SIPPING                                                     J. Rosenberg
Internet-Draft                                               dynamicsoft
Expires: January 16, April 25, 2005                                   H. Schulzrinne
                                                     Columbia University
                                                           O. Levin, Ed.
                                                   Microsoft Corporation
                                                           July 18,
                                                        October 25, 2004

    A Session Initiation Protocol (SIP) Event Package for Conference
                                 State
                draft-ietf-sipping-conference-package-05
                draft-ietf-sipping-conference-package-06

Status of this Memo

   This document is an Internet-Draft and is subject to all provisions
   of section 3 of RFC 3667.  By submitting this Internet-Draft, each
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   which he or she is aware have been or will be disclosed, and any of
   which he or she become aware will be disclosed, in accordance with
   RFC 3668.

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Copyright Notice

   Copyright (C) The Internet Society (2004).  All Rights Reserved.

Abstract

   This document defines a conference event package for the Session
   Initiation Protocol (SIP) Events framework, along with a data format
   used in notifications for this package.  The conference package
   allows users to subscribe to a conference URI.  Notifications are
   sent about changes in the membership of this conference and
   optionally about changes in the state of additional conference
   components.

Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  4  5
   2.  Terminology  . . . . . . . . . . . . . . . . . . . . . . . . .  5  6
   3.  Conference Event Package . . . . . . . . . . . . . . . . . . .  6  7
     3.1   Event Package Name . . . . . . . . . . . . . . . . . . . .  6  7
     3.2   SUBSCRIBE Bodies . . . . . . . . . . . . . . . . . . . . .  6  7
     3.3   Subscription Duration  . . . . . . . . . . . . . . . . . .  6  7
     3.4   NOTIFY Bodies  . . . . . . . . . . . . . . . . . . . . . .  7  8
     3.5   Notifier Processing of SUBSCRIBE Requests  . . . . . . . .  7  8
     3.6   Notifier Generation of NOTIFY Requests . . . . . . . . . .  7  8
     3.7   Subscriber Processing of NOTIFY Requests . . . . . . . . .  8  9
     3.8   Handling of Forked Requests  . . . . . . . . . . . . . . .  8  9
     3.9   Rate of Notifications  . . . . . . . . . . . . . . . . . .  8  9
     3.10  State Agents . . . . . . . . . . . . . . . . . . . . . . .  8  9
   4.  Conference Data Format Model  . . . . . . . . . . . . . . . . . . . . 10
     4.1   Conference Information 11
   5.  Constructing Coherent State  . . . . . . . . . . . . . . . . . 12
   6.  Conference Data  . . 10
       4.1.1   User Element . . . . . . . . . . . . . . . . . . . . . 10
         4.1.1.1   User Attributes 14
     6.1   Conference Information . . . . . . . . . . . . . . . . . 11
         4.1.1.2   User Status Elements . 14
       6.1.1   Conference Type  . . . . . . . . . . . . . . 12
         4.1.1.3   Media Information . . . . . 14
         6.1.1.1   conference-description of
                   conference-description-type  . . . . . . . . . . . 13
           4.1.1.3.1   Media Attributes 14
         6.1.1.2   host-info of host-type . . . . . . . . . . . . . . 14
         6.1.1.3   conference-state of conference-state-type  . 13
           4.1.1.3.2   Media Elements . . . 15
         6.1.1.4   user of user-type  . . . . . . . . . . . . . 14
         4.1.1.4   User Role . . . 15
         6.1.1.5   sidebars-by-ref of uris-type . . . . . . . . . . . 15
         6.1.1.6   sidebar-by-val of conference-type  . . . . . . 14
       4.1.2   Sidebar Element . . 15
       6.1.2   Conference Description Type  . . . . . . . . . . . . . 15
         6.1.2.1   display-text of string type  . . . . 15
       4.1.3   Additional Conference Identifiers . . . . . . . 15
         6.1.2.2   subject of string type . . . . . . 15
       4.1.4   Policy URIs . . . . . . . . 15
         6.1.2.3   free-text of string type . . . . . . . . . . . . . 15
       4.1.5   Recording
         6.1.2.4   keywords of keywords-type  . . . . . . . . . . . . 16
         6.1.2.5   web-page of anyURI type  . . . . . . . . . . . 15
       4.1.6   Streaming . . 16
         6.1.2.6   conf-uris of uris-type . . . . . . . . . . . . . . 16
         6.1.2.7   service-uris of uris-type  . . . . . . . 16
     4.2   Constructing Coherent State . . . . . 16
         6.1.2.8   maximum-user-count of user-count-type  . . . . . . 16
         6.1.2.9   available-media of conference-medias-type  . . . . 16
       4.2.1   The Algorithm
       6.1.3   Host Type  . . . . . . . . . . . . . . . . . . . . 17
     4.3   Schema . . 16
         6.1.3.1   display-text of string type  . . . . . . . . . . . 16
         6.1.3.2   web-page of anyURI type  . . . . . . . . . . . . . 18
     4.4   Example 17
         6.1.3.3   uris of uris-type  . . . . . . . . . . . . . . . . 17
       6.1.4   Conference State Type  . . . . . . . . . 21
   5.  Security Considerations . . . . . . . 17
         6.1.4.1   user-count of user-count-type  . . . . . . . . . . 17
         6.1.4.2   security-level of security-level-type  . . 23
   6.  IANA Considerations . . . . 17
         6.1.4.3   active of Boolean type . . . . . . . . . . . . . . 17
         6.1.4.4   locked of Boolean type . . . 24
     6.1   conference Event Package Registration . . . . . . . . . . 24
     6.2   application/conference-info+xml MIME Registration . 17
         6.1.4.5   recording of uris-type . . . 24
     6.3   URN Sub-Namespace Registration for
           urn:ietf:params:xml:ns:conference-info . . . . . . . . . . 24
     6.4   XML Schema Registration . 17
         6.1.4.6   active-media of conference-medias-type . . . . . . 18
       6.1.5   User Type  . . . . . . . . . . 25
   7.  Acknowledgements . . . . . . . . . . . . 18
         6.1.5.1   display-text of string type  . . . . . . . . . . . 26
   8.  Changes History 18
         6.1.5.2   associated-aors of anyURI type . . . . . . . . . . 18
         6.1.5.3   roles of user-roles-type . . . . . . . . . . . . . 27
     8.1   Changes since -04 18
         6.1.5.4   language of language type  . . . . . . . . . . . . 19
         6.1.5.5   cascaded-focus of anyURI type  . . . . . . . . 27
     8.2   Changes since -03 . . 19
         6.1.5.6   endpoint of endpoint-type  . . . . . . . . . . . . 19
       6.1.6   Endpoint Type  . . . . . . 27
     8.3   Changes since -02 . . . . . . . . . . . . . . 19
         6.1.6.1   display-text of string type  . . . . . . 27
     8.4   Changes since -01 . . . . . 20
         6.1.6.2   referred of execution-type . . . . . . . . . . . . 20
         6.1.6.3   state of endpoint-state-type . . . 28
   9.  References . . . . . . . . 20
         6.1.6.4   joining-method of joining-type . . . . . . . . . . 21
         6.1.6.5   joining-info of execution-type . . . . . . . . 29
   9.1   Normative References . . 21
         6.1.6.6   disconnection-method of disconnection-type . . . . 22
         6.1.6.7   disconnection-info of disconnection-type . . . . . 22
         6.1.6.8   whispering-to of uris-type . . . . . . . . . 29
   9.2   Informative References . . . 22
         6.1.6.9   media of media-type  . . . . . . . . . . . . . . . 22
       6.1.7   Media Type . 29
       Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 23
         6.1.7.1   display-text of string type  . 30
       Intellectual Property and Copyright Statements . . . . . . . . 32

1.  Introduction . . 23
         6.1.7.2   proto of string type . . . . . . . . . . . . . . . 23
         6.1.7.3   ssrc of string type  . . . . . . . . . . . . . . . 23
         6.1.7.4   label of string type . . . . . . . . . . . . . . . 24
         6.1.7.5   state of media-state-type  . . . . . . . . . . . . 24
         6.1.7.6   snd-status of media-state-type . . . . . . . . . . 24
         6.1.7.7   rcv-status state of media-state-type . . . . . . . 24
         6.1.7.8   call of call-type  . . . . . . . . . . . . . . . . 24
   7.  Schema . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
   8.  Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
     8.1   Basic Example  . . . . . . . . . . . . . . . . . . . . . . 33
     8.2   Rich Example . . . . . . . . . . . . . . . . . . . . . . . 35
   9.  Security Considerations  . . . . . . . . . . . . . . . . . . . 40
   10.   IANA Considerations  . . . . . . . . . . . . . . . . . . . . 41
     10.1  conference Event Package Registration  . . . . . . . . . . 41
     10.2  application/conference-info+xml MIME Registration  . . . . 41
     10.3  URN Sub-Namespace Registration for
           urn:ietf:params:xml:ns:conference-info . . . . . . . . . . 41
     10.4  XML Schema Registration  . . . . . . . . . . . . . . . . . 42
   11.   Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 43
   12.   Changes History  . . . . . . . . . . . . . . . . . . . . . . 44
     12.1  Changes since -05  . . . . . . . . . . . . . . . . . . . . 44
     12.2  Changes since -04  . . . . . . . . . . . . . . . . . . . . 44
     12.3  Changes since -03  . . . . . . . . . . . . . . . . . . . . 44
     12.4  Changes since -02  . . . . . . . . . . . . . . . . . . . . 44
     12.5  Changes since -01  . . . . . . . . . . . . . . . . . . . . 45
   13.   References . . . . . . . . . . . . . . . . . . . . . . . . . 46
   13.1  Normative References . . . . . . . . . . . . . . . . . . . . 46
   13.2  Informative References . . . . . . . . . . . . . . . . . . . 46
       Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 47
       Intellectual Property and Copyright Statements . . . . . . . . 49

1.  Introduction

   The Session Initiation Protocol (SIP) [6] Events framework Events
   Framework [7] defines general mechanisms for subscribing to, and
   receiving notifications of, events within SIP networks.  It
   introduces the notion of a package, which is a specific
   "instantiation" of the events framework for a well-defined set of
   events.  Here, we define an event package for SIP conferences.  This
   package provides the conference notification service as outlined in
   the SIP conferencing framework [15].  As described there,
   subscriptions to a conference URI are routed to the focus that is
   handling the conference.  It acts as the notifier, and provides
   clients with updates on conference state.

   The information provided by this package is comprised of conference
   identifier(s), conference participants (optionally with their
   statuses and media description), conference sidebars, conference
   service URIs, etc.

2.  Terminology

   In this document, the key words "MUST", "MUST NOT", "REQUIRED",
   "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY",
   and "OPTIONAL" are to be interpreted as described in RFC 2119 [2] and
   indicate requirement levels for compliant implementations.

3.  Conference Event Package

   The conference event package allows a user to subscribe to a
   conference.  In SIP, conferences are represented by URIs.  These URIs
   route to a SIP user agent, called a focus, that is responsible for
   ensuring that all users in the conference can communicate with each
   other, as described in Conferencing Framework [15].  The focus has
   sufficient information about the state of the conference to inform
   subscribers about it.

   It is possible a participant in the conference may in fact be another
   focus.  In order to provide a more complete participant list, the
   focus MAY subscribe to the conference package of the other focus to
   discover the participant list in the cascaded conference.  This
   information can then be included in notifications by using of the
   "cascaded-focus" element as specified by this package.

