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



    A Session Initiation Protocol (SIP) Event Package for Conference
                                 State
                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
   author represents that any applicable patent or other IPR claims of
   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.


   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups.  Note that
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   Internet-Drafts.


   Internet-Drafts are draft documents valid for a maximum of six months
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   The list of Internet-Draft Shadow Directories can be accessed at
   http://www.ietf.org/shadow.html.


   This Internet-Draft will expire on April 25, 2005.


Copyright Notice


   Copyright (C) The Internet Society (2004).


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




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   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 . . . . . . . . . . . . . . . . . . . . . . . . .  5
   2.  Terminology  . . . . . . . . . . . . . . . . . . . . . . . . .  6
   3.  Conference Event Package . . . . . . . . . . . . . . . . . . .  7
     3.1   Event Package Name . . . . . . . . . . . . . . . . . . . .  7
     3.2   SUBSCRIBE Bodies . . . . . . . . . . . . . . . . . . . . .  7
     3.3   Subscription Duration  . . . . . . . . . . . . . . . . . .  7
     3.4   NOTIFY Bodies  . . . . . . . . . . . . . . . . . . . . . .  8
     3.5   Notifier Processing of SUBSCRIBE Requests  . . . . . . . .  8
     3.6   Notifier Generation of NOTIFY Requests . . . . . . . . . .  8
     3.7   Subscriber Processing of NOTIFY Requests . . . . . . . . .  9
     3.8   Handling of Forked Requests  . . . . . . . . . . . . . . .  9
     3.9   Rate of Notifications  . . . . . . . . . . . . . . . . . .  9
     3.10  State Agents . . . . . . . . . . . . . . . . . . . . . . .  9
   4.  Conference Data Model  . . . . . . . . . . . . . . . . . . . . 11
   5.  Constructing Coherent State  . . . . . . . . . . . . . . . . . 12
   6.  Conference Data  . . . . . . . . . . . . . . . . . . . . . . . 14
     6.1   Conference Information . . . . . . . . . . . . . . . . . . 14
       6.1.1   Conference Type  . . . . . . . . . . . . . . . . . . . 14
         6.1.1.1   conference-description of
                   conference-description-type  . . . . . . . . . . . 14
         6.1.1.2   host-info of host-type . . . . . . . . . . . . . . 14
         6.1.1.3   conference-state of conference-state-type  . . . . 15
         6.1.1.4   user of user-type  . . . . . . . . . . . . . . . . 15
         6.1.1.5   sidebars-by-ref of uris-type . . . . . . . . . . . 15
         6.1.1.6   sidebar-by-val of conference-type  . . . . . . . . 15
       6.1.2   Conference Description Type  . . . . . . . . . . . . . 15
         6.1.2.1   display-text of string type  . . . . . . . . . . . 15
         6.1.2.2   subject of string type . . . . . . . . . . . . . . 15
         6.1.2.3   free-text of string type . . . . . . . . . . . . . 15
         6.1.2.4   keywords of keywords-type  . . . . . . . . . . . . 16
         6.1.2.5   web-page of anyURI type  . . . . . . . . . . . . . 16
         6.1.2.6   conf-uris of uris-type . . . . . . . . . . . . . . 16
         6.1.2.7   service-uris of uris-type  . . . . . . . . . . . . 16
         6.1.2.8   maximum-user-count of user-count-type  . . . . . . 16
         6.1.2.9   available-media of conference-medias-type  . . . . 16
       6.1.3   Host Type  . . . . . . . . . . . . . . . . . . . . . . 16
         6.1.3.1   display-text of string type  . . . . . . . . . . . 16
         6.1.3.2   web-page of anyURI type  . . . . . . . . . . . . . 17
         6.1.3.3   uris of uris-type  . . . . . . . . . . . . . . . . 17
       6.1.4   Conference State Type  . . . . . . . . . . . . . . . . 17
         6.1.4.1   user-count of user-count-type  . . . . . . . . . . 17




