XCON                                                             O. Novo
Internet-Draft                                              G. Camarillo
Intended status: Standards Track                                Ericsson
Expires: October 19, 2007 May 3, 2008                                           D. Morgan
                                                    Fidelity Investments
                                                                 R. Even
                                                                 Polycom
                                                          April 17,
                                                        October 31, 2007

 Conference Information Data Model for Centralized Conferencing (XCON)
                draft-ietf-xcon-common-data-model-05.txt
                draft-ietf-xcon-common-data-model-06.txt

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Copyright Notice

   Copyright (C) The IETF Trust (2007).

Abstract

   This document defines an Extensible Markup Language (XML)-based
   conference information data model for centralized conferencing
   (XCON).  A conference object, which can be manipulated using a
   conference control protocol, at a conference server represents a
   particular instantiation of this information data model. model is designed to convey
   information about the conference and about participation in the
   conference.  The conference information data model defined in this
   document is constitutes an extension of
   (and thus, compatible with) the model data format specified in the
   Session Initiation Protocol (SIP) Event Package for Conference State.

Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  4
   2.  Terminology  . . . . . . . . . . . . . . . . . . . . . . . . .  6
   3.  Overview . . . . . . . . . . . . . . . . . . . . . . . . . . .  6
     3.1.  Data Model Structure Format  . . . . . . . . . . . . . . . . . . . .  6
     3.2.  Role Definitions  Data Model Namespace . . . . . . . . . . . . . . . . . . .  6
     3.3.  The Conference Object Identifier . . . . . . . . . . . . .  7
       3.2.1.  Role in a Floor
     3.4.  Data Model Structure . . . . . . . . . . . . . . . . . . .  8
       3.2.2.  Changing Roles
   4.  Data Model Definition  . . . . . . . . . . . . . . . . . . . .  8
   4.  Data Model Definition  9
     4.1.  <conference-info>  . . . . . . . . . . . . . . . . . . . .  8
     4.1. 12
     4.2.  <conference-description> . . . . . . . . . . . . . . . . . 13
       4.1.1.  <conference-time>
       4.2.1.  <display-text> . . . . . . . . . . . . . . . . . . 14
       4.1.2.  <conf-uris> . . 13
       4.2.2.  <subject>  . . . . . . . . . . . . . . . . . . . 15
       4.1.3.  <service-uris> . . . 13
       4.2.3.  <free-text>  . . . . . . . . . . . . . . . . . 16
       4.1.4.  <maximum-user-count> . . . . 13
       4.2.4.  <keywords> . . . . . . . . . . . . . 16
       4.1.5.  <available-media> . . . . . . . . . 13
       4.2.5.  <allow-sidebars> . . . . . . . . . 16
         4.1.5.1.  <controls> . . . . . . . . . . 13
       4.2.6.  <conference-time>  . . . . . . . . . . 17
           4.1.5.1.1.  mute . . . . . . . . 14
       4.2.7.  <conf-uris>  . . . . . . . . . . . . . 17
           4.1.5.1.2.  pause-video . . . . . . . . 15
       4.2.8.  <service-uris> . . . . . . . . . 17
           4.1.5.1.3.  gain . . . . . . . . . . . 15
       4.2.9.  <maximum-user-count> . . . . . . . . . . 18
           4.1.5.1.4.  video-layout . . . . . . . 15
       4.2.10. <available-media>  . . . . . . . . . . 18
     4.2.  <host-info> . . . . . . . . 15
     4.3.  <host-info>  . . . . . . . . . . . . . . . 19
     4.3.  <conference-state> . . . . . . . . 18
     4.4.  <conference-state> . . . . . . . . . . . . 19
     4.4.  <floor-information> . . . . . . . . 18
       4.4.1.  <allow-conference-event-subscription>  . . . . . . . . 18
       4.4.2.  <user-count> . . . 19
     4.5.  <users> . . . . . . . . . . . . . . . . . . 18
       4.4.3.  <active> . . . . . . . 21
       4.5.1.  <allowed-users-list> . . . . . . . . . . . . . . . . 18
       4.4.4.  <locked> . 22
       4.5.2.  <user> . . . . . . . . . . . . . . . . . . . . . . 19
     4.5.  <floor-information>  . . 22
         4.5.2.1.  <from-mixer>, <to-mixer> . . . . . . . . . . . . . 24
           4.5.2.1.1.  <floor> . . . . 19
       4.5.1.  <conference-ID>  . . . . . . . . . . . . . . . 24
       4.5.3.  <sidebars-by-ref> . . . . 19
       4.5.2.  <allow-floor-events> . . . . . . . . . . . . . . 24
       4.5.4.  <sidebars-by-val> . . . 19
       4.5.3.  <floor-request-handling> . . . . . . . . . . . . . . . 24
   5.  RELAX NG Schema 19
       4.5.4.  <conference-floor-policy>  . . . . . . . . . . . . . . 20
     4.6.  <users>  . . . . . . . . . 25
   6.  XML Schema Extensibility . . . . . . . . . . . . . . . . 20
       4.6.1.  <join-handling>  . . . 32
   7.  XML Example . . . . . . . . . . . . . . . . 21
       4.6.2.  <user-admission-policy>  . . . . . . . . . 33
   8.  Security Considerations . . . . . . 21
       4.6.3.  <allowed-users-list> . . . . . . . . . . . . . 41
   9.  IANA Considerations . . . . 22
       4.6.4.  <user> and Its <user> Sub-elements . . . . . . . . . . 22
         4.6.4.1.  <display-text> . . . . . . . 41
     9.1.  Conference Relax NG Schema Registration . . . . . . . . . 41
     9.2.  Conference Namespace Registration . . 23
         4.6.4.2.  <associated-aors>  . . . . . . . . . . 41
     9.3.  Conference Object Identifier Registration . . . . . . 23
         4.6.4.3.  <provide-anonymity>  . . 41
     9.4.  Conference User Identifier Registration . . . . . . . . . 42
   10. Acknowledgements . . . . 24
         4.6.4.4.  <roles>  . . . . . . . . . . . . . . . . . . . 42
   11. References . . 24
         4.6.4.5.  <languages>  . . . . . . . . . . . . . . . . . . . 24
         4.6.4.6.  <cascaded-focus> . . . . . 42
     11.1. Normative References . . . . . . . . . . . . 24
         4.6.4.7.  <allow-refer-users-dynamically>  . . . . . . . 42
     11.2. Informative References . . 24
         4.6.4.8.  <allow-invite-users-dynamically> . . . . . . . . . 24
         4.6.4.9.  <allow-remove-users-dynamically> . . . . . . . 42
   Appendix A.  Appendix A.  Non-Normative RELAX NG Schema in XML
                Syntax . . 25
         4.6.4.10. <endpoint> . . . . . . . . . . . . . . . . . . . . 25
     4.7.  <sidebars-by-ref>  . 43
   Authors' Addresses . . . . . . . . . . . . . . . . . . . 26
     4.8.  <sidebars-by-val>  . . . . . 66
   Intellectual Property and Copyright Statements . . . . . . . . . . 68

1.  Introduction

   Conference objects are a fundamental concept in Centralized
   conferencing, as described in the XCON Conferencing Framework [4].  A
   conference object contains data that represents a conference during
   each of its various stages (e.g., reserved, started, running, ended,
   etc.).  Conference Objects are instantiations of the conference
   information data model defined in this document.  Consequently,
   conference objects follow the XML format defined in this document.

   A conference object contains the core information of a conference
   (i.e., capabilities, membership, roles, call control signaling,
   media, etc.) and specifies who, and in which way, can manipulate that
   information.

   Figure 1 shows logical functional elements of a conference server as
   defined by the XCON Conferencing Framework [4].  They are a
   Conference Control Server, a Floor Control Server, a number of Foci,
   and a Notification Service.  A conference control protocol provides
   the interface between a conference and media control client, and the
   conference control server.  A floor control protocol (e.g., BFCP [5])
   provides the interface between a floor control client and the floor
   control server.  A call signaling protocol (e.g., SIP, H.323, PSTN,
   etc.) provides the interface between a call signaling client and a
   Focus.  A notification protocol (e.g., SIP-based event notifications
   [6]) provides the interface between the conferencing client and the
   Notification Service.  Within a conference, the conference control
   server, floor control server, and focus can modify the information in
   the conference object.

      ............................................................... . Conferencing Server . .       +---------------------------------------------------+ . .       |       C o n f e r e n c e   o b j e c t           | 26
   5.  RELAX NG Schema  . .     +-+--------------------------------------------------+| . .     |       C o n f e r e n c e   o b j e c t            || . .   +-+---------------------------------------------------+|| . .   |       C o n f e r e n c e   o b j e c t             ||| . .   | +--------------------------------------------------+||| . .   | | Conference Information Data Model                |||| . .   | | +----------------------------------------------+ |||| . .   | | | Conference description  (times, duration)    | |||| . .   | | +----------------------------------------------+ |||| . .   | | +----------------------------------------------+ |||| . .   | | | Host information                             | |||| . 26
   6.  XML Schema Extensibility .   | | +----------------------------------------------+ |||| . .   | | +----------------------------------------------+ |||| . .   | | | Conference state                             | |||| . .   | | +----------------------------------------------+ |||| . .   | | +----------------------------------------------+ |||| . .   | | | Floor information                            | |||| . .   | | +----------------------------------------------+ |||| . .   | | +----------------------------------------------+ |||| . .   | | | Membership (users, roles, capacity)          | |||| . .   | | +----------------------------------------------+ |||| 33
   7.  XML Example  . .   | | +----------------------------------------------+ |||| . .   | | | Sidebars, Etc.                               | |||| . .   | | +----------------------------------------------+ |||| . .   | | +----------------------------------------------+ |||| . .   | | | Etc.                                         | |||| . .   | | +----------------------------------------------+ |||+ . .   | +--------------------------------------------------+|+ . .   +----^------------------^-------------^--------|------+ . .        |                  |             |        | . . +------v-------+ +--------v-----+ +-----v-+ +----v-------+ . . | Conference   | | Floor        | |       | |            | . . | Control      | | Control      | |Foci   | |Notification| . 33
   8.  Security Considerations  . | Server       | | Server       | |       | |Service     | . . +-----^--------+ +---^----------+ +-^-----+ +------------+ .
      ........|..............|..............|..........|.............
              |Conference    |Binary Floor  |Call      |Notification
              |Control       |Control       |Signaling |Protocol
              |Protocol      |Protocol      |Protocol  |
      ........v..............v..............v..........v............. .     C  o  n  f  e  r  e  n  c  i  n  g     C  l i  e  n  t .
      ............................................................... . . . . . . . . . . . . . 41
     8.1.  Authentication . . . . . . . . . . . . . . . . . . . . . . 41
     8.2.  Confidentiality  . . . . . . . . . . . . . . . . . . . . . 41
     8.3.  Integrity  . . . . . . . . . . . . . . . . . . . . . . . . 42
   9.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 42
     9.1.  Conference Relax NG Schema Registration  . . . . . . . . . 42
     9.2.  Conference Namespace Registration  . . . . . . . . . . . . 42
     9.3.  Conference Object Identifier Registration  . . . . . . . . 42
     9.4.  Conference User Identifier Registration  . . . . . . . . . 43
   10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 43
   11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 43
     11.1. Normative References . . . . . . . . . . . . . . . . . . . 43
     11.2. Informative References . . . . . . . . . . . . . . . . . . 43
   Appendix A.  Appendix A.  Non-Normative RELAX NG Schema in XML
                Syntax  . . . . . . . . . . . . . . . . . . . . . . . 44
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 63
   Intellectual Property and Copyright Statements . . . . . . . . . . 65

1.  Introduction

   There is a core data set of conference information that is utilized
   in any conference, independent of the specific conference media.
   This core data set called the 'conference information data model' is
   defined in this document using an Extensible Markup Language (XML)-
   based.  The conference information data model defined in this
   document is logically represented by the conference object.

   Conference objects are a fundamental concept in Centralized
   Conferencing, as described in the Centralized Conferencing Framework
   [4].  A conference object contains data that represents a conference
   during each of its various stages (e.g., created/creation, reserved/
   reservation, active/activation, completed/completion).  A conference
   object can be manipulated using a conference control protocol at a
   conference server.  The conference object represents a particular
   instantiation of a conference information data model.  Consequently,
   conference objects follow the XML format defined in this document.

   A conference object contains the core information of a conference
   (i.e., capabilities, membership, call control signaling, media, etc.)
   and specifies who, and in which way that information can be
   manipulated.

   Figure 1 shows the logical functional elements of a conference server
   as defined by the Centralized Conferencing Framework [4].  They are a
   Conference Control Server, a Floor Control Server, a number of Foci,
   and a Notification Service.  A conference control protocol provides
   the interface between a conference control client and the conference
   control server.  A floor control protocol (e.g., BFCP [5]) provides
   the interface between a floor control client and the floor control
   server.  A call signaling protocol (e.g., SIP, H.323, Q.931, ISUP,
   etc.) provides the interface between a call signaling client and a
   Focus.  A notification protocol (e.g., SIP-based event notifications
   [6]) provides the interface between the conferencing client and the
   Notification Service.  Within a conference, the conference control
   server, floor control server, and focus can modify the information in
   the conference object.

      ...............................................................
      . Conferencing Server                                         .
      .       +---------------------------------------------------+ .
      .       |       C o n f e r e n c e   o b j e c t           | .
      .     +-+--------------------------------------------------+| .
      .     |       C o n f e r e n c e   o b j e c t            || .
      .   +-+---------------------------------------------------+|| .
      .   |       C o n f e r e n c e   o b j e c t             ||| .
      .   | +--------------------------------------------------+||| .
      .   | | Conference Information Data Model                |||| .
      .   | | +----------------------------------------------+ |||| .
      .   | | | Conference description  (times, duration)    | |||| .
      .   | | +----------------------------------------------+ |||| .
      .   | | +----------------------------------------------+ |||| .
      .   | | | Host information                             | |||| .
      .   | | +----------------------------------------------+ |||| .
      .   | | +----------------------------------------------+ |||| .
      .   | | | Conference state                             | |||| .
      .   | | +----------------------------------------------+ |||| .
      .   | | +----------------------------------------------+ |||| .
      .   | | | Floor information                            | |||| .
      .   | | +----------------------------------------------+ |||| .
      .   | | +----------------------------------------------+ |||| .
      .   | | | Membership (users, capacity)                 | |||| .
      .   | | +----------------------------------------------+ |||| .
      .   | | +----------------------------------------------+ |||| .
      .   | | | Sidebars, Etc.                               | |||| .
      .   | | +----------------------------------------------+ |||| .
      .   | | +----------------------------------------------+ |||| .
      .   | | | Etc.                                         | |||| .
      .   | | +----------------------------------------------+ |||+ .
      .   | +--------------------------------------------------+|+  .
      .   +----^------------------^-------------^--------|------+   .
      .        |                  |             |        |          .
      . +------v-------+ +--------v-----+ +-----v-+ +----v-------+  .
      . | Conference   | | Floor        | |       | |            |  .
      . | Control      | | Control      | |Foci   | |Notification|  .
      . | Server       | | Server       | |       | |Service     |  .
      . +-----^--------+ +---^----------+ +-^-----+ +------------+  .
      ........|..............|..............|..........|.............
              |Conference    |Binary Floor  |Call      |Notification
              |Control       |Control       |Signaling |Protocol
              |Protocol      |Protocol      |Protocol  |
      ........v..............v..............v..........v.............
      .     C  o  n  f  e  r  e  n  c  i  n  g     C  l i  e  n  t  .
      ...............................................................

                 Figure 1: Conference Server Architecture
   The Session Initiation Protocol (SIP) Event Package for Conference
   State, specified in RFC 4575 RFC4575 [1], already defines a data model format for
   conferences.  However, that model is SIP specific and lacks elements
   related to some of the functionality defined by the XCON conferencing
   framework Centralized
   Conferencing Framework [4] (e.g., floor control).  The data model
   defined in this document extends constitutes a superset of the one data format
   defined in RFC 4575 RFC4575 [1].  The result is a data model format that supports
   more call signaling protocols besides SIP and that covers all the
   functionality defined in the XCON
   conferencing framework Centralized Conferencing Framework [4].

