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Internet Engineering Task Force

SIPPING WG
Internet Draft                                                     J. Rosenberg
Internet-Draft                                               dynamicsoft
Expires: August 15, 2004                                  H. Schulzrinne
                                                     Columbia U.
draft-ietf-sipping-conference-package-00.txt
June 24, 2002
Expires: December 2002 University
                                                           O. Levin, Ed.
                                                   Microsoft Corporation
                                                       February 15, 2004


    A Session Initiation Protocol (SIP) Event Package for Conference
                                 State

STATUS OF THIS MEMO
                draft-ietf-sipping-conference-package-03

Status of this Memo

   This document is an Internet-Draft and is in full conformance with
   all provisions of Section 10 of RFC2026.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups. Note that other
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   The list of Internet-Draft Shadow Directories, see Directories can be accessed at
   http://www.ietf.org/shadow.html.

   This Internet-Draft will expire on August 15, 2004.

Copyright Notice

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

Abstract

   This document defines a conference event package for the SIP Session
   Initiation Protocol (SIP) Events
   architecture, framework, along with a data format
   used in notifications for this package. The conference package allows
   users to subscribe to a SIP
   URI that is associated with a conference. conference URI. Notifications are sent about
   changes in the membership of this conference, changes the status of users'
   participation in active
   speaker, the conference, and media mixing information.









J. Rosenberg et. the sidebars in the conference.





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Table of Contents



   1

   1.      Introduction ........................................    4
   2 . . . . . . . . . . . . . . . . . . . . . . .  3
   2.      Terminology .........................................  . . . . . . . . . . . . . . . . . . . . . . .  4
   3
   3.      Conference Event Package ............................    4 . . . . . . . . . . . . . . . . .  5
   3.1     Event Package Name .................................. . . . . . . . . . . . . . . . . . . . .  5
   3.2        Event Package Parameters ............................    5
   3.3     SUBSCRIBE Bodies .................................... . . . . . . . . . . . . . . . . . . . . .  5
   3.4
   3.3     Subscription Duration ...............................    6
   3.5  . . . . . . . . . . . . . . . . . .  5
   3.4     NOTIFY Bodies .......................................  . . . . . . . . . . . . . . . . . . . . . .  6
   3.6
   3.5     Notifier Processing of SUBSCRIBE Requests ...........  . . . . . . . .  6
   3.7
   3.6     Notifier Generation of NOTIFY Requests .............. . . . . . . . . . .  6
   3.8
   3.7     Subscriber Processing of NOTIFY Requests ............    6
   3.9 . . . . . . . . .  7
   3.8     Handling of Forked Requests .........................  . . . . . . . . . . . . . . .  7
   3.10
   3.9     Rate of Notifications ...............................  . . . . . . . . . . . . . . . . . .  7
   3.11
   3.10    State Agents ........................................ . . . . . . . . . . . . . . . . . . . . . . .  7
   4
   4.      Conference Data Format ..............................    7 . . . . . . . . . . . . . . . . . .  8
   4.1        Structute of the Format .............................     Conference Information . . . . . . . . . . . . . . . . . .  8
   4.1.1   User Element ........................................    8
   4.1.2      Status .............................................. . . . . . . . . . . . . . . . . . . . . . . .  9
   4.1.3      Dialog ..............................................
   4.1.1.1 User Statuses  . . . . . . . . . . . . . . . . . . . . . .  9
   4.1.4
   4.1.1.2 Media Status ........................................    9 Stream Information . . . . . . . . . . . . . . . . . 10
   4.1.2   Sidebar  . . . . . . . . . . . . . . . . . . . . . . . . . 11
   4.1.3   Additional Conference Identifiers  . . . . . . . . . . . . 11
   4.1.4   Policy URIs  . . . . . . . . . . . . . . . . . . . . . . . 11
   4.2     Constructing Coherent State .........................    9  . . . . . . . . . . . . . . . 11
   4.3     Schema ..............................................   10 . . . . . . . . . . . . . . . . . . . . . . . . . . 12
   4.4     Example .............................................   13
   5  . . . . . . . . . . . . . . . . . . . . . . . . . 15
   5.      Security Considerations .............................   13
   6  . . . . . . . . . . . . . . . . . 16
   6.      IANA Considerations .................................   13  . . . . . . . . . . . . . . . . . . . 17
   6.1     conference Event Package Registration  . . . . . . . . . . 17
   6.2     application/conference-info+xml MIME Registration
   ................................................................   13
   6.2  . . . . 17
   6.3     URN Sub-Namespace Registration for
           urn:ietf:params:xml:ns:conference-info .........................   14
   7 . . . . . . . . . . 18
   6.4     XML Schema Registration  . . . . . . . . . . . . . . . . . 19
   7.      Acknowledgements ....................................   15
   8          Authors Addresses ...................................   15
   9 . . . . . . . . . . . . . . . . . . . . . 20
   8.      Changes since -02  . . . . . . . . . . . . . . . . . . . . 21
   9.      Changes since -01  . . . . . . . . . . . . . . . . . . . . 22
           Normative References ................................   15
   10 . . . . . . . . . . . . . . . . . . . 23
           Informative References ..............................   16