   This section provides the details for defining a SIP Events package,
   as specified by RFC 3265 [7].

3.1  Event Package Name

   The name of this event package is "conference".  This package name is
   carried in the Event and Allow-Events header, as defined in RFC 3265
   [7].

3.2  SUBSCRIBE Bodies

   A SUBSCRIBE for a conference package MAY contain a body.  This body
   defines a filter to apply to the subscription.  Filter documents are
   not specified in this document, and at the time of writing, are
   expected to be the subject of future standardization activity.

   A SUBSCRIBE for a conference package MAY be sent without a body.
   This implies the default subscription filtering policy.  The default
   policy is:
   o  Notifications are generated every time there is any change in the
      state of the conference.
   o  Notifications do not normally contain full state; rather, they
      only indicate the state that has changed.  The exception is a
      NOTIFY sent in response to a SUBSCRIBE.  These NOTIFYs contain the
      full state of the information requested by the subscriber.

3.3  Subscription Duration

   The default expiration time for a subscription to a conference is one
   hour.  Once the conference ends, all subscriptions to that particular
   conference are terminated, with a reason of "noresource" RFC 3265
   [7].

3.4  NOTIFY Bodies

   As described in RFC 3265 [7], the NOTIFY message will contain bodies
   that describe the state of the subscribed resource.  This body is in
   a format listed in the Accept header field of the SUBSCRIBE, or a
   package-specific default if the Accept header field was omitted from
   the SUBSCRIBE.

   In this event package, the body of the notification contains a
   conference information document.  This document describes the state
   of a conference.  All subscribers and notifiers MUST support the
   "application/conference-info+xml" data format described in Section 6.
   The Session Initiation Protocol (SIP) [6] Events framework Events
   Framework [7] defines general mechanisms subscribe request MAY contain an Accept header field.  If no such
   header field is present, it has a default value of
   "application/conference-info+xml".  If the header field is present,
   it MUST include "application/conference-info+xml", and MAY include
   any other types.

   Of course, the notifications generated by the server MUST be in one
   of the formats specified in the Accept header field in the SUBSCRIBE
   request.

3.5  Notifier Processing of SUBSCRIBE Requests

   The conference information contains very sensitive information.
   Therefore, all subscriptions SHOULD be authenticated and then
   authorized before approval.  Authorization policy is at the
   discretion of the administrator, as always.  However, a few
   recommendations can be made.

   It is RECOMMENDED that all users in the conference be allowed to
   subscribe to the conference.

3.6  Notifier Generation of NOTIFY Requests

   Notifications MUST be generated for subscribing to, the conference state when a new
   participant joins (i.e.  gets "connected" to) or a participant leaves
   (i.e.  gets "disconnected" from) the conference.

   Subject to a local focus policy, additional changes in participants'
   status, changes in their media types, and
   receiving notifications of, events within SIP networks.  It
   introduces other optional information
   MAY be reported by the notion focus.

   Changes in sidebar rosters SHOULD be reported by the focus to their
   participants and MAY be reported to others, subject to local policy.

   Changes in conference identifiers and service URIs SHOULD be reported
   by the focus to the Conference package subscribers.

   Changes in other conference state information MAY be reported by the
   focus to the Conference package subscribers.

3.7  Subscriber Processing of NOTIFY Requests

   The SIP Events framework expects packages to specify how a package, which is a subscriber
   processes NOTIFY requests in any package specific
   "instantiation" ways, and in
   particular, how it uses the NOTIFY requests to construct a coherent
   view of the events framework state of the subscribed resource.

   Typically, the NOTIFY for the conference package will only contain
   information about those users whose state in the conference has
   changed.  To construct a well-defined set coherent view of
   events.  Here, we define an event the total state of all
   users, a subscriber to the conference package for SIP conferences.  This will need to combine
   NOTIFYs received over time.

   Notifications within this package provides can convey partial information;
   that is, they can indicate information about a subset of the conference notification service as outlined state
   associated with the subscription.  This means that an explicit
   algorithm needs to be defined in
   the SIP conferencing framework [14].  As described there,
   subscriptions order to a conference URI construct coherent and
   consistent state.  The details of this mechanism are routed specific to the focus that is
   handling the conference.  It acts as the notifier, and provides
   clients with updates
   particular document type.  See Section 5 for information on conference state.

   The
   constructing coherent information provided by this package is comprised from an
   application/conference-info+xml document.

3.8  Handling of conference
   identifier(s), conference participants (optionally with Forked Requests

   By their
   statuses and media description), conference sidebars, conference
   policy URIs, etc.

2.  Terminology

   In this document, nature, the key words "MUST", "MUST NOT", "REQUIRED",
   "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY",
   and "OPTIONAL" conferences supported by this package are to be interpreted as described in RFC 2119 [2] and
   indicate requirement levels
   centralized.  Therefore, SUBSCRIBE requests for compliant implementations.

3.  Conference Event Package

   The a conference event should
   not generally fork.  Users of this package allows a user to subscribe to MUST NOT install more than
   a
   conference.  In SIP, conferences are represented by URIs.  These URIs
   route to single subscription as a SIP user agent, called result of a focus, that single SUBSCRIBE request.

3.9  Rate of Notifications

   For reasons of congestion control, it is responsible for
   ensuring important that all users in the conference can communicate with each
   other, as described in Conferencing Framework [14].  The focus has
   sufficient information about the state rate of
   notifications not become excessive.  As a result, it is RECOMMENDED
   that the conference to inform
   subscribers about it.

   It server not generate notifications for a single subscriber at
   a rate faster than once every 5 seconds.

3.10  State Agents

   Conference state is possible a participant ideally maintained in the conference may element in fact be another
   focus.  In order to provide a more complete participant list, which the
   focus MAY subscribe to
   conference resides.  Therefore, the elements that maintain the
   conference package of are the other focus ones best suited to
   discover the participant list in handle subscriptions to it.
   Therefore, the cascaded conference.  This usage of state agents is NOT RECOMMENDED for this
   package.

4.  Conference Data Model

   Conference information can then is an XML document that MUST be included in notifications by well-formed
   and SHOULD be valid.  Dialog information documents MUST be based on
   XML 1.0 and MUST be encoded using UTF-8.  This specification makes
   use of the
   "cascaded-focus" attribute as specified XML namespaces for identifying dialog information documents
   and document fragments.  The namespace URI for elements defined by
   this package.

   This section provides the details for defining specification is a SIP Events package,
   as specified URN [3], using the namespace identifier
   'ietf' defined by RFC 3265 [7].

3.1  Event Package Name [4] and extended by [1].  This URN is:

   The name of this event package conference information is "conference".  This package name described by a hierarchal XML structure
   with the root element "conference-info".  The root element is
   carried in the Event and Allow-Events header, as defined
   only element in RFC 3265
   [7].

3.2  SUBSCRIBE Bodies

   A SUBSCRIBE the schema that carries meaningful version number for a
   all the elements in the document.  The whole conference package MAY contain a body.  This body
   defines a filter to apply to information
   is associated with this version number.

   All sub-elements in the subscription.  Filter documents are
   not specified "conference-info" hierarchal XML structure
   can be classified in this document, two groups: those that carry relatively small
   amount of data and at the time those that can potentially carry a lot of writing, data.
   During partial notifications, the light elements are
   expected to be updated as
   atomic pieces of data.  On the subject other hand, elements that can carry a
   substantial amount of future standardization activity.

   A SUBSCRIBE data have the general "state" attribute
   attached to them.  That is in order to support partial notifications
   for their content.

   A "state" attribute of a conference package MAY be sent without a body.
   This implies child element in the default subscription filtering policy.  The default
   policy is:
   o  Notifications are generated every time there document MUST adhere to
   its parent "state".  It means that if the parent's "state" is any change in "full",
   the state of its children MUST be "full".  If the conference.
   o  Notifications do not normally contain full state; rather, they
      only indicate the state that has changed.  The exception parent's "state" is a
      NOTIFY sent in response to a SUBSCRIBE.  These NOTIFYs contain
   "partial", the
      full state of its children MAY be either "partial", "full",
   or "deleted".

   For elements with the information requested by optional "state" attribute, if the subscriber.

3.3  Subscription Duration

   The default expiration time for a subscription to a conference attribute is one
   hour.  Once
   omitted from the conference ends, all subscriptions to that particular
   conference are terminated, with a reason of "noresource" RFC 3265
   [7].

3.4  NOTIFY Bodies

   As described in RFC 3265 [7], notification for the NOTIFY message will contain bodies element, it means that describe the
   reported element's state of the subscribed resource.  This body is in "full".

   All sub-elements, with possible multiple appearances under a format listed common
   parent, have keys defined to them in the Accept header field order to uniquely identify each
   element among others of the SUBSCRIBE, or a
   package-specific default if same type in the Accept header field was omitted partial notification
   event.

5.  Constructing Coherent State

   A Conference package subscriber MUST initialize the "version"
   attribute from the SUBSCRIBE.

   In this event package, "conference-info" element with the body of value in the notification contains a
   conference information document.  This
   first document describes the state
   of received.

   The conference package subscriber locally maintains a conference.  All subscribers and notifiers MUST support local element
   for each element in the
   "application/conference-info+xml" data format described schema and a table for each element with
   key(s) in Section 4.
   The subscribe request MAY contain an Accept header field.  If no such
   header field is present, it has the schema and indexed by these key(s).

   Each time a default new NOTIFY is received, the value of "application/
   conference-info+xml".  If the header field is present, it MUST
   include "application/conference-info+xml", local version
   number and MAY include any other
   types capable of representing dialog state.

   Of course, the notifications generated by the server MUST be "version" attribute in one
   of the formats specified in new received document are
   compared.  If the Accept header field value in the SUBSCRIBE
   request.

3.5  Notifier Processing of SUBSCRIBE Requests

   The conference information contains very sensitive information.
   Therefore, all subscriptions SHOULD be authenticated and then
   authorized before approval.  Authorization policy new document is at one higher than the
   discretion of
   local version number, the administrator, as always.  However, a few
   recommendations can be made.

   It local version number is RECOMMENDED that all users increased by one,
   and the document is processed.  If the value in the conference be allowed to
   subscribe to document is more
   than one higher than the conference.

3.6  Notifier Generation of NOTIFY Requests

   Notifications SHOULD be generated for local version number, the conference whenever there local version
   number is a change in set to the state value in any of the information delivered to the
   subscriber.

   The changes generally occur when a new participant joins (i.e.  gets
   "connected" to) or a participant leaves (i.e.  gets "disconnected"
   from) document, the conference.

   Subject document is
   processed, and the subscriber SHOULD generate a refresh request to
   trigger a local focus policy, additional changes in participant's
   status, changes in its media types, and other optional media
   attributes MAY be reported by full state notification.  If the focus.

   Changes value in sidebar rosters SHOULD be reported by the focus to their
   participants and MAY be reported to others, subject to document is
   less than the local policy.

   Changes in conference identifiers and policy URIs SHOULD be reported
   by version, the focus to document is discarded without
   processing.

   Further processing of the conference participants.

3.7  Subscriber Processing of NOTIFY Requests

   The SIP Events framework expects packages to specify how a subscriber
   processes NOTIFY requests in any package specific ways, and in
   particular, how information document depends on
   whether it uses contains full or partial state.  If it contains full
   state, indicated by the NOTIFY requests to construct a coherent
   view value of the state of "state" attribute in the subscribed resource.

