Internet Draft Anne Brown Expires in six months Nortel Networks Greg Vaudreuil Lucent Technologies July 13, 2000 Voice Messaging Directory Service 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". 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. 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 (2000). All Rights Reserved. This Internet-Draft is in conformance with Section 10 of RFC2026. Overview This document provides details of the VPIM directory service. The service provides the email address of the recipient given a telephone number. It optionally provides the spoken name of the recipient and the media capabilities of the recipient. Please send comments on this document to the VPIM working group mailing list Internet Draft VPIM Directory December 1, 2000 Working Group Summary This document is a synthesis of two earlier Internet drafts that define a voice messaging schema's into a single working group submission. These documents are Anne Brown's and Greg Vaudreuil's . Vaudreuil, Parsons Expires 5/1/00 [Page 2] Internet Draft VPIM Directory December 1, 2000 Table of Contents 1. ABSTRACT ..........................................................4 2. SCOPE .............................................................4 2.1 Design Goals ....................................................4 3. ADDRESS VALIDATION SERVER DISCOVERY ....ERROR! BOOKMARK NOT DEFINED. 4. ADDRESS VALIDATION SERVICE (AVS) ..................................4 4.1 vPIMrfc822Mailbox ...............................................5 4.2 vPIMSpokenName ..................................................6 4.3 vPIMTextName ....................................................6 4.4 vPIMSupportedEncodingTypes ......................................6 4.5 extendedAbsenceStatus ...........................................7 4.6 supportedUABehaviors ............................................7 4.7 Maximum Message Size ............................................8 4.8 subMailbox ......................................................8 4.9 mailRecipient ........................Error! Bookmark not defined. 5. SECURITY CONSIDERATIONS ...........................................9 6. REFERENCES ........................................................9 7. ACKNOWLEDGMENTS ..................................................10 8. COPYRIGHT NOTICE .................................................10 9. AUTHORS' ADDRESSES ...............................................10 Vaudreuil, Parsons Expires 5/1/00 [Page 3] Internet Draft VPIM Directory December 1, 2000 1. Abstract 2. Scope 2.1 Design Goals The VPIM directory Schema (VPIMDIR) is accessed from outside the enterprise or service provider domain using the recipients telephone number. 2.2 Performance Constraints Once the identity of the VPIM directory server is known, the email address, capabilities, and spoken name confirmation information can be retreived. This query is expected to use LDAP, a connection-oriented protocol. The protocol transaction includes multiple packet round- trip to execute the query and retreival and is considered to be the most at-risk element of the infrastructure. Further, retreival of the confirmation information may require the return of a spoken name segment up to 20kbytes (5 seconds at 4kbytes/second). Over a sufficiently engineered Internet connection, a 1250 ms response time is believed to be achievable over the Internet at large. 2.3 Scaling Constraints A service provider's namespace is expected to include several million- subscriber entries based on the VPIM inter-domain address form: telephone number@domain_name. A large corporation may have a hundred- thousand entries. It is expected that there will be a single public address validation service for a given service providers network. It is believed that existing directory technology will provide sufficient transaction throughput within the required latency requirements to address this need. The only fundamental new requirement this application imposes on directory servers beyond similar existing services is the ability to return the recipients spoken name, a record an order of magnitude larger than common textual elements. Preliminary investigation suggests that storage and retreival of spoken name will not add appreciable latency, however it will add to the need for storage capacity. 2.4 Reliability Constraints DNS provides well-documented redundancy and load-ballancing capabilities for the VPIMDIR. These capabilities appear to meet the unstated reliability requirements of this service. 3. The VPIM Directory Schema VPIMUser OBJECT-CLASS ::= { STRUCTURAL SUBCLASS OF top MUST CONTAIN Vaudreuil, Parsons Expires 5/1/00 [Page 4] Internet Draft VPIM Directory December 1, 2000 (vPIMrfc822Mailbox, telephoneNumber ) MAY CONTAIN (vPIMSpokenName $ vPIMsupportedUABehaviors $ vPIMSupportedEncodingTypes $ vPIMTextName $ extendedAbsenceStatus $ vPIMMaxMessageSize $ subMailbox) ID } The vPIMUser is a structural object indexed by the telephoneNumber. When present, the vPIMUser may contain information useful to validate that the dialed telephone number corresponds to the intended recipient. This object may further provide capabilities information and mailbox status information useful to guide composition by the sending user and to set delivery expectations at sending time. 3.1 TelephoneNumber The normal search is for the E164 form of the telephone number, including any sub-addressing information provided by the sender. telephoneNumber ATTRIBUTE ::= { WITH SYNTAX caseIgnoreIA5StringSyntax (SIZE (1 .. 