J. Rosenberg et. . . . . . . . . . . . . . . . . . . 24
           Authors' Addresses . . . . . . . . . . . . . . . . . . . . 24
           Intellectual Property and Copyright Statements . . . . . . 26











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1              February 2004


1. Introduction

   The SIP Session Initiation Protocol (SIP) [3] Events framework [1] [2]
   defines general mechanisms for
   subscription subscribing to, and notification receiving
   notifications of, events within SIP networks. It introduces the
   notion of a package, which is a specific "instantiation" of the
   events mechanism framework for a well-defined set of events. Packages have been defined for user presence [9], watcher
   information [10], and message waiting indicators [11], amongst
   others. Here, we define an
   event package for SIP conferences. This package will work for any provides the
   conference notification service as outlined in which there is a central
   signaling element [12].

   The the SIP conferencing package allows
   framework [9]. As described there, subscriptions to a subscriber conference URI
   are routed to learn about the
   identities of participants and their status in the conference, the
   dialogs focus that are used by each user, is handling the media makeup of conference. It acts as
   the
   conference, notifer, and the mixing matrix (i.e., who is receiving whose
   audio). This provides clients with updates on conference state.

   The information is vital to building conferencing
   applications using SIP.

2 Terminology

   In provided by this document, the key words "MUST", package is comprised of conference
   identifier(s), conference participants (optionally with their
   statuses and media types) and conference sidebars.



































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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] [1] and
   indicate requirement levels for compliant implementations.

3













































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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 agent, called a focus, that is responsible for
   ensuring that all users in the conference can communicate with each other. Detailed
   other [9]. The focus has sufficient information on conferencing models can be found in [12]. This package
   can work with any about the state of
   the tightly-coupled models described conference to inform subscribers about it.

   It is possible a participant in that
   specification. However, the conference server may not have in fact be another
   focus.  In order to provide a more complete
   information on the media makeup of participant list, the conference. This is
   focus MAY subscribe to the case
   for multicast-based conferences, where conference package of the server cannot know other focus to
   discover the
   mixing matrix for participant list in the cascaded conference. In this case, that  This
   information
   would simply not can then be reported through this package.

   The specific information conveyed included in notifications in this package
   is:

        o The SIP URI identifying the user.

        o The dialog state associated with that users attachment to the
          conference.




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        o Their status in the conference (active, declined, departed).

        o Their status in terms by using of receiving media in the conference.
   "cascaded-focus" attribute as specified by this package.

   This section provides the details for defining a SIP Events package,
   as specified by [1]. [2].

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 [1]. [2].

3.2 Event Package Parameters

   A single parameter, "recurse" is defined for this package. When
   present, it informs the server that it should check whether any
   participants in the conference are themselves conferences, and if so,
   generate a subscription to their conference state with the "recurse"
   attribute. The users reported in notifications from this recursed
   subscription are reported to the original subscriber. The result is
   that the list of users reported to the subscriber represents the
   complete user list even when cascaded conferences are used.

   Example:


   Event: conference;recurse



3.3 SUBSCRIBE Bodies

   A SUBSCRIBE for a dialog conference package MAY contain a body. This body
   defines a filter to apply to the subscription.