2.  Terminology

   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 RFC 2119 [2].

   This document uses the terminology defined in the XCON Centralized
   Conferencing Framework [4], the SIP SIPPING conferencing framework [7]
   and the BFCP (Binary Floor Control Protocol) specification [5].
   Readers of this document are supposed to should be familiar with the terminology used
   in those documents.

3.  Overview

   The data model defined specified in this document is the result of extending
   the data model format defined in RFC 4575 RFC4575 [1] with new elements, which carry
   information elements.  Examples
   of such as extensions include scheduling elements, media control
   elements, floor control elements, non-SIP URIs or floor-control-related parameters. URIs, and addition of
   localization extensions to text elements.  This data model can be
   used by conference servers providing different types of basic
   conferences.  It is expected that this data model can be further
   extended with new elements in the future in order to
   implement advanced features.

3.1.  Data Model Structure

   The information in this future in order to implement
   additional advanced features.

3.1.  Data Model Format

   A conference object document is an XML [8] document that MUST be well
   formed and SHOULD be valid.  Conference object documents MUST be
   based on XML 1.0 and SHOULD be encoded using UTF-8.

3.2.  Data Model Namespace

   This specification defines a new namespace specification for
   identifying the elements defined in the data model is structured in the following
   manner.  All the information related to a conference model.  This namespace
   is contained in
   a <conference-info> element. as follows:

   urn:ietf:params:xml:ns:xcon-conference-info

3.3.  The <conference-info> element contains
   the following child elements:
   o Conference Object Identifier

   The <conference-description> element describes the conference object identifier (XCON-URI) can be viewed as a
      whole. key to
   accessing a specific conference object.  It has, can be used, for
   instance, information about the URI of the
      conference, maximum users allowed in the conference, media
      available in the conference, or the time by the conference will
      start.
   o  The <host-info> element contains information about the entity
      hosting the control protocol to access, manipulate
   and delete a conference (e.g., its URI).

   o  The <conference-state> element informs the subscribers about the
      changes in the overall object.  A conference information.
   o  The <floor-information> element contains information about the
      status of the different floors in the conference.
   o  The <users> element describes the membership information as a
      whole.  The <users> element contains a set of <user> child
      elements, each describing a single participant in object identifier is
   provided to the conference.
   o  If a participant in conferencing client by the main conference joins a sidebar, notification
   service or through out-of-band mechanisms (e.g.  E-Mail).

   A conferencing system may maintain a new
      element is created in relationship between the
   conference referenced from the
      <sidebars-by-ref> element or under one of the <sidebars-by-val>
      elements.

3.2.  Role Definitions

   This section defines five logical roles for a Conference System to
   represent participants within a Conference Object.  In hierarchical
   order they are: "administrator", "creator", "moderator",
   "participant", and "observer".  A set of semantics object identifiers and the identifiers associated with
   each role is out of the scope complementary centralized conferencing protocols (e.g.,
   call signaling protocols, BFCP, etc.).  To facilitate the maintenance
   of this document.  A Conference System
   MAY choose not to support a particular role.  As well, additional
   roles may be defined in these relationships, the future, conference object identifier acts as necessary, with their
   corresponding schema extensions.

   These five roles have an intrinsic hierarchical order within a
   specific conference.  By hierarchical order, it is implied that
   top level identifier within the
   "administrator" by default SHOULD have higher privileges than a
   "creator", which by default SHOULD have higher privileges than conferencing system for the purpose
   of identifying the interfaces for these other protocols.  This
   implicit binding provides a
   "moderator" and so on.  For example, structured mapping of the "administrator" SHOULD have various
   protocols with the ability to make changes to all associated conference variables during
   instantiation and full lifecycle of object Identifier.  Figure 2
   illustrates the Conference Object.  The
   "creator" is relationship between the 'owner' of identifiers used for the conference
   protocols and has various privileges
   which SHOULD allow them to modify the general conference variables up to the
   time object identifier (XCON-URI).

                            +--------------------------+
                            |       Conference         |
                            |         Object           |
                            |       Identifier         |
                            +--------------------------+
                            |  xcon:Ji092i@example.com |
                            +------+-------------------+
                                        |
                                        |
                                        |
                      +-----------------+---------------+
                      |                                 |
          +-----------+-----------+          +----------+---------+
          |   CSP Conference IDs  |          |BFCP 'Conference ID'|
          +-----------------------+          +--------------------+
          |h323:Ji092i@example.com|          |        Ji092i      |
          |tel:+44(0)2920930033   |          +----------+---------+
          |sip:Ji092i@example.com |                     |
          +-----------------------+             +-------|--------+
                                                | BFCP 'Floor ID'|
                                                +----------------+
                                                |      543       |
                                                |     09cnJk     |
                                                +----------------+
                    Figure 2: Conference Object Mapping

   In Figure 2, the conference is instantiated.  The "moderator" is a logical
   entity that will manage object identifier acts as the conference.  The "participant" is a
   logical entity with generic privileges that will be attending a
   conference.  The "observer" is a logical entity which can only
   receive media streams from top level
   key in the conference.  All Conference Systems
   MUST identification process.  The call signaling protocols have a role defined
   an associated conference user identifier, often represented in the
   form of URIs.  The binary floor control protocol, as "participant".

   Each user participating defined in [5],
   defines the 'conference ID' identifier which represents a conference
   instance is an entity that
   can assume one or more roles.  Any entity can be allocated to an
   appropriate logical role.  A role can also be assumed in conjunction
   with the users identity within floor control.  When created within the Conference System as a result of
   an identity assertion transaction on conferencing
   system, the Conference System.  If no
   roles are defined for an entity, they SHOULD by default be a
   "participant" but local policy MAY define an alternative.

3.2.1.  Role in 'conference ID' has a Floor

   Floor control in centralized conferencing is described in 1:1 mapping to the Binary
   Floor Control Protocol (BFCP) [5].  Floors can be specified in unique
   conference object Identifier(XCON-URI).  Operations associated with
   the
   Conference System or created dynamically.  Users can be added or
   deleted from a floor when conference control protocols are directly associated with the
   conference object, thus the primary identifier associated with these
   protocols is active.

   A floor chair is a logical entity that manages a floor (grants,
   denies, or revokes a floor). the conference object identifier(XCON-URI).  The floor chair is usually in an
   "administrator", "moderator", or "creator" role.  A floor participant
   mappings between additional protocols/interface is not strictly 1:1
   and does allow for multiple occurrences.  For example, multiple call
   signaling protocols will each have a logical entity representation that requests floors, is
   implicitly linked to the top level conference object identifier e.g.
   H323 and possibly information
   about them from a floor control server.  They are usually in a
   "participant" or even a "moderator" role [5].

   Users in SIP URIs that represent a conference MAY assume different roles in different floors.
   They MAY also assume different roles in the same floor, as floor
   transactions are processed.

3.2.2.  Changing Roles

   Users can change roles during a conference.  This can instance.  It should be done in two
   ways: First, the user can join
   noted that a new floor in conferencing system is free to structure such
   relationships as required and this information is just included as a different role.
   Second, an "administrator" or "creator" can dynamically change
   guideline that
   user's role.  This can be accomplished before the conference is
   instantiated, or during the conference, using an appropriate
   conference control protocol.  A logical entity whose role has been
   changed will typically have access used.

   Further elements can be added to the media streams associated
   with that role.

4. tree representation in Figure 2
   to enable a complete representation of a conference instance within a
   conferencing system.

3.4.  Data Model Definition

   A conference object document is an XML [8] document that MUST be well
   formed and SHOULD be valid.  Conference object Structure

   The information in this data model documents
   MUST be based on XML 1.0 and SHOULD be encoded using UTF-8.

   A conference object document begins with is structured in the root element tag
   <conference-info>, which following
   manner.  All the information related to a conference is defined contained in [1].
   a <conference-info> element.  The <conference-info> element has an 'entity' attribute that contains a conference object
   identifier (XCON-URI) that identifies
   the following child elements:

   o  The <conference-description> element describes the conference being described as a
      whole.  It has, for instance, information about the URI of the
      conference, maximum users allowed in the document.

   A conferencing system may maintain a relationship between conference, media
      available in the
   conference object identifiers and conference, or the identifiers associated with
   each of time the complimentary centralized conferencing protocols (e.g.,
   call signaling protocols, BFCP, etc.).

   This implicit binding provides a structured mapping of conference will
      start.
   o  The <host-info> element contains information about the various
   protocols with entity
      hosting the associated conference object Identifier.  Figure 2
   illustrates (e.g., its URI).
   o  The <conference-state> element informs the relationship between subscribers about the identifiers used for
      changes in the overall conference information.
   o  The <floor-information> element contains information about the
   protocols within
      status of the framework [4] and different floors in the general XCON-URI.

                            +--------------------------+
                            |       Conference         |
                            |         Object           |
                            |       Identifier         |
                            +--------------------------+
                            |  xcon:Ji092i@example.com |
                            +------+-------------------+
                                        |
                                        |
                                        |
                      +-----------------+---------------+
                      |                                 |
          +-----------+-----------+             +-------+-------+
          |   CSP Conference IDs  |             | BFCP 'confid' |
          +-----------------------+             +---------------+
          |h323:Ji092i@example.com|             |    Ji092i     |
          |tel:+44(0)2920930033   |             +-------+-------+
          |sip:Ji092i@example.com |                     |
          +-----------------------+             +-------|-------+
                                                | BFCP 'floorid |
                                                +---------------+
                                                |    UEK78d     |
                                                |    09cnJk     |
                                                +---------------+

                    Figure 2: Conference Object Mapping

   Further elements can be added to conference.
   o  The <users> element describes the tree representation in Figure 2
   to enable membership information as a complete representation
      whole.  The <users> element contains a set of <user> child
      elements, each describing a single participant in the conference.

   o  If a participant in the main conference instance within joins a
   conferencing system.

   The <conference-info> sidebar, a new
      element contains is created in the conference referenced from the
      <sidebars-by-ref> element or under one of the <conference-description>,
   <host-info>, <conference-state>, <floor-information>, <users>,
   <sidebars-by-ref>, <sidebars-by-val> child
      elements.  All these
   elements, except <floor-information>,

   Note that some of the elements described above such <conference-
   info>, <conference-description>, <sidebars-by-ref>, or <sidebars-by-
   val> are not defined in the data model but are defined in the data
   format of RFC 4575 [1].  A
   conference document MUST at least include  We describe them here because they are part
   of the <conference-
   description>, <host-info>, <conference-state>, and <users> child
   elements. basic structure of the data model.

4.  Data Model Definition

   The following non-normative diagram shows the structure of conference
   object documents.  The operator "!" preceding an element indicates
   that the element is mandatory in the data model.  The operator "*"
   following an element indicates that the element is introduced and
   defined in this document.  That is, elements without a "*" have
   already been defined in RFC 4575 [1].

   !<conference-info>
        |
        |--!<conference-description>
        |     |--<display-text>
        |     |--<subject>
        |     |--<free-text>*     |--<free-text>
        |     |--<keywords>
        |     |--<allow-sidebars>*
        |     |--<conference-time>*
        |     |      |--<entry>*
        |     |      |    |--<base>*
        |     |      |    |--<mixing-start-offset>*
        |     |      |    |--<mixing-end-offset>*
        |     |      |    |--<can-join-after-offset>*
        |     |      |    |--<must-join-before-offset>*
        |     |      |    |--<request-user>*
        |     |      |    |--<notify-end-of-conference>*
        |     |      |    |--<allowed-extend-mixing-end-offset>*
        |     |           ...
        |     |--<conf-uris>
        |     |      |--<entry>*
        |    |--<base>*
        |     |    |--<uri>      |    |--<mixing-start-offset>*
        |     |    |--<display-text>      |    |--<mixing-end-offset>*
        |     |    |--<purpose>      |    |--<can-join-after-offset>*
        |      |--<H323>*     |      |    |--<must-join-before-offset>*
        |    |--<H.323-alias>*     |      |    |--<request-user>*
        |    |--<H.323-URI>*     |      |      |--<PSTN-ISDN>*    |--<notify-end-of-conference>*
        |     |      |    |--<phone number>*    |--<allowed-extend-mixing-end-offset>*
        |     |           ...
        |     |--<service-uris>     |--<conf-uris>
        |     |      |--<entry>*      |--<entry>
        |     |      |    |--<uri>
        |     |      |    |--<display-text>
        |     |      |    |--<purpose>
        |     |      |--<H323>*      ...
        |     |--<service-uris>
        |     |      |--<entry>
        |    |--<H.323-alias>*     |      |    |--<uri>
        |    |--<H.323-URI>*     |      |      |--<PSTN-ISDN>*    |--<display-text>
        |     |      |    |--<phone number>*    |--<purpose>
        |     |      ...
        |     |--<maximum-user-count>
        |     |      ...
        |     |--!<available-media>     |--<available-media>
        |     |      |--!<entry>
        |     |      |     |--<type>
        |     |      |     |--<display-text>
        |     |      |     |--<status>
        |     |      |     |--<mixing-mode>*
        |     |      |     |--<mix-level>*
        |     |      |     |--<codecs>*
        |     |      |     |    |--<entry>*
        |     |      |     |    |--<entry>*
        |     |      |     |    ...
        |     |      |     |--<controls>*
        |     |      |     |    |--<mute>*
        |     |      |     |    |--<gain>*
        |     |      |     |   ...
        |     |      |--<entry>
        |     |      |     |--<type>
        |     |      |     |--<display-text>
        |     |      |     |--<status>
        |     |      |     |--<mixing-mode>*
        |     |      |     |--<mix-level>*
        |     |      |     |--<codecs>*
        |     |      |     |    |--<entry>*
        |     |      |     |    |--<entry>*
        |     |      |     |    ...
        |     |      |     |--<controls>*
        |     |      |     |    |--<pause-video>*
        |     |      |     |    |--<video-layout>*
        |     |      |     |   ...
        |     |      ...
        |
        |--<host-info>
        |     |--<display-text>
        |     |--<web-page>
        |     |--!<uris>     |--<uris>
        |     |     |--!<entry>     |--<entry>
        |     |     |    |--!<uri>    |--<uri>
        |     |     |    |--<display-text>
        |     |     |--<H323>*
        |     |     |    |--<H.323-alias>*
        |     |     |    |--<H.323-URI>*
        |     |     |--<PSTN-ISDN>*
        |     |     |    |--<phone number>*
        |           ...
        |--<conference-state>
        |     |--<allow-conference-event-subscription>*
        |     |--<user-count>
        |     |--!<active>     |--<active>
        |     |--<locked>
        |
        |--<floor-information>*
        |     |--<conference-ID>*
        |     |--<allow-floor-events>*
        |     |--<floor-request-handling>*
        |     |--<conference-floor-policy>*
        |     |     |--<floor>*
        |     |     |    |--<media-types>*    |--!<media-label>*
        |     |     |    |--<algorithm>*    |--!<algorithm>*
        |     |     |    |--<max-floor-users>*
        |     |     |    |--<chair-id>*
        |     |     |    |--<chair-id>*    |--<moderator-id>*
        |     |     |   ...
        |     |     ...
        |
        |--!<users>
        |     |--<join-handling>*
        |     |--<user-admission-policy>*
        |     |--<allowed-users-list>*
        |     |     |--<target>*
        |     |     |-- ...
        |     |
        |     |
        |     |--!<user>     |--<user>
        |     |    |--<display-text>
        |     |    |--<associated-aors>
        |     |    |--<provide-anonymity>*
        |     |    |--<roles>
        |     |    |    |
        |     |    |   ...
        |     |    |--<languages>
        |     |    |--<cascaded-focus>
        |     |    |--<allow-refer-users-dynamically>*
        |     |    |--<allow-invite-users-dynamically>*
        |     |    |--<allow-remove-users-dynamically>*
        |     |    |--!<endpoint>
        |     |    |      |--<display-text>
        |     |    |      |--<referred>
        |     |    |      |--<status>
        |     |    |      |--<joining-method>
        |     |    |      |--<joining-info>
        |     |    |      |--<disconnection-method>
        |     |    |      |--<disconnection-info>
        |     |    |      |--!<media>      |--<media>
        |     |    |      |    |--<type>
        |     |    |      |    |--<display-text>
        |     |    |      |    |--<label>
        |     |    |      |    |--<src-id>
        |     |    |      |    |--<status>
        |     |    |      |    |--<to-mixer>*
        |     |    |      |    |      |--<floor>*
        |     |    |      |    |      |--<controls>*
        |     |    |      |    |      |      |--<mute>*
        |     |    |      |    |      |      |--<gain>*
        |     |    |      |    |      |     ...
        |     |    |      |    |--<from-mixer>*
        |     |    |      |    |      |--<floor>*
        |     |    |      |    |      |--<controls>*
        |     |    |      |    |      |      |--<pause-video>*
        |     |    |      |    |      |     ...
        |     |    |      |   ...
        |     |    |      |--<call-info>
        |     |    |      |    |--<sip>
        |     |    |      |    |   |--<display-text>
        |     |    |      |    |   |--<call-id>
        |     |    |      |    |   |--<from-tag>
        |     |    |      |    |   |--<to-tag>
        |          ...    ...
        |--<sidebars-by-ref>
        |     |--<entry>
        |     |     |-- <user>
        |     |     |-- <display-text>
        |     |--<entry>
        |     |     |-- <user>
        |     |     |-- <display-text>
        |     ...
        |--<sidebars-by-val>
        |     |--<entry>
        |     |     |
        |     |    ...
        |     |--<entry>
        |     |     |
        |     ...   ...