   Typically,
   "conference-info" element, the NOTIFY for whole local content is flushed and
   repopulated from the conference package will only contain
   information about those users whose state document.  If it contains "deleted" state,
   indicated by the value of the "state" attribute in the
   "conference-info" element, it means that the conference has
   changed.  To construct a coherent view of ceased to
   exist and the total state of all
   users, a subscriber to SHOULD terminate the conference package will need to combine
   NOTIFYs received over time.

   Notifications within this package can convey SUBSCRIBE dialog.

   If the document contains partial information;
   that is, they can indicate information about a subset state, as indicated by the value of
   the state
   associated with "state" attribute in the subscription.  This means that an explicit
   algorithm needs "conference-info" element, the document
   is used to be defined update the local content as described below.

   Starting from outer elements in order to construct coherent and
   consistent state.  The details of this mechanism are specific to the
   particular document type.  See Section 4.2 for information on
   constructing coherent information received document,

   1.  If the parent element contains "full" state, the whole local
   element content is flushed and repopulated from an application/
   conference-info+xml the document.

3.8  Handling of Forked Requests

   By their nature,

   2.  Otherwise, if the conferences supported by this package are
   centralized.  Therefore, SUBSCRIBE requests for a conference should
   not generally fork.  Users of this package parent element contains "deleted" state, the
   whole element MUST NOT install more than
   a single subscription as be removed from the local content.

   3.  Otherwise, if the parent element contains "partial" state:

   3.1 For elements with keys, the subscriber compares the keys received
   in the update with the keys in the local tables.

   3.1.1 If a result of key does not exist in the local table, a single SUBSCRIBE request.

3.9  Rate of Notifications

   For reasons of congestion control, it row is added, and
   its content is important that set to the rate of
   notifications not become excessive.  As element information from the update.

   3.1.2 Otherwise, if a result, it is RECOMMENDED
   that key of the server not generate notifications same value does exist, for a single subscriber at
   a rate faster than once every 5 seconds.

3.10  State Agents

   Conference state is ideally maintained each
   sub-element in the row the algorithm is applied from step 2.2.

   3.2 For each atomic element received in which the
   conference resides.  Therefore, schema, the elements that maintain element is
   replaced with the
   conference are new information as a whole.  Also, for each
   non-atomic element received in the ones best suited to handle subscriptions to it.
   Therefore, schema with either no "state"
   attribute included or the usage of state agents attribute is NOT RECOMMENDED for this
   package.

4.  Conference Data Format

   Conference information set to "full", the
   element is replaced with the new information as a whole.

   3.2.1 If an XML document element, which doesnĘt have key(s), is updated or created
   such that MUST be well-formed
   and SHOULD be valid.  Dialog information documents MUST be based on
   XML 1.0 and MUST be encoded using UTF-8.  This specification makes
   use of XML namespaces for identifying dialog information documents
   and document fragments.  The namespace URI for elements defined by
   this specification its content is a URN [3], using empty, that element MAY be removed from the namespace identifier
   'ietf' defined by [4] and extended by [1].  This URN is:
   local content at any time.

   3.3 For each non-atomic element with the state attribute set to
   "partial", the algorithm is applied recursively starting from step 3.

6.  Conference Data

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

   A conference information document begins with the root element tag
   "conference-info".

4.1

6.1  Conference Information

   Conference information begins with the

   A conference instance is defined as a top level element
   "conference-info".
   "conference-info" of a type "conference-type".  Sections below
   describe the complex types composing the hierarchal
   "conference-type".  The full XML schema is defined in Section 7.

6.1.1  Conference Type

   This element type has three mandatory the following attributes:

   version: This mandatory attribute allows the recipient of conference
      information documents to properly order them.  Versions start at 0
      and increment by one for each new document sent to a subscriber.
      Versions are scoped within a subscription.  Versions MUST be
      represented using a 32 bit integer.

   entity: This mandatory attribute contains the conference URI that
      identifies the conference being described in the document.

   state: This mandatory attribute indicates whether the document
      contains the full whole conference information, or whether it contains information ("full"), only the
      information that has changed since the previous document
      (partial).
   entity:
      ("partial"), or the conference ceased to exist ("deleted").  For
      more details see Section 5.

   This mandatory attribute contains type defines an extendable sequence of the following optional
   child elements:

6.1.1.1  conference-description of conference-description-type

   This element contains conference URI information that
      identifies is derived from
   system conference policies, is set before the conference being described in activation,
   and is rarely changed during the document.

   The "conference-info" conference lifetime.

6.1.1.2  host-info of host-type

   This element has zero or more "user" sub-elements
   which contain contains information on about the users in entity that hosts the
   conference.  This is
   followed by zero or more "sidebar" sub-elements which contain information on the sidebars in the conference.  This is followed by
   zero or more "conf-uri" sub-elements which contain information on
   additional URIs that set before the conference can be accessed by.  This
   activation, and is
   followed by zero or more "policy-uri" sub-elements which contain
   information on additional URIs that rarely changed during the conference policies can be
   accessed by.  This is followed by "recording" and "streaming"
   elements describing recording and streaming statuses of the
   conference.

4.1.1  User Element

4.1.1.1  User Attributes

   The user element has one mandatory attribute, "uri" that indicates
   the URI for lifetime,
   unless the user in the conference.  This whole conference is a logical
   identifier, which corresponds moved to the authenticated identity of the
   participant.  The "uri" attribute MUST be unique in the user hosted by another entity.

6.1.1.3  conference-state of conference-state-type

   This element
   list because it is used as contains the key in partial notifications dynamic information about
   users' state.

   If a conference participant has more than a single signaling dialog
   associated with the conference, current state
   of the conference focus MAY present focus.

6.1.1.4  user of user-type

   This element contains the
   user's aggregated information (e.g.  the statuses) and display all
   its media streams under about a single user element.

   Note, that participant in the optional
   conference.  The element "instance" of "media" (see below) MAY
   be used the user-type can have unbounded number
   of appearance in this case to specify the actual signaling dialog conference-type for each
   media stream.

   An anonymous participant in the
   conference.

6.1.1.5  sidebars-by-ref of uris-type

   This element provides a conference SHOULD be represented by an
   anonymous URI generated by pointer to sidebar information through
   sidebar URIs.  The recipient of the focus.  For multiple anonymous
   participants, information can then subscribe to
   sidebar information independently from the focus must ensure that each anonymous URI is
   unique.  The guidelines for generating anonymous URIs in RFC 3323 [8]
   should be followed.  For example,

   "Anonymous1" <sip:anonymous1@anonymous.invalid>

    could be used for main Conference package
   subscription.

6.1.1.6  sidebar-by-val of conference-type

   This element provides sidebar information as a participant requesting privacy.

   The optional attribute "display-name" part of the main
   Conference package information.

6.1.2  Conference Description Type

   This element contains a display name for the
   user.  The standard "xml:lang" language "state" attribute which can also be present
   to indicate contain the language
   values "full", "partial", or deleted".

   This type defines an extendable sequence of the display-name.

   The following optional attribute "cascaded-focus"
   child elements:

6.1.2.1  display-text of string type

   This element contains text information about the conference.

6.1.2.2  subject of string type

   This element contains information about the subject of a conference.

6.1.2.3  free-text of string type

   This element contains free form text about the conference.

6.1.2.4  keywords of keywords-type

   This element contains a list of keywords which describe the
   conference topic.

6.1.2.5  web-page of anyURI type

   This element contains a URI of a web page that contains information
   related to the conference.

6.1.2.6  conf-uris of uris-type

   This element contains information about additional conference URIs
   that this conference can be accessed by.  Examples of such URIs
   include h323: [14] and tel: [13] URIs.

6.1.2.7  service-uris of uris-type

   This element contains a conference URI
   (different from the main conference URI) for users that are connected service-related URIs.  These URIs can be
   used to manipulate the main conference as policies or state, for example.

6.1.2.8  maximum-user-count of user-count-type

   This element contains a result count of focus cascading.  In accordance
   with the SIP conferencing framework [14], this package allows for
   representation maximum number of peer-to-peer (i.e.  "flat") focus cascading only. users
   permitted in the conference.  The actual cascading graph count can not be deduced from the information
   provided specified for all
   participants in total (using the package alone.  Advanced applications can construct sub-element with value "any") or
   count the graph users by subscribing to both this package and their roles in the Dialog Package
   [15] conference.

6.1.2.9  available-media of conference-medias-type

   This element contains information about the cascaded foci and correlating the relevant information.

   If the main conference "state" is "full", the state of its user(s) media types available in
   a conference.  The "entry" sub-element MUST "full".  If be a value registered for
   "proto" of SDP [12].

6.1.3  Host Type

   This element contains the main conference "state" is "partial", attribute which can contain the state
   of its user(s) MAY be either "partial"
   values "full", "partial", or "full".

4.1.1.2  User Status Elements

   Three optional status elements are defined: status, joining-mode, and
   disconnection-reason.
   o  "status": provides information about user's current level deleted".

   This type defines an extendable sequence of
      participation in the conference.
   o  "joining-mode": if present, provides following optional
   child elements:

6.1.3.1  display-text of string type

   This element contains display text information about the way the user joined hosting
   the conference.
   o  "disconnection-reason": if present, provides information

6.1.3.2  web-page of anyURI type

   This element contains a web page URI about the
      way the user left hosting the
   conference.

6.1.3.3  uris of uris-type

   The following statuses are defined for "entity" sub-element contains additional URIs relating to the "status" element:
   connected: The
   user is hosting the conference.

6.1.4  Conference State Type

   This element contains the "state" attribute which can contain the
   values "full", "partial", or deleted".

   This type defines an extendable sequence of the following optional
   child elements.

6.1.4.1  user-count of user-count-type

   This element contains a participant count of the current number of users in the
   conference.  Depending on
      the media policies, he/she can send and receive media to and from
      other participants.
   disconnected:  The user is not a participant count can be specified for all participants in total
   (using the conference and no
      active dialog exists between the user and the focus.
   on-hold: Active SIP dialog exists between a user and a focus, but
      user is "on-hold" for this conference, i.e.  neither he/she is
      "hearing" sub-element with value "any") or count the conference mix, nor is his/her media being mixed users by their
   roles in the conference.  As an example, the user has asked to join

6.1.4.2  security-level of security-level-type

   This element contains information about the conference using SIP, but his/her participation is pending based
      on moderator approval.  In security
   level.  The values can be "none", "low", "medium", or "high".

6.1.4.3  active of Boolean type

   This element contains information about whether the meantime he/she conference is hearing
      music-on-hold
   currently active or some other kind not.

6.1.4.4  locked of related content.
   muted-via-focus: Active SIP dialog exists between a user and a focus
      and the user can "listen" to Boolean type

   This element contains information about whether the conference, but user's media conference is
      not being mixed into the conference.  Note
   currently locked.  In this context, locked means that sometimes a subset
      of user media streams the conference
   roster can not be muted by focus (such as poor quality
      video) while others (such as voice added to (although participants may leave or IM) can still be active.  In
      this case, it is RECOMMENDED that
   removed from the "aggregated" user
      connectivity "status" reflects conference).

6.1.4.5  recording of uris-type

   The "entry" sub-element contains URIs related to the status recording of the mostly active
      media.
   blocked: User is denied from ever participating in this conference.
   pending: User is not yet
   conference.

6.1.4.6  active-media of conference-medias-type

   This element contains information about the media types currently
   active in the session, but it conference which is anticipated that
      he/she will join a subset of those listed in the near future.
   calling:
   "available-media" element.

