwersdfmniwrjj jrgoij3o45itj09fiuvdkjgWlakgQ93ijkpokfpgokQ90gQ5tkjpokfgW dlkgpokpeowrit09== --MessageBoundary2-- --MessageBoundary-- Vaudreuil, Parsons Expires January 12,2001 [Page 50]
Internet Draft VPIM v2 July 12, 2000 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 <MAILER-DAEMON@vm.company.com> Message-Id: <199407072116.RAA14128@vm1.company.com> Subject: Returned voice message To: 2175552345@VM2.mycompany.com MIME-Version: 1.0 (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-Description: Spoken Delivery Status Notification Content-Disposition: inline; voice= Voice-Message-Notification Content-Transfer-Encoding: Base64 glslfdslsertiflkTfpgkTportrpkTpfgTpoiTpdadadffsssddasdasd (This is a voiced description of the error in base64) jrgoij3o45itj09fiuvdkjgWlakgQ93ijkpokfpgokQ90gdffkjpokfgW dlkgpokpeowrit09== --RAA14128.773615765/VM1.COMPANY.COM Content-type: message/delivery-status Reporting-MTA: dns; vm1.company.com Original-Recipient: rfc822; 2145551234@VM1.mycompany.com Final-Recipient: rfc822; 2145551234@VM1.mycompany.com Action: failed Status: 5.1.1 (User does not exist) Diagnostic-Code: smtp; 550 Mailbox not found Last-Attempt-Date: Thu, 7 Jul 1994 17:15:49 -0400 --RAA14128.773615765/VM1.COMPANY.COM content-type: message/rfc822 [original VPIM message goes here] --RAA14128.773615765/VM1.COMPANY.COM-- Vaudreuil, Parsons Expires January 12,2001 [Page 51]
Internet Draft VPIM v2 July 12, 2000 The following example is for a receipt notification sent to the original sender for a message which has been played. This delivered VPIM message was received by a corporate gateway and relayed to a unified mailbox. Date: Thu, 7 Jul 1994 17:16:05 -0400 From: "Greg Vaudreuil" <22722@vm.company.com> Message-Id: <199407072116.RAA14128@exchange.company.com> Subject: Voice message played To: 2175552345@VM2.mycompany.com MIME-Version: 1.0 (Voice 2.0) Content-Type: multipart/report; Report-type=disposition-notification; Boundary="RAA14128.773615765/EXCHANGE.COMPANY.COM" --RAA14128.773615765/EXCHANGE.COMPANY.COM Content-type: Audio/32KADPCM Content-Description: Spoken Disposition Notification Content-Disposition: inline; voice= Voice-Message-Notification Content-Transfer-Encoding: Base64 glslfdslsertiflkTfpgkTportrpkTpfgTpoiTpdadadffsssddasdasd (Voiced description of the disposition action in base64) jrgoij3o45itj09fiuvdkjgWlakgQ93ijkpokfpgokQ90gdffkjpokfgW dlkgpokpeowrit09== --RAA14128.773615765/EXCHANGE.COMPANY.COM Content-type: message/disposition-notification Reporting-UA: gregs-laptop.dallas.company.com (Unified FooMail 3.0) Original-Recipient: rfc822;22722@vm.company.com Final-Recipient: rfc822;Greg.Vaudreuil@foomail.company.com Original-Message-ID: <199509192301.12345@vm2.mycompany.com > Disposition: manual-action/MDN-sent-automatically; displayed --RAA14128.773615765/EXCHANGE.COMPANY.COM Content-type: message/rfc822 [original VPIM message goes here] --RAA14128.773615765/EXCHANGE.COMPANY.COM-- Vaudreuil, Parsons Expires January 12,2001 [Page 52]
Internet Draft VPIM v2 July 12, 2000 16. Appendix C - Example Error Voice Processing Error Codes The following common voice processing errors and their corresponding status codes are given as examples. The text after the error codes is intended only for reference to describe the error code. Implementations should provide implementation specific informative comments after the error code rather than the text below. Error condition RFC 1893 Error codes ----------------------------- -------------------------------- Analog delivery failed 4.4.0 Persistent connection error because remote system is busy - other Analog delivery failed 4.4.1 Persistent protocol error because remote system is - no answer from host ring-no-answer Remote system did not answer 5.5.5 Permanent protocol error AMIS-Analog handshake ("D" in - wrong version response to "C" at connect time) Mailbox does not exist 5.1.1 Permanent mailbox error - does not exist Mailbox full or over quota 4.2.2 Persistent mailbox error - full Disk full 4.3.1 Persistent system error - full Command out of sequence 5.5.1 Permanent protocol error - invalid command Frame Error 5.5.2 Permanent protocol error - syntax error Mailbox does not support FAX 5.6.1 Permanent media error - not supported Mailbox does not support TEXT 5.6.1 Permanent media error - not supported Sender is not authorized 5.7.1 Permanent security error - sender not authorized Message marked private, but 5.3.3 Permanent system error system is not private capable - not feature capable Vaudreuil, Parsons Expires January 12,2001 [Page 53]