   A SUBSCRIBE for a conference package MAY be sent without a 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 set
      state of users participating in the conference, or a change
          their state (dialog state, media mixing state, etc.) conference.

   o  Notifications do not normally contain full state; rather, they
      only indicate the state of the participant whose state that has changed. The exception is a
      NOTIFY sent in response to a SUBSCRIBE. These NOTIFYs contain the complete view
      full state of
          conference state.



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        o For a given user, the notifications contain the identity information and status.

3.4 requested by the subscriber.


3.3 Subscription Duration

   The default expiration time for a subscription to a conference is one
   hour. Of course, once Once the conference ends, all subscriptions to that particular



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   conference are terminated, with a reason of "noresource"
   [1].

3.5 [2].

3.4 NOTIFY Bodies

   The

   As described in RFC 3265 [2], 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 implementations subscribers and notifiers  MUST support the type
   "application/conference-info+xml", defined
   "application/conference-info+xml" data format described in Section 4. Other
   formats MAY be supported.

   When a client generates a SUBSCRIBE request, and that
   The subscribe request
   contains MAY contain an Accept header, the "application/conference-info+xml"
   format MUST be included in the header. Other formats MAY be listed.
   The header field. If no such
   header field is present, it has a default value for of "application/
   conference-info+xml". If the Accept header when it is not present in a
   request field is "application/conference-info+xml". present, it MUST include
   "application/conference-info+xml", and MAY include any other types
   capable of representing dialog state.

   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.

3.6

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.

3.7

3.6 Notifier Generation of NOTIFY Requests

   Notifications SHOULD be generated for the conference whenever there
   is a change in the state in any of the information delivered to the
   subscriber.

   The changes generally occur when a new participant joins, a
   participant leaves, and a dial-out attempt
   succeeds or fails. Notifications a participant is put on-hold. Subject to a
   local focus policy, changes in media types and other optional media
   attributes MAY be generated for the conference
   whenever reported by the media mixing status focus. In addition, creation and
   deletion of a user changes.

3.8 sidebars together with their rosters MAY be reported by
   the focus, subject to its local policy.




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3.7 Subscriber Processing of NOTIFY Requests

   The SIP Events framework expects packages to specify how a subscriber



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   processes NOTIFY requests in any package specific ways, and in
   particular, how it uses the NOTIFY requests to contruct 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 dialog 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 4.2 for information on
   constructing coherent information from an application/conference-
   info+xml application/
   conference-info+xml document.

3.9

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.

3.10

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.

3.11

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
   package.

4








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4. Conference Data Format

   Conference information is an XML document [3] that MUST be well-
   formed 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



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   specification is a URN [4], using the namespace identifier 'ietf'
   defined by [5] and extended by [6]. This URN is:


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

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

4.1 Structute of the Format Conference Information

   Conference information begins with the top level element
   "conference-info". This element has three mandatory and one optional
   attributes:

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

   state: This mandatory attribute indicates whether the document
      contains the full conference information, or whether it contains
      only the information on those users whose state have that has changed since the previous document
      (partial).

   entity: This mandatory attribute contains a the conference URI that
      identifies the conference whose information is reported being described in the remainder
             of the document.

   recording: This optional attribute indicates whether the conference
      is being recorded at this moment ("on") or not ("off").

   The "conference-info" element has zero or more "user" sub-elements
   which contain information on the users in the conference.

4.1.1 User Element

   Each user element has This is
   followed by zero or one "status" elements, indicating their
   status more "sidebar" sub-elements which contain
   information on the sidebars in the conference, conference. This is followed by
   zero or one "dialog" elements, indicating
   their dialog information, and more "conf-uri" sub-elements which contain information on
   additional URIs that the conference can be accessed by. This is
   followed by zero or one "media-state" elements,
   indicating their media reception information. more "policy-uri" sub-elements which contain
   information on additional URIs that the conference policies can be
   accessed by.



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4.1.1 User Element

   The user element has one mandatory attribute, "uri" that indicates
   the URI for the user in the conference. This is a logical identifier,
   not a machine specific one (i.e., its it's taken from the To/From, not authenticated
   identity of the
   Contact). participant). The optional attribute "display-name"
   contains a display name for the user. The standard "xml:lang"
   language attribute can also be present to indicate the language of
   the display name.




