Internet Draft D. Dunne Document: draft-ema-vpim-cb-00.txt Nortel Networks Category: Informational G. Parsons Expires in Six Months Nortel Networks July 14, 2000 Voice Messaging IMAP Client Behaviour STATUS OF THIS MEMO: This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. 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 draft documents 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 "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. Abstract This document defines the expected behaviour of an IMAP client to various aspects of a VPIM message. Table of Contents 1. Introduction 1.1 Conventions Used in This Document 2. Message Icon 2.1 Proposed Mechanism 3. Sender's Number Column 3.1 Proposed Mechanism 4. Message Size 4.1 Proposed Mechanism 5. Media Viewer 5.1 Proposed Mechanism 6. Mark Message Read only if Primary Content Read 7. Security Considerations 8. References 9. Acknowledgements Dunne & Parsons Informational [Page 1]
Internet Draft Voice Messaging IMAP Client Behaviour July 2000 10. Author's Address 11. Full Copyright Statement Dunne & Parsons Informational [Page 2]
Internet Draft Voice Messaging IMAP Client Behaviour July 2000 1. Introduction As Internet messaging evolves into Unified messaging, the term "e- mail" no longer refers to text-only messages. Today's "e-mail" can also have voice and/or fax parts, as well as text. Each of voice, fax, and text have their own distinct characteristics, which are intuitive to the user. For example, each of these message types require a different media viewer (text editor for text, audio player for voice, and image viewer for fax), and the dimensions of message size are also different for all three (kilobytes for text, seconds for voice, and pages for fax). How the messaging client responds to, and acts on these differences is termed "Client Behaviour". This is heavily dependant on the concept of "Primary Content" [2], which defines whether the message is a voice mail, fax, or text message. The client can utilize this header to determine the appropriate behaviour for a particular message. Note that this document deals only with IMAP clients. Where appropriate, this document suggests how some of the desired behaviours may be implemented using IMAP, but these should be properly defined in other specifications. 1.1 Conventions Used in This Document In examples, "C:" and "S:" indicate lines sent by the client and server respectively. 2. Message Icon The preferred method to distinguish between voice, fax, and text messages is with a visual cue, or icon. As it is possible for the message to contain more than one media type, the icon should describe the primary message content, as defined by the "Primary-Content" header. Obvious choices for the icon/message pairs would be a telephone for a voice message, a fax machine for a fax message, and an envelope for a text message. This could be taken a step further, and have the icon change to indicate that the message has been read (as is currently done in many email clients). For example, a telephone with the receiver off- hook could indicate that the voice message has been played. A fax machine with paper at the bottom, as opposed to the top, would show that the fax had been viewed. Finally, as is currently the norm, an open envelope indicates that a text message has been read. 2.1 Proposed Mechanism Dunne & Parsons Informational [Page 3]
Internet Draft Voice Messaging IMAP Client Behaviour July 2000 As the choice of icon is determined by the primary message type, the client should obtain this information from the "Primary-Content" message header. This header is defined in the Internet Draft draft- burger-vpim-pc-00.txt [2]. 3. Sender's Number Column As is the case with most email clients today, important message information is organized into columns when presented to the user. Typical columns include the message subject, and the date the message was received. Another important piece of information for the user is the origin of the message. For a voice or fax message, the origin is typically a telephone or fax machine respectively, each of which has an associated telephone number. This telephone number is critical to the user if they wish to return the call. 3.1 Proposed Mechanism There is currently a proposal to add a new Internet message header to hold the originating telephone number [3]. The client should extract this information, and display it to the user in a column. As this header is defined to only hold the digits of the telephone number, it is left to the client to add any separating characters (e.g. "-"). 4. Message Size In the cases of large attachments, small clients and slow links there is also a need for the client to see the length of the message in a suitable format before opening it. Currently, message size is normally given in kilobytes (kB). This is sufficient for plain text messages, but it is not very useful in terms of voice and fax. Instead, the size should give an indication of the length of the message, i.e. the duration (in seconds) of a voice message, and the number of pages of a fax. Again, the message may contain multiple types, so the size displayed should be that of the primary content type. 4.1 Proposed Mechanism There are three suggested methods to relay this information, of them, method 1 is favoured: 4.1.1 MIME Header Content-Duration as described in RFC 2424 [5] For fax messages a new MIME Header, Content-Page-Length, would be defined, similar to Content-Duration with the exception that number of pages would be specified, rather than number of seconds. (e.g. Content-Page-Length:3). This would be created at originator. Dunne & Parsons Informational [Page 4]
