Internet Draft Greg Vaudreuil
Expires in six months Lucent Technologies
July 07, 2004
Voice Messaging Directory Service
<draft-ietf-vpim-vpimdir-07.txt>
Status of this Memo
This document is an Internet-Draft and is subject to all provisions of
Section 10 of RFC 2026.
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/1id-abstracts.html
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html
Intellectual Property Notice
By submitting this Internet-Draft, I certify that any applicable
patent or other IPR claims of which I am aware have been disclosed, or
will be disclosed, and any of which I become aware will be disclosed,
in accordance with RFC 3668.
Copyright Notice
Copyright (C) The Internet Society (2004). 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 <vpim@lists.neystadt.org>
Internet Draft VPIM Directory July 07, 2004
Working Group Summary
This document combines two earlier drafts, one from Anne Brown, and
one from Greg Vaudreuil defining a voice messaging schema into a
single working group submission.
Vaudreuil Expires 1/07/05 [Page 2]
Internet Draft VPIM Directory July 07, 2004
Table of Contents
1. ABSTRACT ..........................................................4
2. SCOPE .............................................................4
2.1 Design Goals ....................................................4
2.2 Performance Constraints .........................................4
2.3 Scaling Constraints .............................................4
2.4 Reliability Constraints .........................................4
3. THE VPIMUSER DIRECTORY SCHEMA .....................................5
3.1 vPIMTelephoneNumber .............................................5
3.2 vPIMRfc822Mailbox ...............................................5
3.3 vPIMSpokenName ..................................................6
3.4 vPIMTextName ....................................................6
3.5 vPIMSupportedAudioMediaTypes ....................................6
3.6 vPIMSupportedMessageContext .....................................7
3.7 vPIMExtendedAbsenceStatus .......................................7
3.8 vPIMSupportedUABehaviors ........................................7
3.9 vPIMMaxMessageSize ..............................................8
3.10 vPIMSubMailboxes ...............................................8
4. SECURITY CONSIDERATIONS ...........................................9
5. IANA CONSIDERATIONS ...............................................9
6. NORMATIVE REFERENCES .............................................10
7. INFORMATIVE REFERENCES ...........................................10
8. ACKNOWLEDGMENTS ..................................................10
9. INTELLECTUAL PROPERTY NOTICE .....................................11
10. COPYRIGHT NOTICE .................................................11
11. AUTHORS' ADDRESS .................................................11
Vaudreuil Expires 1/07/05 [Page 3]
Internet Draft VPIM Directory July 07, 2004
1. Abstract
The VPIM directory Schema provides essential additional attributes to
recreate the voice mail user experience using standardized
directories. This user experience provides, at the time of
addressing, basic assurances that the message will be delivered as
intended.
2. Scope
2.1 Design Goals
The VPIM directory Schema (VPIMDIR) is accessed from outside the
enterprise or service provider domain using the recipient's 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
retrieved. This query is expected to use LDAP [LDAP], a connection-
oriented protocol. The protocol transaction includes multiple packet
round-trips to execute the query and retrieval and is considered to be
the highest latency element of the messaging service. Further,
retrieval 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 entries for tens
of million subscribers in a flat namespace based on the VPIM inter-
domain address form: telephone_number@domain_name. A large
corporation may have a hundred-thousand entries while a large service
provider may have tens of millions of entries in a single domain. 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 including horizontal scalability through
replication 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
recipient's spoken name. Preliminary investigation suggests that
storage and retrieval 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-balancing
capabilities for the VPIMDIR. However, the latency requirements to
the end-user may not permit client-side fail-over to a secondary
server and may require the directory server to be implemented as a
high-availability service.
Vaudreuil Expires 1/07/05 [Page 4]
Internet Draft VPIM Directory July 07, 2004
3. The VPIMUser Directory Schema
( 2.16.840.1.113778.1.9.2.1 NAME 'vPIMUser'
SUP 'top'
AUXILIARY
MUST ( vPIMRfc822Mailbox $
vPIMTelephoneNumber )
MAY ( vPIMSpokenName $
vPIMSupportedUABehaviors $
vPIMSupportedAudioMediaTypes $
vPIMSupportedMessageContext $
vPIMTextName $
vPIMExtendedAbsenceStatus $
vPIMMaxMessageSize $
vPIMSubMailboxes ) )
When present, the vPIMUser object contains information useful for
verifying that the dialed telephone number corresponds to the intended
recipient. This object also provides capability information and
mailbox status information useful to guide composition by the sender
and to set delivery expectations at sending time.
3.1 vPIMTelephoneNumber
The full E.164 form of the telephone number [E164], including any sub-
addressing portion. The normal search will be for this attribute.
( 2.16.840.1.113694.1.2.1.1.1 NAME 'vPIMTelephoneNumber'
EQUALITY caseIgnoreMatch
SYNTAX 1.3.6.1.4.1.1466.115.121.1.44 )
Example: A North American telephone number with the sub address of 12
would be represented as "+12145551212+12".