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4.1.2 Status display-name.

   The status element optional attribute "cascaded-focus" contains a conference URI
   (different from the status of the user in the conference.
   The following statuses main conference URI) for users that are defined:

        active: The user is in an active dialog with connected
   to the main conference
             host.

        departed: The user sent as a BYE, thus leaving result of focus cascading. In accordance
   with the conference.

        booted: The user was sent a BYE by SIP conferencing framework [9], this defined package allows
   for representation of peer-to-peer (i.e. "flat") focus cascading
   only. The actual cascading graph is not explicitly expressed in this
   package because most applications do not care about the actual
   topology of the cascaded focuses as long as the information about
   their participants is available. In addition, an advanced application
   can construct the graph by subscribing to both this package and the
   Dialog Package [10] of the involved focuses and correlating the
   required information.

4.1.1.1 User Statuses

   Three optional status elements are defined: status, joining-mode, and
   disconnection-reason.

   o  "status": provides information about user's current level of
      participation in the conference.

   o  "joining-mode": if present, provides information about the way the
      user joined the conference.

   o  "disconnection-reason": if present, provides information about the
      way the user left the conference.

   The following statuses are defined for the "status" element:

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






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   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" the conference mix, nor is his/her media being mixed in
      the conference. As an example, the user 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-by-focus: Active SIP dialog exists between a user and a focus
      and the user can "listen" to the conference, but user's media is
      not being mixed into the conference.

   The following statuses are defined for the "joining-mode" element:

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

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

   focus-owner: The user is the focus itself for this conference.

   The following statuses are defined for the disconnection-reason
   element:

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

   booted: The user was sent a BYE by the conference host, focus, booting
             them him/her out of
      the conference. Alternatively, the user 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 user into the conference, but
      its attempt to contact the specific user resulted in a non-200
      class final response.

4.1.3 Dialog

   The dialog element is defined in [7].

4.1.4 Alternatively, the user tried to dial into
      the conference without success due to technical reasons.


4.1.1.2 Media Status

   The "media-status" Stream Information

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

   Each "media-stream" element indicates the types of media stream that the user
   is currently receiving connected to. Here, "connected to" implies that a user
   has a media line in the conference. It consists of their SDP [12]. With this definition, a series of
   "media-stream" sub-elements, each of one describes user is
   connected to a particular media
   stream. Each stream even if they are not sending any media.

   The "media-stream" element has a mandatory "media-type" attribute that indicates



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   which identifies the MIME media type for (e.g. audio, video, message and
   application) and MUST have one of the stream. There is values registered for "media"
   of SDP [12].

   The "media-stream" element has also an optional "send-status" and "recv-status" attribute which
   attribute "proto" sub-element,
   which indicates MUST has the status value registered for "proto" of SDP [12]).

   An optional "ssrc" sub-element, if present, carries the media to/from that user.

   If value of SSRC
   (RTP/RTCP [8]) as generated by the "send-status" is "received-by-all", user for the stream it means that sends.

   When an RTP mixer generates a CSRC list according to RTP/RTCP [8], it
   inserts a list of the media
   for SSRC identifiers of the sources that stream
   contributed to the generation of a particular packet into the RTP
   header of that packet. "An example application is being generated by audio conferencing
   where a mixer indicates all the user is being mixed by 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)."

4.1.2 Sidebar

   The sidebar element has one attribute - "entity" that indicates the
   URI which identifiers the sidebar. A sidebar has zero or more users
   that are of type "user-type" as the users of the main conference are.

4.1.3 Additional Conference Identifiers

   In addition to the Conference URI present in the "entity" attribute,
   a conference MAY have additional URIs of various types. Connecting to
   these URIs will result in joining to the server same conference.

4.1.4 Policy URIs

   A policy URI specifies where and sent how a certain policy pertaining to all recipients. "muted" means that no one is
   receiving their media. If it is "unknown",
   the server does not know
   the status, perhaps because the media conference can be accessed. The actual policy name and usage is being distributed via
   multicast or multi-unicast.

   If
   deduced from the "recv-status" is "receiving-all" it means that URI schema name.