                      Figure 3: Non-normative diagram

   The following sections describe these elements in detail.  The full
   Relax NG schema is provided Section 5.

4.1.  <conference-description>

   The <conference-description> element,  <conference-info>

   A conference object document begins with the root element tag
   <conference-info>, which is defined in [1],
   describes the conference as a whole.  It SHOULD have an extra
   attribute 'xml:lang' to specify the language used RFC4575 [1].  The <conference-
   info> attributes are described in RFC4575 [1].  Notice that the contents of
   this
   <conference-info> element as defined in Section 2.12 of [8].  It is comprised of
   <display-text>, <subject>, <free-text>, <keywords>, <allow-sidebars>,
   <conference-time>, <conf-uris>, <service-uris>, <maximum-user-count>,
   and <available-media>.

   The <display-text>, <subject>, <free-text> does not have the attributes 'state' and <keywords> elements
   are
   'version' defined in [1].  They are used RFC4575[1] for this element because this
   attribute only applies to describe notifications mechanism.  RFC4575 [1]
   defines as well an 'entity' attribute that contains the conference's
   content.

   The child element <allow-sidebars> describes conference
   object identifier (XCON-URI) that identifies the capabilities of conference being
   described in the
   conference. document.

   The <conference-time> child <conference-info> element contains information related to
   conference time and duration of the conference.  The <conf-uris> <conference-description>,
   <host-info>, <conference-state>, <floor-information>, <users>,
   <sidebars-by-ref>, and
   <service-uris> <sidebars-by-val> child elements.  All these
   elements, except <floor-information>, are used to describe defined in [1].  A
   conference document MUST at least include the conference-related
   identifiers.  The <maximum-user-count> <conference-
   description> and <users> child element indicates the
   number of users that can be invited to the conference. elements.

4.2.  <conference-description>

   The
   <available-media> child element <conference-description> element, which is defined in RFC4575
   [1], describes the conference as a whole.  It should have an extra
   attribute 'lang' to specify the language used to describe in the media
   characteristics contents of the conference. this
   element.  It is comprised of <display-text>, <subject>, <free-text>,
   <keywords>, <allow-sidebars>, <conference-time>, <conf-uris>,
   <service-uris>, <maximum-user-count>, and <available-media>.

   The following sections describe these elements in more detail.  Other
   child elements MAY be defined in the future to extend the
   <conference-description> element.

4.1.1.

4.2.1.  <display-text>

   The <display-text> element is described in section 5.3 of RFC 4575
   [1].

4.2.2.  <subject>

   The <subject> element is described in section 5.3 of RFC 4575 [1].

4.2.3.  <free-text>

   The <free-text> element is described in section 5.3 of RFC 4575 [1].

4.2.4.  <keywords>

   The <keywords> element is described in section 5.3 of RFC 4575 [1].

4.2.5.  <allow-sidebars>

   The <allow-sidebars> element represents a boolean action.  If set to
   TRUE, the conference is allowed to create sidebar conferences.

4.2.6.  <conference-time>

   The <conference-time> element contains the information related to
   conference time and duration of a conference.  The <conference-time>
   element contains one or more <entry> elements each defining the time
   information specifying a single conference occurrence.

   Every <entry> element contains a <mixing-start-offset> the following child elements:

   o  <base>: The <base> child element
   that specifies when conference media mixing starts before the
   conference starts, <mixing-end-offset> iCalendar object of
      the conference.  The iCalendar object components are defined in
      RFC 2445 [3].
   o  <mixing-start-offset>: The <mixing-start-offset> child element that
      specifies when the time a conference media mixing stops after starts before the
      conference stops. starts.  The <mixing-end-offset> <mixing-start-offset> child element
      expresses the offset as signed integers representing seconds
      before/after DTEND field.  The <mixing-
   start-offset> child element expresses the offset as signed integers
   representing seconds before/after iCalendar DTSTART field. field [3].  If the <mixing-
      start-offset> element is not present, it indicates that the
      conference media mixing starts immediately.  If the <mixing-end-
   offset> element is not present, it indicates that the conference
   occurrence is not bounded. <mixing-start-offset> and <mixing-end-  The <mixing-start-
      offset> elements both have has the mandatory 'require-participant' 'required-participant' attribute.  This
      attribute has one of 4 values: "none", "administrator",
      "moderator", and "participant".  For <mixing-start-
   offset>, this  This attribute allows a
      privileged user to define when media mixing starts based on the
      latter of the mixing start time, and the time the first
      participant, administrator, or moderator arrives.  If the value is
      set to "none'", mixing starts according to the mixing start time.  For <mixing-end-offset>, this
   o  <mixing-end-offset>: The <mixing-end-offset> child element that
      specifies the time a conference media mixing stops after the
      conference stops.  The <mixing-end-offset> child element expresses
      the offset as signed integers representing seconds before/after
      the iCalendar DTEND field [3].  If the <mixing-end-offset> element
      is not present, it indicates that the conference occurrence is not
      bounded.  The <mixing-end-offset> elements both have the mandatory
      'required-participant' attribute.  This attribute has one of 4
      values: "none", "administrator", "moderator", and "participant".
      This attribute allows a privileged user to define when media
      mixing ends based on the earlier of the <mixing-end-offset>, and
      the time the last participant, or moderator leaves.  If the value
      is set to "none", mixing stops according to the <mixing-end-offset>. <mixing-end-
      offset>.  If the conference policy was modified so that last
      privileged user is now a normal conference participant, and the
      conference requires a privileged user to continue; that conference
      MUST terminate.
   o  <can-join-after-offset>: An administrator can indicate the time
      when users can join a conference by populating the <can-join-after-offset> <can-join-
      after-offset> element.
   Similarly, an

   o  <must-join-before-offset>: An administrator can define the time
      after which new users are not allowed to join the conference
      anymore.  This is done by populating the <must-join-before-offset>
      element expressing the offset as signed integers representing
      seconds before/after DTSTART field.

   The <base> child element specifies the iCalendar object of the
   conference.  The iCalendar object components are defined in [3].

   The <entry> element also contains the <request-user> child element.
   o  <request-user>: It is possible to define the time when users or
      resources on the <allowed-users-list> is are requested to join the
      conference by using the <request-users> element.  This element
      expresses the offset as signed integers representing seconds
      before/after DTSTART field.
   o  <notify-end-of-conference>: The <notify-end-of-conference> element
      defines in seconds when the system has to send a notification when
      the end of the conference is approaching.  If the <notify-end-of-conference> <notify-end-of-
      conference> element is not present, it indicates that the system
      does not notify the users when the end of the conference is
      approaching.  The <notify-end-of-
   conference> <notify-end-of-conference> child element
      expresses the offset as signed integers representing seconds before/after after
      DTSTART field.
   o  <allowed-extend-mixing-end-offset>: The <allowed-
   extend-mixing-end-offset> <allowed-extend-mixing-
      end-offset> refers to the possibility to extend the conference.
      It has two values: "allowed", "denied".

4.1.2. a boolean value.

4.2.7.  <conf-uris>

   The <conf-uris> contains the identifiers to be used in order to
   access the conference by different signaling means.  It contains a
   sequence of child elements: <entry>, <H.323>, and <PSTN-ISDN>.  The
   <entry> <conf-uris>
   element refers to the SIP protocol.  It keeps the same name
   that is defined in [1] to maintain backwards compatibility with this
   RFC.  The <entry> element contains the <uri>, <display-text>, and
   <purpose> which are described in [1].  The currently defined
   <purpose> values to be used with the <conf-uris> are:
   o  participation: Accessing a URI with this <purpose> will bring the
      party into the conference
   o  streaming: Accessing a URI with this <purpose> will commence
      streaming the conference, but not allow active participation
   The <H.323> element includes either a <H.323-alias> or a <H.323-URI>
   child elements.  The <PSTN-ISDN> has an attribute 'PIN code' with the
   PIN code section 5.3.1 of the conference if used and a 'purpose' attribute that
   describes to the user which phone number RFC 4575[1].  Future
   extensions to use.  The <PSTN-ISDN>
   element this schema may include one or more <phone number> child elements.

4.1.3. define new values and register them
   with IANA.

4.2.8.  <service-uris>

   The <service-uris> describes auxiliary services available for the
   conference.  It contains a sequence of child elements: <entry>,
   <H.323>, and <PSTN-ISDN>.  The <entry> child element contains <uri>,
   <display-text>, and <purpose>.  The purpose will be used to describe
   the service.  The currently defined <purpose> values to be used with
   the <service-uris> are:
   o  web-page: Indicates the web page containing the additional
      information about the conference
   o  recording: Indicates the link at which the recorded conference
      context can be retrieved
   o  event: Indicates the URI at which a subscription to the conference
      event package may be requested.  This would typically be the
      conference URI of the main conference element is described in section 5.3.2
   of RFC4575[1].  Future extensions to this schema may define new
   values and register them with IANA.  These elements are described in [1]. <H.323>, and
   <PSTN-ISDN> child elements are described in the <conf-uris> section.

4.1.4.

4.2.9.  <maximum-user-count>

   The <maximum-user-count> contains the overall number of users allowed
   to join the conference.  Note that this value is set by an
   administrator and can reflect any local policies such as network
   consumption, CPU processing power, and licensing rules.

4.1.5.

4.2.10.  <available-media>

   The <available-media> has the 'label' attribute that is the media
   stream identifier assigned by the conferencing server.  This  The attribute
   'label' is described in RFC 4575 [1], section 5.3.4.  The <available-
   media> element contains a sequence of <entry> child elements of conference-medium-
   type. elements.  Each
   <entry> element contains the <type>, <display-text>,
   <status>, <mixing-mode>, <mix-level>, <controls> and <codecs> following child
   elements. elements:

   o  The <type> element is described in section 5.3.4 of RFC 4575 [1].
   o  The <display-text> element is described in section 5.3.4 of RFC
      4575 [1].
   o  The attribute 'label' and the <type>, <display-text>, and <status> elements are element is described in section 5.3.4 of RFC 4575
      [1].
   o  The child element <mixing-mode> describes a default policy by
      which the mixer will build the outgoing stream from the incoming
      streams.  Notice that this policy is different than the policy
      describing the floors for each media.  The <mixing-mode> child
      element MUST contain one and only one of the "Moderator-
      controlled", "FCFS", and "Automatic" values indicating the default
      algorithm to use with every media stream.  The "Moderator-
      controlled" value indicates that the moderator of the conference,
      controls the media stream policy.  The "FCFS" value indicates a
      'first-come-first-served' policy.
   o  The <codecs> element specifies the allowed codecs in the
      conference.  It has an attribute 'decision' that specifies if the
      focus decides the common codec automatically or needs the approval
      of the moderator of the conference ("automatic", "moderator-controlled"). "moderator-
      controlled").  The <codecs> element contains <entry> elements.  A
      <entry> element can have the attribute 'name' and 'policy'.  The
      'name' attribute identifies a
   codec, and the 'decision' attribute contains the policy for that
   codec (allowed, or disallowed).

   The child elements <mixing-mode> and <mix-level> describe a default
   policy by which the mixer will build the outgoing stream from the
   incoming streams.  Notice that this policy is different than the
   policy describing the floors for each media. codec.  The <mix-level> child
   element describes the number of participants in audio media streams
   or the number of sub-windows in video media streams (for instance, a
   value list of "4" in the <mix-level> element for video streams implies possible codecs
      accepted as a
   2x2 layout).  The <mixing-mode> child element MUST contain one and
   only one 'name' attribute is defined by the IANA registry for
      RTP Payload Types.  The possible values of the "Moderator-controlled", "FCFS", and "Automatic" attribute 'name'
      are the values indicating of the default algorithm to be use with every 'subtype' column of the RTP Payload Format
      media
   stream. types per RFC4855[9] defined in IANA [10].  The next section explains 'policy'
      attribute contains the <controls> child element.

4.1.5.1.  <controls> policy for that codec (allowed, or
      disallowed).
   o  The <controls> element contains the basic audio and video global
   controls
      control elements for a conference.  It is expected that for the
      majority of the basic conferences, these controls are sufficient.
      If the conference server wants to support more advanced controls,
      then it is recommended that an extension of to the data model be
      used.  In the <controls> element the schema is extensible, hence
      new control types can be added in the future.  Similarly, controls that apply to a
   specific user would appear under the <users>/<user>/<endpoint>
   element.  So moderator
      controls that affect all media output would go under the
      <available-media> element.

4.1.5.1.1.  mute  The 'mute' control following controls elements are
      defined for <controls>:
      *  The <mute> element is used in conjunction with an audio stream
         to cease transmission of associated media.  That means that for
         the entire duration where mute is applicable, all current and
         future participants of the conference are muted and will not
         receive any audio.  It has a "boolean" value.  If this control
         is not specified, access to the control is not available to the client and media SHOULD NOT be transported for the
   associated media stream.

4.1.5.1.2.  pause-video
         client.
      *  The 'pause-video' control <pause-video> element is used in conjunction with a video
         stream to cease transmission of associated media.  It has a
         "boolean" value.  If this control is not specified, the access
         to the control is not available to the client and media SHOULD NOT be transported for the
   associated media stream.

4.1.5.1.3.  gain client.
      *  The 'gain' control <gain> element is used in conjunction with a media output
         stream to indicate the amount of amplification of an audio
         stream.  It has a an "int" number value.  This control has two
         attributes that defines the minimum and maximum amplification
         levels: 'min' and 'max'.  If this control is not specified,
         access to the control is not available to the client.