Internet Draft VPIM v2 July 12, 2000 17. Appendix D - Example Voice Processing Disposition Types The following common voice processing disposition conditions and their corresponding MDN Disposition (which contains the disposition mode, type and modifier, if applicable) are given as examples. Implementers should refer to [MDN] for a full description of the format of message disposition notifications. Notification event MDN Disposition mode, type & modifier ------------------------------ ------------------------------------ Message played by recipient, manual-action/MDN-sent-automatically; receipt automatically returned displayed Message deleted from mailbox manual-action/MDN-sent-automatically; by user without listening deleted Message cleared when mailbox manual-action/MDN-sent-automatically; deleted by admin deleted/mailbox-terminated Message automatically deleted automatic-action/ when older than administrator MDN-sent-automatically; deleted/ set threshold expired Message processed, however manual-action/MDN-sent-automatically; audio encoding unknown - processed/error unable to play to user Error: unknown audio encoding Vaudreuil, Parsons Expires January 12,2001 [Page 54]
Internet Draft VPIM v2 July 12, 2000 18. Appendix E - IANA Registrations There are no changes to the registrations of the voice content disposition parameter defined in the earlier VPIM V2 document, RFC 2421. It is presented here for information. 18.1 Voice Content-Disposition Parameter Definition To: IANA@IANA.ORG Subject: Registration of new Content-Disposition parameter Content-Disposition parameter name: voice Allowable values for this parameter: Voice-Message - the primary voice message, Voice-Message-Notification - a spoken delivery notification or spoken disposition notification, Originator-Spoken-Name - the spoken name of the originator, Recipient-Spoken-Name - the spoken name of the recipient if available to the originator and present if there is ONLY one recipient, Spoken-Subject- the spoken subject of the message, typically spoken by the originator Description: In order to distinguish between the various types of audio contents in a VPIM voice message a new disposition parameter "voice" is defined with the preceding values to be used as appropriate. Note that there SHOULD only be one instance of each of these types of audio contents per message level. Additional instances of a given type (i.e., parameter value) may occur within an attached forwarded voice message. Vaudreuil, Parsons Expires January 12,2001 [Page 55]
Internet Draft VPIM v2 July 12, 2000 19. Appendix F - Change History: RFC 2421 (VPIM V2) to this Document The updated profile in this document is based on the implementation and operational deployment experience of several vendors. The changes are categorized as general, content, transport and compliance. They are summarized below: 1. General - Various and substantial editorial updates to improve readability. - Separated send rules from reception rules to aid clarity. Clarified the behavior upon reception of unrecognized content types (eg. Unsupported non-audio contents should be discarded to deliver the audio message.) expected with the interworking between voice and unified messaging systems. - added _ Normal_ sensitivity for consistency - should not use MDN Content-Disposition options - reorganized the content type descriptions for clarity 2. Content - Changed handling of received lines by a gateway to SHOULD NOT delete in a gateway. In gateways to systems such as AMIS, it is not possible to preserve this information. It is intended that such systems be able to claim conformance. - Eliminated the vCard as a supported VPIM V2 content type. 3. Transport - None 4. Compliance - Aligned the table of Appendix A to the requirements in the text. Vaudreuil, Parsons Expires January 12,2001 [Page 56]