6.1.5  User is being called by Type

   This type has the focus.
   ringing: An PSTN ALERTING or SIP 180 Ringing was returned following attributes:

   entity: The mandatory attribute contains the URI for the
      outbound call, user is being alerted.
   dialing-in: User is dialing into the conference, not yet in the
      roster (probably being authenticated).
   disconnecting: Focus
      conference.  This is in a logical identifier, which corresponds to
      the process authenticated identity of disconnecting user (either
      DISCONNECT or BYE was sent to the user's device).
   removed: This status is used to remove participant.  The "entity"
      attribute MUST be unique in the user from element list because it is
      used as the roster using key in partial notifications mechanism.

   Note that the defined transient states (e.g., calling, ringing, etc.)
   could generate about users' state.  An
      anonymous participant in a lot of notifications.  Implementations MAY choose
   not to generate notifications on these to all participants if it will
   generate too much traffic. conference SHOULD be represented by an
      anonymous URI generated by the focus.  For multiple anonymous
      participants, the focus must ensure that each anonymous URI is
      unique.  The following statuses are defined guidelines for generating anonymous URIs in RFC 3323
      [8] should be followed.  For example,

   "Anonymous1" <sip:anonymous1@anonymous.invalid>

       could be used for a participant requesting privacy.

   state: This mandatory attribute indicates whether the "joining-mode" element:
   dialed-in: The user dialed into document
      contains the conference, i.e.  sent INVITE to whole conference information ("full"), only the focus, which resulted in successful dialog establishment.
   dialed-out: The focus
      information that has brought changed since the user into previous document
      ("partial"), or the conference by
      sending a successful INVITE ceased to exist ("deleted").

   This type defines an extendable sequence of the user.
   focus-owner: The user is following optional
   child elements.

6.1.5.1  display-text of string type

   This element contains the focus display text for this conference. the user.

6.1.5.2  associated-aors of anyURI type

   This status
      is used only when a participant UA acts as a conference focus.

   The following statuses are defined for element contains associated URIs of the disconnection-reason
   element:
   departed: The user sent user.  Usually this
   information will be manually provided by a BYE, thus leaving system administrator
   showing the conference.
   booted: The user was sent a BYE by logical association between signaling entities otherwise
   independent.

6.1.5.3  roles of user-roles-type

   This element contains the focus, booting him/her out roles of the conference.  Alternatively, user.

6.1.5.4  language of language type

   This element contains the user tried to dial into to
      conference without success because was rejected language used by the focus
      according to local policy decisions.
   failed: The server tried to bring the user into the conference, but
      its attempt to contact the specific user resulted in user.

6.1.5.5  cascaded-focus of anyURI type

   This element contains a non-200
      class final response.  Alternatively, the user tried to dial into
      the conference without success due to technical reasons.

4.1.1.3  Media Information

   Each user has zero or more "media" sub-elements.

   Each "media" element indicates the media that URI (different from the user is currently
   connected to.  Here, "connected to" implies main
   conference URI) for users that a user has a media
   line in his/her SDP [12] document(s).  With this definition, a user
   is are connected to a media stream even if he/she is not sending any
   media.

4.1.1.3.1  Media Attributes

   The "media" element has a mandatory "media-type" attribute which
   identifies the media type (e.g.  audio, video, message and
   application) and MUST have one main conference
   as a result of focus cascading.  In accordance with the values registered SIP
   conferencing framework [15], this package allows for "media" representation
   of SDP [12]. peer-to-peer (i.e.  "flat") focus cascading only.  The optional "id" attribute serves as a unique reference to a "media"
   element within the "user" element.  It MUST actual
   cascading graph can not be included for each
   "media" element for all notifications if deduced from the focus uses "partial"
   user notifications for this conference.  Otherwise, information provided in
   the  "id"
   attribute MAY be omitted.

   If package alone.  Advanced applications can construct the user "state" is "full", graph by
   subscribing to both this package and the state Dialog Package [16] of its "media" element(s)
   MUST be "full".  If the user "state" is "partial",
   cascaded foci and correlating the state relevant information.

6.1.5.6  endpoint of its
   "media" element(s) MAY be either "partial" or "full".

4.1.1.3.2  Media Elements

   The "media" endpoint-type

   This element has also contains information about an optional "proto" sub-element, which
   MUST has endpoint of the value registered for "proto" user.  The
   element of SDP [12].

   An optional "ssrc" sub-element, if present, carries the value endpoint-type can have unbounded number of SSRC
   (defined appearance
   in RTP/RTCP [10]) as generated by the user user-type for each endpoint of the stream it
   sends.

   When an RTP mixer generates user participating in the
   conference.  In a CSRC list according to RTP/RTCP [10],
   it inserts case when authentication is performed per endpoint
   (rather than per user) in a list of the SSRC identifiers system, a focus can be not aware of the sources that
   contributed to
   logical association among endpoints being used by the generation of a particular packet into same user.  In
   this case the RTP
   header of that packet.  "An example application is audio conferencing
   where a mixer indicates all focus MAY present the talkers whose speech was combined endpoints as belonging to
   produce the outgoing packet, allowing
   separate users in the receiver conference schema.

   In a different case, due to indicate privacy concerns for a user the
   current talker, even though all focus may
   want to shield the audio packets contain information about multiple endpoints from the same
   SSRC identifier (that
   recipients of the mixer)."

   An optional "info" sub-element, if present, carries a human readable
   description for this stream populated by Conference document.  To do so the focus.  The value of
   this element corresponds to focus MAY
   aggregate the multiple endpoint information media attribute "i" in
   SDP [12].

   An optional "label" sub-element, if present, carries into a unique
   identifier for single endpoint
   element under this stream among all streams in the conference and is
   assigned by user.

6.1.6  Endpoint Type

   This type has the focus. following attributes:

   entity: The value of this element corresponds to the
   "label" media mandatory attribute in SDP [12] and defined in [18].

   An optional "instance" sub-element, if present, carries a URI, which
   MUST uniquely identify contains the signaling dialog being used endpoint URI for
   establishing of this media stream. the
      user in the conference.  In SIP, for example, values of SIP terms, this is the Contact URI or GRUU [17] can
      GRUU.  The "entity" attribute MUST be used for this purpose.  It unique in the endpoint
      element list because it is
   RECOMMENDED to include used as the "instance" information for every user that
   has more than key in partial
      notifications about users' endpoints.  An anonymous participant in
      a single dialog associated with the conference.  This
   element conference SHOULD NOT be included for represented by an anonymous participant.

   An optional "status" sub-element, if present, URI generated
      by the focus.  For multiple anonymous participants, the focus must
      ensure that each anonymous URI is used to remove
   "media" elements during partial notifications.

   Optional "snd-status" and "rcv-status" sub-elements, if present,
   describe unique.  The guidelines for
      generating anonymous URIs in RFC 3323 [8] should be followed.

   state: This mandatory attribute indicates whether the element
      contains the whole endpoint information ("full"), only the
      information that has changed since the status previous document
      ("partial"), or the endpoint has been deleted from the conference
      ("deleted").

   This type defines an extendable sequence of media streams in each direction.

4.1.1.4  User Role

   The the following optional "role"
   child elements.

6.1.6.1  display-text of string type

   This element contains the display text for the endpoint.

6.1.6.2  referred of execution-type

   This element conveys contains the role URI of the user who's action resulted in
   this endpoint being brought into the
   conference, e.g.  participant, presenter, panelist, host, etc.
   User's role MAY change dynamically in the course of conference (e.g.  the conference.
   Also, a user MAY have more than
   identified by this URI sent a single role in one time.

   This document does not define fixed values for REFER to the "role" element,
   instead it is expected that conferencing applications will define
   custom-fit roles by templates.

4.1.2  Sidebar Element

   The sidebar focus).

6.1.6.3  state of endpoint-state-type

   This element is contains the state of the general "conference-type" endpoint, and MAY use
   all can assume the attributes and elements defined by it.  Typically, only
   following values:

   connected: The endpoint is a participant in the
   "entity", which uniquely identifies conference.
      Depending on the sidebar, media policies, he/she can send and the "user"
   elements will be useful to present receive media
      to the majority of the
   participants and from other participants.

   disconnected: The endpoint is not a participant in the conference.

   The "conference-type" mandatory attributes MUST be included for each
   sidebar.

   The value of conference and
      no active dialog exists between the "version" attribute endpoint and the focus.

   on-hold: Active SIP dialog exists between an endpoint and a focus,
      but endpoint is meaningless "on-hold" for "sidebar"
   elements and MUST be ignored because it this conference, i.e.  neither
      he/she is always overruled by "hearing" the
   "version" attribute of conference mix, nor is his/her media being
      mixed in the main "conference-info".

   If conference.  As an example, the endpoint has asked to
      join the main conference "state" using SIP, but his/her participation is "full",
      pending based on moderator approval.  In the meantime he/she is
      hearing music-on-hold or some other kind of related content.

   muted-via-focus: Active SIP dialog exists between an endpoint and a
      focus and the state of its sidebar(s)
   MUST be "full".  If endpoint can "listen" to the main conference "state" conference, but
      endpoint's media is "partial", not being mixed into the
   state conference.  Note
      that sometimes a subset of its sidebar(s) MAY endpoint media streams can be either "full" muted by
      focus (such as poor quality video) while others (such as voice or "partial".

   The "entity" URI attribute MUST
      IM) can still be unique among active.  In this case, it is RECOMMENDED that the sidebar
   identifiers
      "aggregated" endpoint connectivity "status" reflects the status of
      the same conference.  Attribute "entity" mostly active media.

   pending: Endpoint is used as not yet in the key for "sidebar" elements session, but it is anticipated
      that he/she will join in partial notifications the near future.

   alerting: A PSTN ALERTING or SIP 180 Ringing was returned for
   "conference-info".

4.1.3  Additional Conference Identifiers

   In addition to the Conference URI present in
      outbound call, endpoint is being alerted.

   dialing-in: Endpoint is dialing into the "entity" attribute,
   a conference MAY have additional URIs of various types.  Connecting
   to these URIs will result conference, not yet in joining the
      roster (probably being authenticated).

   dialing-out: Focus has dialed out to connect the same conference.

4.1.4  Policy URIs

   A policy URI specifies where and how a certain policy pertaining endpoint to the conference can be accessed.  The actual policy name and usage is
   deduced from
      conference, but the URI schema name.

   An example for endpoint is not yet in the "policy-uri" usage roster (probably
      being authenticated).

   disconnecting: Focus is inclusion of in the URI process of the
   CPCP [16].  A subscriber disconnecting endpoint
      (either DISCONNECT or BYE was sent to the Conference package can use the Policy
   URI to access and modify endpoint's device).

   Note that the conference policy.

4.1.5  Recording

   In many cases, legal regulations require conference providers defined transient states (e.g., disconnecting,
   alerting, etc.) could generate a lot of notifications.
   Implementations MAY choose not to
   announce generate notifications on these to the
   all participants that a specific conference is being
   recorded.

   In addition to the recording "status" information, the "recording" if it will generate too much traffic.

6.1.6.4  joining-method of joining-type

   This element MAY include contains method by which the URIs specifying endpoint joined the location
   conference, and the format
   of the recorded data.  Typically, the recorded data becomes available
   after the conference ends.  Multiple URIs can be provided, for
   example, specifying different content types.  For Web-Page embedded
   media, a plain HTTP URI MAY be provided.

4.1.6  Streaming assume the following values:

   dialed-in: The "streaming" element, if present, specifies whether endpoint dialed into the conference
   output is being streamed (to general public, for example), conference, i.e.  sent INVITE
      to the focus, which resulted in what
   streaming format, and at what (e.g.  multicast) addresses it can be
   listened at.  RTSP [11] is an example of such streaming protocol.