4.1.5.1.4.  video-layout
      *  The 'video-layout' control <video-layout> element is used in conjunction with a video
         stream to specify how the video streams (participants) (of participants) are
         viewed by each participant.  Only one layout type can be
         specified for each output stream.  If there are fewer
         participants than panels in the specified layout, then blanking
         (black screen) MAY be mixed into the stream on the behalf of
         the missing input streams.  If unspecified, the <video-
   layout> <video-layout>
         default type SHOULD be "single-view".  The <layout> types are
         as follows: follows, although any number of custom layouts may be
         specified in future extensions:
         +  single-view: Only one stream is presented by the focus to
            all participants in one panel.
         +  dual-view: This dual view option will present the video
            side-by-side in 2 panels and not alter the aspect ratio of
            the streams.  This will require the focus to introduce
            blanking on parts of the overall image as viewed by the
            participants.
         +  dual-view-crop: This side-by-side layout option instructs
            the focus to alter the aspect ratio of the streams (alter-aspect-ratio=TRUE) (alter-
            aspect-ratio=TRUE) so that blanking is not necessary.  The
            focus handles the cropping of the streams.
         +  dual-view-2x1: This layout option instructs the focus to
            place one stream above the other, in essence with two rows
            and one column.  In this option the aspect ratio is not
            altered and blanking is introduced.
         +  dual-view-2x1-crop: This layout option also instructs the
            focus to place one stream above the other, in essence with
            two rows and one column.  In this option the aspect ratio is
            altered and the video streams are cropped.
         +  quad-view: Four equal-sized panels in a 2x2 layout is
            presented by the focus to all participants.  Typically the
            aspect ratio of the streams are maintained (alter-aspect-ratio= (alter-aspect-
            ratio= FALSE).
         +  multiple-3x3: Nine equal-sized panels in a 3x3 layout is
            presented by the focus to all participants.  Typically the
            aspect ratio of the streams are preserved.

         +  multiple-4x4: Sixteen equal-sized panels in a 4x4 layout is
            presented by the focus to all participants.  Typically the
            aspect ratio of the streams are preserved.
         +  multiple-5x1: This option refers to a 5x1 layout where one
            panel will occupy 4/9 of the mixed video stream while the
            others will each occupy 1/9 of the stream.  Typically the
            aspect ratio of the streams is preserved.
         +  automatic: This option allows the focus to add panels as
            streams are
   added up to a limit of "panels".

4.2. added.

4.3.  <host-info>

   The <host-info> element contains information about the entity hosting
   the conference.  This information is set before the conference
   activation, and is rarely changed during the conference lifetime.
   The <host-info> element contains the <display-text>, <web-page> and
   <uris> child elements.  The <display-text> and <web-page> its child elements are explained in [1].  The <uris> child element contains a
   sequence of child elements: <entry>, <H.323>, and <PSTN-ISDN>.  The
   <entry> element refers to the SIP protocol.  It keeps the same name
   that is defined described in [1] to maintain backwards compatibility with this
   RFC.
   RFC4575[1], section 5.4.  Future extensions to the <uris> <host-info>
   element may define new values.

4.3.

4.4.  <conference-state>

   The <conference-state> is introduced in RFC4575 [1].  The
   <conference-state> element and contains the <allow-conference-event-
   subscription>, <user-count>, <active>, and <locked> child elements are explained in section 5.5 of [1]. elements.

4.4.1.  <allow-conference-event-subscription>

   The <allow-conference-event-subscription> element represents a
   boolean action.  If set to TRUE, the focus is instructed to allow the
   subscription to conference state events, such as the SIP RFC4575 'SIP Event
   Package for Conference State State' [1].  If set to FALSE, the subscription
   to conference state events would be rejected.  If this element is
   undefined it has a default value of TRUE, causing the subscription to
   conference state events to be accepted.

4.4.

4.4.2.  <user-count>

   The <user-count> child element is explained in RFC 4575 [1], section
   5.5.1.

4.4.3.  <active>

   The <active> child element is explained in RFC 4575 [1], section
   5.5.2.

4.4.4.  <locked>

   The <locked> child element is explained in RFC 4575 [1], section
   5.5.3.

4.5.  <floor-information>

   The <floor-information> element has contains the <conference-ID>, <allow-
   floor-events>, <floor-request-handling>, and <conference-floor-
   policy> child elements.  Other elements from different namespaces MAY
   be present for the purposes of extensibility.  This element has its
   own XML namespace.  The absence of this namespace and its elements
   element from an XML document indicates that the conference does not
   have a floor.

4.5.1.  <conference-ID>

   The <conference-ID> is used by a floor control server to provide 32-bit BFCP conference identifier defined in
   RFC4582 [5] section 5.1. that identifies the BFCP conference the
   message belongs to.  This identifier represents a
   client with conference instance
   within floor control.  When created within the conferencing system,
   the 'conference-ID' has a 1:1 mapping to the unique conference ID. object
   Identifier (XCON-URI).

4.5.2.  <allow-floor-events>

   The <allow-floor-events> element represents a boolean action.  If set
   to TRUE, the focus is instructed to accept the subscription to floor
   control events.  If set to FALSE, the focus is instructed to reject
   the subscription.  If this element is undefined, it has a default
   value of FALSE, causing the subscription to floor control events to
   be rejected.

   There are two methods which a conference participant subscribes
   himself to a floor control event.  One method is using an offer/
   answer exchange mechanism (RFC3264 [11]) using SIP INVITE and BFCP
   parameters in the SDP (RFC4583 [12]).  The other method is a general
   authorization mechanism described in section 9 of RFC4582 [5] and in
   RFC5018 [13].  Future documentation may define additional connection
   mechanisms.

4.5.3.  <floor-request-handling>

   The <floor-request-handling> element defines the actions used by the
   conference focus to control floor requests.  This element defines the
   action that the focus is to take when processing a particular request
   to a floor within a conference.  This element defines values of:

   o  "block": This action instructs the focus to deny the floor
      request.  This action is the default action taken in the absence
      of any other actions.
   o  "confirm": This action instructs the focus to allow the request.
      The focus then uses the defined floor algorithm to further allow
      or deny the floor.  The algorithms used are outside the scope of
      this document.

   Note that placing a this section discusses floor control information,
   therefore, the value of "block" for this element does not
   guarantee that in a participant <floor-request-handling> element is blocked from joining
   not related with the conference.
   Any other rule that might evaluate to TRUE for this participant that
   carried an action whose value was higher than "block" would
   automatically grant confirm/allow permission to that participant. value in the <join-handling> element
   (see Section 4.6).

4.5.4.  <conference-floor-policy>

   The <conference-floor-policy> element is mandatory and contains the
   required boolean attribute that indicates if the floor is moderator
   controlled or not. mandatory.  One or more
   <floor> elements can appear in the <conference-floor-policy> element.

   Each <floor> element has the following child elements:

   o  <media-label>: Every floor is defined using the
   'label' attribute. identified for one or more mandatory
      <media-label> element.  If the <available-media> information is
      included in the conference document, the value of this attribute element
      MUST be equal to the 'label' value of the corresponding media
      stream <entry> in the <available-media> container.  The number of
      those elements indicates how many floors the conference can have.
      A floor can be used for one or more media types; the mandatory <media-types> element can contain
   zero or more of the <video>, <audio>, <application>, <data>
   ,<control>, <message>, and <text> elements indicating the media of
   the floor.  One type of media can only appear once.  Other media
   types can be defined by extensions.
   o  <algorithm>: A floor can be controlled using many algorithms; the
      mandatory <algorithm> element MUST contain one and only one be set to any of the <moderator-
   controlled>, <FCFS>, and <random> elements
      "moderator-controlled", "FCFS" or "random" values indicating the
      algorithm.  The "Moderator-controlled" value indicates that the
      moderator of the conference controls the floor.  The "FCFS" value
      states for 'first-come-first-served' floor control.
   o  <max-floor-users>: The <max-floor-users> child element in the
      <floor> element is optional and, if present, dictates the maximum
      number of users who can have the floor at one time.
   o  <moderator-id>: The optional <chair-id> <moderator-id> indicates the BFCP UserID 'User
      ID' of the moderator.  The 'User ID' is a BFCP identifier defined
      in RFC4582 [5] section 5.1.  It MUST be set if the attribute
   moderator-controlled element
      <algorithm> is set to TRUE.

4.5. "Moderator-controlled" value.  Note that
      RFC4582 [5] refers to the moderator role as a 'floor chair'.

4.6.  <users>

   The <users> element is described in RFC4575 [1] and contains the
   <join-handling>, <user-admission-
   policy>, <allowed-users-list>, <user-admission-policy>, and <allowed-users-list>
   defined in this document and <user> child elements. elements defined in
   RFC4575[1].  Notice that the <users> element does not have the
   attribute 'state' defined in RFC4575[1] for this element because this
   attribute only applies to notifications mechanism.  The following
   sections describe these elements in more detail.  Other child
   elements and attributes can be used to extend <users> in the future.

4.6.1.  <join-handling>

   The <join-handling> element defines the actions used by the
   conference focus to control conference participation.  This element
   defines the action that the focus is to take when processing a
   particular request to join a conference.  This element defines values
   of:
   o  "block": This action instructs the focus to deny access to the
      conference.  This action is the default action taken in the
      absence of any other actions.
   o  "confirm": This action instructs the focus to place the
      participant on a pending list (e.g., by parking the call on a
      music-on-hold server), awaiting moderator input for further
      actions.
   o  "allow": This action instructs the focus to accept the conference
      join request and grant access to the conference within the
      instructions specified in the transformations of this rule.
   o  "IVR":  "authenticate": This action instructs the focus that the user has
      to provide the PIN code. a combination of username/password.
   o  "directed-operator": This action instructs the focus to direct the
      user to an operator.

   Note that placing a value of block for this element does not
   guarantee that a participant is blocked from joining the conference.
   Any other rule that might evaluate to TRUE for this participant that
   carried an action whose value was higher than "block" would
   automatically grant confirm/allow permission to that participant.

4.6.2.  <user-admission-policy>

   The <user-admission-policy> is an element that lets an organizer (or
   a participant with appropriate rights) choose a policy for the
   conference that controls how users are allowed into the conference.
   The list of possible values are:

   o  "closedAuthenticated": A 'closedAuthenticated' policy requires
      each conference participant to be in the allowed users list
      (listed under the <allowed-users-
   list> <allowed-users-list> XML element) with each
      participant being sufficiently (up to local policy) authenticated.
      Conference join requests for users not in the allowed users list
      or participants not authenticated should be rejected unless a
      <join-handling> action of 'confirm' is selected in which case the
      user is placed on a pending list as indicated earlier.
   o  "openAuthenticated": An 'openAuthenticated' policy requires each
      conferencing participant to be sufficiently authenticated (as
      before) but does not restrict which participants can join the
      conference.  Typically this implies that anyone capable of
      authenticating with the conferencing system may join the
      conference.

   o  "anonymous": An 'anonymous' policy allows any join requests in and
      is the least restrictive in policies.

   The following sections describe the remaining elements in more
   detail.  Other child elements can be used to extend <conference-
   description> in the future.

4.5.1. policy.

4.6.3.  <allowed-users-list>

   The <allowed-users-list> child element contains a list of user URIs,
   PSTN phone numbers, roles, or domains (*@example.com) that the focus
   uses to determine who can join the conference, who can be invited to
   join a conference, or who the focus needs to "refer to" the
   conference.  The <allowed-users-list> element includes zero or more
   <target> child elements.  This child element includes the mandatory
   'uri' attribute and the mandatory 'method' attribute.  The same 'uri'
   attribute with different method values can appear in the list more
   than once.

   The 'method' attribute is a list with the following values: "dial-in", "dial-out", and "refer".

   o  "dial-in": The value "dial-in" is used by the focus to determine
      who can join the conference.
   o  "dial-out": The value "dial-out" contains a list of resources that
      the focus will initiate a session with.
   o  "refer": The value "refer" is used by the focus to determine the
      resources that the focus needs to "refer to" the conference.  In
      SIP, this is achieved by the focus sending a REFER request to
      those potential participants.  In a different paradigm, this could
      also mean that the focus sends an SMS or an email to the referred
      user.  This list can be updated during the conference lifetime so
      it can be used for mid-
   conference mid-conference refers as well.

   The "refer" value differs from the "dial-out" in that the "dial-out"
   contains a list of resources that the focus will initiate a session
   with.  The resources
   on the "refer" value, on the other hand, value are expected to initiate the session
   establishment toward the focus themselves.  It is also envisioned
   that difference different users will have different access rights to those lists
   and therefore a separation between the two is needed.

4.5.2.

4.6.4.  <user> and Its <user> Sub-elements

   The element <user> is described in RFC5475[1] and describes a single
   participant in the conference.  The following elements of <user> are defined in [1], section 5.6:
   <display-text>, <associated-aors>, <roles>, <languages>, <cascaded-
   focus>, and <endpoint>. <user> element has two attributes: 'entity' and
   'state'.  The an attribute
   'entity'.  Notice that the <user> element does not have the attribute
   'state' is defined in [1], section 5.6. RFC4575[1] for this element because this attribute
   only applies to notifications mechanism.

   o  The attribute 'entity' contains a unique conference user identifier.
      identifier (XCON_USERID).  Other user identifiers can be
      associated with this conference user identifier and enable the
      conferencing system to correlate and map these multiple
      authenticated user identities to a single global user identifier.

      Figure 4 illustrates an example using the conference user
      identifier in association with the user identity defined for BFCP,
      SIP, and H323 user identity.  It should be noted that a
      conferencing system is free to structure such relationships as
      required and this information is just included as a guideline that
      can be used.

                                 +--------------+
                                 |  Conference  |
                                 |     User     |
                                 |  Identifier  |
                                 +--------------+
                                 |    John      |
                                 +------+-------+
                                        |
                                        |
                                        |
                  +---------------------+---------------------+
                  |                     |                     |
          +-------+--------+    +-------+-------+    +--------+-------+
          |  BFCP User ID  |    |  SIP User ID  |    |  H323 User ID  |
          +----------------+    +---------------+    +----------------+
          |   HK37ihdaj    |    |    123674     |    |     928373     |
          +----------------+    +---------------+    +----------------+

                    Figure 4: Conference Object Mapping

   The element <user> element contains the <display-text>, <associated-
   aors>, <provide-anonymity>, <roles>, <languages>, <cascaded-focus>,
   <allow-refer-users-dynamically>, <allow-invite-users-dynamically>,
   <allow-remove-users-dynamically>, and <endpoint>.  The following
   sections describe these elements in more detail.

4.6.4.1.  <display-text>

   The <display-text> child element is explained in RFC 4575 [1],
   section 5.6.1.

4.6.4.2.  <associated-aors>

   The <associated-aors> child element is explained in RFC 4575 [1],
   section 5.6.2.

4.6.4.3.  <provide-anonymity>

   The <provide-anonymity> element provides anonymity to the user.  In
   this case, the focus provides focus provides to the rest of the participants an
   anonymous identity for that user, for example anonymousX.  This
   element only affects the way the user information is provided to the
   other participants.  The real information about the user is still
   stored in the data model.  This can be achieved by using the
   <provide-anonymity> element.  It is a boolean transformation.  If set
   to TRUE, the conference participants will see an anonymous identity
   for the user.

4.6.4.4.  <roles>

   The <roles> child element is explained in RFC 4575 [1], section
   5.6.3.

4.6.4.5.  <languages>

   The <languages> child element is explained in RFC 4575 [1], section
   5.6.4.

4.6.4.6.  <cascaded-focus>

   The <cascaded-focus> child element is explained in RFC 4575 [1],
   section 5.6.5.

4.6.4.7.  <allow-refer-users-dynamically>

   The <allow-refer-users-dynamically> element represents a boolean
   action.  If set to TRUE, a participant is allowed to instruct the
   focus to refer a user to the conference without modifying the
   <allowed-users-list> (in SIP terms, a participant is allowed to send
   a REFER request to the focus which results in the focus sending a
   REFER request to the user the referrer wishes to join the
   conference).  If set to FALSE, the refer request is rejected.  If
   this element is undefined it has a value of FALSE, causing the refer
   to be rejected.

4.6.4.8.  <allow-invite-users-dynamically>

   The <allow-invite-users-dynamically> element represents a boolean
   action.  If set to TRUE, a participant is allowed to instruct the
   focus to invite a user to the conference without modifying the
   <allowed-users-list> list (in SIP terms, a participant is allowed to
   send a REFER request to the rest of focus which results in the participants focus sending
   an
   anonymous identity for that user, for example anonymousX.  This
   element only affects the way INVITE request to the user information is shown the referrer wishes to join the
   oher participants.  The real information about
   conference).  If set to FALSE, the user refer request is still
   stored in rejected.  If
   this element is undefined it has a value of FALSE, causing the data model.  This can refer
   to be achieved by using the
   <provide-anonymity> element.  It is rejected.