   An example for the user is
   hearing all other participants. If it "policy-uri" usage is "anchor-only", inclusion of the user is
   hearing media from just a single participant. If it is "unknown", URI of the
   server does not know
   CPCP [11]. A subscriber to the status, perhaps because Conference package can use the media is being
   distributed via multicast or multi-unicast. Policy
   URI to access and modify the conference policy.

4.2 Constructing Coherent State

   The conference information subscriber maintains a table for the list
   of users in the conference. The table contains a row for each user.



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   Each row is indexed by a URI, present in the "uri" attribute of the
   "user" element. The contents of each row contain the state of that
   user as conveyed in the document.



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   The table is also associated with a 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 is received, the value of the local version
   number, and the "version" attribute in the new 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.

   The 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"
   "conference-info" element, the contents of the table are is flushed. They are It
   is repopulated from the document. A new row in the user table is
   created for each "user" element. If the document contains partial
   state, as indicated by the value of the "state" attribute in the "conference-
   info"
   "conference-info" element, the document is used to update the table.
   For each "user" element in the document, the subscriber checks to see
   whether a row exists for that user. user in the user table. This check is
   done by comparing the URI in the "uri" attribute of the "user"
   element with the URI associated with the row. If the user doesn't
   exist in the table, a row is added, and its state is set to the
   information from that "user" element. If the user does exist, its
   state is updated to be the information from that "user" element. If a
   row is updated or created, such that its state is now disconnected,
   booted, failed or departed, that entry MAY be removed from the table
   at any time.

4.3 Schema

   The following is the schema for the application/conference-info+xml
   type:



   <?xml version="1.0" encoding="UTF-8"?> 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:di="urn:ietf:params:xml:ns:dialog-info" xmlns="urn:ietf:params:xml:ns:conference-info" elementFormDefault="qualified" attributeFormDefault="unqualified">



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   <!--
    This import brings in the XML language attribute xml:lang--> xml:lang
     -->
     <xs:import namespace="http://www.w3.org/XML/1998/namespace"
                schemaLocation="http://www.w3.org/2001/03/xml.xsd"/>

     <!-- This import brings in the dialog-info element dialog-->
     <xs:import namespace="urn:ietf:params:xml:ns:dialog-info"
                schemaLocation="http://www.jdrosen.net/dialog-info.xsd"/> schemaLocation="http://www.w3.org/2001/03/xml.xsd" />

   <xs:element name="conference-info">
       <xs:complexType name="c-info-type">

   <xs:complexType>



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   <xs:sequence>
     <xs:element name="user" type="tns:user-type" type="user-type" minOccurs="0" maxOccurs="unbounded" />
     <xs:element name="sidebar" type="sidebar-type" minOccurs="0" maxOccurs="unbounded" />
     <xs:element name="conf-uri" type="xs:anyURI" minOccurs="0" maxOccurs="unbounded"/> maxOccurs="unbounded" />
     <xs:element name="policy-uri" type="xs:anyURI" minOccurs="0" maxOccurs="unbounded" />
     <xs:any namespace="##other" processContents="lax" minOccurs="0" maxOccurs="unbounded"/> maxOccurs="unbounded" />
   </xs:sequence>

     <xs:attribute name="version" type="xs:nonNegativeInteger"
                       use="required"/> use="required" />
     <xs:attribute name="state" use="required">
       <xs:simpleType>
        <xs:restriction base="xs:string">
           <xs:enumeration value="full"/> value="full" />
           <xs:enumeration value="partial"/> value="partial" />
        </xs:restriction>
       </xs:simpleType>
     </xs:attribute>

     <xs:attribute name="entity" type="xs:anyURI" use="required"/> use="required" />
     <xs:attribute name="recording" type="tns:recording-type" use="optional" />

     <xs:anyAttribute />

   </xs:complexType>
   </xs:element>

   <xs:complexType name="user-type">
    <xs:sequence>
     <xs:element name="status" type="tns:status-type" minOccurs="0"/> minOccurs="0" />
     <xs:element ref="di:dialog" minOccurs="0"/> name="joining-mode" type="tns:joining-mode-type" minOccurs="0" />
     <xs:element name="media-status" minOccurs="0">
           <xs:complexType name="media-status-type">
             <xs:sequence> name="disconnection-reason" type="tns:disconnection-reason-type" minOccurs="0" />
     <xs:element name="media-stream" type="tns:media-stream-type" minOccurs="0" maxOccurs="unbounded"/> maxOccurs="unbounded" />
     <xs:any namespace="##other" processContents="lax" minOccurs="0" maxOccurs="unbounded"/>
             </xs:sequence>
           </xs:complexType>
         </xs:element> maxOccurs="unbounded" />
     </xs:sequence>