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         6.1.4.2   security-level of security-level-type  . . . . . . 17
         6.1.4.3   active of Boolean type . . . . . . . . . . . . . . 17
         6.1.4.4   locked of Boolean type . . . . . . . . . . . . . . 17
         6.1.4.5   recording of uris-type . . . . . . . . . . . . . . 17
         6.1.4.6   active-media of conference-medias-type . . . . . . 18
       6.1.5   User Type  . . . . . . . . . . . . . . . . . . . . . . 18
         6.1.5.1   display-text of string type  . . . . . . . . . . . 18
         6.1.5.2   associated-aors of anyURI type . . . . . . . . . . 18
         6.1.5.3   roles of user-roles-type . . . . . . . . . . . . . 18
         6.1.5.4   language of language type  . . . . . . . . . . . . 19
         6.1.5.5   cascaded-focus of anyURI type  . . . . . . . . . . 19
         6.1.5.6   endpoint of endpoint-type  . . . . . . . . . . . . 19
       6.1.6   Endpoint Type  . . . . . . . . . . . . . . . . . . . . 19
         6.1.6.1   display-text of string type  . . . . . . . . . . . 20
         6.1.6.2   referred of execution-type . . . . . . . . . . . . 20
         6.1.6.3   state of endpoint-state-type . . . . . . . . . . . 20
         6.1.6.4   joining-method of joining-type . . . . . . . . . . 21
         6.1.6.5   joining-info of execution-type . . . . . . . . . . 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 . . . . . . . . . . . . 22
         6.1.6.9   media of media-type  . . . . . . . . . . . . . . . 22
       6.1.7   Media Type . . . . . . . . . . . . . . . . . . . . . . 23
         6.1.7.1   display-text of string type  . . . . . . . . . . . 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




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     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














































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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.


































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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.














































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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




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   [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 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 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 other optional information
   MAY be reported by the focus.


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





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   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 subscriber
   processes NOTIFY requests in any package specific ways, and in
   particular, how it uses the NOTIFY requests to construct a coherent
   view of the 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 coherent view of the total state of all
   users, a subscriber to the conference package will need to combine
   NOTIFYs received over time.


   Notifications within this package can convey partial information;
   that is, they can indicate information about a subset of the state
   associated with the subscription.  This means that an explicit
   algorithm needs to be defined in order to construct coherent and
   consistent state.  The details of this mechanism are specific to the
   particular document type.  See Section 5 for information on
   constructing coherent information from an
   application/conference-info+xml document.


3.8  Handling of Forked Requests


   By their nature, the conferences supported by this package are
   centralized.  Therefore, SUBSCRIBE requests for a conference should
   not generally fork.  Users of this package MUST NOT install more than
   a single subscription as a result of a single SUBSCRIBE request.


3.9  Rate of Notifications


   For reasons of congestion control, it is important that the rate of
   notifications not become excessive.  As a result, it is RECOMMENDED
   that the server not generate notifications for a single subscriber at
   a rate faster than once every 5 seconds.


3.10  State Agents


   Conference state is ideally maintained in the element in which the
   conference resides.  Therefore, the elements that maintain the
   conference are the ones best suited to handle subscriptions to it.
   Therefore, the usage of state agents is NOT RECOMMENDED for this




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   package.



















































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4.  Conference Data Model


   Conference information is an XML document 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 is a URN [3], using the namespace identifier
   'ietf' defined by [4] and extended by [1].  This URN is:


   The conference information is described by a hierarchal XML structure
   with the root element "conference-info".  The root element is the
   only element in the schema that carries meaningful version number for
   all the elements in the document.  The whole conference information
   is associated with this version number.


   All sub-elements in the "conference-info" hierarchal XML structure
   can be classified in two groups: those that carry relatively small
   amount of data and those that can potentially carry a lot of data.
   During partial notifications, the light elements are updated as
   atomic pieces of data.  On the other hand, elements that can carry a
   substantial amount of 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 child element in the document MUST adhere to
   its parent "state".  It means that if the parent's "state" is "full",
   the state of its children MUST be "full".  If the parent's "state" is
   "partial", the state of its children MAY be either "partial", "full",
   or "deleted".


