Voice Messaging Directory Service
RFC 4237
Network Working Group G. Vaudreuil
Request for Comments: 4237 Lucent Technologies
Category: Standards Track October 2005
Voice Messaging Directory Service
Status of This Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2005).
Abstract
This document provides details of the Voice Profile for Internet Mail
(VPIM) directory service. The service provides the email address of
the recipient that is given a telephone number. It optionally
provides the spoken name of the recipient and the media capabilities
of the recipient.
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. This document combines two earlier documents, one from
Anne Brown and one from Greg Vaudreuil, that define a voice messaging
schema into a single working group submission.
Vaudreuil Standards Track [Page 1]
RFC 4237 Voice Messaging Directory Service October 2005
Table of Contents
1. Scope ...........................................................2
1.1. Design Goals ...............................................2
1.2. Performance Constraints ....................................2
1.3. Scaling Constraints ........................................3
1.4. Reliability Constraints ....................................3
2. The VPIMUser Directory Schema ...................................3
2.1. vPIMTelephoneNumber ........................................4
2.2. vPIMRfc822Mailbox ..........................................4
2.3. vPIMSpokenName .............................................4
2.4. vPIMTextName ...............................................5
2.5. vPIMSupportedAudioMediaTypes ...............................5
2.6. vPIMSupportedMessageContext ................................5
2.7. vPIMExtendedAbsenceStatus ..................................6
2.8. vPIMSupportedUABehaviors ...................................6
2.9. vPIMMaxMessageSize .........................................7
2.10. vPIMSubMailboxes ..........................................8
3. Security Considerations .........................................8
4. IANA Considerations .............................................9
4.1. Object Identifiers .........................................9
4.2. Object Identifier Descriptors ..............................9
5. References .....................................................10
5.1. Normative References ......................................10
5.2. Informative References ....................................10
1. Scope
1.1. Design Goals
The VPIM directory Schema (VPIMDIR) is accessed from outside the
enterprise or service provider domain using the recipient's telephone
number.
1.2. 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 of 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.
Vaudreuil Standards Track [Page 2]
RFC 4237 Voice Messaging Directory Service October 2005
1.3. Scaling Constraints
A service provider's namespace is expected to include entries for
tens of millions of 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 provider's network. It is
believed that existing directory technology, including horizontal
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