4.6.4.9.  <allow-remove-users-dynamically>

   The <allow-remove-users-dynamically> element represents a boolean transformation.
   action.  If set to TRUE, a participant is allowed to instruct the
   focus to remove a user from the conference participants will see without modifying the
   ruleset (in SIP terms, a participant is allowed to send a REFER
   request to the focus which results in the focus sending an anonymous identity
   for BYE
   request to the user whose identity the referrer wishes to leave the conference).  If
   set to FALSE, the refer request is present in rejected.  If this element is
   undefined it has a value of FALSE, causing the conditions. refer to be rejected.

4.6.4.10.  <endpoint>

   The <endpoint> child element is defined in RFC4575[1].  It can
   provide the desired level of detail about the user's devices and
   their signaling sessions taking part in the conference and has the
   following child elements defined in RFC
   4575 RFC4575 [1]: <display-text>,
   <referred>, <status>, <joining-method>, <joining-info>,
   <disconnection-method>, <disconnection-info>, <media>, and <call-info>.  The <call-
   info>.  Notice that the <endpoint> element does not have the
   attribute 'state' defined in RFC4575[1] for this element because this
   attribute only applies to notifications mechanism.

   Besides the <endpoint>/<media> child elements defined in RFC 4575[1],
   the <endpoint>/<media> element has two other child elements: <to-mixer>, <to-
   mixer>, and <from-mixer> described in the following section.

4.5.2.1. list:

   o  <from-mixer>, <to-mixer>

   Similar to the controls defined in the <available-media> element, <to-mixer>: These are controls that apply to a particular user appear at this place in
      user's media stream being sent from the
   data structure. mixer to the participants
      endpoint or to the mixer from the participants endpoint.  The <to-mixer> <to-
      mixer> element details properties associated with the incoming
      streams to the mixer. mixer (streams sent to the mixer from the
      participant).  The <from-mixer> element details properties
      associated with the outgoing streams from the
   mixer. mixer (sent from the
      mixer to the participant).  Both of these elements have the
      attribute 'name'.  The 'name' attribute has the values "VideoIn",
      "VideoOut", "AudioOut", and "AudioIn".  The "VideoOut" and
      "AudioOut" media streams detail properties associated with the
      outgoing video and audio from the mixer.  The "VideoIn" and
      "AudioIn" media stream details properties associated with the
      incoming video and audio to the mixer.  More values can be defined
      in the future.  Each of these elements have the <floor> and
      <controls> child
   elements.

4.5.2.1.1.  <floor> elements:

      *  The <floor> element describes a floor that joins this
         participant in the conference.  If a participant, for instance,
         needs to talk in the conference, it first needs to get the
         floor from the chair of the conference.  The <floor> element
         has a "Boolean" value.  A value of FALSE indicates that this
         user does not hold the floor in this moment.  If this control
         is not specified, this user SHOULD NOT specify the floor
   option.

4.5.3. floor
         option.
      *  Controls that apply to a specific user would appear under the
         <controls> element.

4.7.  <sidebars-by-ref>

   The <sidebars-by-ref> element contains a set of <entry> child
   elements.  Each <entry> child  This element contains a <user> child is described in RFC4575 [1], 5.9.1.  Notice
   that the <sidebars-by-ref> element
   with a sidebar unique conference user identifier and a <display-text>
   child element.

4.5.4. does not have the attribute
   'state' defined in RFC4575[1] for this element because this attribute
   only applies to notifications mechanism.

4.8.  <sidebars-by-val>

   The <sidebars-by-val> element contains a set of <entry> child
   elements each containing information about a single sidebar.  By
   using this element, the server can include a full or partial
   description of each sidebar (as a sub-conference)  This
   element is described in RFC4575 [1], 5.9.2.  Notice that the body of
   <sidebars-by-val> element does not have the
   main conference document. attribute 'state' defined
   in RFC4575[1] for this element because this attribute only applies to
   notifications mechanism.

5.  RELAX NG Schema

   In accordance with the XCON framework Centralized Conferencing Framework document
   [4], the Conference Object is a logical representation of a
   conference instance.  The conference information schema contains core
   information that is utilized in any conference.  It also contains the
   variable information part of the Conference Object.

   This specification defines some document fragments in RELAX NG
   format. format
   [14].

   namespace a = "http://relaxng.org/ns/compatibility/annotations/1.0"
   namespace local = ""
   namespace ns1 ns2 = "urn:ietf:params:xml:ns:conference-info-urn" "urn:ietf:params:xml:ns:conference-info"
   default namespace ns2 ns1 = "urn:ietf:params:xml:ns:conference-schema" "urn:ietf:params:xml:ns:xcon-conference-info"

   start = element conference-info { conference-type }
   # CONFERENCE TYPE
   conference-type =
     attribute entity { text },
     attribute version { xsd:unsignedInt }?,
     attribute state { state-type }?,
     anyAttribute,
     conference-description-type,
     element host-info { host-type conference-info-urn* }?,
     element conference-state { conference-state-type }?,
     element floor-information { floor-information-type }?,
     element users { users-type },
     element sidebars-by-ref { sidebars-by-ref-type }?,
     element sidebars-by-val { sidebars-by-val-type }?,
     anyElement*
   # CONFERENCE DESCRIPTION TYPE
   conference-description-type =
     element conference-description {
       attribute xml:lang lang { xsd:language }?,
       attribute state { state-type }?,
       anyAttribute,
       element display-text { text }?,
       element subject { text }?,
       element free-text { text }?,
       element keywords {
         list { xsd:string* }
       }?,
       element allow-sidebars { xsd:boolean }?,
       element conference-time { conferencetime-type }?,
       element conf-uris { uris-type conference-info-urn* }?,
       element service-uris { uris-type conference-info-urn* }?,
       element maximum-user-count { xsd:int }?,
       element available-media { conference-media-type }?,
       anyElement*
     }
   # CONFERENCE TIME
   conferencetime-type =
     anyAttribute,
     element entry {
       element base { text }?,
       element mixing-start-offset {
         xsd:dateTime { pattern = ".+T.+Z.*" },
         attribute required-participant { single-role-type },
         anyAttribute
       }?,
       element mixing-end-offset {
         xsd:dateTime { pattern = ".+T.+Z.*" },
         attribute required-participant { single-role-type },
         anyAttribute
       }?,
       element can-join-after-offset {
         xsd:dateTime { pattern = ".+T.+Z.*" }
       }?,
       element must-join-before-offset {
         xsd:dateTime { pattern = ".+T.+Z.*" }
       }?,
       element notify-end-of-conference { xsd:int }?,
       element allowed-extend-mixing-end-offset {
         allowed-extend-mixing-values xsd:boolean }?,
       anyElement*
     }*,
     anyElement*
   # ALLOWED EXTEND MIXING VALUES
   allowed-extend-mixing-values =
     xsd:string "allowed" | xsd:string "denied"
   # URIS TYPE
   uris-type =
     attribute state { state-type }?,
     (element entry { uri-type }*
      & element H323 { H323-type }*
      & element PSTN-ISDN { PSTN-type }*),
     anyElement*
   # SIP TYPE
   uri-type =
     (element uri { xsd:anyURI },
      element display-text { text }?,
      element purpose { text }?,
      anyElement*)*
   # H323 TYPE
   H323-type =
     element H.323-alias { text }?,
     element H.323-URI { xsd:anyURI }?,
     anyElement*
   # PSTN TYPE
   PSTN-type =
     attribute PIN-code { xsd:unsignedInt },
     attribute purpose { xsd:unsignedInt },
     (element phone-number { xsd:unsignedInt },
      anyElement*)+
   # CONFERENCE MEDIA TYPE
   conference-media-type =
     attribute state { state-type }?,
     anyAttribute,
     element entry { conference-medium-type }*,
     anyElement*
   # CONFERENCE MEDIUM TYPE
   conference-medium-type =
     attribute label { text },
     anyAttribute,
     element display-text { text }?,
     element type { text }?,
     element status { media-status-type }?,
     element mixing-mode { mix-mode-type }?,
     element mix-level { xsd:unsignedInt }?,
     element codecs { codecs-type }?,
     element controls { controls-type }?,
     anyElement*
   # CONTROLS TYPE
   controls-type =
     attribute state { state-type }?,
     anyAttribute,
     element control { control-type }*,
     anyElement*
   # MIX MODE TYPE
   mix-mode-type =
     xsd:string "moderator-controlled"
     | xsd:string "FCFS"
     | xsd:string "automatic"
   # CODECS TYPE
   codecs-type =
     attribute decision { decision-type },
     anyAttribute,
     element codec { codec-type }*,
     anyElement*
   # CODEC TYPE
   codec-type =
     attribute name { text },
     attribute policy { policy-type } },
     anyAttribute
   # DECISION TYPE
   decision-type =
     xsd:string "automatic" | xsd:string "moderator-controlled"
   # POLICY TYPE
   policy-type = xsd:string "allowed" | xsd:string "disallowed"
   # CONTROL TYPE
   control-type =
     element
     anyAttribute,
     (element mute { xsd:boolean }
      | element pause-video { xsd:boolean }
      | element gain {
          xsd:int { minInclusive = "-127" maxInclusive = "127" }
        }
      | element video-layout {
          xsd:string "single-view"
          | xsd:string "dual-view"
          | xsd:string "dual-view-crop"
          | xsd:string "dual-view-2x1"
          | xsd:string "dual-view-2x1-crop"
          | xsd:string "quad-view"
          | xsd:string "multiple-3x3"
         | xsd:string "multiple-4x4"
         | xsd:string "multiple-5x1"
         | xsd:string "automatic"
       }
     | anyElement*
   # HOST TYPE
   host-type =
     (element display-text { text },
      element web-page { xsd:anyURI },
      element uris { uris-type },
      anyElement*)*
          | xsd:string "multiple-4x4"
          | xsd:string "multiple-5x1"
          | xsd:string "automatic"
        }
      | anyElement*)
   # CONFERENCE STATE TYPE
   conference-state-type =
     anyAttribute,
     element allow-conference-event-subscription { xsd:boolean }?,
     element user-count { xsd:unsignedInt }?,
     element active { xsd:boolean }?,
     element locked { xsd:boolean }?,
     anyElement*
   # FLOOR INFORMATION TYPE
   floor-information-type =
     anyAttribute,
     (element conference-ID { xsd:unsignedInt },
      element allow-floor-events { xsd:boolean },
      element floor-request-handling { floor-request-type },
      element conference-floor-policy { Conference-floor-policy },
      anyElement*)*
   # FLOOR REQUEST TYPE
   floor-request-type = xsd:string "block" | xsd:string "confirm"
   # CONFERENCE FLOOR POLICY
   Conference-floor-policy =
     anyAttribute,
     element floor {
       attribute moderator-controlled { xsd:boolean },
       attribute label { text },
       anyAttribute,
       (element media-types {
          xsd:string "video"
          | xsd:string "audio"
          | xsd:string "application"
          | xsd:string "data"
          | xsd:string "control"
          | xsd:string "message"
          | xsd:string "text"
        },
       element media-label { xsd:nonNegativeInteger }+,
       (element algorithm {
          xsd:string "moderator-controlled"
          | xsd:string "FCFS"
          | xsd:string "random"
        },
        element max-floor-users { xsd:nonNegativeInteger },
        element chair-id moderator-id { xsd:anyURI text },
        anyElement*)*
     }+
   # USERS TYPE
   users-type =
     attribute state { state-type }?,
     anyAttribute,
     element join-handling { join-handling-type }?,
     element user-admission-policy { user-admission-policy-type }?,
     element user-must-be-specified { xsd:boolean }?,
     element allowed-users-list { UserList }?,
     element user { user-type }*,
     anyElement*
   # USERS ADMISSION POLICY
   user-admission-policy-type =
     xsd:string "closedAuthenticated"
     | xsd:string "openAuthenticated"
     | xsd:string "anonymous"
   # JOIN HANDLING TYPE
   join-handling-type =
     xsd:string "block"
     | xsd:string "allow" "confirm"
     | xsd:string "confirm" "allow"
     | xsd:string "IVR" "authenticate"
     | xsd:string "directed-operator"
   # USERLIST
   UserList =
     anyAttribute,
     element target { target-type }*,
     anyElement*
   # TARGET TYPE
   target-type =
     attribute uri { xsd:anyURI },
     attribute method { method-type } },
     anyAttribute
   # METHOD TYPE
   method-type =
     xsd:string "dial-in" | xsd:string "dial-out" | xsd:string "refer"
   # USER TYPE
   user-type =
     attribute entity { xsd:anyURI },
     attribute state { state-type }?,
     anyAttribute,
     element display-text { text }?,
     element associated-aors { uris-type conference-info-urn* }?,
     element provide-anonymity { xsd:boolean }?,
     element roles { roles-type text }?,
     element languages {
       list { xsd:language }
     }?,
     element cascaded-focus { xsd:anyURI }?,
     element allow-refer-users-dynamically { xsd:boolean }?,
     element allow-invite-users-dynamically { xsd:boolean }?,
     element allow-remove-users-dynamically { xsd:boolean }?,
     element endpoint { endpoint-type }*,
     anyElement*
   # ENDPOINT TYPE
   endpoint-type =
     attribute entity { text },
     attribute state { state-type }?,
     anyAttribute,
     element display-text { text }?,
     element referred { conference-info-urn* }?,
     element status { endpoint-status-type }?,
     element joining-method { joining-type }?,
     element joining-info { conference-info-urn* }?,
     element disconnection-method { disconnection-type }?,
     element disconnection-info { conference-info-urn* }?,
     element media { media-type }*,
     element call-info { conference-info-urn* }?,
     anyElement*
   # MEDIA TYPE
   media-type =
     attribute id { xsd:int },
     attribute state { state-type }?,
     anyAttribute,
     element display-text { text }?,
     element type { text }?,
     element label { text }?,
     element src-id { text }?,
     element status { media-status-type }?,
     element to-mixer { mixer-type }?,
     element from-mixer { mixer-type }?,
     anyElement*
   # MIXER TYPE
   mixer-type =
     attribute state { state-type }?,
     anyAttribute,
     (element floor { xsd:boolean },
      element controls { controls-type })?,
     anyElement*
   # SIDEBARS-BY-REF TYPE
   sidebars-by-ref-type =
     attribute state { state-type }?,
     anyAttribute,
     element entry { uri-type conference-info-urn* }*,
     anyElement*
   # SIDEBARS-BY-VAL TYPE
   sidebars-by-val-type =
     attribute state { state-type }?,
     anyAttribute,
     element entry { conference-type }*,
     anyElement*
   # ROLES_TYPE
   roles-type =
     element entry { single-role-type }*,
     anyElement*
   # SINGLE ROLE TYPE
   single-role-type =
     xsd:string "administrator"
     | xsd:string "creator"
     | xsd:string "moderator"
     | xsd:string "participant"
     | xsd:string "observer" "none"
   # *********************************
   # EXTENSIBILITY OF THE SCHEMA
   # *********************************

   # EXTENSIBILITY ELEMENTS
   anyElement =
     element * {
       (attribute * { text }
        | text
        | anyElement)*
     }
   # EXTENSIBILITY ATTRIBUTES
   anyAttribute =
     attribute * - (entity
                    | version
                    | state
                    | xml:lang lang
                    | required-participant
                    | PIN-code
                    | purpose
                    | role
                    | type
                    | min
                    | max
                    | label
                    | decision
                    | name
                    | policy
                    | moderator-controlled
                    | uri
                    | method
                    | id
                    | domain
                    | local:*
                    | ns2:*) ns1:*) { text }*
   # *************************************************************
   # TYPES DEFINED IN THE EVENT PACKAGE FOR CONFERENCE STATE
   #  -  RFC4575 -
   # *************************************************************

   # WILDCARD FOR EVENT-PACKAGE NAMESPACE
   conference-info-urn =
     element ns1:* * - (ns2:* | local:*) {
       mixed {
         (attribute * { text }
          | conference-info-urn)*
       }
   # DEFINITION OF STATE TYPE
   state-type = "full" | "partial" | "deleted"
     }
   # DEFINITION OF ENDPOINT STATUS TYPE
   media-status-type = "recvonly" | "sendonly" | "sendrecv" | "inactive"
   # ENDPOINT STATUS TYPE
   endpoint-status-type =
     "pending"
     | "dialing-out"
     | "dialing-in"
     | "alerting"
     | "on-hold"
     | "connected"
     | "muted-via-focus"
     | "disconnecting"
     | "disconnected"
   # JOINING TYPE
   joining-type = "dialed-in" | "dialed-out" | "focus-owner"
   # DISCONNECTION TYPE
   disconnection-type = "departed" | "booted" | "failed" | "busy"

6.  XML Schema Extensibility

   The Conference Information Data Model defined in this document is
   meant to be extensible toward specific application domains.  Such
   extensions are accomplished by defining elements, child elements and
   attributes that are specific to the desired application domain.  The
   IETF MAY extend the data model schema with extension elements from
   the same namespace, but other instances are free to extend it from
   other than urn:ietf:params:xml:ns:conference-schema. urn:ietf:params:xml:ns:xcon-conference-info.