     <xs:attribute name="uri" type="xs:anyURI" use="required"/> use="required" />
     <xs:attribute name="display-name" type="xs:string" use="optional"/> use="optional" />
     <xs:attribute ref="xml:lang"/> ref="xml:lang" use="optional" />
     <xs:attribute name="cascaded-focus" type="xs:anyURI" use="optional" />
     <xs:anyAttribute />

   </xs:complexType>



J. Rosenberg et.

   <xs:complexType name="sidebar-type">
    <xs:sequence>
     <xs:element name="user" type="user-type" minOccurs="0" maxOccurs="unbounded" />
     <xs:any processContents="lax" minOccurs="0" maxOccurs="unbounded" />



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     <xs:complexType name="status-type">
       <xs:simpleContent>
         <xs:restriction base="xs:string">
           <xs:enumeration value="active"/>
           <xs:enumeration value="departed"/>
           <xs:enumeration value="booted"/>
           <xs:enumeration value="failed"/>
         </xs:restriction>
       </xs:simpleContent>              February 2004


    </xs:sequence>

     <xs:attribute name="entity" type="xs:anyURI" use="required" />
   </xs:complexType>

   <xs:complexType name="media-stream-type">
    <xs:sequence>
     <xs:element name="proto" type="xs:string" minOccurs="0" />
     <xs:element name="ssrc" type="xs:nonNegativeInteger" minOccurs="0" />
     <xs:any processContents="lax" minOccurs="0" maxOccurs="unbounded" />
    </xs:sequence>

     <xs:attribute name="media-type" type="tns:mimetypes" use="required"/>
       <xs:attribute name="send-status" type="tns:send-status-type"
                     use="optional"/>
       <xs:attribute name="recv-status" type="tns:recv-status-type"
                     use="optional"/> name="media" type="xs:string" use="required" />
   </xs:complexType>

   <xs:simpleType name="mimetypes"> name="status-type">
    <xs:restriction base="xs:string">
     <xs:enumeration value="audio"/> value="connected" />
     <xs:enumeration value="video"/> value="disconnected" />
     <xs:enumeration value="message"/> value="on-hold" />
     <xs:enumeration value="application"/> value="muted-by-focus" />
    </xs:restriction>
   </xs:simpleType>

   <xs:simpleType name="send-status-type"> name="joining-mode-type">
    <xs:restriction base="xs:string">
     <xs:enumeration value="received-by-all"/> value="dialed-in" />
     <xs:enumeration value="muted"/> value="dialed-out" />
     <xs:enumeration value="unknown"/> value="focus-owner" />
    </xs:restriction>
   </xs:simpleType>

   <xs:simpleType name="recv-status-type">
       <xs:restriction base="xs:string">
        <xs:enumeration value="receiving-all"/>
        <xs:enumeration value="anchor-only"/>
         <xs:enumeration value="unknown"/>
       </xs:restriction>
     </xs:simpleType>
   </xs:schema>




        OPEN ISSUE: We need to register the schema for the dialog
        info package in order to have a stable reference for it in
        the conference info schema above.




J. Rosenberg et. name="disconnection-reason-type">
    <xs:restriction base="xs:string">
     <xs:enumeration value="departed" />
     <xs:enumeration value="booted" />
     <xs:enumeration value="failed" />
    </xs:restriction>
   </xs:simpleType>

   <xs:simpleType name="recording-type">
    <xs:restriction base="xs:string">
     <xs:enumeration value="on" />
     <xs:enumeration value="off" />
    </xs:restriction>
   </xs:simpleType>

   </xs:schema>



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4.4 Example

   The following is an example conference information document:



   <conference-info version="0" state="full" entity="conf233@example.com"> entity="sip:conf233@example.com" recording="on">

