--- 1/draft-ietf-sipping-conference-package-10.txt	2006-02-05 01:48:00.000000000 +0100
+++ 2/draft-ietf-sipping-conference-package-11.txt	2006-02-05 01:48:00.000000000 +0100
@@ -1,49 +1,46 @@
 
 SIPPING                                                     J. Rosenberg
 Internet-Draft                                             Cisco Systems
-Expires: September 26, 2005                               H. Schulzrinne
+Expires: December 7, 2005                                 H. Schulzrinne
                                                      Columbia University
                                                            O. Levin, Ed.
                                                    Microsoft Corporation
-                                                          March 25, 2005
+                                                            June 5, 2005
 
-    A Session Initiation Protocol (SIP) Event Package for Conference
-                                 State
-                draft-ietf-sipping-conference-package-10
+ A Session Initiation Protocol (SIP) Event Package for Conference State
+                draft-ietf-sipping-conference-package-11
 
 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.
+   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 becomes
+   aware will be disclosed, in accordance with Section 6 of BCP 79.
 
    Internet-Drafts are working documents of the Internet Engineering
    Task Force (IETF), its areas, and its working groups.  Note that
-   other groups may also distribute working documents as
-   Internet-Drafts.
+   other groups may also distribute working documents as Internet-
+   Drafts.
 
    Internet-Drafts are draft documents valid for a maximum of six months
    and may be updated, replaced, or obsoleted by other documents at any
    time.  It is inappropriate to use Internet-Drafts as reference
    material or to cite them other than as "work in progress."
 
    The list of current Internet-Drafts can be accessed at
    http://www.ietf.org/ietf/1id-abstracts.txt.
 
    The list of Internet-Draft Shadow Directories can be accessed at
    http://www.ietf.org/shadow.html.
 
-   This Internet-Draft will expire on September 26, 2005.
+   This Internet-Draft will expire on December 7, 2005.
 
 Copyright Notice
 
    Copyright (C) The Internet Society (2005).
 
 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
@@ -51,105 +48,109 @@
    sent about changes in the membership of this conference and
    optionally about changes in the state of additional conference
    components.
 