   Elements or attributes from unknown namespaces MUST be ignored.

7.  XML Example

   The following is an example of a conference information document.
   The conference starts on October 17, 2007, at 10:30 AM in New York
   City and finishes the same day at 12:30 PM every week.  In this
   example, there are currently 3 participants in a conference, one
   administrator, one moderator, and one participant.  Note that
   sidebars are allowed in this conference and there is one sidebar in
   the conference.  Also note that there is one floor moderator for the
   audio and a different floor moderator for the video.

 <?xml version="1.0" encoding="UTF-8"?>
   <conference-info xmlns="urn:ietf:params:xml:ns:conference-schema"
       entity="conference123@example.com" state="full"> xmlns="urn:ietf:params:xml:ns:xcon-conference-info"
       entity="conference123@example.com">
       <!--
           CONFERENCE DESCRIPTION
       -->

       <conference-description xml:lang="en-us"> lang="en-us">
           <display-text>Discussion of Formula-1 racing</display-text>
           <subject> Sports:Formula-1</subject>
           <free-text>This is a conference example</free-text>
           <keywords>Formula-1, cars</keywords>
           <webpage>http://www.example.com/users/formula-1</webpage>
           <security-level>low</security-level>
           <allow-sidebars>true</allow-sidebars>
           <conference-stage>running</conference-stage>
           <!--
           CONFERENCE TIME
           -->
           <conference-time>
               <entry>
                   <base>BEGIN:VCALENDAR
 PRODID:-//LlamaSpinner Inc.//NONSGML CamelCall//EN
 VERSION:2.0
 BEGIN:VEVENT
 DTSTAMP:20061103T140728Z
 UID:20061103T140728Z-345FDA-carol@example.com
 ORGANIZER:MAILTO:carol@example.com
 DTSTART:20071017T143000Z
 RRULE:FREQ=WEEKLY
 DTEND:20071217T163000Z
 END:VEVENT
 END:VCALENDAR</base>
                   <mixing-start-offset required-participant="moderator"
                      > 2007-10-17T14:29:00Z</mixing-start-offset>
                   <mixing-end-offset required-participant="participant"
                      > 2007-10-17T16:31:00Z</mixing-end-offset>
                   <must-join-before-offset
                      > 2007-10-17T15:30:00Z</must-join-before-offset>
               </entry>
           </conference-time>
           <!--
           CONFERENCE UNIQUE IDENTIFIERS
           -->
           <conf-uris state="full">
               <SIP>
           <conf-uris>
               <entry>
                   <uri>tel:+3585671234</uri>
                   <display-text>Conference Bridge</display-text>
                   <purpose>participation</purpose>
               </SIP>
               <SIP>
                   <uri>http://www.example.comlive.ram</uri>
               </entry>
               <entry>
                   <uri>http://www.example.com/live.ram</uri>
                   <purpose>streaming</purpose>
               </SIP>
               </entry>
           </conf-uris>
           <!--
             SERVICE URIS
           -->
           <service-uris state="full">
               <SIP>
           <service-uris>
               <entry>
                   <uri>http://www.example.com/formula1/</uri>
                   <purpose>web-page</purpose>
               </SIP>
               </entry>
           </service-uris>
           <!--
             MAXIMUM USER COUNT
           -->
           <maximum-user-count>
               <entry role="administrator">2</entry>
               <entry role="moderator">5</entry>
               <entry role="participant">150</entry>
           </maximum-user-count>
           <!--
             AVAILABLE MEDIA
           -->
           <available-media>
               <entry label="10234">
                   <display-text>main audio</display-text>
                   <type>audio</type>
                   <status>sendrecv</status>
                   <mixing-mode>automatic</mixing-mode>
                   <mix-level>3</mix-level>
                   <codecs decision="automatic">
                       <codec name="PCMU" policy="allowed"/>
                   </codecs>
               </entry>
               <entry label="10235">
                   <display-text>main video</display-text>
                   <type>video</type>
                   <status>sendrecv</status>
                   <mixing-mode>automatic</mixing-mode>
                   <mix-level>4</mix-level>
                   <codecs decision="automatic">
                       <codec name="H.263" policy="allowed"/>
                   </codecs>
               </entry>
           </available-media>
       </conference-description>
       <!--
           HOST INFO
         -->
       <host-info>
           <display-text>Formula1</display-text>
           <web-page>http://www.example.com/formula1/</web-page>
           <uris state="full">
               <SIP>
           <uris>
               <entry>
                   <uri>sip:alice@example.com</uri>
               </SIP>
               <SIP>
               </entry>
               <entry>
                   <uri>sip:carol@example.com</uri>
               </SIP>
               </entry>
           </uris>
       </host-info>
       <!--
           CONFERENCE STATE
         -->
       <conference-state>
           <allow-conference-state>true</allow-conference-state>
           <user-count>3</user-count>
           <active>true</active>
           <locked>false</locked>
       </conference-state>
       <!--
           FLOOR INFORMATION
         -->
       <floor-information>
           <conference-ID>567</conference-ID>
           <allow-floor-events>true</allow-floor-events>
           <floor-request-handling>confirm</floor-request-handling>
           <conference-floor-policy>
               <floor moderator-controlled="true" label="10234">
                   <media-types>audio</media-types>
                   <algorithm>moderator-controlled</algorithm>
                   <max-floor-users>1</max-floor-users>
                   <chair-id>sip:alice@example.com</chair-id>
               </floor>
               <floor moderator-controlled="true" label="10235">
                   <media-types>video</media-types>
               <floor>
                   <media-label>10234</media-label>
                   <media-label>10235</media-label>
                   <algorithm>moderator-controlled</algorithm>
                   <max-floor-users>1</max-floor-users>
                   <chair-id>sip:carol@example.com</chair-id>
                   <moderator-id>234</moderator-id>
               </floor>
           </conference-floor-policy>
       </floor-information>
       <!--
           USERS
         -->
       <users state="full">
       <users>
           <join-handling>allow</join-handling>
           <user-admission-policy
               >openAuthenticated</user-admission-policy>
           <!--
            ALLOWED USERS LIST
           -->
           <allowed-users-list>
               <target uri="sip:bob@example.com" method="dial-out"/>
               <target uri="sip:alice@example.com" method="dial-out"/>
               <target uri="sip:carol@example.com" method="dial-out"/>
               <target uri="sip:john@example.com" method="refer"/>
           </allowed-users-list>
           <!--
             USER BOB
           -->
           <user entity="bob534" state="partial"> entity="bob534">
               <display-text>Bob Hoskins</display-text>
               <associated-aors state="full">
               <associated-aors>
                   <SIP>
                       <uri>mailto:bob@example.com</uri>
                       <display-text>email</display-text>
                   </SIP>
               </associated-aors>
               <provide-anonymity>false</provide-anonymity>
               <roles>
                   <entry>participant</entry>
               </roles>
               <languages>en</languages>
               <sphere value="work"/>
               <allow-refer-users-dynamically
                   >false</allow-refer-users-dynamically>
               <allow-invite-users-dynamically
                   >false</allow-invite-users-dynamically>
               <allow-remove-users-dynamically
                   >false</allow-remove-users-dynamically>
               <!--
                   ENDPOINTS
               -->
               <endpoint entity="sip:bob@example.com" state="full"> entity="sip:bob@example.com">
                   <display-text>Bob's Laptop</display-text>
                   <referred>
                       <when>2006-10-17T14:00:00Z</when>
                       <reason>expert required</reason>
                       <by>sip:alice@example.com</by>
                   </referred>
                   <status>connected</status>
                   <joining-method>dialed-out</joining-method>
                   <joining-info>
                       <when>2006-10-17T14:00:00Z</when>
                       <reason>invitation</reason>
                       <by>sip:alice@example.com</by>
                   </joining-info>

                   <!--
                       MEDIA
                   -->
                   <media id="1">
                       <label>10235</label>
                       <src-id>432424</src-id>
                   </media>
                   <!--
                       CALL INFO
                   -->
                   <call-info>
                       <sip>
                           <display-text>full info</display-text>
                           <call-id>hsjh8980vhsb78</call-id>
                           <from-tag>vav738dvbs</from-tag>
                           <to-tag>8954jgjg8432</to-tag>
                       </sip>
                   </call-info>
               </endpoint>
           </user>

           <!--
               USER ALICE
           -->

           <user entity="alice334" state="full"> entity="alice334">
               <display-text>Alice Kay</display-text>
               <associated-aors state="full">
               <associated-aors>
                   <SIP>
                       <uri>mailto:alice@example.com</uri>
                       <display-text>email</display-text>
                   </SIP>
               </associated-aors>
               <provide-anonymity>false</provide-anonymity>
               <roles>
                   <entry>moderator</entry>
               </roles>
               <languages>en</languages>
               <sphere value="work"/>
               <allow-refer-users-dynamically
                   >true</allow-refer-users-dynamically>
               <allow-invite-users-dynamically
                   >true</allow-invite-users-dynamically>
               <allow-remove-users-dynamically
                   >true</allow-remove-users-dynamically>
               <!--
                   ENDPOINTS
               -->
               <endpoint entity="sip:alice@example.com" state="full"> entity="sip:alice@example.com">
                   <display-text>Alice's Desktop</display-text>
                   <status>connected</status>
                   <joining-method>dialed-in</joining-method>
                   <joining-info>
                       <when>2006-10-17T13:35:08Z</when>
                       <reason>invitation</reason>
                       <by>sip:conference@example.com</by>
                   </joining-info>
                   <!--
                       MEDIA
                   -->
                   <media id="1">
                       <label>10235</label>
                       <src-id>432424</src-id>
                       <status>sendrecv</status>
                   </media>
                   <media id="2">
                       <label>10234</label>
                       <src-id>532535</src-id>
                       <status>sendrecv</status>
                   </media>
                   <!--
                       CALL INFO
                   -->
                   <call-info>
                       <sip>
                           <display-text>full info</display-text>
                           <call-id>truy45469123478</call-id>
                           <from-tag>asd456cbgt</from-tag>
                           <to-tag>3456jgjg1234</to-tag>
                       </sip>
                   </call-info>
               </endpoint>
           </user>

           <!--
                  USER CAROL
                   -->
           <user entity="carol233" state="full"> entity="carol233">
               <display-text>Carol More</display-text>
               <associated-aors state="full">
               <associated-aors>
                   <SIP>
                       <uri>mailto:carol@example.com</uri>
                       <display-text>email</display-text>
                   </SIP>
               </associated-aors>
               <provide-anonymity>false</provide-anonymity>
               <roles>
                   <entry>administrator</entry>
               </roles>
               <languages>en</languages>
               <sphere value="work"/>
               <allow-refer-users-dynamically
                   >true</allow-refer-users-dynamically>
               <allow-invite-users-dynamically
                   >true</allow-invite-users-dynamically>
               <allow-remove-users-dynamically
                   >true</allow-remove-users-dynamically>
               <!--
                   ENDPOINTS
               -->
               <endpoint entity="sip:carol@example.com" state="full"> entity="sip:carol@example.com">
                   <display-text>Carol's Computer</display-text>
                   <status>connected</status>
                   <joining-method>dialed-in</joining-method>
                   <joining-info>
                       <when>2006-10-17T13:30:05Z</when>
                       <reason>invitation</reason>
                       <by>sip:conference@example.com</by>
                   </joining-info>
                   <!--
                       MEDIA
                   -->
                   <media id="1">
                       <label>10235</label>
                       <src-id>432424</src-id>
                       <status>sendrecv</status>
                   </media>
                   <media id="2">
                       <label>10234</label>
                       <src-id>532535</src-id>
                       <status>sendrecv</status>
                   </media>
                   <!--
                       CALL INFO
                   -->
                   <call-info>
                       <sip>
                           <display-text>full info</display-text>
                           <call-id>wevb12562321894</call-id>
                           <from-tag>asw456wedf</from-tag>
                           <to-tag>2365dfrt3497</to-tag>
                       </sip>
                   </call-info>
               </endpoint>
           </user>
       </users>
       <!--
            SIDEBARS BY REFERENCE
          -->
       <sidebars-by-ref state="full">
       <sidebars-by-ref>
           <entry>
               <uri>sips:conference123;grid=40</uri>
               <uri>conf223</uri>
               <display-text>private with Bob</display-text>
           </entry>
       </sidebars-by-ref>
       <!--
            SIDEBARS BY VALUE
          -->
       <sidebars-by-val>
           <entry entity="conference123;grid=40"> entity="conf223">
               <users>
                   <user entity="bob534"/>
                   <user entity="carol233"/>
               </users>
           </entry>
       </sidebars-by-val>
   </conference-info>

   Note that due to RFC formatting conventions, this documents splits
   lines whose content would exceed 72 characters.  Two backslash
   characters mark where line folding has taken place.  These
   backslashes would not appear in the actual XML data model.

8.  Security Considerations

   There are numerous security considerations for this document.  This
   section considers them.

8.1.  Authentication

   A malicious user can manipulate parts of the Conference Information
   Data Model privileges document giving themselves and others
   privileges to manipulate the document.  It is very important that
   only authorized clients are able to manipulate the Conference
   Information Data Model document.

   The security considerations for authentication (section 10.1)
   described in the centralized conferencing framework [1] applies to
   this document.  The focus must ensure that only authorized entities
   are able to manipulate the data to access the information.

8.2.  Confidentiality

   Participants of a conference may not want to reveal some private
   information to other users.  The Conference Information Data Model
   contains sensitive data which should not be analyzed or given to
   anyone.  Confidentiality is provided through encryption.  Strong end-
   to-end authentication and encryption can be done using public keys,
   and end-to-end encryption can be done using private keys.  It is
   RECOMMENDED that the protocols that manipulated the conference
   information data model. model use a strong encryption for conference
   information protection.

8.3.  Integrity

   It is very important that the Conference Information Data Model can only
   be accessed or modified by those authorized clients are able to manipulate users.  Without
   integrity, the Conference Information Data Model document.  Any conference control protocol
   MUST provide authentication, confidentiality and integrity. could be modified,
   fooling the user into believing incorrect information.  Measures
   taken to ensure integrity include maintaining rigorous authentication
   practices.