Internet Draft Voice Messaging IMAP Client Behaviour July 2000 4.1.2 FETCH item USERSIZE similar to FETCH items described in IMAP4rev1 [6]. This would be created at reception. 4.1.2.1 USERSIZE is a non-negative number. Its meaning depends on document type. C: abc FETCH 1:2 (USERSIZE) S: *1 FETCH (12) S: *2 FETCH (57) S: abc FETCH completed. 4.1.2.2 USERSIZE is a pair of number and unit. There is a small set of unit tokens. C: abc FETCH 1:2 (USERSIZE) S: *1 FETCH (12 pages) S: *2 FETCH (57 seconds) S: abc FETCH completed. 4.1.2.3 USERSIZE is a sequence of pairs, in case something extends in more than one unit. C: abc FETCH 1:2 (USERSIZE) S: *1 FETCH (12 lines) S: *1 FETCH (57 pages 6 hours) S: abc FETCH completed. Servers that support USERSIZE SHOULD list the USERSIZE capability in response to the CAPABILITY command. 4.1.3 Message length indicated as a parameter of an existing Header Field [7]. This would be created at the source. This method would allow the message length to be passed to the client by default. 4.1.3.1 Content-Type Header Field Content-Type=audio/*; length=50 Content-Type=image/tiff; pages=3 4.1.3.2 Subject Header Field Subject=Voice Message (0:04) Subject=Fax Message (3) The advantage of the subject field is that it is automatically displayed to the user. 5. Media Viewer Dunne & Parsons Informational [Page 5]
Internet Draft Voice Messaging IMAP Client Behaviour July 2000 When a message is initially opened, the client should, by default, open the proper media viewer to display the primary message content, i.e. an audio player for voice messages, image viewer for fax, and text editor for text messages. Where there is more than one body part, obviously the appropriate viewer should be used depending on which body part the user has selected. In the case where several viewers are available for a single media type, the user should be prompted to select the desired viewer on the first occasion that the message type is encountered. That viewer should then become the default viewer for that media type. The user should have the ability to change the default viewer for a media type at any time. 5.1 Proposed Mechanism As mentioned, the default viewer displayed to the user should be the appropriate one for the primary message type. The client is able to determine the primary message type from the "Primary-Content" message header. This header is defined in the Internet Draft draft- burger-vpim-pc-00.txt [2]. 6. Mark Message as Read Obviously, the user must be able to know which messages they have read, and which are unread. This feature would also control the message icon as mentioned in section 1. With the use of multipart messages there should be a separate BODY PART READ indicator for each body part or, at least, to only indicate READ when the primary body part has been read. There are two suggested methods. Favoured is method 2. IMAP4rev1 servers that support body part read indicators SHOULD list the keyword SEEN-BY-PART in response to the CAPABILITY command. 6.1 Proposed Mechanism 6.1.1 \SEEN per BODY PART For example, if a client retrieves the text part of a message without looking at the audio attachment, the indicator would show that only the text part had been read and not the entire message. 6.1.2 \SEEN only after Primary Message Type has been opened. Primary Message Type is discussed in VPIM Unified Message [8]. In the case of multiple attachments the \SEEN flag would be set after the first attachment of the primary content type has been opened. Dunne & Parsons Informational [Page 6]
Internet Draft Voice Messaging IMAP Client Behaviour July 2000 For example, if the primary content type is multipart/voice-message, the \SEEN flag would be set after the first voice message is opened. This could be the spoken name of the sender or the spoken subject as opposed to the actual voice message. 7. Security Considerations The desirable client behaviours described here are intended to provide the user with a better desktop experience. However, it is open to the same risks as any IMAP client. That is, the client is not responsible for the format of the message received, it only interprets. As a result, messages could be spoofed or masqueraded to look like a message they are not to elicit a desired client behaviour. This could be used to fool the end user, for example, into thinking a message was a voice message (because of the icon) when it was not. 8. References 1. Parsons, G., Vaudreuil, G., "Voice Profile for Internet Mail - version 2", draft-ema-vpim-vpimv2r2-02.txt, October 1999 2. Burger, E., Candell, E., "Primary Content of Internet Mail", draft-burger-vpim-pc-00.txt, Work in Progress 3. Dunne, D., "Calling Line Identification for VPIM Messages", draft- ema-vpim-clid-00.txt, Work in Progress 4. Parsons, G., "IMAP Voice Extensions", draft-ema-vpim-imap-01.txt, June 1999 5. Vaudreuil, G., Parsons, G., "Content Duration MIME Header Definition", RFC2424, September 1998 6. Crispin, M., "Internet Message Access Protocol - Version 4rev1", RFC 2060, December 1996 7. Freed, N., Borenstein, N., "Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies", RFC 2045, November 1996 8. Parsons, G., Cohen, M., Vaudreuil, G., "VPIM Unified Message MIME Sub-Type Registration", <draft-ema-vpim-um-01.txt>, Work In Progress 9. Schulzrinne, H., Rao, A., Lanphier, R., "Real Time Streaming Protocol (RTSP)", RFC 2326, April 1998 10. Newman, C., "IMAP URL Scheme", RFC 2192, September 1997 9 Acknowledgements The "Proposed Mechanism" of sections 4 and 6 of this document are borrowed from draft-ema-vpim-imap-01.txt [4]. The authors would like to acknowledge all those who contributed to that document. 10. Author's Address Derrick Dunne Nortel Networks P.O. Box 3511, Station C Ottawa, ON Dunne & Parsons Informational [Page 7]
Internet Draft Voice Messaging IMAP Client Behaviour July 2000 K1Y 4H7 Phone:+1-613-768-4087 Fax: +1-613-763-4461 Email:dunned@nortelnetworks.com Glenn Parsons Nortel Networks P.O. Box 3511, Station C Ottawa, ON K1Y 4H7 Phone: +1-613-763-7582 Fax: +1-613-763-4461 Email: gparsons@nortelnetworks.com 11. Full Copyright Statement Copyright (C) The Internet Society (1999). 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. Dunne & Parsons Informational [Page 8]