 Table of Contents
 
    1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  4
    2.  Terminology  . . . . . . . . . . . . . . . . . . . . . . . . .  4
    3.  Conference Event Package . . . . . . . . . . . . . . . . . . .  4
      3.1   Event Package Name . . . . . . . . . . . . . . . . . . . .  4
-     3.2   SUBSCRIBE Bodies . . . . . . . . . . . . . . . . . . . . .  5
+     3.2   Filtering  . . . . . . . . . . . . . . . . . . . . . . . .  5
      3.3   Subscription Duration  . . . . . . . . . . . . . . . . . .  5
      3.4   NOTIFY Bodies  . . . . . . . . . . . . . . . . . . . . . .  5
-     3.5   Notifier Processing of SUBSCRIBE Requests  . . . . . . . .  6
+     3.5   Notifier Processing of SUBSCRIBE Requests  . . . . . . . .  5
      3.6   Notifier Generation of NOTIFY Requests . . . . . . . . . .  6
      3.7   Subscriber Processing of NOTIFY Requests . . . . . . . . .  6
      3.8   Handling of Forked Requests  . . . . . . . . . . . . . . .  7
      3.9   Rate of Notifications  . . . . . . . . . . . . . . . . . .  7
      3.10  State Agents . . . . . . . . . . . . . . . . . . . . . . .  7
    4.  Conference Document  . . . . . . . . . . . . . . . . . . . . .  7
      4.1   Format . . . . . . . . . . . . . . . . . . . . . . . . . .  7
      4.2   Namespace  . . . . . . . . . . . . . . . . . . . . . . . .  7
      4.3   Versioning . . . . . . . . . . . . . . . . . . . . . . . .  7
      4.4   Partial Notifications Mechanism  . . . . . . . . . . . . .  8
-     4.5   Element Keys . . . . . . . . . . . . . . . . . . . . . . .  9
+     4.5   Element Keys . . . . . . . . . . . . . . . . . . . . . . .  8
      4.6   Constructing Coherent State Procedure  . . . . . . . . . .  9
-   5.  Conference Data  . . . . . . . . . . . . . . . . . . . . . . . 10
-     5.1   <conference-info>  . . . . . . . . . . . . . . . . . . . . 11
-     5.2   <conference-description> . . . . . . . . . . . . . . . . . 11
-       5.2.1   <conf-uris>  . . . . . . . . . . . . . . . . . . . . . 12
-       5.2.2   <service-uris> . . . . . . . . . . . . . . . . . . . . 13
-       5.2.3   <maximum-user-count> . . . . . . . . . . . . . . . . . 13
-       5.2.4   <available-media>  . . . . . . . . . . . . . . . . . . 13
-     5.3   <host-info>  . . . . . . . . . . . . . . . . . . . . . . . 14
-       5.3.1   <display-text> . . . . . . . . . . . . . . . . . . . . 14
-       5.3.2   <web-page> . . . . . . . . . . . . . . . . . . . . . . 14
-       5.3.3   <uris> . . . . . . . . . . . . . . . . . . . . . . . . 14
-     5.4   <conference-state> . . . . . . . . . . . . . . . . . . . . 14
-       5.4.1   <user-count> . . . . . . . . . . . . . . . . . . . . . 14
-       5.4.2   <active> . . . . . . . . . . . . . . . . . . . . . . . 15
-       5.4.3   <locked> . . . . . . . . . . . . . . . . . . . . . . . 15
-     5.5   <users> of <user>  . . . . . . . . . . . . . . . . . . . . 15
-       5.5.1   <display-text> . . . . . . . . . . . . . . . . . . . . 16
-       5.5.2   <associated-aors>  . . . . . . . . . . . . . . . . . . 16
-       5.5.3   <roles>  . . . . . . . . . . . . . . . . . . . . . . . 16
-       5.5.4   <language> . . . . . . . . . . . . . . . . . . . . . . 16
-       5.5.5   <cascaded-focus> . . . . . . . . . . . . . . . . . . . 16
-       5.5.6   <endpoint> . . . . . . . . . . . . . . . . . . . . . . 16
-     5.6   <endpoint> . . . . . . . . . . . . . . . . . . . . . . . . 17
-       5.6.1   <display-text> . . . . . . . . . . . . . . . . . . . . 17
-       5.6.2   <referred> . . . . . . . . . . . . . . . . . . . . . . 17
-       5.6.3   <status> . . . . . . . . . . . . . . . . . . . . . . . 18
-       5.6.4   <joining-method> . . . . . . . . . . . . . . . . . . . 19
-       5.6.5   <joining-info> . . . . . . . . . . . . . . . . . . . . 19
-       5.6.6   <disconnection-method> . . . . . . . . . . . . . . . . 19
-       5.6.7   <disconnection-info> . . . . . . . . . . . . . . . . . 20
-       5.6.8   <media>  . . . . . . . . . . . . . . . . . . . . . . . 20
-       5.6.9   <call-info>  . . . . . . . . . . . . . . . . . . . . . 20
-     5.7   <media>  . . . . . . . . . . . . . . . . . . . . . . . . . 21
-       5.7.1   <display-text> . . . . . . . . . . . . . . . . . . . . 21
-       5.7.2   <type> . . . . . . . . . . . . . . . . . . . . . . . . 21
-       5.7.3   <label>  . . . . . . . . . . . . . . . . . . . . . . . 21
-       5.7.4   <src-id> . . . . . . . . . . . . . . . . . . . . . . . 21
-       5.7.5   <status> . . . . . . . . . . . . . . . . . . . . . . . 22
-     5.8   <sidebars-by-ref>  . . . . . . . . . . . . . . . . . . . . 22
-     5.9   <sidebar-by-val> . . . . . . . . . . . . . . . . . . . . . 22
-   6.  XML Schema . . . . . . . . . . . . . . . . . . . . . . . . . . 22
-   7.  Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
-     7.1   Basic Example  . . . . . . . . . . . . . . . . . . . . . . 30
-     7.2   Rich Example . . . . . . . . . . . . . . . . . . . . . . . 32
-   8.  Security Considerations  . . . . . . . . . . . . . . . . . . . 35
-   9.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 36
-     9.1   conference Event Package Registration  . . . . . . . . . . 36
-     9.2   application/conference-info+xml MIME Registration  . . . . 36