   For elements with the optional "state" attribute, if the attribute is
   omitted from the notification for the element, it means that the
   reported element's state is "full".


   All sub-elements, with possible multiple appearances under a common
   parent, have keys defined to them in order to uniquely identify each
   element among others of the same type in the partial notification
   event.













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5.  Constructing Coherent State


   A Conference package subscriber MUST initialize the "version"
   attribute from the "conference-info" element with the value in the
   first document received.


   The conference package subscriber locally maintains a local element
   for each element in the schema and a table for each element with
   key(s) in the schema and indexed by these key(s).


   Each time a new NOTIFY is received, the value of the local version
   number and the "version" attribute in the new received document are
   compared.  If the value in the new document is one higher than the
   local version number, the local version number is increased by one,
   and the document is processed.  If the value in the document is more
   than one higher than the local version number, the local version
   number is set to the value in the new document, the document is
   processed, and the subscriber SHOULD generate a refresh request to
   trigger a full state notification.  If the value in the document is
   less than the local version, the document is discarded without
   processing.


   Further processing of the conference information document depends on
   whether it contains full or partial state.  If it contains full
   state, indicated by the value of the "state" attribute in the
   "conference-info" element, the whole local content is flushed and
   repopulated from the document.  If it contains "deleted" state,
   indicated by the value of the "state" attribute in the
   "conference-info" element, it means that the conference ceased to
   exist and the subscriber SHOULD terminate the SUBSCRIBE dialog.


   If the document contains partial state, as indicated by the value of
   the "state" attribute in the "conference-info" element, the document
   is used to update the local content as described below.


   Starting from outer elements in the received document,


   1.  If the parent element contains "full" state, the whole local
   element content is flushed and repopulated from the document.


   2.  Otherwise, if the parent element contains "deleted" state, the
   whole element MUST 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.





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   3.1.1 If a key does not exist in the local table, a row is added, and
   its content is set to the element information from the update.


   3.1.2 Otherwise, if a key of the same value does exist, for each
   sub-element in the row the algorithm is applied from step 2.2.


   3.2 For each atomic element received in the schema, the element is
   replaced with the new information as a whole.  Also, for each
   non-atomic element received in the schema with either no "state"
   attribute included or the state attribute is set to "full", the
   element is replaced with the new information as a whole.


   3.2.1 If an element, which doesnÆt have key(s), is updated or created
   such that its content is empty, that element MAY be removed from the
   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.


































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6.  Conference Data



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


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


6.1  Conference Information


   A conference instance is defined as a top level element
   "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 type has 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 whole conference information ("full"), only the
      information that has changed since the previous document
      ("partial"), or the conference ceased to exist ("deleted").  For
      more details see Section 5.


   This 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 information that is derived from
   system conference policies, is set before the conference activation,
   and is rarely changed during the conference lifetime.


6.1.1.2  host-info of host-type


   This element contains information about the entity that hosts the
   conference.  This information is set before the conference
   activation, and is rarely changed during the conference lifetime,




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   unless the whole conference is moved to be hosted by another entity.


6.1.1.3  conference-state of conference-state-type


   This element contains the dynamic information about the current state
   of the focus.


6.1.1.4  user of user-type


   This element contains the information about a participant in the
   conference.  The element of the user-type can have unbounded number
   of appearance in the conference-type for each participant in the
   conference.


6.1.1.5  sidebars-by-ref of uris-type


   This element provides a pointer to sidebar information through
   sidebar URIs.  The recipient of the information can then subscribe to
   sidebar information independently from the main Conference package
   subscription.


6.1.1.6  sidebar-by-val of conference-type


   This element provides sidebar information as a part of the main
   Conference package information.


6.1.2  Conference Description 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:


6.1.2.1  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.







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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 the service-related URIs.  These URIs can be
   used to manipulate the conference policies or state, for example.


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


   This element contains a count of the maximum number of users
   permitted in the conference.  The count can be specified for all
   participants in total (using the sub-element with value "any") or
   count the users by their roles in the conference.


6.1.2.9  available-media of conference-medias-type


   This element contains information about the media types available in
   a conference.  The "entry" sub-element MUST be a value registered for
   "proto" of SDP [12].