4.2  Constructing Coherent State successful dialog establishment.

   dialed-out: The focus has brought the endpoint into the conference information is described by
      sending a hierarchal XML structure
   with successful INVITE to the root element "conference-info". endpoint.

   focus-owner: The root element endpoint is the
   only element in the schema that carries meaningful version number focus for
   all the elements in the document.  The whole conference information
   is associated with this version number.

   The version number MUST be initialized with the value of the
   "version" attribute from the "conference-info" element in the first
   document received.  Each time a new document conference.  This
      status is received, the value used only when a participant UA acts as a conference
      focus.

6.1.6.5  joining-info of execution-type

   This element contains information about how the local version number, endpoint joined and
   can contain the "version" attribute in the new
   document, are compared.  If following sub-elements:

   when: This element contains the value in date and time that the new document is one
   higher than endpoint
      joined the local version number, conference.

   reason: This element contains the local version number is
   increased by one, and reason the document is processed.  If endpoint joined the value in
      conference.

   by: This element contains the
   document is more than one higher than URI of the local version number, entity who caused the
   local version number is set
      endpoint to join the value in conference.

6.1.6.6  disconnection-method of disconnection-type

   This element contains method by which the new document, endpoint departed the
   document is processed,
   conference, and can assume the subscriber SHOULD generate following values:

   departed: The endpoint sent a refresh
   request to trigger BYE, thus leaving the conference.

   booted: The endpoint was sent a full state notification.  If BYE by the value in focus, booting him/her out
      of the
   document is less than conference.  Alternatively, the endpoint tried to dial into
      to conference without success because was rejected by the focus
      according to local version, policy decisions.

   failed: The server tried to bring the document is discarded endpoint into the conference,
      but its attempt to contact the specific endpoint resulted in a
      non-200 class final response.  Alternatively, the endpoint tried
      to dial into the conference without processing.

   Further processing success due to technical
      reasons.

6.1.6.7  disconnection-info of disconnection-type

   This element contains information about the endpoint's departure from
   the conference information document depends on
   whether it contains full or partial state.  If it and can contain the following sub-elements:

   when: This element contains full
   state, indicated by the value of date and time that the "state" attribute in endpoint
      departed the
   "conference-info" element, conference.

   reason: This element contains the whole local content is flushed and
   repopulated from reason the document.

   If endpoint departed the document
      conference.

   by: This element contains partial state, as indicated by the value URI of the "state" attribute in the "conference-info" element, entity who caused the document
   is used
      endpoint to update depart the local content as described below.

   All sub-elements conference.

6.1.6.8  whispering-to of uris-type

   If an endpoint is participating in a whisper session with other
   entities, the "conference-info" hierarchal XML structure
   can URIs of these other entities MAY be classified contained in two groups: those that carry relatively small
   amount this
   element.

6.1.6.9  media of media-type

   This element contains information about a media stream of data and those that this
   endpoint.  The element of the media-type can potentially carry a lot have unbounded number of data.
   During partial notifications,
   appearance in the light elements are updated as
   atomic pieces endpoint-type for each media stream of data.  On the other hand, elements
   endpoint.  Note that can carry it is possible that media streams listed under a
   substantial amount of data have
   common endpoint MAY be established by separate signaling means and
   consequently belong to different signaling "calls".

6.1.7  Media Type

   This type has the general "state" following attributes:

   entity: The mandatory attribute
   attached to them.  That is in order to support partial notifications
   for their content.

   A "state" attribute a unique identifier of a child media
      stream on a per endpoint basis.  This attribute is used as a key
      to identify media streams which may be added and deleted on a
      dynamic basis during the conference.  The value of this element
      SHOULD correspond to the "mid" value in the SDP document MUST adhere to
   its parent "state".  It means that if as
      defined in Grouping of Media Lines in the parent's "state" is "full", SDP [9].

   state: This mandatory attribute indicates whether the state of its children MUST be "full".  If element
      contains the parent's "state" is
   "partial", whole media information ("full"), only the state of its children MAY be either "partial"
      information that has changed since the previous document
      ("partial"), or
   "full".

   For elements with optional "state" attribute, if the attribute is not
   included for media element has been deleted from the
      conference document ("deleted").

   This type defines an element, it means that extendable sequence of the element's state is "full".

   For a parent following optional
   child elements.

6.1.7.1  display-text of string type

   This element with "state", its sub-elements with possible
   multiple appearances under contains the parent have keys that uniquely
   identify each display text for the media stream.

6.1.7.2  proto of string type

   This element among others in contains the same list.

4.2.1  The Algorithm media type for the media stream.  The conference package subscriber locally maintains a local value
   of this element MUST be a value registered for each "proto" of SDP [12].

6.1.7.3  ssrc of string type

   The "ssrc" element in carries the schema and a table for each "element with
   key(s)" value of SSRC (defined in the schema.  The tables are indexed RTP/RTCP
   [10]) as generated by the key(s) defined
   in schema endpoint for the element.

   Starting from outer elements in the received document,

   1.  If stream it sends.  When an
   RTP mixer generates a CSRC list according to RTP/RTCP [10], it
   inserts a list of the parent element contains full state, SSRC identifiers of the element is
   replaced with sources that
   contributed to the new information as generation of a whole.

   2.  Otherwise, if particular packet into the parent element contains partial state,

   2.1 For elements with keys, RTP
   header of that packet.  "An example application is audio conferencing
   where a mixer indicates all the subscriber compares talkers whose speech was combined to
   produce the keys received
   in outgoing packet, allowing the update with receiver to indicate the keys in
   current talker, even though all the local tables.

   2.1.1 If a key doesn't exist in audio packets contain the local table, a row is added, and
   its content is set to same
   SSRC identifier (that of the mixer)."

6.1.7.4  label of string type

   The element information from the update.

   2.1.2 Otherwise, if "label" carries a key of the same value does exist, unique identifier for each
   sub-element this stream among
   all streams in the row the algorithm conference and is applied from step 2.2.

   2.2 For each atomic assigned by the focus.  The
   value of this element received corresponds to the "label" media attribute in
   SDP [12] and defined in [19].

6.1.7.5  state of media-state-type

   The element "state" contains the schema, state of the element is
   replaced with media stream and can
   have the new information as a whole.  Also, for each
   non-atomic values "active", "inactive", or "muted".

6.1.7.6  snd-status of media-state-type

   The element received in the schema with either no "state"
   attribute included or contains the state attribute is set to "full", of the
   element is replaced with sending media stream
   (from the new information as a whole.

   2.2.1 If perspective of the updated endpoint) and can have the values
   "active", "inactive", or created "muted".

6.1.7.7  rcv-status state of media-state-type

   The element carries "state" contains the "removed" status,
   that element SHOULD be removed from state of the local content.  If receiving media stream
   (from the
   element is updated perspective of the endpoint) and can have the values
   "active", "inactive", or created, such that it is empty, that "muted".

6.1.7.8  call of call-type

   The "call" element
   MAY be removed from contains the local content at any time.

   2.3 For each non-atomic element with "sip" sub-element which contains the state attribute set to
   "partial",
   SIP dialog identifier of the algorithm is applied recursively starting from step 2.

4.3 endpoint's dialog with the focus.  The
   "sip" element includes sub-elements "display-text", "call-id",
   "to-tag", "from-tag"

7.  Schema

   <?xml version="1.0" encoding="UTF-8" ?>
   <xs:schema targetNamespace="urn:ietf:params:xml:ns:conference-info" xmlns:tns="urn:ietf:params:xml:ns:conference-info" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns="urn:ietf:params:xml:ns:conference-info" elementFormDefault="qualified" attributeFormDefault="unqualified">
   <!--
    This import brings in the XML language attribute xml:lang
     -->
     <xs:import namespace="http://www.w3.org/XML/1998/namespace" schemaLocation="http://www.w3.org/2001/03/xml.xsd" />

        <!--
          CONFERENCE  ELEMENT
        -->
        <xs:element name="conference-info" type="tns:conference-type"/> type="conference-type"/>
        <!--
          CONFERENCE TYPE
        -->
        <xs:complexType name="conference-type">
                <xs:sequence>
                        <xs:element name="conference-description" type="conference-description-type" minOccurs="0"/>
                        <xs:element name="host-info" type="host-type" minOccurs="0"/>
                        <xs:element name="conference-state" type="conference-state-type" minOccurs="0"/>
                        <xs:element name="user" type="user-type" minOccurs="0" maxOccurs="unbounded"/>
                        <xs:element name="sidebars-by-ref" type="uris-type" minOccurs="0"/>
                        <xs:element name="sidebar-by-val" type="conference-type" minOccurs="0" maxOccurs="unbounded"/>
                        <xs:element name="extended" type="extended-type" minOccurs="0" maxOccurs="unbounded"/>
                </xs:sequence>
                <xs:attribute name="entity" type="xs:anyURI" use="required"/>
                <xs:attribute name="state" type="state-type" use="optional"/>
                <xs:attribute name="version" type="xs:string" use="optional"/>
                <xs:anyAttribute/>
        </xs:complexType>
        <!--
        STATE TYPE
        -->
        <xs:simpleType name="state-type">
                <xs:restriction base="xs:string">
                        <xs:enumeration value="full" /> value="full"/>
                        <xs:enumeration value="partial" /> value="partial"/>
                        <xs:enumeration value="deleted"/>
                </xs:restriction>
        </xs:simpleType>
        <!--
          CONFERENCE DESCRIPTION TYPE
        -->
        <xs:complexType name="conference-description-type">
                <xs:sequence>
                        <xs:element name="display-text" type="xs:string" minOccurs="0"/>
                        <xs:element name="subject" type="xs:string" minOccurs="0"/>
                        <xs:element name="free-text" type="xs:string" minOccurs="0"/>
                        <xs:element name="keywords" type="keywords-type" minOccurs="0"/>
                        <xs:element name="web-page" type="xs:anyURI" minOccurs="0"/>
                        <xs:element name="conf-uris" type="uris-type" minOccurs="0"/>
                        <xs:element name="service-uris" type="uris-type" minOccurs="0"/>
                        <xs:element name="maximum-user-count" type="user-count-type" minOccurs="0"/>
                        <xs:element name="available-media" type="conference-medias-type" minOccurs="0"/>
                        <xs:element name="extended" type="extended-type" minOccurs="0" maxOccurs="unbounded"/>
                </xs:sequence>
                <xs:attribute name="state" type="state-type" use="optional"/>
                <xs:anyAttribute/>
        </xs:complexType>
        <!--
          HOST TYPE
        -->
        <xs:complexType name="host-type">
                <xs:sequence>
                        <xs:element name="display-text" type="xs:string" minOccurs="0"/>
                        <xs:element name="web-page" type="xs:anyURI" minOccurs="0"/>
                        <xs:element name="uris" type="uris-type" minOccurs="0"/>
                        <xs:element name="extended" type="extended-type" minOccurs="0" maxOccurs="unbounded"/>
                </xs:sequence>
                <xs:attribute name="state" type="state-type" use="optional"/>
                <xs:anyAttribute/>
        </xs:complexType>
        <!--
          CONFERENCE STATE TYPE -->
        <xs:complexType name="conference-type"> name="conference-state-type">
                <xs:sequence>
                        <xs:element name="user" type="user-type" minOccurs="0" maxOccurs="unbounded" /> name="user-count" type="user-count-type" minOccurs="0"/>
                        <xs:element name="sidebar" type="conference-type" minOccurs="0" maxOccurs="unbounded" /> name="security-level" type="security-level-type" minOccurs="0"/>
                        <xs:element name="conf-ids" type="conf-ids-type" minOccurs="0" maxOccurs="1" /> name="active" type="xs:boolean" minOccurs="0"/>
                        <xs:element name="policy-ids" type="policy-ids-type" minOccurs="0" maxOccurs="1" /> name="locked" type="xs:boolean" minOccurs="0"/>
                        <xs:element name="recording" type="recording-type" minOccurs="0" maxOccurs="1" /> type="uris-type" minOccurs="0"/>
                        <xs:element name="streaming" type="streaming-type" minOccurs="0" maxOccurs="1" />
     <xs:any processContents="lax" name="active-media" type="conference-medias-type" minOccurs="0"/>
                        <xs:element name="extended" type="extended-type" minOccurs="0" maxOccurs="unbounded" /> maxOccurs="unbounded"/>
                </xs:sequence>
                <xs:attribute name="version" type="xs:nonNegativeInteger" use="required"/>
     <xs:attribute name="state"   type="tns:state-type"        use="required"/> type="state-type" use="optional"/>
                <xs:anyAttribute/>
        </xs:complexType>
        <!--
          CONFERENCE MEDIAS TYPE
        -->
        <xs:complexType name="conference-medias-type">
                <xs:sequence>
                        <xs:element name="entry" type="conference-media-type" maxOccurs="unbounded"/>
                </xs:sequence>
                <xs:attribute name="entity"  type="xs:anyURI"             use="required"/>
     <xs:anyAttribute /> name="state" type="state-type" use="optional"/>
                <xs:anyAttribute/>
        </xs:complexType>
        <!--
          CONFERENCE MEDIA TYPE
        -->
        <xs:complexType name="conf-ids-type"> name="conference-media-type">
                <xs:sequence>
                        <xs:element name="conf-uri" type="xs:anyURI" minOccurs="0" maxOccurs="unbounded" />
     <xs:any processContents="lax" name="proto" type="xs:string"/>
                        <xs:element name="extended" type="extended-type" minOccurs="0" maxOccurs="unbounded" /> maxOccurs="unbounded"/>
                </xs:sequence>