Note vPIMTelephoneNumber is by default a multi-valued attribute. But
if an entry has multiple values for this attribute, those values MUST
be distinct from each other in the telephone number portion. It is
expected that each submailbox of a single telephone number will have
its own vPIMUser entry.
The vPIMTelephoneNumber differs from telephoneNumber in [LDAP] in its
support for sub-addressing information and its use as a voice
messaging address. In most cases, these values will be the same.
The telephone number is stored with no parenthesis, spaces, dots, or
hypens. The leading '+' and the '+' delineating the submailbox are
required markup.
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
Vaudreuil Expires 1/07/05 [Page 5]
Internet Draft VPIM Directory July 07, 2004
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.
( 2.16.840.1.113694.1.2.1.1.2 NAME 'vPIMRfc822Mailbox'
EQUALITY caseIgnoreIA5Match
SYNTAX 1.3.6.1.4.1.1466.115.121.1.26{256} )
3.3 vPIMSpokenName
The vPIMSpokenName attribute is an octet string and MUST 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 five seconds.
Private or additional encoding types are outside the scope of this
version.
( 2.16.840.1.113694.1.2.1.1.3 NAME 'vPIMSpokenName'
EQUALITY octetStringMatch
SYNTAX 1.3.6.1.4.1.1466.115.121.1.40{20000}
SINGLE-VALUE )
3.4 vPIMTextName
The text name is designed to be consistent with the unstructured text
name databases used for calling name delivery service of caller ID.
( 2.16.840.1.113694.1.2.1.1.4 NAME 'vPIMTextName'
EQUALITY caseIgnoreMatch
SYNTAX 1.3.6.1.4.1.1466.115.121.1.15{20}
SINGLE-VALUE )
The VPIMTextName MUST be a UTF-8 encoded string [UTF8].
3.5 vPIMSupportedAudioMediaTypes
The vPIMSupportedAudioMediaTypes attribute indicates the type(s) of
audio encodings that can be received at the address specified in
vPIMRfc822Mailbox.
( 2.16.840.1.113694.1.2.1.1.5 NAME 'vPIMSupportedAudioMediaTypes'
EQUALITY caseIgnoreIA5Match
SYNTAX 1.3.6.1.4.1.1466.115.121.1.26 )
The allowable values of DirectoryString for this attribute are the
MIME audio subtypes registered with IANA. Non-standard and private
encoding types must be indicated by prepending the new type name with
either "X-" or "x-".
The audio32kadpcm value must be present if this attribute is present.
Vaudreuil Expires 1/07/05 [Page 6]
Internet Draft VPIM Directory July 07, 2004
3.6 vPIMSupportedMessageContext
The message context provides guidance to the sender about the message
contexts the recipient is likely to accept. Message context provides
less precision about a given recipient's capabilities than a list of
media types. However, given the growing role of media-conversion
gateways, the context indicator provides more useful guidance to a
sender in a "unified messaging" environment.
( 2.16.840.1.113694.1.2.1.1.6 NAME 'vPIMSupportedMessageContext'
EQUALITY caseIgnoreIA5Match
SYNTAX 1.3.6.1.4.1.1466.115.121.1.26 )
The set of valid message context values are defined in [CONTEXT].
3.7 vPIMExtendedAbsenceStatus
It is common to have an attribute to indicate to the subscriber
whether the recipient is accepting messages during his absence. 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 its own cultural and operational
nuances.
( 2.16.840.1.113694.1.2.1.1.7 NAME 'vPIMExtendedAbsenceStatus'
EQUALITY caseIgnoreMatch
SYNTAX 1.3.6.1.4.1.1466.115.121.1.15
SINGLE-VALUE )
The three values defined are:
"Off", "On", "MsgBlocked"
"Off" indicates the recipient either does not support extended absence
or has not set such an indicator. "Off" is the default condition if
this attribute is not returned.
"On" indicates the recipient has set an extended absence indicator,
but the mailbox is still accepting messages for review at an
unspecified future time.
"MsgBlocked" indicates the recipient has set an extended absence
indicator and the mailbox is currently configured to reject incoming
messages. Messages SHOULD NOT be sent to the recipient if this value
is returned in the vPIMExtendedAbsenceStatus attribute.
3.8 vPIMSupportedUABehaviors
Internet mail does not provide facilities for the sender to know
whether the recipient supports a number of optional features that can
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
Vaudreuil Expires 1/07/05 [Page 7]
Internet Draft VPIM Directory July 07, 2004
listed as mandatory 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.
( 2.16.840.1.113694.1.2.1.1.8 NAME 'vPIMSupportedUABehaviors'
EQUALITY caseIgnoreMatch
SYNTAX 1.3.6.1.4.1.1466.115.121.1.15 )
The following behaviors are defined:
MessageDispositionNotification
MessageSensitivity
MessageImportance
The presence of the MessageDispositionNotification value indicates
that the recipient will send a MDN in response to an MDN request.