+   5.  Conference Data  . . . . . . . . . . . . . . . . . . . . . . . 11
+     5.1   Overview . . . . . . . . . . . . . . . . . . . . . . . . . 11
+     5.2   <conference-info>  . . . . . . . . . . . . . . . . . . . . 13
+     5.3   <conference-description> . . . . . . . . . . . . . . . . . 13
+       5.3.1   <conf-uris>  . . . . . . . . . . . . . . . . . . . . . 14
+       5.3.2   <service-uris> . . . . . . . . . . . . . . . . . . . . 15
+       5.3.3   <maximum-user-count> . . . . . . . . . . . . . . . . . 15
+       5.3.4   <available-media>  . . . . . . . . . . . . . . . . . . 15
+     5.4   <host-info>  . . . . . . . . . . . . . . . . . . . . . . . 16
+       5.4.1   <display-text> . . . . . . . . . . . . . . . . . . . . 16
+       5.4.2   <web-page> . . . . . . . . . . . . . . . . . . . . . . 17
+       5.4.3   <uris> . . . . . . . . . . . . . . . . . . . . . . . . 17
+     5.5   <conference-state> . . . . . . . . . . . . . . . . . . . . 17
+       5.5.1   <user-count> . . . . . . . . . . . . . . . . . . . . . 17
+       5.5.2   <active> . . . . . . . . . . . . . . . . . . . . . . . 17
+       5.5.3   <locked> . . . . . . . . . . . . . . . . . . . . . . . 17
+     5.6   <users> and its <user> sub-elements  . . . . . . . . . . . 17
+       5.6.1   <display-text> . . . . . . . . . . . . . . . . . . . . 18
+       5.6.2   <associated-aors>  . . . . . . . . . . . . . . . . . . 18
+       5.6.3   <roles>  . . . . . . . . . . . . . . . . . . . . . . . 19
+       5.6.4   <languages>  . . . . . . . . . . . . . . . . . . . . . 19
+       5.6.5   <cascaded-focus> . . . . . . . . . . . . . . . . . . . 19
+       5.6.6   <endpoint> . . . . . . . . . . . . . . . . . . . . . . 19
+     5.7   <endpoint> . . . . . . . . . . . . . . . . . . . . . . . . 20
+       5.7.1   <display-text> . . . . . . . . . . . . . . . . . . . . 20
+       5.7.2   <referred> . . . . . . . . . . . . . . . . . . . . . . 20
+       5.7.3   <status> . . . . . . . . . . . . . . . . . . . . . . . 21
+       5.7.4   <joining-method> . . . . . . . . . . . . . . . . . . . 22
+       5.7.5   <joining-info> . . . . . . . . . . . . . . . . . . . . 22
+       5.7.6   <disconnection-method> . . . . . . . . . . . . . . . . 23
+       5.7.7   <disconnection-info> . . . . . . . . . . . . . . . . . 23
+       5.7.8   <media>  . . . . . . . . . . . . . . . . . . . . . . . 24
+       5.7.9   <call-info>  . . . . . . . . . . . . . . . . . . . . . 24
+     5.8   <media>  . . . . . . . . . . . . . . . . . . . . . . . . . 24
+       5.8.1   <display-text> . . . . . . . . . . . . . . . . . . . . 24
+       5.8.2   <type> . . . . . . . . . . . . . . . . . . . . . . . . 24
+       5.8.3   <label>  . . . . . . . . . . . . . . . . . . . . . . . 25
+       5.8.4   <src-id> . . . . . . . . . . . . . . . . . . . . . . . 25
+       5.8.5   <status> . . . . . . . . . . . . . . . . . . . . . . . 25
+     5.9   Sidebars . . . . . . . . . . . . . . . . . . . . . . . . . 25
+       5.9.1   <sidebars-by-ref>  . . . . . . . . . . . . . . . . . . 26
+       5.9.2   <sidebar-by-val> . . . . . . . . . . . . . . . . . . . 26
+   6.  XML Schema . . . . . . . . . . . . . . . . . . . . . . . . . . 26
+   7.  Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
+     7.1   Basic Example  . . . . . . . . . . . . . . . . . . . . . . 34
+     7.2   Rich Example . . . . . . . . . . . . . . . . . . . . . . . 36
+   8.  Security Considerations  . . . . . . . . . . . . . . . . . . . 40
+     8.1   Connection Security  . . . . . . . . . . . . . . . . . . . 40
+     8.2   Authorization Considerations . . . . . . . . . . . . . . . 40
+   9.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 41
+     9.1   conference Event Package Registration  . . . . . . . . . . 41
+     9.2   application/conference-info+xml MIME Registration  . . . . 41
      9.3   URN Sub-Namespace Registration for
-           urn:ietf:params:xml:ns:conference-info . . . . . . . . . . 37
-     9.4   XML Schema Registration  . . . . . . . . . . . . . . . . . 38
-     9.5   URI Purposes Sub-registry Establishment  . . . . . . . . . 38
-   10.   Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 39
-   11.   References . . . . . . . . . . . . . . . . . . . . . . . . . 39
-     11.1  Normative References . . . . . . . . . . . . . . . . . . . 39
-     11.2  Informative References . . . . . . . . . . . . . . . . . . 40
-       Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 41
-       Intellectual Property and Copyright Statements . . . . . . . . 43
+           urn:ietf:params:xml:ns:conference-info . . . . . . . . . . 42
+     9.4   XML Schema Registration  . . . . . . . . . . . . . . . . . 43
+     9.5   URI Purposes Sub-registry Establishment  . . . . . . . . . 43
+   10.   Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 44
+   11.   References . . . . . . . . . . . . . . . . . . . . . . . . . 44
+     11.1  Normative References . . . . . . . . . . . . . . . . . . . 44
+     11.2  Informative References . . . . . . . . . . . . . . . . . . 46
+       Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 47
+       Intellectual Property and Copyright Statements . . . . . . . . 48
 