6.1.3  Host 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:


6.1.3.1  display-text of string type


   This element contains display text information about the user hosting
   the conference.






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6.1.3.2  web-page of anyURI type


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


6.1.3.3  uris of uris-type


   The "entity" sub-element contains additional URIs relating to the
   user 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 count of the current number of users in the
   conference.  The count can be specified for all participants in total
   (using the sub-element with value "any") or count the users by their
   roles in the conference.


6.1.4.2  security-level of security-level-type


   This element contains information about the conference 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 conference is
   currently active or not.


6.1.4.4  locked of Boolean type


   This element contains information about whether the conference is
   currently locked.  In this context, locked means that the conference
   roster can not be added to (although participants may leave or be
   removed from the conference).


6.1.4.5  recording of uris-type


   The "entry" sub-element contains URIs related to the recording of the
   conference.






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6.1.4.6  active-media of conference-medias-type


   This element contains information about the media types currently
   active in the conference which is a subset of those listed in the
   "available-media" element.


6.1.5  User Type


   This type has the following attributes:


   entity: The mandatory attribute contains the URI for the user in the
      conference.  This is a logical identifier, which corresponds to
      the authenticated identity of the participant.  The "entity"
      attribute MUST be unique in the user element list because it is
      used as the key in partial notifications about users' state.  An
      anonymous participant in a 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 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 document
      contains the whole conference information ("full"), only the
      information that has changed since the previous document
      ("partial"), or the conference ceased to exist ("deleted").


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


6.1.5.1  display-text of string type


   This element contains the display text for the user.


6.1.5.2  associated-aors of anyURI type


   This element contains associated URIs of the user.  Usually this
   information will be manually provided by a system administrator
   showing the logical association between signaling entities otherwise
   independent.


6.1.5.3  roles of user-roles-type


   This element contains the roles of the user.





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6.1.5.4  language of language type


   This element contains the language used by the user.


6.1.5.5  cascaded-focus of anyURI type


   This element contains a conference URI (different from the main
   conference URI) for users that are connected to the main conference
   as a result of focus cascading.  In accordance with the SIP
   conferencing framework [15], this package allows for representation
   of peer-to-peer (i.e.  "flat") focus cascading only.  The actual
   cascading graph can not be deduced from the information provided in
   the package alone.  Advanced applications can construct the graph by
   subscribing to both this package and the Dialog Package [16] of the
   cascaded foci and correlating the relevant information.


6.1.5.6  endpoint of endpoint-type


   This element contains information about an endpoint of the user.  The
   element of the endpoint-type can have unbounded number of appearance
   in the user-type for each endpoint of the user participating in the
   conference.  In a case when authentication is performed per endpoint
   (rather than per user) in a system, a focus can be not aware of the
   logical association among endpoints being used by the same user.  In
   this case the focus MAY present the endpoints as belonging to
   separate users in the conference schema.


   In a different case, due to privacy concerns for a user the focus may
   want to shield the information about multiple endpoints from the
   recipients of the Conference document.  To do so the focus MAY
   aggregate the multiple endpoint information into a single endpoint
   element under this user.


6.1.6  Endpoint Type


   This type has the following attributes:


   entity: The mandatory attribute contains the endpoint URI for the
      user in the conference.  In SIP terms, this is the Contact URI or
      GRUU.  The "entity" attribute MUST be unique in the endpoint
      element list because it is used as the key in partial
      notifications about users' endpoints.  An anonymous participant in
      a 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 guidelines for
      generating anonymous URIs in RFC 3323 [8] should be followed.






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


   This type defines an extendable sequence of the following optional
   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 contains the URI of the user who's action resulted in
   this endpoint being brought into the conference (e.g.  the user
   identified by this URI sent a REFER to the focus).