    <xs:anyAttribute />
                <xs:anyAttribute/>
        </xs:complexType>
        <!--
          CONFERENCE URIs TYPE
        -->
        <xs:complexType name="policy-ids-type"> name="uris-type">
                <xs:sequence>
                        <xs:element name="policy-uri" type="xs:anyURI" minOccurs="0" maxOccurs="unbounded" />
     <xs:any processContents="lax" minOccurs="0" maxOccurs="unbounded" /> name="entry" type="uri-type" maxOccurs="unbounded"/>
                </xs:sequence>

    <xs:anyAttribute />

                <xs:attribute name="state" type="state-type" use="optional"/>
                <xs:anyAttribute/>
        </xs:complexType>
        <!--
          CONFERENCE URI TYPE
        -->
        <xs:complexType name="recording-type"> name="uri-type">
                <xs:sequence>
                        <xs:element name="uri" type="xs:anyURI" minOccurs="0" maxOccurs="unbounded" />
     <xs:any processContents="lax" type="xs:anyURI"/>
                        <xs:element name="label" type="xs:string" minOccurs="0"/>
                        <xs:element name="modified" type="execution-type" minOccurs="0"/>
                        <xs:element name="extended" type="extended-type" minOccurs="0" maxOccurs="unbounded" /> maxOccurs="unbounded"/>
                </xs:sequence>
                <xs:anyAttribute/>
        </xs:complexType>
        <!--
          USER COUNT TYPE
        -->
        <xs:complexType name="user-count-type">
                <xs:sequence>
                        <xs:element name="entry" type="count-type" maxOccurs="unbounded"/>
                </xs:sequence>
                <xs:attribute name="status" type=="stream-status-type" use="required"/>
    <xs:anyAttribute /> name="state" type="state-type" use="optional"/>
                <xs:anyAttribute/>
        </xs:complexType>
        <!--
          COUNT TYPE
        -->
        <xs:complexType name="streaming-type"> name="count-type">
                <xs:sequence>
                        <xs:element name="uri" type="xs:anyURI" minOccurs="0" maxOccurs="unbounded" />
     <xs:any processContents="lax" name="role" type="user-role-type"/>
                        <xs:element name="count" type="xs:nonNegativeInteger"/>
                        <xs:element name="extended" type="extended-type" minOccurs="0" maxOccurs="unbounded" /> maxOccurs="unbounded"/>
                </xs:sequence>

    <xs:attribute name="status" type="stream-status-type" use="required"/>
    <xs:anyAttribute />
                <xs:anyAttribute/>
        </xs:complexType>
        <!--
          SECURITY LEVEL TYPE
        -->
        <xs:simpleType name="security-level-type">
                <xs:restriction base="xs:string">
                        <xs:enumeration value="none"/>
                        <xs:enumeration value="low"/>
                        <xs:enumeration value="medium"/>
                        <xs:enumeration value="high"/>
                </xs:restriction>
        </xs:simpleType>
        <!--
          KEWORDS TYPE
        -->
        <xs:simpleType name="keywords-type">
                <xs:list itemType="xs:string"/>
        </xs:simpleType>
        <!--
          USER TYPE
        -->
        <xs:complexType name="user-type">
                <xs:sequence>
                        <xs:element name="status" type="tns:user-status-type" name="display-text" type="xs:string" minOccurs="0"/>
                        <xs:element name="joining-mode" type="tns:user-joining-mode-type" name="associated-aors" type="uris-type" minOccurs="0"/>
                        <xs:element name="disconnection-reason" type="tns:user-disconnection-reason-type" name="roles" type="user-roles-type" minOccurs="0"/>
                        <xs:element name="media" type="tns:media-type" minOccurs="0" maxOccurs="unbounded"/> name="language" type="xs:language" minOccurs="0"/>
                        <xs:element name="role" type="xs:string" name="cascaded-focus" type="xs:anyURI" minOccurs="0"/>
                        <xs:element name="endpoint" type="endpoint-type" minOccurs="0" maxOccurs="unbounded"/>
     <xs:any processContents="lax"
                        <xs:element name="extended" type="extended-type" minOccurs="0" maxOccurs="unbounded"/>
                </xs:sequence>
                <xs:attribute name="uri"          type="xs:anyURI"   use="required"/> name="entity" type="xs:anyURI"/>
                <xs:attribute name="display-name" type="xs:string" name="state" type="state-type" use="optional"/>
                <xs:anyAttribute/>
        </xs:complexType>
        <!--
          USER ROLES TYPE
        -->
        <xs:complexType name="user-roles-type">
                <xs:sequence>
                        <xs:element name="entry" type="user-role-type" maxOccurs="unbounded"/>
                </xs:sequence>
                <xs:attribute ref="xml:lang" name="state" type="state-type" use="optional"/>
                <xs:anyAttribute/>
        </xs:complexType>
        <!--
          USER ROLE TYPE
        -->
        <xs:complexType name="user-role-type">
                <xs:choice>
                        <xs:element name="label" type="xs:string"/>
                </xs:choice>
                <xs:attribute name="cascaded-focus" type="xs:anyURI" name="conf-template" type="xs:string" use="optional"/>
        </xs:complexType>
        <!--
          ENDPOINT TYPE
        -->
        <xs:complexType name="endpoint-type">
                <xs:sequence>
                        <xs:element name="display-text" type="xs:string" minOccurs="0"/>
                        <xs:element name="referred" type="execution-type" minOccurs="0"/>
                        <xs:element name="state" type="endpoint-state-type" minOccurs="0"/>
                        <xs:element name="whispering-to" type="uris-type" minOccurs="0"/>
                        <xs:element name="joining-method" type="joining-type" minOccurs="0"/>
                        <xs:element name="joining-info" type="execution-type" minOccurs="0"/>
                        <xs:element name="disconnection-method" type="disconnection-type" minOccurs="0"/>
                        <xs:element name="disconnection-info" type="execution-type" minOccurs="0"/>

                        <xs:element name="media" type="media-type" minOccurs="0" maxOccurs="unbounded"/>
                        <xs:element name="extended" type="extended-type" minOccurs="0" maxOccurs="unbounded"/>
                </xs:sequence>
                <xs:attribute name="entity" type="xs:anyURI"/>
                <xs:attribute name="state" type="tns:state-type" type="state-type" use="optional"/>
    <xs:anyAttribute />
                <xs:anyAttribute/>
        </xs:complexType>
        <!--
          ENDPOINT STATE TYPE
        -->
        <xs:simpleType name="user-status-type"> name="endpoint-state-type">
                <xs:restriction base="xs:string">
                        <xs:enumeration value="connected"/>
     <xs:enumeration value="disconnected"/>
     <xs:enumeration value="on-hold"/> value="pending"/>
                        <xs:enumeration value="muted-via-focus"/> value="dialing-out"/>
                        <xs:enumeration value="blocked"/> value="dialing-in"/>
                        <xs:enumeration value="pending"/> value="alerting"/>
                        <xs:enumeration value="calling"/> value="on-hold"/>
                        <xs:enumeration value="ringing"/> value="connected"/>
                        <xs:enumeration value="dialing-in"/> value="muted-via-focus"/>
                        <xs:enumeration value="disconnecting"/>
                        <xs:enumeration value="removed"/> value="disconnected"/>
                </xs:restriction>
        </xs:simpleType>
        <!--
        JOINING TYPE
        -->
        <xs:simpleType name="user-joining-mode-type"> name="joining-type">
                <xs:restriction base="xs:string">
                        <xs:enumeration value="dialed-in" /> value="dialed-in"/>

                        <xs:enumeration value="dialed-out" /> value="dialed-out"/>
                        <xs:enumeration value="focus-owner" /> value="focus-owner"/>
                </xs:restriction>
        </xs:simpleType>
        <!--
        DISCONNECTION TYPE
        -->
        <xs:simpleType name="user-disconnection-reason-type"> name="disconnection-type">
                <xs:restriction base="xs:string">
                        <xs:enumeration value="departed" /> value="departed"/>
                        <xs:enumeration value="booted" /> value="booted"/>
                        <xs:enumeration value="failed" /> value="failed"/>
                </xs:restriction>
        </xs:simpleType>
        <!--
        EXECUTION TYPE
        -->
        <xs:complexType name="media-type"> name="execution-type">
                <xs:sequence>
                        <xs:element name="proto" name="when" type="xs:dateTime" minOccurs="0"/>
                        <xs:element name="reason" type="xs:string" minOccurs="0"/>
                        <xs:element name="ssrc"       type="xs:nonNegativeInteger" name="by" type="xs:anyURI" minOccurs="0"/>
                </xs:sequence>
                <xs:anyAttribute/>
        </xs:complexType>
        <!--
          MEDIA TYPE
        -->
        <xs:complexType name="media-type">
                <xs:sequence>
                        <xs:element name="info" name="display-text" type="xs:string" minOccurs="0"/>
                        <xs:element name="label" name="proto" type="xs:string" minOccurs="0"/>
                        <xs:element name="instance"   type="xs:anyURI" name="ssrc" type="xs:string" minOccurs="0"/>
                        <xs:element name="label" type="xs:string" minOccurs="0"/>
                        <xs:element name="status"     type="tns:media-status-type" name="state" type="media-state-type" minOccurs="0"/>
                        <xs:element name="snd-status" type="tns:stream-status-type" type="media-state-type" minOccurs="0"/>
                        <xs:element name="rcv-status" type="tns:stream-status-type" type="media-state-type" minOccurs="0"/>
     <xs:any processContents="lax"
                        <xs:element name="call" type="call-type" minOccurs="0"/>
                        <xs:element name="extended" type="extended-type" minOccurs="0" maxOccurs="unbounded"/>
                </xs:sequence>
                <xs:attribute name="media" name="entity" type="xs:string" use="required"/>
                <xs:attribute name="id"     type="nonNegativeInteger"    use="optional"/>
     <xs:attribute name="state"  type="tns:state-type" type="state-type" use="optional"/>
     <xs:anyAttribute />
                <xs:anyAttribute/>
        </xs:complexType>
        <!--
          MEDIA STATUS TYPE
        -->
        <xs:simpleType name="media-status-type">
    <xs:restriction base="xs:string">
     <xs:enumeration value="removed" />
    </xs:restriction>
   </xs:simpleType>