 1.  Introduction
 
-   The Session Initiation Protocol (SIP) Events Framework [9] defines
+   The Session Initiation Protocol (SIP) Events Framework [10] 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
-   [19].  As described there, subscriptions to a conference URI are
+   [16].  As described there, subscriptions to a conference URI are
    routed to the focus that is handling the conference.  It acts as the
    notifier, and provides clients with updates on conference state.
 
    The information provided by this package is comprised of conference
    identifier(s), conference participants (optionally with their
    statuses and media description), conference sidebars, conference
    service URIs, etc.
 
 2.  Terminology
 
@@ -157,96 +158,92 @@
    "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY",
    and "OPTIONAL" are to be interpreted as described in RFC 2119 [1] and
    indicate requirement levels for compliant implementations.
 
 3.  Conference Event Package
 
    The conference event package allows a user to subscribe to a
    conference.  In SIP, conferences are represented by URIs.  These URIs
    route to a SIP user agent, called a focus, that is responsible for
    ensuring that all users in the conference can communicate with each
-   other, as described in Conferencing Framework [19].  The focus has
+   other, as described in Conferencing Framework [16].  The focus has
    sufficient information about the state of the conference to inform
    subscribers about it.
 
    It is possible that 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 use of the
    <cascaded-focus> element as specified by this package.
 
    This section provides the details for defining a SIP-specific event
-   notification package, as specified by RFC 3265 [9].
+   notification package, as specified by RFC 3265 [10].
 
 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
-   [9].
+   [10].
 
-3.2  SUBSCRIBE Bodies
+3.2  Filtering
 
-   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.
+   Filters to conference subscriptions are a desirable feature, which
+   can be considered as a subject of future standardization activities.
+   This document does not define the filters for the conference package
+   to be included in the SUBSCRIBE body.
 