6.1.6.3  state of endpoint-state-type


   This element contains the state of the endpoint, and can assume the
   following values:


   connected: The endpoint is a participant in the conference.
      Depending on the media policies, he/she can send and receive media
      to and from other participants.


   disconnected: The endpoint is not a participant in the conference and
      no active dialog exists between the endpoint and the focus.


   on-hold: Active SIP dialog exists between an endpoint and a focus,
      but endpoint is "on-hold" for this conference, i.e.  neither
      he/she is "hearing" the conference mix, nor is his/her media being
      mixed in the conference.  As an example, the endpoint has asked to
      join the conference using SIP, but his/her participation is
      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 endpoint can "listen" to the conference, but
      endpoint's media is not being mixed into the conference.  Note
      that sometimes a subset of endpoint media streams can be muted by
      focus (such as poor quality video) while others (such as voice or
      IM) can still be active.  In this case, it is RECOMMENDED that the
      "aggregated" endpoint connectivity "status" reflects the status of
      the mostly active media.




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   pending: Endpoint is not yet in the session, but it is anticipated
      that he/she will join in the near future.


   alerting: A PSTN ALERTING or SIP 180 Ringing was returned for the
      outbound call, endpoint is being alerted.


   dialing-in: Endpoint is dialing into the conference, not yet in the
      roster (probably being authenticated).


   dialing-out: Focus has dialed out to connect the endpoint to the
      conference, but the endpoint is not yet in the roster (probably
      being authenticated).


   disconnecting: Focus is in the process of disconnecting endpoint
      (either DISCONNECT or BYE was sent to the endpoint's device).


   Note that the defined transient states (e.g., disconnecting,
   alerting, etc.) could generate a lot of notifications.
   Implementations MAY choose not to generate notifications on these to
   all participants if it will generate too much traffic.


6.1.6.4  joining-method of joining-type


   This element contains method by which the endpoint joined the
   conference, and can assume the following values:


   dialed-in: The endpoint dialed into the conference, i.e.  sent INVITE
      to the focus, which resulted in successful dialog establishment.


   dialed-out: The focus has brought the endpoint into the conference by
      sending a successful INVITE to the endpoint.


   focus-owner: The endpoint is the focus for this conference.  This
      status is 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 endpoint joined and
   can contain the following sub-elements:


   when: This element contains the date and time that the endpoint
      joined the conference.








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   reason: This element contains the reason the endpoint joined the
      conference.


   by: This element contains the URI of the entity who caused the
      endpoint to join the conference.


6.1.6.6  disconnection-method of disconnection-type


   This element contains method by which the endpoint departed the
   conference, and can assume the following values:


   departed: The endpoint sent a BYE, thus leaving the conference.


   booted: The endpoint was sent a BYE by the focus, booting him/her out
      of the conference.  Alternatively, the endpoint tried to dial into
      to conference without success because was rejected by the focus
      according to local policy decisions.


   failed: The server tried to bring the 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 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 and can contain the following sub-elements:


   when: This element contains the date and time that the endpoint
      departed the conference.


   reason: This element contains the reason the endpoint departed the
      conference.


   by: This element contains the URI of the entity who caused the
      endpoint to depart the conference.


6.1.6.8  whispering-to of uris-type


   If an endpoint is participating in a whisper session with other
   entities, the URIs of these other entities MAY be contained in this
   element.


6.1.6.9  media of media-type


   This element contains information about a media stream of this
   endpoint.  The element of the media-type can have unbounded number of




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   appearance in the endpoint-type for each media stream of the
   endpoint.  Note that it is possible that media streams listed under a
   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 following attributes:


   entity: The mandatory attribute is a unique identifier of a 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 as
      defined in Grouping of Media Lines in the SDP [9].


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


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


6.1.7.1  display-text of string type


   This element contains the display text for the media stream.


6.1.7.2  proto of string type


   This element contains the media type for the media stream.  The value
   of this element MUST be a value registered for "proto" of SDP [12].


6.1.7.3  ssrc of string type


   The "ssrc" element carries the value of SSRC (defined in RTP/RTCP
   [10]) as generated by the endpoint for the stream it sends.  When an
   RTP mixer generates a CSRC list according to RTP/RTCP [10], it
   inserts a list of the SSRC identifiers of the sources that
   contributed to the generation of a particular packet into the RTP
   header of that packet.  "An example application is audio conferencing
   where a mixer indicates all the talkers whose speech was combined to
   produce the outgoing packet, allowing the receiver to indicate the
   current talker, even though all the audio packets contain the same
   SSRC identifier (that of the mixer)."