20)) -- from RFC 1274 ID ?? } 3.2 vPIMrfc822Mailbox The attribute vPIMrfc822Mailbox stores the inter-domain SMTP address of the voice mailbox associated with a given telephone number. It is defined as a distinct attribute to distinguish it from the rfc822Mailbox attribute that may be used for other purposes. Although it would be preferable to define vPIMrfc822Mailbox as a subtype of rfc822Mailbox, it is defined here as an entirely new attribute because some directory implementations do not support sub-typing. ASN.1 definition: vPIMrfc822Mailbox ATTRIBUTE ::= { WITH SYNTAX caseIgnoreIA5StringSyntax (SIZE (1 .. 64)) -- from RFC 1274 ID ?? } BNF definition: (2.16.840.1.113694.1.2.1.1.2 NAME 'vPIMrfc822Mailbox' EQUALITY 1.3.6.1.4.1.1466.109.114.2 SYNTAX '1.3.6.1.4.1.1466.115.121.1.26 {256}') Vaudreuil, Parsons Expires 5/1/00 [Page 5] Internet Draft VPIM Directory December 1, 2000 3.3 vPIMSpokenName The vPIMSpokenName attribute is an octet string and should be encoded in 32 kbit/s ADPCM exactly as defined by [32KADPCM]. vPIMSpokenName shall contain the spoken name of the user in the voice of the user. The length of the spoken name segment must not exceed 5 seconds. Private or additional encoding types are outside the scope of this version. The ASN.1 definition for X.500 implementations is: vPIMSpokenName ATTRIBUTE ::= { WITH SYNTAX OCTET STRING (SIZE (1..ub-vpim-at-vPIMSpokenName) EQUALITY MATCHING RULE octetStringMatch ID id-vpim-at-vPIMSpokenName } ub-vpim-at-vPIMSpokenName INTEGER ::= 4000 The BNF definition for use with LDAP is: (2.16.840.1.113694.1.2.1.1.3 NAME 'vPIMSpokenName' EQUAILTY 2.5.13.17 SYNTAX '1.3.6.1.4.1.1466.115.121.1.40 {4000}') 3.4 vPIMTextName The text name is designed to be consistent with the text name databases used for calling name delivery service of caller ID and when cached may be used for address-by-name functions within a telephone user interface. vPIMTextName ATTRIBUTE ::= { WITH SYNTAX IA5String (SIZE (1..20)) ID ?? } OPEN ISSUE The character set of this attribute is not yet determined. 3.5 vPIMSupportedEncodingTypes The vPIMSupportedEncodingTypes attribute indicates the type(s) of encodings that can be received at the address specified in vPIMrfc822Mailbox. The ASN.1 definition for X.500 implementations is: vPIMSupportedEncodingTypes ATTRIBUTE ::= { WITH SYNTAX DirectoryString EQUALITY MATCHING RULE caseIgnoreMatch ID id-vpim-at-vPIMSupportedEncodingTypes } The BNF definition of vPIMSupportedEncodingTypes for use with LDAP is: Vaudreuil, Parsons Expires 5/1/00 [Page 6] Internet Draft VPIM Directory December 1, 2000 (2.16.840.1.113694.1.2.1.1.4 NAME 'vPIMSupportedEncodingTypes' EQUALITY 2.5.13.2 SYNTAX '1.3.6.1.4.1.1466.115.121.1.15') The allowable values of DirectoryString for this version of the schema are: audio/32KADPCM image/tiff Additional publicly defined extensions, registered with IANA as specified in RFC 2048, may be used. Non-standard and private encoding types must be indicated by prepending the new type name with either "X-" or "x-". The existance of the value "image/tiff" indicates that simple-mode fax is enabled for the mailbox whose address is defined by the vPIMrfc822mailbox attribute. 3.6 extendedAbsenceStatus It is common to have an attribute to indicate to the subscriber whether the recipient is likely to check messages in the near future. This feature called "extended absence" provides an advisory message at sending time. It is similar in concept to "vacation notices" common for textual email but has it's own cultural and operational nuances. extendedAbsenceStatus ATTRIBUTE ::= { WITH SYNTAX IA5string (SIZE (1..10)) ID ?? } The three values defined are: "Off", "On", "MsgBlocked" "Off" indicates that the recipient either does not support extended absence or has not set such an indicator. "Off" if the default condition if this attribute is not returned. "On" indicates that the recipient has set an extended absence indicator, but the mailbox is still accepting messages for review at an unspecified future time. "MsgBlocked" indicates that the recipient has set an extended absence indicator and the mailbox is temporarly configured to reject incoming messages. Messages should not be sent to the recipient if this value is returned in the extendedAbsenceStatus attribute. 