   <xs:simpleType name="stream-status-type"> name="media-state-type">
                <xs:restriction base="xs:string">
                        <xs:enumeration value="on"/> value="active"/>
                        <xs:enumeration value="off"/> value="inactive"/>
                        <xs:enumeration value="muted" /> value="muted"/>
                </xs:restriction>
        </xs:simpleType>
        <!--
          CALL TYPE
        -->
        <xs:complexType name="call-type">
                <xs:choice>
                        <xs:element name="sip" type="sip-dialog-id-type"/>
                        <xs:element name="extended" type="extended-type" minOccurs="0" maxOccurs="unbounded"/>
                </xs:choice>
                <xs:anyAttribute/>
        </xs:complexType>
        <!--
          SIP DIALOG ID TYPE
        -->
        <xs:complexType name="sip-dialog-id-type">
                <xs:sequence>
                        <xs:element name="display-text" type="xs:string" minOccurs="0"/>
                        <xs:element name="dialog-id" type="xs:string"/>
                        <xs:element name="from-tag" type="xs:string"/>
                        <xs:element name="to-tag" type="xs:string"/>
                        <xs:element name="extended" type="extended-type" minOccurs="0" maxOccurs="unbounded"/>
                </xs:sequence>
                <xs:anyAttribute/>
        </xs:complexType>
        <!--
          EXTENDED TYPE
        -->
        <xs:complexType name="extended-type">
                <xs:sequence>
                        <xs:any minOccurs="0" maxOccurs="unbounded"/>
                </xs:sequence>
                <xs:attribute name="target-namespace" type="xs:string" use="required"/>
        </xs:complexType>
   </xs:schema>

4.4

8.  Examples

8.1  Basic Example

   The following is an example conference information document:

   <?xml version="1.0" encoding="utf-8" ?>

   <conference-info version="0" state="full" entity="sip:conf233@example.com"> entity="sips:conf233@example.com" state="partial" version="5" >
        <!--
        CONFERENCE INFO
        -->
        <conference-description>
                <subject>Agenda: This month's target</subject>
                <service-uris>
                        <entry>
                                <uri>http://salesgroup.example.com/conference-policies/sales-weekly-meeting.xml</uri>
                                <label>CPCP</label>
                        </entry>
                </service-uris>
        </conference-description>
        <!--
          CONFERENCE STATE
        -->
        <conference-state>
                <user-count>
                        <entry>
                                <role>
                                        <label>any</label>
                                </role>
                                <count>33</count>
                        </entry>
                </user-count>
                <active-media>
                        <entry>
                                <proto>audio</proto>
                        </entry>
                </active-media>
        </conference-state>

        <!--
          USER
        -->
        <user uri="sip:bob@example.com" display-name="Bob Jones">
               <status>connected</status>
               <joining-mode>dialed-in</joining-mode> entity="sip:bob@example.com" state="full">
                <display-text>Bob Hoskins</display-text>
        <!--
          ENDPOINTS
        -->
                <endpoint entity="sip:bob@pc33.example.com">
                        <display-text>Bob's Laptop</display-text>
                        <state>disconnected</state>
                        <disconnection-method>departed</disconnection-method>
                        <disconnection-info>
                                <when>2005-03-04T20:00:00Z</when>
                                <reason>bad voice quality</reason>
                                <by>sip:mike@example.com</by>
                        </disconnection-info>

        <!--
          MEDIA
        -->
                        <media media="audio">
                     <proto>RTP/AVP</proto>
                     <ssrc>583398</ssrc> entity="1">
                                <display-text>main audio</display-text>
                                <proto>audio</proto>
                                <ssrc>432424</ssrc>
                                <label>34567</label>
                                <state>active</state>
                        </media>
                </endpoint>
        </user>

        <!--
          USER
        -->
        <user uri="sip:barbara@example.com" display-name="Barbara Jones">
               <status>on-hold</status>
         </user>
         <user uri="sip:bill@example.com" display-name="Bill Minelli">
               <status>on-hold</status> entity="sip:alice@example.net" state="full">
                        <display-text>Alice</display-text>
        <!--
                        ENDPOINTS
        -->
         <endpoint entity="sip:4kfk4j392jsu@example.net;grid=433kj4j3u">
                        <state>connected</state>
                         <joining-method>dialed-out</joining-method>
                         <joining-info>

                                 <when>2005-03-04T20:00:00Z</when>
                                 <by>sip:mike@example.com</by>
                         </joining-info>
        <!--
          MEDIA
        -->
                         <media entity="1">
                                        <display-text>main audio</display-text>
                                        <proto>audio</proto>
                                        <ssrc>534232</ssrc>
                                        <label>34564</label>
                                        <state>active</state>
                        </media>
                </endpoint>
        </user>

         <sidebar version="0" state="full" entity="sip:conf233.1@example.com">
               <user uri="sip:barbara@example.com" />
               <user uri="sip:bill@example.com" />
         </sidebar>

         <conf-ids>
               <conf-uri>tel:+18005671234</conf-uri>
               <conf-uri>h323:conf545@example.com</conf-uri>
         </conf-ids>

         <recording status="on">
               <uri>http://quicktime.streaming.com/54634/recording.mov</uri>
               <uri>http://real.streaming.com/54634/recording.ram</uri>
               <uri>http://windowsmedia.streaming.com/54634/recording.wmv</uri>
               <uri>http://www.streaming.com/54634/recording.html</uri>
         </recording>
   </conference-info>

   This

8.2  Rich Example

   The following is an example conference currently has three users, two information document.  In this
   example of which a partial state notification, there are 32 participants in
   a
   sidebar conversation. voice conference.  The user Bob has been booted from the conference is being recorded.  There are
   additional means
   by Mike due to join bad voice quality.  Note that there are three sidebars
   in the conference either conference, two are referenced just by phone using tel their sidebar URI
   [14] or by H.323 protocol using H.323 URL [13].

5. and
   information about the third sidebar is included in this notification.
   Also note that while this conference offers both audio and video
   capabilities, only audio is currently in use.

   <conference-info entity="sips:conf233@example.com" state="partial" version="5" >
        <!--
        CONFERENCE INFO
        -->
        <conference-description>
                <display-text>Weekly Sales Meeting</display-text>
                <subject>Agenda: This month's target</subject>
                <free-text>xyz</free-text>
                <keywords>sales, meeting, weekly</keywords>
                <web-page>http://sharepoint/salesgroup/</web-page>
                <conf-uris>
                        <entry>
                                <uri>tel:+18005671234</uri>
                                <label>TTI Bridge</label>
                        </entry>
                        <entry>
                                <uri>h323:conf545@h323.example.com</uri>
                        </entry>
                </conf-uris>
                <service-uris>
                        <entry>
                                <uri>http://salesgroup.example.com/conference-policies/sales-weekly-meeting.xml</uri>
                                <label>CPCP</label>
                        </entry>
                </service-uris>
                <maximum-user-count>
                        <entry>
                                <role>
                                        <label>any</label>
                                </role>
                                <count>52</count>
                        </entry>
                        <entry>
                                <role conf-template="Basic">
                                        <label>participant</label>
                                </role>
                                <count>50</count>
                        </entry>
                </maximum-user-count>
                <available-media>
                        <entry>
                                <proto>audio</proto>
                        </entry>
                        <entry>
                                <proto>video</proto>
                        </entry>
                </available-media>
        </conference-description>
        <!--
          HOST INFO
        -->
        <host-info>
                <display-text>Sales Host</display-text>
                <web-page>http://sharepoint/salesgroup/hosts/</web-page>
                <uris>
                        <entry>
                                <uri>sip:sales@example.com</uri>
                        </entry>
                </uris>
        </host-info>
        <!--
          CONFERENCE STATE
        -->
        <conference-state>
                <user-count>
                        <entry>
                                <role>
                                        <label>any</label>
                                </role>
                                <count>33</count>
                        </entry>
                        <entry>
                                <role conf-template="Basic">
                                        <label>participant</label>
                                </role>
                                <count>32</count>
                        </entry>
                </user-count>
                <security-level>medium</security-level>
                <active>true</active>
                <locked>false</locked>
                <recording>
                        <entry>
                                <uri>http://quicktime.streaming.com/54634/recording.mov</uri>
                                <label>Quicktime</label>
                        </entry>
                        <entry>
                                <uri>http://real.streaming.com/54634/recording.ram</uri>
                        </entry>
                </recording>
                <active-media>
                        <entry>
                                <proto>audio</proto>
                        </entry>
                </active-media>
        </conference-state>

        <!--
          USERS
        -->
        <user entity="sip:bob@example.com" state="full">
                <display-text>Bob Hoskins</display-text>
                <associated-aors>
                        <entry>
                                <uri>mailto:bob@example.com</uri>
                                <label>email</label>
                        </entry>
                </associated-aors>
                <roles>
                        <entry>
                                <label>participant</label>
                        </entry>
                </roles>
                <language>en</language>
        <!--
          ENDPOINTS
        -->
                <endpoint entity="sip:bob@pc33.example.com">
                        <display-text>Bob's Laptop</display-text>
                        <referred>
                                <when>2005-03-04T20:00:00Z</when>
                                <by>sip:mike@example.com</by>
                        </referred>
                        <state>disconnecting</state>
                        <whispering-to>
                        <entry>
                                <uri>sip:rob@example.com</uri>
                        </entry>
                        <entry>
                                <uri>sip:helen@example.com</uri>
                        </entry>
                        </whispering-to>
                        <joining-method>dialed-out</joining-method>
                        <joining-info>
                                <when>2005-03-04T20:00:00Z</when>
                                <reason>invitation</reason>
                                <by>sip:mike@example.com</by>
                        </joining-info>
                        <disconnection-method>booted</disconnection-method>
                        <disconnection-info>
                                <when>2005-03-04T20:00:00Z</when>
                                <reason>bad voice quality</reason>
                                <by>sip:mike@example.com</by>
                        </disconnection-info>

        <!--
          MEDIA
        -->
                        <media entity="1" state="full">
                                <display-text>main audio</display-text>
                                <proto>audio</proto>
                                <ssrc>432424</ssrc>
                                <label>34567</label>
                                <state>active</state>
                                <call>
                                        <sip>
                                                <display-text>full info</display-text>
                                                <dialog-id>hsjh8980vhsb78</dialog-id>
                                                <from-tag>vav738dvbs</from-tag>

                                                <to-tag>8954jgjg8432</to-tag>
                                        </sip>
                                </call>
                        </media>

                </endpoint>

        </user>

        <!--
          SIDEBARS BY REFERENCE
        -->
                        <sidebars-by-ref>
                                <entry>
                                        <uri>sips:conf233@example.com; grid=45</uri>
                                        <label>sidebar with Carol</label>
                                </entry>
                                <entry>
                                        <uri>sips:conf233@example.com; grid=21</uri>
                                        <label>private sidebar with Peter</label>
                                </entry>
                        </sidebars-by-ref>
        <!--
          SIDEBARS BY VALUE
        -->
                        <sidebar-by-val entity="sips:conf233@example.com; grid=77" state="partial">
                                <user entity="sip:bob@example.com" state="partial"></user>
                                <user entity="sip:mark@example.com" state="partial"></user>
                                <user entity="sip:dan@example.com" state="partial"></user>
                        </sidebar-by-val>

   </conference-info>

9.  Security Considerations

   Subscriptions to conference state can reveal very sensitive
   information.  For this reason, the document recommends authentication
   and authorization, and provides guidelines on sensible authorization
   policies.