9.  IANA Considerations

9.1.  Conference Relax NG Schema Registration

     URI:  urn:ietf:params:xml:ns:conference-schema  urn:ietf:params:xml:ns:xcon-conference-info

     Relax NG Schema:  The Relax NG schema to be registered is contained
        in Section 4. 5.  Its first line is

     namespace a = "http://relaxng.org/ns/compatibility/annotations/1.0"

        and its last line is

     disconnection-type = "departed" | "booted" | "failed" | "busy"

9.2.  Conference Namespace Registration

   URI: urn:ietf:params:xml:ns:conference-schema urn:ietf:params:xml:ns:xcon-conference-info

9.3.  Conference Object Identifier Registration

    XCON_URI = "xcon" ":" [conf-object-id "@"] hostport
                              ; hostport as defined in RFC3261 host [ ":" port ]

    conf-object-id = 1*( unreserved / "+" / "=" / "/" )
                              ;

   host, port, and unreserved as are defined in RFC3986 RFC3986[15]

9.4.  Conference User Identifier Registration

    XCON_USERID = "xcon_userid" ":" conf-object-id

    conf-object-id = 1*( unreserved / "+" / "=" / "/" )
                              ;

   unreserved as is defined in RFC3986 RFC3986[15]

10.  Acknowledgements

   This document is really a distillation of many ideas discussed over a
   long period of time.  These ideas were contributed by many different
   drafts in the XCON working group and the SIPPING working group.  We
   would like to thank Orit Levin, Adam Roach, Mary Barnes, Chris
   Boulton, Umesh Chandra, Hisham Khartabil, Petri Koskelainen, Aki
   Niemi, and Jari Urpilainen Urpilainen, Rohan Mahy, and Henning Schulzrinne for their
   comments.  Also, We we would like to thank Mary Barnes, and Chris
   Boulton for letting us use the conference and user identifier
   information of their xcon drafts.  Last but not least, I would like
   to express my gratitude to all those reviewers for their invaluable
   contribution: Simon Pietro Romano, Lorenzo Miniero, Tobia Castaldi,
   Miguel Garcia, Mary Barnes, Srivatsa Srinivasan, Avshalom Houri, and
   Ben Campbell.

11.  References

11.1.  Normative References

   [1]   Rosenberg, J., Schulzrinne, H., and O. Levin, "A Session
         Initiation Protocol (SIP) Event Package for Conference State",
         RFC 4575, August 2006.

   [2]   Bradner, S., "Key words for use in RFCs to Indicate Requirement
         Levels", BCP 14, RFC 2119, March 1997.

   [3]   Dawson, F. and Stenerson, D., "Internet Calendaring and
         Scheduling Core Object Specification (iCalendar)", RFC 2445,
         November 1998.

11.2.  Informative References

   [4]   Barnes, M., "A Framework and Data Model for Centralized Conferencing", draft-ietf-xcon-framework-07
         draft-ietf-xcon-framework-09 (work in progress),
        January August 2007.

   [5]   Camarillo, G., Ott, J., and K. Drage, "The Binary Floor Control
         Protocol (BFCP)", RFC 4582, November 2006.

   [6]   Roach, A., "Session Initiation Protocol (SIP)-Specific Event
         Notification", RFC 3265, June 2002.

   [7]   Rosenberg, J., "A Framework for Conferencing with the Session
         Initiation Protocol (SIP)", RFC 4353, February 2006.

   [8]   Paoli, J., Maler, E., Sperberg-McQueen, C., Bray, T., and E. Maler, T. Bray,
         "Extensible Markup Language (XML) 1.0 (Second Edition)", World
         Wide Web Consortium FirstEdition REC-xml-20001006,
         October 2000, <http://www.w3.org/TR/2000/REC-xml-20001006>.

   [9]   Casner, S., "Media Type Registration of RTP Payload Formats",
         RFC 4855, February 2007.

   [10]  "IANA registry for RTP Payload Types"
         "http://www.iana.org/assignments/rtp-parameters".

   [11]  Rosenberg, J. and H. Schulzrinne, "An Offer/Answer Model with
         Session Description Protocol (SDP)", RFC 3264, June 2002.

   [12]  Camarillo, G., "Session Description Protocol (SDP) Format for
         Binary Floor Control Protocol (BFCP) Streams", RFC 4583,
         November 2006.

   [13]  Camarillo, G., "Connection Establishment in the Binary Floor
         Control Protocol (BFCP)", RFC 5018, September 2007.

   [14]  "RELAX NG Home Page" "http://relaxng.org/".

   [15]  Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
         Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986,
         January 2005.

Appendix A.  Appendix A.  Non-Normative RELAX NG Schema in XML Syntax

   <?xml version="1.0" encoding="UTF-8"?>
   <grammar ns="urn:ietf:params:xml:ns:conference-schema" ns="urn:ietf:params:xml:ns:xcon-conference-info"
    xmlns="http://relaxng.org/ns/structure/1.0"
    xmlns:a="http://relaxng.org/ns/compatibility/annotations/1.0"
    datatypeLibrary="http://www.w3.org/2001/XMLSchema-datatypes">
    <start>
     <element name="conference-info">
      <ref name="conference-type"/>
     </element>
    </start>
    <!--
           CONFERENCE TYPE
       -->
    <define name="conference-type">
     <attribute name="entity">
      <text/>
     </attribute>
     <optional>
      <attribute name="version">
       <data type="unsignedInt"/>
      </attribute>
     </optional>
     <optional>
      <attribute name="state">
     <ref name="state-type"/>
      </attribute>
     </optional> name="anyAttribute"/>
     <ref name="conference-description-type"/>
     <optional>
      <element name="host-info">
        <zeroOrMore>
         <ref name="host-type"/> name="conference-info-urn"/>
        </zeroOrMore>
      </element>
     </optional>
     <optional>
     <element name="conference-state">
       <ref name="conference-state-type"/>
     </element>
     </optional>
     <optional>
      <element name="floor-information">
       <ref name="floor-information-type"/>
      </element>
     </optional>
     <element name="users">
      <ref name="users-type"/>
     </element>
     <optional>
      <element name="sidebars-by-ref">
       <ref name="sidebars-by-ref-type"/>
      </element>
     </optional>
     <optional>
      <element name="sidebars-by-val">
       <ref name="sidebars-by-val-type"/>
      </element>
     </optional>
     <zeroOrMore>
      <ref name="anyElement"/>
     </zeroOrMore>
    </define>
    <!--
           CONFERENCE DESCRIPTION TYPE
       -->
    <define name="conference-description-type">
     <element name="conference-description">
      <optional>
       <attribute name="xml:lang"> name="lang">
        <data type="language"/>
       </attribute>
      </optional>
      <optional>
       <attribute name="state">
      <ref name="state-type"/>
       </attribute>
      </optional> name="anyAttribute"/>
      <optional>
       <element name="display-text">
        <text/>
       </element>
      </optional>
      <optional>
       <element name="subject">
        <text/>
       </element>
      </optional>
      <optional>
       <element name="free-text">
        <text/>
       </element>
      </optional>
      <optional>
       <element name="keywords">
        <list>
         <zeroOrMore>
          <data type="string"/>
         </zeroOrMore>
        </list>
       </element>
      </optional>
      <optional>
       <element name="allow-sidebars">
        <data type="boolean"/>
       </element>
      </optional>
      <optional>
       <element name="conference-time">
        <ref name="conferencetime-type"/>
       </element>
      </optional>
      <optional>
       <element name="conf-uris">
         <zeroOrMore>
          <ref name="uris-type"/> name="conference-info-urn"/>
         </zeroOrMore>
       </element>
      </optional>
      <optional>
       <element name="service-uris">
         <zeroOrMore>
          <ref name="uris-type"/> name="conference-info-urn"/>
         </zeroOrMore>
       </element>
      </optional>
      <optional>
       <element name="maximum-user-count">
        <data type="int"/>
       </element>
      </optional>
      <optional>
       <element name="available-media">
        <ref name="conference-media-type"/>
       </element>
       </optional>
      <zeroOrMore>
       <ref name="anyElement"/>
      </zeroOrMore>
     </element>
    </define>
    <!--
           CONFERENCE TIME
       -->
    <define name="conferencetime-type">
     <ref name="anyAttribute"/>
     <zeroOrMore>
      <element name="entry">
       <optional>
        <element name="base">
         <text/>
        </element>
       </optional>
       <optional>
        <element name="mixing-start-offset">
         <data type="dateTime">
          <param name="pattern">.+T.+Z.*</param>
         </data>
         <attribute name="required-participant">
          <ref name="single-role-type"/>
         </attribute>
         <ref name="anyAttribute"/>
        </element>
       </optional>
       <optional>
        <element name="mixing-end-offset">
         <data type="dateTime">
          <param name="pattern">.+T.+Z.*</param>
         </data>
         <attribute name="required-participant">
          <ref name="single-role-type"/>
         </attribute>
         <ref name="anyAttribute"/>
        </element>
       </optional>
       <optional>
        <element name="can-join-after-offset">
         <data type="dateTime">
          <param name="pattern">.+T.+Z.*</param>
         </data>
        </element>
       </optional>
       <optional>
        <element name="must-join-before-offset">
         <data type="dateTime">
          <param name="pattern">.+T.+Z.*</param>
         </data>
        </element>
       </optional>
       <optional>
        <element name="notify-end-of-conference">
         <data type="int"/>
        </element>
       </optional>
       <optional>
        <element name="allowed-extend-mixing-end-offset">
         <ref name="allowed-extend-mixing-values"/>
        </element>
       </optional>
       <zeroOrMore>
        <ref name="anyElement"/>
       </zeroOrMore>
      </element>
     </zeroOrMore>
     <zeroOrMore>
      <ref name="anyElement"/>
     </zeroOrMore>
    </define>
    <!--
           ALLOWED EXTEND MIXING VALUES
       -->
    <define name="allowed-extend-mixing-values">
     <choice>
      <value type="string">allowed</value>
      <value type="string">denied</value>
     </choice>
    </define>
    <!--
           URIS TYPE
       -->
    <define name="uris-type">
     <optional>
      <attribute name="state">
       <ref name="state-type"/>
      </attribute>
     </optional>
     <interleave>
      <zeroOrMore>
       <element name="entry">
        <ref name="uri-type"/>
       </element>
      </zeroOrMore>
      <zeroOrMore>
       <element name="H323">
        <ref name="H323-type"/>
       </element>
      </zeroOrMore>
      <zeroOrMore>
       <element name="PSTN-ISDN">
        <ref name="PSTN-type"/>
       </element>
      </zeroOrMore>
     </interleave>
     <zeroOrMore>
         </attribute>
         <ref name="anyElement"/>
     </zeroOrMore>
    </define>
    <!--
           SIP TYPE
       -->
    <define name="uri-type">
     <zeroOrMore> name="anyAttribute"/>
        </element>
       </optional>
       <optional>
        <element name="uri"> name="mixing-end-offset">
         <data type="anyURI"/> type="dateTime">
          <param name="pattern">.+T.+Z.*</param>
         </data>
         <attribute name="required-participant">
          <ref name="single-role-type"/>
         </attribute>
         <ref name="anyAttribute"/>
        </element>
       </optional>
       <optional>
        <element name="display-text">
        <text/> name="can-join-after-offset">
         <data type="dateTime">
          <param name="pattern">.+T.+Z.*</param>
         </data>
        </element>
       </optional>
       <optional>
        <element name="purpose">
        <text/> name="must-join-before-offset">
         <data type="dateTime">
          <param name="pattern">.+T.+Z.*</param>
         </data>
        </element>
       </optional>
      <zeroOrMore>
       <ref name="anyElement"/>
      </zeroOrMore>
     </zeroOrMore>
    </define>
    <!--
           H323 TYPE
      -->
    <define name="H323-type">
       <optional>
        <element name="H.323-alias">
       <text/> name="notify-end-of-conference">
         <data type="int"/>
        </element>
       </optional>
       <optional>
        <element name="H.323-URI"> name="allowed-extend-mixing-end-offset">
         <data type="anyURI"/> type="boolean"/>
        </element>
       </optional>
       <zeroOrMore>
        <ref name="anyElement"/>
       </zeroOrMore>
    </define>
    <!--
           PSTN TYPE
       -->
    <define name="PSTN-type">
     <attribute name="PIN-code">
      <data type="unsignedInt"/>
     </attribute>
     <attribute name="purpose">
      <data type="unsignedInt"/>
     </attribute>
     <oneOrMore>
      <element name="phone-number">
       <data type="unsignedInt"/>
      </element>
     </zeroOrMore>
     <zeroOrMore>
      <ref name="anyElement"/>
     </zeroOrMore>
     </oneOrMore>
    </define>