-   A SUBSCRIBE for a conference package MAY be sent without a body.
-   This implies the default subscription filtering policy.  The default
+   A SUBSCRIBE for a conference package, being sent without a body,
+   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" as defined
-   in RFC 3265 [9].
+   in RFC 3265 [10].
 
 3.4  NOTIFY Bodies
 
-   As described in RFC 3265 [9], the NOTIFY message will contain bodies
+   According to RFC 3265 [10], 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
+   conference information document that describes the state of a
+   conference.  All subscribers and notifiers MUST support the
    "application/conference-info+xml" data format described in Section 5.
-   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.
+   By default, i.e. if no Accept header is specified to a SUBSCRIBE
+   request, the NOTIFY will contain a body in the "application/
+   conference-info+xml" data format.  If the Accept header field is
+   present, it MUST include "application/conference-info+xml" and MAY
+   include any other types.
 
 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.
+   discretion of the administrator, as always.
 
-   It is RECOMMENDED that all users in the conference be allowed to
-   subscribe to the conference event package.
+   However, it is RECOMMENDED that all users in the conference be
+   allowed to subscribe to the conference event package.
 
 3.6  Notifier Generation of NOTIFY Requests
 
    Notifications SHOULD 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.
@@ -272,73 +269,72 @@
    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 4.6 for information on
-   constructing coherent information from an
-   application/conference-info+xml document.
+   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 doesn't 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
-   package.
+   conference resides.  Therefore, a conference focus is the best suited
+   element to handle subscriptions to it.  Cascaded foci MAY implement
+   state agents (as defined in RFC 3265 [10]) for this package.
 
 4.  Conference Document
 
 4.1  Format
 
    Conference information is an XML document that MUST be well-formed
    and valid.  It MUST be based on Extensible Markup Language (XML) 1.0
-   and MUST be encoded using UTF-8 [12].
+   and MUST be encoded using UTF-8 [14].
 
 4.2  Namespace
 
    This specification makes use of XML namespaces for identifying
    conference information documents and document fragments.  The
    namespace URI for elements defined by this specification is a URN
    [2], using the namespace identifier 'ietf' defined by [6] and
-   extended by RFC 3688 [13].  This URN is:
+   extended by RFC 3688 [21].  This URN is:
 
    urn:ietf:params:xml:ns:conference-info
 
 4.3  Versioning
 
    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.
 
-   The 'version' attribute MUST be included in the root
-   <conference-info> element.
+   The 'version' attribute MUST be included in the root <conference-
+   info> element.
 
 4.4  Partial Notifications Mechanism
 
    This specification defines a basic partial notifications mechanism by
    using a 'state' attribute as described below.  This mechanism MUST be
    supported by all subscribing clients.  Additional general partial
    notifications mechanisms can be defined and applied to this package
    in the future.
 
    All sub-elements in the <conference-info> hierarchal XML structure
@@ -360,25 +356,28 @@
    o  Element <user>
    o  Element <endpoint>
    o  Element <sidebars-by-val>
    o  Element <sidebars-by-ref>
 
    The 'state' attribute value indicates whether the reported
    information about the element is "full", "partial" or the element is
    "deleted" from the conference state document.  The default value of
    any 'state' attribute is "full".
 
-   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".
+   A 'state' attribute of a child element in the document MUST be
+   consistent with its parent 'state'.  This 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".  A parent element with
+   "deleted" 'state' SHOULD NOT contain child elements.  Any information
+   provided for child elements of a "deleted" parent MUST be ignored by
+   the package subscriber.
 
 4.5  Element Keys
 
    The defined XML schema has a property of unique identification among
    sub-elements of a common parent, which makes it possible to use the
    partial notifications mechanism defined in this document.  This
    property is achieved by defining a key to each sub-element that can
    appear multiple times under the common parent.
 