   Since the data in notifications is sensitive as well, end-to-end SIP
   encryption mechanisms using S/MIME SHOULD be used to protect it.

   Since a focus provides participants identity information using this
   event package, participant privacy needs to be taken into account.  A
   focus MUST support requests by participants for privacy.  Privacy can
   be indicated by the conference policy - for every participant or
   select participants.  It can also be indicated in the session
   signaling.  In SIP this can be done using the Privacy header field
   described in RFC 3323 [8].  For a participant requesting privacy, no
   identity information SHOULD be revealed by the focus such as a URI
   (e.g.  the Address of Record, Contact, or GRUU).  For these cases,
   the anonymous URI generation method outlined in section "User
   Element" of this document MUST be followed.

6.

10.  IANA Considerations

   This document registers a SIP event package, a new MIME type,
   application/conference-info+xml, a new XML namespace, and a new XML
   schema.

6.1

10.1  conference Event Package Registration

   This specification registers an event package, based on the
   registration procedures defined in RFC 3265 [7].  The following is
   the information required for such a registration:
   Package Name: conference
   Package or Template-Package: This is a package.
   Published Document: RFC XXXX (Note to RFC Editor: Please fill in XXXX
      with the RFC number of this specification).
   Person to Contact: Jonathan Rosenberg, jdrosen@jdrosen.net.

6.2

10.2  application/conference-info+xml MIME Registration
   MIME media type name: application
   MIME subtype name: conference-info+xml
   Mandatory parameters: none
   Optional parameters: Same as charset parameter application/xml as
      specified in RFC 3023 [5].
   Encoding considerations: Same as encoding considerations of
      application/xml as specified in RFC 3023 [5].
   Security considerations: See Section 10 of RFC 3023 [5] and Section 5 9
      of this specification.
   Interoperability considerations: none.
   Published specification: This document.
   Applications which use this media type: This document type has been
      used to support SIP conferencing applications.
   Additional Information:
      Magic Number: None
      File Extension: .cif or .xml
      Macintosh file type code: "TEXT"
   Personal and email address for further information: Jonathan
      Rosenberg, <jdrosen@jdrosen.net>
   Intended usage: COMMON
   Author/Change controller: The IETF.

6.3

10.3  URN Sub-Namespace Registration for
     urn:ietf:params:xml:ns:conference-info

   This section registers a new XML namespace, as per the guidelines in
   [1].

   URI: The URI for this namespace is
      urn:ietf:params:xml:ns:conference-info.
   Registrant Contact: IETF, SIPPING working group, <sipping@ietf.org>,
      Jonathan Rosenberg <jdrosen@jdrosen.net>.
   XML:

   BEGIN
   <?xml version="1.0"?>
   <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML Basic 1.0//EN"
             "http://www.w3.org/TR/xhtml-basic/xhtml-basic10.dtd">
   <html xmlns="http://www.w3.org/1999/xhtml">
   <head>
     <meta http-equiv="content-type"
        content="text/html;charset=iso-8859-1"/>
     <title>Conference Information Namespace</title>
   </head
   <body>
     <h1>Namespace for Conference Information</h1>
     <h2>urn:ietf:params:xml:ns:conference-info</h2>
     <p>See <a href="[[[URL of published RFC]]]">RFCXXXX</a>.</p>
   </body>
   </html>
   END

6.4

10.4  XML Schema Registration

   This specification registers a schema, as per the guidelines in in
   [1].
      URI: please assign.
      Registrant Contact: IETF, SIPPING Working Group
      (sipping@ietf.org), Jonathan Rosenberg (jdrosen@jdrosen.net).
      XML: The XML can be found as the sole content of Section 4.3. 7.

11.  Acknowledgements

   The authors would like to thank Dan Petrie, Sean Olson, Alan
   Johnston, and Rohan Mahy for their comments and inputs.

8.

12.  Changes History

8.1

12.1  Changes since -05
   o  General schema clean-up.
   o  Definition of common types being used by multiple elements.
   o  Introduction of an "endpoint" element as a part of hierarchy:
      user/endpoint/media.

12.2  Changes since -04
   o
   o  "Sidebar-type" has been removed.  "Sidebar" conference element is
      defined using the general "conference-type".
   o  "Recording" conference attribute has been replaced with
      "recording" and "streaming" elements within "conference-type".
      New "recording-type" and "streaming-type" have been introduced.
   o  Attribute "state" has been added to "user-type".
   o  Element "media-stream" within "user-type" has been renamed to
      "media".
   o  Element "role" within "user-type" has been introduced.
   o  The following statuses have been added to "user-status-type":
      blocked, pending, calling, ringing, dialing-in, disconnecting,
      removed.
   o  User status "muted-by-focus" has been renamed to
      "muted-via-focus".
   o  Attributes "id" and "state" have been added to "media-type".
   o  Elements "status", "snd-status" and "rcv-status" have been added
      to "media-type".
   o  Element "dialog-id" has been renamed to "instance".
   o  "Constructing Coherent State" section has been updated to include
      user and media partial notifications.

8.2

12.3  Changes since -03
   o  "Constructing Coherent State" section has been updated.
   o  In order to support partial notifications, two placeholders
      "conference-ids" and "policy-ids" (for "conf-uri" and "policy-uri"
      elements, correspondingly) are created.
   o  Discussion and security considerations regarding anonymous
      participation have been added.
   o  Optional elements "dialog-uri", "info" and "label" per media
      stream are added.

8.3

12.4  Changes since -02
   o  State "muted-by-focus" is added to user's status.
   o  Optional conference attribute "recording" is added.
   o  Policy URI placeholder (i.e.  element "policy-uri") is created.
   o  Example's syntax is corrected.
   o  Optional attribute "cascaded-focus" URI per user is added.

   o  Optional additional conference identifiers (i.e.  element
      "conf-uri") are added.
   o  In order to cover all possible cases, participant's status is
      expressed using three optional statuses: "status", "joining-mode"
      and "disconnection-reason".  That is instead of "activity-status",
      "history-status" and "is-on-dial-out-list".

8.4

12.5  Changes since -01
   o  Package parameters are removed.  Decision about performing
      "recursive" membership algorithm is perceived as a focus local
      policy.
   o  General information (i.e.  pointers to additional available
      services) is removed.  The defined XML schema can be extended in
      future to include those when XCON work matures.
   o  Dialog information is removed.  It can be obtained by direct
      subscription to a dialog package of a participant.
   o  Media stream information is aligned with SDP definitions (media
      and proto) and SSRC attribute is added.
   o  Participant's status is expressed using two optional statuses:
      "activity" and "history".  Optional "is-on-a-dial-out-list"
      indication is added.
   o  Normative references to XCON work are removed.
   o  Optional sidebar rosters are added.

9.

13.  References

9.1

13.1  Normative References

   [1]   Mealling, M., "The IETF XML Registry",
         draft-mealling-iana-xmlns-registry-05 (work in progress), June
         2003.

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

   [3]   Moats, R., "URN Syntax", RFC 2141, May 1997.

   [4]   Moats, R., "A URN Namespace for IETF Documents", RFC 2648,
         August 1999.

   [5]   Murata, M., St. Laurent, S. and D. Kohn, "XML Media Types", RFC
         3023, January 2001.

   [6]   Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A.,
         Peterson, J., Sparks, R., Handley, M. and E. Schooler, "SIP:
         Session Initiation Protocol", RFC 3261, June 2002.

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

   [8]   Peterson, J., "A Privacy Mechanism for the Session Initiation
         Protocol (SIP)", RFC 3323, November 2002.

   [9]   Camarillo, G., Eriksson, G., Holler, J. and H. Schulzrinne,
         "Grouping of Media Lines in the Session Description Protocol
         (SDP)", RFC 3388, December 2002.

   [10]  Schulzrinne, H., Casner, S., Frederick, R. and V. Jacobson,
         "RTP: A Transport Protocol for Real-Time Applications", STD 64,
         RFC 3550, July 2003.

9.2

13.2  Informative References

   [11]  Schulzrinne, H., Rao, A. and R. Lanphier, "Real Time Streaming
         Protocol (RTSP)", RFC 2326, April 1998.

   [12]  Handley, M. and V. Jacobson, "SDP: Session Description
         Protocol", RFC 2327, April 1998.

   [13]  Vaha-Sipila, A., "URLs for Telephone Calls", RFC 2806, April
         2000.

   [14]  Levin, O., "H.323 Uniform Resource Locator (URL) Scheme
         Registration", RFC 3508, April 2003.

   [14]

   [15]  Rosenberg, J., "A Framework for Conferencing with the Session
         Initiation Protocol",
         draft-ietf-sipping-conferencing-framework-02
         draft-ietf-sipping-conferencing-framework-03 (work in
         progress), June October 2004.

   [15]

   [16]  Rosenberg, J. and H. Schulzrinne, "An INVITE Inititiated Dialog
         Event Package for the Session Initiation  Protocol (SIP)",
         draft-ietf-sipping-dialog-package-04 (work in progress),
         February 2004.

   [16]

   [17]  Koskelainen, P. and H. Khartabil, "Requirements for Conference
         Policy Control Protocol", draft-ietf-xcon-cpcp-reqs-03 draft-ietf-xcon-cpcp-reqs-04 (work in
         progress), April August 2004.

   [17]

   [18]  Rosenberg, J., "Obtaining and Using Globally Routable User
         Agent (UA) URIs (GRUU) in the  Session Initiation Protocol
         (SIP)", draft-ietf-sip-gruu-02 (work in progress), July 2004.

   [18]

   [19]  Levin, O. and G. Camarillo, "The SDP (Session Description
         Protocol) Label Attribute",
         draft-levin-mmusic-sdp-media-label-00
         draft-ietf-mmusic-sdp-media-label-00 (work in progress), July
         September 2004.

Authors' Addresses

   Jonathan Rosenberg
   dynamicsoft
   600 Lanidex Plaza
   Parsippany, NJ  07054
   US

   Phone: +1 973 952-5000
   EMail: jdrosen@dynamicsoft.com
   URI:   http://www.jdrosen.net
   Henning Schulzrinne
   Columbia University
   M/S 0401
   1214 Amsterdam Ave.
   New York, NY  10027
   US

   EMail: schulzrinne@cs.columbia.edu
   URI:   http://www.cs.columbia.edu/~hgs

   Orit Levin (editor)
   Microsoft Corporation
   One Microsoft Way
   Redmond, WA  98052
   USA

   EMail: oritl@microsoft.com

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