MessageSensitivity indicates that the recipient fully supports the
sensitivity indication as defined in VPIM [VPIMV2].
MessageImportance indicates that the recipient fully supports the
importance indication as defined in VPIM [VPIMV2].
These may be further extended without standardization to include
proprietary user interface functional extensions. These proprietary
extension values must be prefixed with an "X-" or "x-".
3.9 vPIMMaxMessageSize
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 to
determine if a message is too long in bytes, that is an unreliable
guide to the composer when multiple encodings, multiple media, or
variable bit-rate encodings are supported.
( 2.16.840.1.113694.1.2.1.1.9 NAME 'vPIMMaxMessageSize'
EQUALITY integerMatch
SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
SINGLE-VALUE )
3.10 vPIMSubMailboxes
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.
( 2.16.840.1.113694.1.2.1.1.10 NAME 'vPIMSubMailboxes'
EQUALITY numericStringMatch
SYNTAX 1.3.6.1.4.1.1466.115.121.1.36{4} )
The allowable values include a list of sub-mailbox numbers with a
numeric range of 1-9999. The user interface may use this information
Vaudreuil Expires 1/07/05 [Page 8]
Internet Draft VPIM Directory July 07, 2004
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.
1) Service provider customer information is very sensitive, especially
in this time of local phone competition. Service providers require
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
retrieved 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 recipient's spoken name,
a data element much harder to auto-process.
2) Service providers operate in a regulated environment where certain
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 curently available on
the Internet. The protection of this data is essential, but is up to
the individual service providers to appropriately limit disclosure of
this information.
5. IANA Considerations
The OID specified in this draft for the VPIMUser is from the Lucent
proprietary branch. The objects are using OIDs from the Nortel
proprietary branch. It anticipated that IANA will provide a
replacement value from the IANA standards branch and will replace the
OIDs in this document upon publication as a standards-track document.
Vaudreuil Expires 1/07/05 [Page 9]
Internet Draft VPIM Directory July 07, 2004
6. Normative References
[LDAP] Hodges, J., Morgan, R., "Lightweight Directory Access Protocol
(v3): Technical Specification", RFC 3377, September 2004.
[32KADPCM] Greg Vaudreuil, Glenn Parsons, "Toll Quality Voice - 32
kbit/s ADPCM: MIME Sub-type Registration", RFC 3802, June 2004.
[CONTEXT] Eric Burger, Emily Candell, Graham Klyne, Charles Eliott,
"Message Context for Internet Mail", RFC 3458, January 2003
[E164] CCITT Recommendation E.164 (1991), Telephone Network and ISDN
Operation, Numbering, Routing and Mobile Service - Numbering Plan
for the ISDN Era.
[UTF8] RFC 2279 UTF-8, a transformation format of ISO 10646. F. Yergeau.
January 1998.
7. Informative References
[VPIM2] Vaudreuil, Greg, Parsons, Glen, "Voice Profile for Internet
Mail, Version 2", RFC 3801, June 2004.
8. Acknowledgments
This experimental directory builds upon the earlier work of Carl
Malamud and Marshall Rose in their TPC.INT remote printing experiment
and the work lead by Anne Brown as part of the EMA voice messaging
committee's directory effort. Anne Brown has provided important
leadership and was a co-author of the original draft of this document.
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 Alliance (TMA) for their early work in
pioneering a shared directory service for voice messaging and their
continuing efforts to apply that work to this effort.
Greg White and Jeff Bouis, both of Lucent Technologies, provided
invaluable assistance in reviewing and sanity checking. Countless
errors and inconsistencies were corrected with their diligent review.
Vaudreuil Expires 1/07/05 [Page 10]
Internet Draft VPIM Directory July 07, 2004
9. Intellectual Property Notice
The IETF takes no position regarding the validity or scope of any
intellectual property or other rights that might be claimed to pertain
to the implementation or use of the technology described in this
document or the extent to which any license under such rights might or
might not be available; neither does it represent that it has made any
effort to identify any such rights. Information on the IETF's
procedures with respect to rights in standards-track and standards-
related documentation can be found in BCP-11. Copies of claims of
rights made available for publication and any assurances of licenses
to be made available, or the result of an attempt made to obtain a
general license or permission for the use of such proprietary rights
by implementors or users of this specification can be obtained from
the IETF Secretariat.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights which may cover technology that may be required to practice
this standard. Please address the information to the IETF Executive
Director.
10. Copyright Notice
"Copyright (C) The Internet Society (2004). 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."
11. Authors' Address
Vaudreuil Expires 1/07/05 [Page 11]
Internet Draft VPIM Directory July 07, 2004
Gregory M. Vaudreuil
Lucent Technologies
7380 Hilltop Dr.
Frederick, MD 21702
Email: GregV@ieee.org
Vaudreuil Expires 1/07/05 [Page 12]