    In the context of this specification, the element key is the set of
@@ -395,43 +394,48 @@
 
    o  Element <user> uses as the key 'entity'
    o  Element <endpoint> uses as the key 'entity'
    o  Element <media> uses as the key 'id'
    o  Element <entry> (child to <sidebars-by-val>) uses as the key
       'entity'
    o  Element <sidebars-by-ref> uses as the key <uri>
 
 4.6  Constructing Coherent State Procedure
 
-   A conference package subscriber maintains a local version number, a
-   local element for each element in the schema, and a table for each
-   element with its key as defined above.
+   This section describes the algorithm for constructing a coherent
+   conference state by a subscriber to the conference package.  Using
+   software programming abstraction, the subscriber maintains a single
+   local version number for the whole conference document and a local
+   element instance for each element in the schema.  Also, for each
+   element with keys (as defined above), the subscriber maintains a
+   virtual table with a row for each existing key value.
 
    The first time a NOTIFY with a "full" document is received (as
-   indicated by the value of the 'state' attribute in the
-   <conference-info> element), the conference package subscriber MUST
-   set the local 'version' number to the value of the 'version'
-   attribute from the received <conference-info> and populate local data
-   with the received information.
+   indicated by the value of the 'state' attribute in the <conference-
+   info> element), the conference package subscriber MUST set the local
+   'version' number to the value of the 'version' attribute from the
+   received <conference-info> and populate local data with the received
+   information.
 
    Each time a new NOTIFY is received, the value of the local version
    number and the value of the 'version' attribute in the new received
    document are compared.  If the value in the document is equal or less
    than the local version, the document is discarded without processing.
 
    Otherwise, if the received NOTIFY contains a "full" or "deleted"
    state, the conference package subscriber MUST set the local 'version'
    number to the value of the 'version' attribute from the received
    <conference-info> and replace the local information with the received
-   document.  Receiving "deleted" state means that the conference ceased
-   to exist and the subscriber SHOULD terminate the subscription by
-   sending the SUBSCRIBE with Expires = 0.
+   document.  Receiving "deleted" state for the <conference-info>
+   element means that the conference has ceased to exist and the
+   subscriber SHOULD terminate the subscription by sending the SUBSCRIBE
+   with Expires = 0.
 
    Otherwise (i.e.  if the received NOTIFY contains "partial" state), if
    the 'version' number in the received document is more than one number
    higher than the previous local version number, the subscriber MUST
    generate a subscription refresh request to trigger a full state
    notification.  If the 'version' number in the document is one higher
    than the local version number, the local version number is updated
    accordingly and the document is used to update the local content as
    described below.
 
@@ -445,381 +449,499 @@
    element MUST be removed from the local content.
 
    3.  Otherwise, if the element contains "partial" state:
 
    3.1 For elements with keys, the subscriber compares the keys received
    in the update with the keys in the local tables.
 
    3.1.1 If a 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 3.2.
+   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 3.2.
 
    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.
+   replaced with the new information as a whole.  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.  Also, for each element
+   with the state attribute set to "deleted", the whole element is
+   removed from the local content.
 
    3.3 For each non-atomic element with the state attribute set to
    "partial", the algorithm is applied recursively starting from step
    3.1.
 
 5.  Conference Data
 
-5.1  <conference-info>
+5.1  Overview
+
+   The <conference-info> document format is designed to convey
+   information about the conference and about participation in the
+   conference.  The following non-normative diagram gives an example of
+   the overall hierarchy used in this format.  Conferences contain users
+   who can be represented by multiple endpoints, each of which can have
+   multiple media streams.  Conferences can also include or reference
+   "sidebar conferences".  When sidebar information is incorporated into
+   a conference information document in a <sidebar-by-value> element,
+   each <entry> element represents a sidebar and can include any sub-
+   elements permitted in the <conference-info> top-level element.
+
+   conference-info
+     |
+     |-- conference-description
+     |
+     |-- host-info
+     |
+     |-- conference-state
+     |
+     |-- users
+     |    |-- user
+     |    |    |-- endpoint
+     |    |    |    |-- media
+     |    |    |    |-- media
+     |    |    |    |-- call-info
+     |    |    |
+     |    |    |-- endpoint
+     |    |         |-- media
+     |    |-- user
+     |         |-- endpoint
+     |              |-- media
+     |
+     |-- sidebars-by-ref
+     |    |-- entry
+     |    |-- entry
+     |
+     |-- sidebars-by-val
+          |-- entry
+          |    |-- users
+          |         |-- user
+          |         |-- user
+          |-- entry
+               |-- users
+                    |-- user
+                    |-- user
+                    |-- user
+
+   In most cases, this document doesn't mandate how the information,
+   presented through the conference document to the subscribers, is
+   obtained by the focus.  In many cases, the information can be
+   dynamically learned from the call signaling and also be manually
+   populated by an administrator - all subject to local policies.  This
+   document specifies what the XML elements mean in order to allow the
+   subscribers to appropriately interpret it.  Some portions of the
+   information are intended for automata processing, others - for human
+   consumption only.  For example, the <display-text> sub-elements of
+   elements <conf-uris>, <service-uris>, <available-media>, <host-info>,
+   <endpoint>, and <media> are intended for display to human subscribers
+   only.
+
+   Following sections describe the XML schema in more details.
+
+5.2  <conference-info>
 