     <user uri="sip:jdrosen@dynamicsoft.com" display-name="Jonathan Rosenberg">
       <status>active</status>
       <media-status> uri="sip:bob@example.com" display-name="Bob Jones">
       <status>connected</status>
       <joining-mode>dialed-in</joining-mode>
       <media-stream media-type="audio"/>
       </media-status> media-type="audio">
          <proto> RTP/AVP </proto>
          <ssrc> 583398 </ssrc>
       </media-stream>
     </user>

     <user uri="sip:barbara@example.com" display-name="Barbara Jones">
       <status>on-hold</status>
     </user>

     <user uri="sip:hgs@cs.columbia.edu" display-name="Henning Schulzrinne">
       <status>active</status> uri="sip:bill@example.com" display-name="Bill Minelli">
       <status>on-hold</status>
     </user>

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

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

   </conference-info>

   This document describes a conference with two currently has three users, both two of which are active.

5 in a
   sidebar conversation. The conference is being recorded. There are
   additional means to join the conference either by phone using tel URI
   [14] or by H.323 protocol using h323 URL [13].












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5. 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.

6










































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6. IANA Considerations

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

6.1 conference Event Package Registration

   This specification registers an event package, based on the
   registration procedures defined in RFC 3265 [2]. 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 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 [8].




J. Rosenberg et. al.                                         [Page 13]

Internet Draft             Conference Package              June 24, 2002 [7].

   Encoding considerations: Same as encoding considerations of
      application/xml as specified in RFC 3023 [8]. [7].

   Security considerations: See Section 10 of RFC 3023 [8] [7] and Section 5
      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.






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   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.

6.2


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

   This section registers a new XML namespace, as per the guidelines in
   [6].

   URI: The URI for this namespace is
      urn:ietf:params:xml:ns:conference-info.

   Registrant Contact: IETF, SIMPLE SIPPING working group,
             <simple@mailman.dynamicsoft.com>, <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">



J.
   <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



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6.4 XML Schema Registration

   This specification registers a schema, as per the guidelines in in
   [6].

      URI: please assign.

      Registrant Contact: IETF, SIPPING Working Group
      (sipping@ietf.org), Jonathan Rosenberg et. (jdrosen@jdrosen.net).

      XML: The XML can be found as the sole content of Section 4.3.








































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7. Acknowledgements

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















































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8. 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  ExampleÆs 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".
































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             <head>
               <meta http-equiv="content-type"
                  content="text/html;charset=iso-8859-1"/>
               <title>Dialog Information Namespace</title>
             </head
             <body>
               <h1>Namespace for              February 2004


9. 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</h1>
               <h2>application/conference-info+xml</h2>
               <p>See <a href="[[[URL information is removed. It can be obtained by direct
      subscription to a dialog package of published RFC]]]">RFCXXXX</a>.</p>
             </body>
             </html>
             END



7 Acknowledgements

   The authors would like 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 thank Dan Petrie ans Sean Olson for their
   comments.

8 Authors Addresses


   Jonathan Rosenberg
   dynamicsoft
   72 Eagle Rock Avenue
   First Floor
   East Hanover, NJ 07936
   email: jdrosen@dynamicsoft.com

   Henning Schulzrinne
   Columbia University
   M/S 0401
   1214 Amsterdam Ave.
   New York, NY 10027-7003
   email: schulzrinne@cs.columbia.edu



9 XCON work are removed.

   o  Optional sidebar rosters are added.




























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Normative References

   [1] A. Roach, "SIP-specific event notification," Internet Draft,
   Internet Engineering Task Force, Mar. 2002.  Work in progress.

   [2] S.  Bradner, S., "Key words for use in RFCs to indicate requirement
   levels," Indicate Requirement
        Levels", BCP 14, RFC 2119, Internet Engineering Task Force, Mar. March 1997.

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

   [3] W. W. W. C. (W3C), "Extensible markup language (xml) 1.0." The



J. Rosenberg et. al.                                         [Page 15]

Internet Draft             Conference Package  Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A.,
        Peterson, J., Sparks, R., Handley, M. and E. Schooler, "SIP:
        Session Initiation Protocol", RFC 3261, June 24, 2002


   XML 1.0 spec can be found at http://www.w3.org/TR/1998/REC-xml-
   19980210. 2002.