3.7 supportedUABehaviors Internet mail does not provide facilities for the sender to know whether the recipient supports a number of optional features that can Vaudreuil, Parsons Expires 5/1/00 [Page 7] Internet Draft VPIM Directory December 1, 2000 be requested or indicated in the RFC822 headers. This attribute provides a list of the attributes considered optional by VPIM and other vendor-specific attributes that may be supported by the recipient. If this attribute is not supported, only those attributes listed as manditory in VPIM are assumed to be supported. Undisclosed behaviors may be indicated in the RFC822 message, however there is no assurance by the receiving system of their support. VPIMSupportedUABehaviors ATTRIBUTE ::= { WITH SYNTAX IA5String (SIZE (1..30)) MULTIVALUE ID ?? } The following behaviors: MessageDispositionNotication The presense of the MessageDispositionNotification value indicates that the recipient will send a MDN in response to an MDN request. These may be further extended without standardization to include proprietary user interface functional extensions. These proprietary extension values must be prefixed with an X. 3.8 Maximum Message Size At the time of composition, the message can be checked for acceptable length using the maximum message size attribute. Maximum message size is an attribute usually configured by policy of the receiving system, typically in units of minutes. While ESMTP provides a mechanism at the transport layer to determine if a message is too long, that is an unreliable guide to the composer when multiple encodings, multiple media, or variable bit-rate encodings are supported. The ASN.1 definition for X.500 implementations is: vPIMMaxMessageSize ATTRIBUTE ::= { WITH SYNTAX NumericString EQUALITY MATCHING RULE numericStringMatch ID id-vpim-at-vPIMMaxMessageSize} The BNF definition for use with LDAP is: (2.16.840.1.113694.1.2.1.1.5 NAME 'vPIMMaxMessageSize' EQUALITY 2.5.13.8 SYNTAX '1.3.6.1.4.1.1466.115.121.1.36') 3.9 subMailbox This attribute indicates the presence of sub-mailboxes for the queried telephone number. This information may be used to provide a post-dial sub-addressing menu to the sender. Vaudreuil, Parsons Expires 5/1/00 [Page 8] Internet Draft VPIM Directory December 1, 2000 subMailbox ATTRIBUTE ::= { WITH SYNTAX IA5String (SIZE (1..9999)) MULTIVALUE ID ?? } The allowable values include a list of submailbox numbers with a numeric range of 1-9999. The user interface may use this information to prompt the sender to select a sub-mailbox. Spoken names associated with each sub-mailbox may be individually retrieved by subsequent queries to the recipient's VPIMDIR service. 4. Security Considerations The following are known security issues taken into consideration in the definition of this directory service. 1) Service provider customer information is very sensitive, especially in this time of local phone competition. Service providers require the maximum flexibility to protect this data. Because of the dense nature of telephone number assignments, this data is subject to "go fish" queries via repeated LDAP queries to determine a complete list of current or active messaging subscribers. To reduce the value of this retreived data, service providers may limit disclosure of data useful for telemarketing such as the textual name and disclose only information useful to the sender such as the recipients spoken name, a data element much harder to auto-process. 2) Service providers operate in a regulated environment where certian information about a subscriber must not be disclosed. Voice Messaging is subject to caller-ID blocking restrictions, restrictions enforced in the telephony network. No such protection is available on the Internet. The protection of this data is essential, but is up to the individual service providers to appropriately limit dislosure of this information. 5. References [32KADPCM] G. Vaudreuil and G. Parsons, "Toll Quality Voice - 32 kbit/s ADPCM: MIME Sub-type Registration", RFC 2422, September 1998. [MIMEDIR] F. Dawson, T. Howes, & M. Smith, "A MIME Content-Type for Directory Information", Work In Progress, , March 1998 [E164] CCITT Recommendation E.164 (1991), Telephone Network and ISDN Operation, Numbering, Routing and Mobile Service - Numbering Plan for the ISDN Era. [VPIM2] Vaudreuil, Greg, Parsons, Glen, "Voice Profile for Internet Mail, Version 2", RFC 2421, September 1998. Vaudreuil, Parsons Expires 5/1/00 [Page 9] Internet Draft VPIM Directory December 1, 2000 6. Acknowledgments This experimental directory builds upon the earlier work of Carl Malamud and Marshall Rose in thier TPC.INT remote printing experiment and the work lead by Anne Brown as part of the EMA voice messaging committee's directory effort. Bernhard Elliot working with the TMIA has provided most of the organizational impetus to get this project moving, a substantial task given the sometimes slow and bureaucratic nature of the voice mail industry and regulatory environment. Dave Dudley and the Messaging Aliance (TMA) for their early work in pioneering a shared directory service for voice messaging and their continuing efforts to apply those learnings to this effort. 7. 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." 8. Authors' Addresses Anne R. Brown Nortel Networks P.O. Box 3511, Station C Ottawa, ON K1Y 4H7 Canada Phone: +1-613-765-5274 Vaudreuil, Parsons Expires 5/1/00 [Page 10] Internet Draft VPIM Directory December 1, 2000 Fax: +1-613-763-2697 Email: ARBrown@NortelNetworks.com Gregory M. Vaudreuil Lucent Technologies, 17080 Dallas Parkway Dallas, TX 75248-1905 United States Phone/Fax: +1-972-733-2722 Email: GregV@ieee.org Vaudreuil, Parsons Expires 5/1/00 [Page 11]