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6.1.7.4  label of string type


   The element "label" carries a unique identifier for this stream among
   all streams in the conference and is assigned by the focus.  The
   value of this element 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 state of the media stream and can
   have the values "active", "inactive", or "muted".


6.1.7.6  snd-status of media-state-type


   The element "state" contains the state of the sending media stream
   (from the perspective of the endpoint) and can have the values
   "active", "inactive", or "muted".


6.1.7.7  rcv-status state of media-state-type


   The element "state" contains the state of the receiving media stream
   (from the perspective of the endpoint) and can have the values
   "active", "inactive", or "muted".


6.1.7.8  call of call-type


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






















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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="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"/>
                        <xs:enumeration value="partial"/>
                        <xs:enumeration value="deleted"/>
                </xs:restriction>
        </xs:simpleType>
        <!--
          CONFERENCE DESCRIPTION TYPE
        -->
        <xs:complexType name="conference-description-type">
                <xs:sequence>




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                        <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-state-type">
                <xs:sequence>
                        <xs:element name="user-count" type="user-count-type" minOccurs="0"/>
                        <xs:element name="security-level" type="security-level-type" minOccurs="0"/>
                        <xs:element name="active" type="xs:boolean" minOccurs="0"/>
                        <xs:element name="locked" type="xs:boolean" minOccurs="0"/>
                        <xs:element name="recording" type="uris-type" minOccurs="0"/>
                        <xs:element name="active-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>
        <!--
          CONFERENCE MEDIAS TYPE
        -->
        <xs:complexType name="conference-medias-type">
                <xs:sequence>
                        <xs:element name="entry" type="conference-media-type" maxOccurs="unbounded"/>




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                </xs:sequence>
                <xs:attribute name="state" type="state-type" use="optional"/>
                <xs:anyAttribute/>
        </xs:complexType>
        <!--
          CONFERENCE MEDIA TYPE
        -->
        <xs:complexType name="conference-media-type">
                <xs:sequence>
                        <xs:element name="proto" type="xs:string"/>
                        <xs:element name="extended" type="extended-type" minOccurs="0" maxOccurs="unbounded"/>
                </xs:sequence>
                <xs:anyAttribute/>
        </xs:complexType>
        <!--
          CONFERENCE URIs TYPE
        -->
        <xs:complexType name="uris-type">
                <xs:sequence>
                        <xs:element name="entry" type="uri-type" maxOccurs="unbounded"/>
                </xs:sequence>


                <xs:attribute name="state" type="state-type" use="optional"/>
                <xs:anyAttribute/>
        </xs:complexType>
        <!--
          CONFERENCE URI TYPE
        -->
        <xs:complexType name="uri-type">
                <xs:sequence>
                        <xs:element name="uri" 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"/>
                </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="state" type="state-type" use="optional"/>
                <xs:anyAttribute/>
        </xs:complexType>
        <!--




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          COUNT TYPE
        -->
        <xs:complexType name="count-type">
                <xs:sequence>
                        <xs:element name="role" type="user-role-type"/>
                        <xs:element name="count" type="xs:nonNegativeInteger"/>
                        <xs:element name="extended" type="extended-type" minOccurs="0" maxOccurs="unbounded"/>
                </xs:sequence>
                <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="display-text" type="xs:string" minOccurs="0"/>
                        <xs:element name="associated-aors" type="uris-type" minOccurs="0"/>
                        <xs:element name="roles" type="user-roles-type" minOccurs="0"/>
                        <xs:element name="language" type="xs:language" minOccurs="0"/>
                        <xs:element name="cascaded-focus" type="xs:anyURI" minOccurs="0"/>
                        <xs:element name="endpoint" type="endpoint-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="state-type" use="optional"/>
                <xs:anyAttribute/>
        </xs:complexType>
        <!--
          USER ROLES TYPE
        -->
        <xs:complexType name="user-roles-type">