   [4] R.  Moats, R., "URN syntax," Syntax", RFC 2141, Internet Engineering Task
   Force, May 1997.

   [5] R.  Moats, R., "A URN namespace Namespace for IETF documents," Documents", RFC 2648,
   Internet Engineering Task Force, Aug.
        August 1999.

   [6] M.  Mealling, M., "The IANA IETF XML registry," Internet Draft, Internet
   Engineering Task Force, Nov. 2001.  Work Registry",
        draft-mealling-iana-xmlns-registry-05 (work in progress.

   [7] J. Rosenberg and H. Schulzrinne, "A session initiation protocol
   (SIP) event package for dialog state," Internet Draft, Internet
   Engineering Task Force, progress), June 2002.  Work in progress.

   [8] M.
        2003.

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

   [8]  Schulzrinne, H., Casner, S., Frederick, R. and V. Jacobson,
        "RTP: A Transport Protocol for Real-Time Applications", RFC
   3023, Internet Engineering Task Force, Jan. 2001.

10
        3550, July 2003.
























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Informative References

   [9] J.   Rosenberg, "Session initiation protocol (SIP) extensions J., "A Framework for
   presence," Internet Draft, Internet Engineering Task Force, May 2002.
   Work in progress. Conferencing with the Session
         Initiation Protocol",
         draft-ietf-sipping-conferencing-framework-01 (work in
         progress), October 2003.

   [10] J.  Rosenberg, "A session initiation protocol (SIP)event
   template-package for watcher information," Internet Draft, Internet
   Engineering Task Force, May 2002.  Work in progress.

   [11] R. Mahy, "A message summary J. and message waiting indication event
   package H. Schulzrinne, "An INVITE Inititiated Dialog
         Event Package for the session initiation protocol (SIP)," Internet Draft,
   Internet Engineering Task Force, June 2002.  Work in progress. Session Initiation  Protocol (SIP)",
         draft-ietf-sipping-dialog-package-03 (work in progress),
         October 2003.

   [11]  Koskelainen, P., "Requirements for Conference Policy Control
         Protocol", draft-ietf-xcon-cpcp-reqs-02 (work in progress),
         February 2004.

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

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

   [14]  Schulzrinne, "Models H., "The tel URI for multi party
   conferencing Telephone Numbers",
         draft-ietf-iptel-tel-rfc2806bis-03 (work in progress), February
         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

   EMail: oritl@microsoft.com

































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Intellectual Property Statement

   The IETF takes no position regarding the validity or scope of any
   intellectual property or other rights that might be claimed to
   pertain to the implementation or use of the technology described in SIP," Internet Draft, Internet Engineering Task
   Force, Nov. 2001.  Work
   this document or the extent to which any license under such rights
   might or might not be available; neither does it represent that it
   has made any effort to identify any such rights. Information on the
   IETF's procedures with respect to rights in standards-track and
   standards-related documentation can be found in progress. BCP-11. Copies of
   claims of rights made available for publication and any assurances of
   licenses to be made available, or the result of an attempt made to
   obtain a general license or permission for the use of such
   proprietary rights by implementors or users of this specification can
   be obtained from the IETF Secretariat.

   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
   rights which may cover technology that may be required to practice
   this standard. Please address the information to the IETF Executive
   Director.


Full Copyright Statement

   Copyright (c) (C) The Internet Society (2002). (2004). All Rights Reserved.

   This document and translations of it may be copied and furnished to
   others, and derivative works that comment on or otherwise explain it
   or assist in its implementation may be prepared, copied, published
   and distributed, in whole or in part, without restriction of any
   kind, provided that the above copyright notice and this paragraph are
   included on all such copies and derivative works. However, this



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   document itself may not be modified in any way, such as by removing
   the copyright notice or references to the Internet Society or other
   Internet organizations, except as needed for the purpose of
   developing Internet standards in which case the procedures for
   copyrights defined in the Internet Standards process must be
   followed, or as required to translate it into languages other than
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   The limited permissions granted above are perpetual and will not be
   revoked by the Internet Society or its successors or assigns. assignees.

   This document and the information contained herein is provided on an
   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION



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   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.


































J. Rosenberg et.


Acknowledgment

   Funding for the RFC Editor function is currently provided by the
   Internet Society.











































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----