    A conference information document begins with the root element tag
    <conference-info> of conference-type.
 
    The following attributes are defined for <conference-info>:
 
    entity: This attribute contains the conference URI that identifies
-      the conference being described in the document.
+      the conference being described in the document.  This is the SIP
+      URI that an interested entity needs to SUBSCRIBE to in order to
+      get the conference package information.  Note that this URI can be
+      listed as one of the URIs to be used in order to access the
+      conference by SIP means and in accordance with  Section 5.3.1
+      below.
 
    state: This 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 detail see
       Section 4.
 
    version: This attribute allows the recipient of conference
       information documents to properly order them and it MUST be
       included when used in the root <conference-info> element.  Version
       number is a 32 bit monotonically increasing integer scoped within
       a subscription.  A server MUST increment the version number by one
       for each new partial notification being sent to a subscriber.
 
-   The <conference-info> element is comprised of
-   <conference-description>, <host-info>, <conference-state>, <users>,
-   <sidebar-by-ref> and <sidebars-by-val> child elements.  A "full"
-   conference document MUST at least include the
-   <conference-description> and <users> child elements.
+   The <conference-info> element is comprised of <conference-
+   description>, <host-info>, <conference-state>, <users>, <sidebar-by-
+   ref> and <sidebars-by-val> child elements.  A "full" conference
+   document MUST at least include the <conference-description> and
+   <users> child elements.
 
    Following sections describe these elements in detail.  The full XML
    schema is provided in Section 6.
 
-5.2  <conference-description>
+5.3  <conference-description>
 
    The <conference-description> element describes the conference as a
    whole.
 
    The child elements <display-text>, <subject>, <free-text>, and
    <keywords> are used to describe the conference content:
 
-   <display-text>: Contains a text suitable for human consumption and
-      directory listing
+   <display-text>: Contains descriptive text suitable for human
+      consumption, for example, listing in a directory
 
    <subject>: Contains the subject of the conference
+
    <free-text>: Contains an additional longer description of the
       conference
 
-   <keywords>: Contains a list of comma-separated keywords that can be
-      used by search engines to better classify the conference
+   <keywords>: Contains a list of space-separated string tokens that can
+      be used by search engines to better classify the conference
 
    Additional child elements <conf-uris> and <service-uris> are used to
    describe the conference-related URIs; <maximum-user-count> and
    <available-media> are used to describe the overall characteristics.
 
    This information is typically derived from the system conference
    policies, is set before the conference activation, and is rarely
    changed during the conference lifetime.
 
    The following sections describe the remaining elements in more
    detail.  Other sub-elements can extend <conference-description> in
    the future.
 
-5.2.1  <conf-uris>
+5.3.1  <conf-uris>
 
-   This element is a set of <entry> child elements - each containing the
-   URI to be used in order to access the conference by different
-   signaling means.  The value of the URI MUST be unique in the
-   conference context and is included in the <uri> sub-element.
+   This element contains a sequence of <entry> child elements - each
+   containing the URI to be used in order to access the conference by
+   different signaling means.  The value of the URI MUST be unique in
+   the conference context and is included in the <uri> sub-element.
 