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                <xs:sequence>
                        <xs:element name="entry" type="user-role-type" maxOccurs="unbounded"/>
                </xs:sequence>
                <xs:attribute 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="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="state-type" use="optional"/>
                <xs:anyAttribute/>
        </xs:complexType>
        <!--
          ENDPOINT STATE TYPE
        -->
        <xs:simpleType name="endpoint-state-type">
                <xs:restriction base="xs:string">
                        <xs:enumeration value="pending"/>
                        <xs:enumeration value="dialing-out"/>
                        <xs:enumeration value="dialing-in"/>
                        <xs:enumeration value="alerting"/>
                        <xs:enumeration value="on-hold"/>
                        <xs:enumeration value="connected"/>
                        <xs:enumeration value="muted-via-focus"/>




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                        <xs:enumeration value="disconnecting"/>
                        <xs:enumeration value="disconnected"/>
                </xs:restriction>
        </xs:simpleType>
        <!--
        JOINING TYPE
        -->
        <xs:simpleType name="joining-type">
                <xs:restriction base="xs:string">
                        <xs:enumeration value="dialed-in"/>


                        <xs:enumeration value="dialed-out"/>
                        <xs:enumeration value="focus-owner"/>
                </xs:restriction>
        </xs:simpleType>
        <!--
        DISCONNECTION TYPE
        -->
        <xs:simpleType name="disconnection-type">
                <xs:restriction base="xs:string">
                        <xs:enumeration value="departed"/>
                        <xs:enumeration value="booted"/>
                        <xs:enumeration value="failed"/>
                </xs:restriction>
        </xs:simpleType>
        <!--
        EXECUTION TYPE
        -->
        <xs:complexType name="execution-type">
                <xs:sequence>
                        <xs:element name="when" type="xs:dateTime" minOccurs="0"/>
                        <xs:element name="reason" type="xs:string" minOccurs="0"/>
                        <xs:element 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="display-text" type="xs:string" minOccurs="0"/>
                        <xs:element name="proto" type="xs:string" minOccurs="0"/>
                        <xs:element name="ssrc" type="xs:string" minOccurs="0"/>
                        <xs:element name="label" type="xs:string" minOccurs="0"/>
                        <xs:element name="state" type="media-state-type" minOccurs="0"/>
                        <xs:element name="snd-status" type="media-state-type" minOccurs="0"/>
                        <xs:element name="rcv-status" type="media-state-type" minOccurs="0"/>




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                        <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="entity" type="xs:string" use="required"/>
                <xs:attribute name="state" type="state-type" use="optional"/>
                <xs:anyAttribute/>
        </xs:complexType>
        <!--
          MEDIA STATUS TYPE
        -->
        <xs:simpleType name="media-state-type">
                <xs:restriction base="xs:string">
                        <xs:enumeration value="active"/>
                        <xs:enumeration value="inactive"/>
                        <xs:enumeration 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"/>




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        </xs:complexType>
   </xs:schema>


















































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8.  Examples


8.1  Basic Example


   The following is an example conference information document:



   <conference-info 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 entity="sip:bob@example.com" state="full">
                <display-text>Bob Hoskins</display-text>
        <!--
          ENDPOINTS
        -->
                <endpoint entity="sip:bob@pc33.example.com">




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                        <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 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 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>




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                </endpoint>
        </user>
   </conference-info>



8.2  Rich Example


   The following is an example conference information document.  In this
   example of a partial state notification, there are 32 participants in
   a voice conference.  The user Bob has been booted from the conference
   by Mike due to bad voice quality.  Note that there are three sidebars
   in the conference, two are referenced just by their sidebar URI 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>




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                        </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>




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                <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>




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                        </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>




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                                        <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>



































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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.































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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.


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.


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 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.


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].







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   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




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 7.
















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11.  Acknowledgements


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
















































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12.  Changes History


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.


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.


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.





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   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".


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.





























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13.  References


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.


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.





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


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


   [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.


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


   [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.


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














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   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


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Internet-Draft             Conference Package               October 2004



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