    <!--
           CONFERENCE MEDIA TYPE
       -->
    <define name="conference-media-type">
     <optional>
      <attribute name="state">
     <ref name="state-type"/>
      </attribute>
     </optional> name="anyAttribute"/>
     <zeroOrMore>
      <element name="entry">
       <ref name="conference-medium-type"/>
      </element>
     </zeroOrMore>
     <zeroOrMore>
      <ref name="anyElement"/>
     </zeroOrMore>
    </define>
    <!--
           CONFERENCE MEDIUM TYPE
       -->
    <define name="conference-medium-type">
     <attribute name="label">
      <text/>
     </attribute>
     <ref name="anyAttribute"/>
     <optional>
      <element name="display-text">
       <text/>
      </element>
     </optional>
     <optional>
      <element name="type">
       <text/>
      </element>
     </optional>
     <optional>
      <element name="status">
       <ref name="media-status-type"/>
      </element>
     </optional>
     <optional>
      <element name="mixing-mode">
       <ref name="mix-mode-type"/>
      </element>
     </optional>
     <optional>
      <element name="mix-level">
       <data type="unsignedInt"/>
      </element>
     </optional>
     <optional>
      <element name="codecs">
       <ref name="codecs-type"/>
      </element>
     </optional>
     <optional>
      <element name="controls">
       <ref name="controls-type"/>
      </element>
     </optional>
     <zeroOrMore>
      <ref name="anyElement"/>
     </zeroOrMore>
    </define>
    <!--
           CONTROLS TYPE
       -->
    <define name="controls-type">
     <optional>
      <attribute name="state">
     <ref name="state-type"/>
      </attribute>
     </optional> name="anyAttribute"/>
     <zeroOrMore>
      <element name="control">
       <ref name="control-type"/>
      </element>
     </zeroOrMore>
     <zeroOrMore>
      <ref name="anyElement"/>
     </zeroOrMore>
    </define>
    <!--
           MIX MODE TYPE
       -->
    <define name="mix-mode-type">
     <choice>
      <value type="string">moderator-controlled</value>
      <value type="string">FCFS</value>
      <value type="string">automatic</value>
     </choice>
    </define>
    <!--
           CODECS TYPE
       -->
    <define name="codecs-type">
     <attribute name="decision">
      <ref name="decision-type"/>
     </attribute>
     <ref name="anyAttribute"/>
     <zeroOrMore>
      <element name="codec">
       <ref name="codec-type"/>
      </element>
     </zeroOrMore>
     <zeroOrMore>
      <ref name="anyElement"/>
     </zeroOrMore>
    </define>
    <!--
           CODEC TYPE
       -->
    <define name="codec-type">
     <attribute name="name">
      <text/>
     </attribute>
     <attribute name="policy">
      <ref name="policy-type"/>
     </attribute>
     <ref name="anyAttribute"/>
    </define>
    <!--
           DECISION TYPE
       -->
    <define name="decision-type">
     <choice>
      <value type="string">automatic</value>
      <value type="string">moderator-controlled</value>
     </choice>
    </define>
    <!--
           POLICY TYPE
       -->
    <define name="policy-type">
     <choice>
      <value type="string">allowed</value>
      <value type="string">disallowed</value>
     </choice>
    </define>
    <!--
           CONTROL TYPE
       -->
    <define name="control-type">
     <ref name="anyAttribute"/>
     <choice>
      <element name="mute">
       <data type="boolean"/>
      </element>
      <element name="pause-video">
       <data type="boolean"/>
      </element>
      <element name="gain">
       <data type="int">
        <param name="minInclusive">-127</param>
        <param name="maxInclusive">127</param>
       </data>
      </element>
      <element name="video-layout">
       <choice>
        <value type="string">single-view</value>
        <value type="string">dual-view</value>
        <value type="string">dual-view-crop</value>
        <value type="string">dual-view-2x1</value>
        <value type="string">dual-view-2x1-crop</value>
        <value type="string">quad-view</value>
        <value type="string">multiple-3x3</value>
        <value type="string">multiple-4x4</value>
        <value type="string">multiple-5x1</value>
        <value type="string">automatic</value>
       </choice>
      </element>
      <zeroOrMore>
       <ref name="anyElement"/>
      </zeroOrMore>
     </choice>
    </define>
    <!--
           HOST TYPE
       -->
    <define name="host-type">
     <zeroOrMore>
      <element name="display-text">
       <text/>
      </element>
      <element name="web-page">
       <data type="anyURI"/>
      </element>
      <element name="uris">
       <ref name="uris-type"/>
      </element>
      <zeroOrMore>
       <ref name="anyElement"/>
      </zeroOrMore>
     </zeroOrMore>
    </define>
    <!--
           CONFERENCE STATE TYPE
       -->
    <define name="conference-state-type">
     <ref name="anyAttribute"/>
     <optional>
      <element name="allow-conference-event-subscription">
       <data type="boolean"/>
      </element>
     </optional>
     <optional>
      <element name="user-count">
       <data type="unsignedInt"/>
      </element>
     </optional>
     <optional>
      <element name="active">
       <data type="boolean"/>
      </element>
     </optional>
     <optional>
      <element name="locked">
       <data type="boolean"/>
      </element>
     </optional>
     <zeroOrMore>
      <ref name="anyElement"/>
     </zeroOrMore>
    </define>
    <!--
           FLOOR INFORMATION TYPE
       -->
    <define name="floor-information-type">
     <ref name="anyAttribute"/>
     <zeroOrMore>
      <element name="conference-ID">
       <data type="unsignedInt"/>
      </element>
      <element name="allow-floor-events">
       <data type="boolean"/>
      </element>
      <element name="floor-request-handling">
       <ref name="floor-request-type"/>
      </element>
      <element name="conference-floor-policy">
       <ref name="Conference-floor-policy"/>
      </element>
      <zeroOrMore>
       <ref name="anyElement"/>
      </zeroOrMore>
     </zeroOrMore>
    </define>
    <!--
           FLOOR REQUEST TYPE
       -->
    <define name="floor-request-type">
     <choice>
      <value type="string">block</value>
      <value type="string">confirm</value>
     </choice>
    </define>
    <!--
           CONFERENCE FLOOR POLICY
       -->
    <define name="Conference-floor-policy">
     <ref name="anyAttribute"/>
     <oneOrMore>
      <element name="floor">
       <attribute name="moderator-controlled">
        <data type="boolean"/>
       </attribute>
       <attribute name="label">
        <text/>
       </attribute>
       <ref name="anyAttribute"/>
       <zeroOrMore>
       <oneOrMore>
        <element name="media-types">
         <choice>
          <value type="string">video</value>
          <value type="string">audio</value>
          <value type="string">application</value>
          <value type="string">data</value>
          <value type="string">control</value>
          <value type="string">message</value>
          <value type="string">text</value>
         </choice> name="media-label">
         <data type="nonNegativeInteger"/>
        </element>
        </oneOrMore>
        <zeroOrMore>
        <element name="algorithm">
         <choice>
          <value type="string">moderator-controlled</value>
          <value type="string">FCFS</value>
          <value type="string">random</value>
         </choice>
        </element>
        <element name="max-floor-users">
         <data type="nonNegativeInteger"/>
        </element>
        <element name="chair-id">
         <data type="anyURI"/> name="moderator-id">
         <text/>
        </element>
        <zeroOrMore>
         <ref name="anyElement"/>
        </zeroOrMore>
       </zeroOrMore>
      </element>
     </oneOrMore>
    </define>
    <!--
           USERS TYPE
       -->
    <define name="users-type">
     <optional>
      <attribute name="state">
     <ref name="state-type"/>
      </attribute>
     </optional> name="anyAttribute"/>
     <optional>
      <element name="join-handling">
       <ref name="join-handling-type"/>
      </element>
     </optional>
     <optional>
      <element name="user-admission-policy">
       <ref name="user-admission-policy-type"/>
      </element>
     </optional>
     <optional>
      <element name="user-must-be-specified">
       <data type="boolean"/>
      </element>
     </optional>
     <optional>
      <element name="allowed-users-list">
       <ref name="UserList"/>
      </element>
     </optional>
     <zeroOrMore>
      <element name="user">
       <ref name="user-type"/>
      </element>
     </zeroOrMore>
     <zeroOrMore>
      <ref name="anyElement"/>
     </zeroOrMore>
    </define>
    <!--
           USERS ADMISSION POLICY
       -->
    <define name="user-admission-policy-type">
     <choice>
      <value type="string">closedAuthenticated</value>
      <value type="string">openAuthenticated</value>
      <value type="string">anonymous</value>
     </choice>
    </define>
    <!--
           JOIN HANDLING TYPE
       -->
    <define name="join-handling-type">
     <choice>
      <value type="string">block</value>
      <value type="string">allow</value>
      <value type="string">confirm</value>
      <value type="string">IVR</value> type="string">allow</value>
      <value type="string">authenticate</value>
      <value type="string">directed-operator</value>
     </choice>
    </define>
    <!--
           USERLIST
       -->
    <define name="UserList">
     <ref name="anyAttribute"/>
     <zeroOrMore>
      <element name="target">
       <ref name="target-type"/>
      </element>
     </zeroOrMore>
     <zeroOrMore>
      <ref name="anyElement"/>
     </zeroOrMore>
    </define>
    <!--
           TARGET TYPE
       -->
    <define name="target-type">
     <attribute name="uri">
      <data type="anyURI"/>
     </attribute>
     <attribute name="method">
      <ref name="method-type"/>
     </attribute>
     <ref name="anyAttribute"/>
    </define>
    <!--
           METHOD TYPE
       -->
    <define name="method-type">
     <choice>
      <value type="string">dial-in</value>
      <value type="string">dial-out</value>
      <value type="string">refer</value>
     </choice>
    </define>
    <!--
           USER TYPE
       -->
    <define name="user-type">
     <attribute name="entity">
      <data type="anyURI"/>
     </attribute>
     <optional>
      <attribute name="state">
     <ref name="state-type"/>
      </attribute>
     </optional> name="anyAttribute"/>
     <optional>
      <element name="display-text">
       <text/>
      </element>
     </optional>
     <optional>
      <element name="associated-aors">
       <zeroOrMore>
        <ref name="uris-type"/> name="conference-info-urn"/>
       </zeroOrMore>
      </element>
     </optional>
     <optional>
      <element name="provide-anonymity">
       <data type="boolean"/>
      </element>
     </optional>
     <optional>
      <element name="roles">
       <ref name="roles-type"/>
       <text/>
      </element>
     </optional>
     <optional>
      <element name="languages">
       <list>
        <data type="language"/>
       </list>
      </element>
     </optional>
     <optional>
      <element name="cascaded-focus">
       <data type="anyURI"/>
      </element>
     </optional>
     <optional>
      <element name="allow-refer-users-dynamically">
       <data type="boolean"/>
      </element>
     </optional>
     <optional>
      <element name="allow-invite-users-dynamically">
       <data type="boolean"/>
      </element>
     </optional>
     <optional>
      <element name="allow-remove-users-dynamically">
       <data type="boolean"/>
      </element>
     </optional>
     <zeroOrMore>
      <element name="endpoint">
       <ref name="endpoint-type"/>
      </element>
     </zeroOrMore>
     <zeroOrMore>
      <ref name="anyElement"/>
     </zeroOrMore>
    </define>
    <!--
           ENDPOINT TYPE
       -->
    <define name="endpoint-type">
     <attribute name="entity">
      <text/>
     </attribute>
     <optional>
      <attribute name="state">
     <ref name="state-type"/>
      </attribute>
     </optional> name="anyAttribute"/>
     <optional>
      <element name="display-text">
       <text/>
      </element>
     </optional>
     <optional>
      <element name="referred">
       <zeroOrMore>
        <ref name="conference-info-urn"/>
       </zeroOrMore>
      </element>
     </optional>
     <optional>
      <element name="status">
       <ref name="endpoint-status-type"/>
      </element>
     </optional>
     <optional>
      <element name="joining-method">
       <ref name="joining-type"/>
      </element>
     </optional>
     <optional>
      <element name="joining-info">
       <zeroOrMore>
        <ref name="conference-info-urn"/>
       </zeroOrMore>
      </element>
     </optional>
     <optional>
      <element name="disconnection-method">
       <ref name="disconnection-type"/>
      </element>
     </optional>
     <optional>
      <element name="disconnection-info">
       <zeroOrMore>
        <ref name="conference-info-urn"/>
       </zeroOrMore>
      </element>
     </optional>
     <zeroOrMore>
      <element name="media">
       <ref name="media-type"/>
      </element>
     </zeroOrMore>
     <optional>
      <element name="call-info">
       <zeroOrMore>
        <ref name="conference-info-urn"/>
       </zeroOrMore>
      </element>
     </optional>
     <zeroOrMore>
      <ref name="anyElement"/>
     </zeroOrMore>
    </define>
    <!--
           MEDIA TYPE
       -->
    <define name="media-type">
     <attribute name="id">
      <data type="int"/>
     </attribute>
     <optional>
      <attribute name="state">
       <ref name="state-type"/>
      </attribute>
     </optional>
     <ref name="anyAttribute"/>
     <optional>
      <element name="display-text">
       <text/>
      </element>
     </optional>
     <optional>
      <element name="type">
       <text/>
      </element>
     </optional>
     <optional>
      <element name="label">
       <text/>
      </element>
     </optional>
     <optional>
      <element name="src-id">
       <text/>
      </element>
     </optional>
     <optional>
      <element name="status">
       <ref name="media-status-type"/>
      </element>
     </optional>
     <optional>
      <element name="to-mixer">
       <ref name="mixer-type"/>
      </element>
     </optional>
     <optional>
      <element name="from-mixer">
       <ref name="mixer-type"/>
      </element>
     </optional>
     <zeroOrMore>
      <ref name="anyElement"/>
     </zeroOrMore>
    </define>
    <!--
           MIXER TYPE
       -->
    <define name="mixer-type">
     <optional>
      <attribute name="state">
     <ref name="state-type"/>
      </attribute>
     </optional> name="anyAttribute"/>
     <optional>
      <element name="floor">
       <data type="boolean"/>
      </element>
      <element name="controls">
       <ref name="controls-type"/>
      </element>
     </optional>
     <zeroOrMore>
      <ref name="anyElement"/>
     </zeroOrMore>
    </define>
    <!--
           SIDEBARS-BY-REF TYPE
       -->
    <define name="sidebars-by-ref-type">
     <optional>
      <attribute name="state">
     <ref name="state-type"/>
      </attribute>
     </optional> name="anyAttribute"/>
     <zeroOrMore>
      <element name="entry">
       <zeroOrMore>
        <ref name="uri-type"/> name="conference-info-urn"/>
       </zeroOrMore>
      </element>
     </zeroOrMore>
     <zeroOrMore>
      <ref name="anyElement"/>
     </zeroOrMore>
    </define>
    <!--
           SIDEBARS-BY-VAL TYPE
       -->
    <define name="sidebars-by-val-type">
     <optional>
      <attribute name="state">
     <ref name="state-type"/>
      </attribute>
     </optional> name="anyAttribute"/>
     <zeroOrMore>
      <element name="entry">
       <ref name="conference-type"/>
      </element>
     </zeroOrMore>
     <zeroOrMore>
      <ref name="anyElement"/>
     </zeroOrMore>
    </define>
    <!--
           ROLES_TYPE
       -->
    <define name="roles-type">
     <zeroOrMore>
      <element name="entry">
       <ref name="single-role-type"/>
      </element>
     </zeroOrMore>
     <zeroOrMore>
      <ref name="anyElement"/>
     </zeroOrMore>
    </define>
    <!--
           SINGLE ROLE TYPE
       -->
    <define name="single-role-type">
     <choice>
      <value type="string">administrator</value>
      <value type="string">creator</value>
      <value type="string">moderator</value>
      <value type="string">participant</value>
      <value type="string">observer</value> type="string">none</value>
     </choice>
    </define>
    <!--
           *********************************
           EXTENSIBILITY OF THE SCHEMA
           *********************************
       -->
    <!--
           EXTENSIBILITY ELEMENTS
       -->
    <define name="anyElement">
     <element>
      <anyName/>
      <zeroOrMore>
       <choice>
        <attribute>
         <anyName/>
        </attribute>
        <text/>
        <ref name="anyElement"/>
       </choice>
      </zeroOrMore>
     </element>
    </define>
    <!--
           EXTENSIBILITY ATTRIBUTES
       -->
    <define name="anyAttribute">
     <zeroOrMore>
      <attribute>
       <anyName>
        <except>
         <name ns="">entity</name>
         <name ns="">version</name>
         <name ns="">state</name>
         <name ns="">xml:lang</name> ns="">lang</name>
         <name ns="">required-participant</name>
         <name ns="">PIN-code</name>
         <name ns="">purpose</name>
         <name ns="">role</name>
         <name ns="">type</name>
         <name ns="">min</name>
         <name ns="">max</name>
         <name ns="">label</name>
         <name ns="">decision</name>
         <name ns="">name</name>
         <name ns="">policy</name>
         <name ns="">moderator-controlled</name>
         <name ns="">uri</name>
         <name ns="">method</name>
         <name ns="">id</name>
         <name ns="">domain</name>
         <nsName ns=""/>
         <nsName ns="urn:ietf:params:xml:ns:conference-schema"/> ns="urn:ietf:params:xml:ns:xcon-conference-info"/>
        </except>
       </anyName>
       <text/>
      </attribute>
     </zeroOrMore>
    </define>
    <!--
           *************************************************************
           TYPES DEFINED IN THE EVENT PACKAGE FOR CONFERENCE STATE
           -  RFC4575 -
           *************************************************************
       -->
    <!--
           WILDCARD FOR EVENT-PACKAGE NAMESPACE
       -->
    <define name="conference-info-urn">
     <element>
      <anyName>
       <except>
      <nsName ns="urn:ietf:params:xml:ns:conference-info-urn"/> ns="urn:ietf:params:xml:ns:conference-info"/>
        <nsName ns=""/>
       </except>
      </anyName>
      <mixed>
      <zeroOrMore>
        <choice>
         <attribute>
          <anyName/>
         </attribute>
         <ref name="conference-info-urn"/>
        </choice>
       </zeroOrMore>
      </mixed>
     </element>
    </define>

    <!--
           DEFINITION OF STATE TYPE
       -->
    <define name="state-type">
     <choice>
      <value>full</value>
      <value>partial</value>
      <value>deleted</value>
     </choice>
    </define>
    <!--
           DEFINITION OF ENDPOINT STATUS TYPE
       -->
    <define name="media-status-type">
     <choice>
      <value>recvonly</value>
      <value>sendonly</value>
      <value>sendrecv</value>
      <value>inactive</value>
     </choice>
    </define>
    <!--
           ENDPOINT STATUS TYPE
       -->
    <define name="endpoint-status-type">
     <choice>
      <value>pending</value>
      <value>dialing-out</value>
      <value>dialing-in</value>
      <value>alerting</value>
      <value>on-hold</value>
      <value>connected</value>
      <value>muted-via-focus</value>
      <value>disconnecting</value>
      <value>disconnected</value>
     </choice>
    </define>
    <!--
           JOINING TYPE
       -->
    <define name="joining-type">
     <choice>
      <value>dialed-in</value>
      <value>dialed-out</value>
      <value>focus-owner</value>
     </choice>
    </define>
    <!--
           DISCONNECTION TYPE
       -->
    <define name="disconnection-type">
     <choice>
      <value>departed</value>
      <value>booted</value>
      <value>failed</value>
      <value>busy</value>
     </choice>
    </define>

   </grammar>

Authors' Addresses

   Oscar Novo
   Ericsson
   Hirsalantie 11
   Jorvas  02420
   Finland

   Email: Oscar.Novo@ericsson.com

   Gonzalo Camarillo
   Ericsson
   Hirsalantie 11
   Jorvas  02420
   Finland

   Email: Gonzalo.Camarillo@ericsson.com

   David P. Morgan
   Fidelity Investments
   82 Devonshire St, MZ V3C
   Boston, MA  02109-3614
   USA

   Email: Dave.Morgan@fmr.com

   Roni Even
   Polycom
   94 Derech Em Hamoshavot
   Petach Tikva  49130
   Israel

   Email: roni.even@polycom.co.il

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