    Each <entry> can contain additional optional information useful to
    the participant when accessing the conference.
 
    An <entry> element MAY contain the <display-text> sub-element that
    provides a textual description meant for human consumption.
 
    Each <entry> element SHOULD contain a <purpose> sub-element that
    describes what happens when accessing the URI.  The currently defined
    <purpose> values to be used with the <conf-uris> are:
 
    participation: Accessing a URI with this <purpose> will bring the
       party into the conference
    streaming: Accessing a URI with this <purpose> will commence
       streaming the conference, but not allow active participation
 
-   Examples of suitable URI schemes include sip: and sips: [8], h323:
-   [18], and tel: [17] URIs.  The rtsp [14] URI is suitable for
-   streaming.
+   Examples of suitable URI schemes include sip: and sips: [8], xmpp:
+   [22], h323: [20], and tel: [19] URIs.  The rtsp [18] URI is suitable
+   for streaming.
 
    Future extensions to this schema may define new values and register
    them with IANA under the registry established by this specification.
 
-5.2.2  <service-uris>
+5.3.2  <service-uris>
 
    This element describes auxiliary services available for the
    conference.  Like <conference-uris>, this element contains a set of
    <entry> child elements - each containing the URI to be used in order
    to access different services available for the particular conference.
    The value of the URI MUST be unique in the conference context and is
    included in the <uri> sub-element.
 
    An <entry> element MAY contain the <display-text> sub-element that
    provides a textual description meant for user consumption.
 
    Each <entry> element SHOULD contain a <purpose> sub-element.  The
    currently defined <purpose> values to be used with the <service-uris>
    are:
 
    web-page: Indicates the web page containing the additional
       information about the conference
    recording: Indicates the link at which the recorded conference
       context can be retrieved
-   event: Indicates the URI to which the subscription to the conference
-      event package needs to be performed.  This would typically be the
+   event: Indicates the URI at which a subscription to the conference
+      event package may be requested.  This would typically be the
       conference URI of the main conference
 
    Future extensions to this schema may define new values and register
    them with IANA under the registry established by this specification.
 
-5.2.3  <maximum-user-count>
+5.3.3  <maximum-user-count>
 
-   This element, if used, specifies the maximum number of users
-   permitted in the conference.
+   The value of this element provides a hint to the recipient of the
+   conference document about the number of users that can be invited to
+   the conference.  Typically, this value represents the overall number
+   of users allowed to join the conference by different means as
+   published through the conference document in <conf-uris>.  Note that
+   this value is set by an administrator and can reflect any local
+   policies combination such as network consumption, CPU processing
+   power, and licensing rules.
 
-5.2.4  <available-media>
+5.3.4  <available-media>
 
    This element contains a sequence of <entry> child elements of
    conference-medium-type, each being indexed by the attribute 'label'.
 
    The 'label' attribute is the media stream identifier being assigned
    by the conferencing server such as its value is unique in the
-   <conference-info> context.  The value of this attribute MAY
-   correspond to the SDP "label" media attribute defined in [22].
+   <conference-info> context.  If a corresponding media stream between a
+   participant and a focus is established using the Session Description
+   Protocol  (SDP) [3] and the SDP "label" media attribute defined in
+   [17], the value of the SDP "label" attribute MUST be equal to the
+   value of the 'label' attribute in <available-media>.
 
    Each <entry> describes a single media stream available to the
    participants in the conference and contains the following
    information:
 
    <display-text> This element contains the display text for the media
       stream.
 
    <type> This element contains the media type of the media stream.  The
       value of this element MUST be one of the values registered for
-      "media" of SDP [3] and its later revision(s).
+      "media" of SDP [3] and its later revision(s).  For example:
+      "audio", "video", "text", and "message".
 
-   <status> This element indicates the status in both directions of the
-      media stream and has the values "sendrecv", "sendonly",
+   <status> This element indicates the available status of the media
+      stream available to the conference participants.  For example,
+      this would be the status of the media stream, which would be
+      offered by the focus, in a 'dial-out' scenario.  Using normal SIP
+      offer answer mechanisms (being defined in RFC 3264 [9])in both
+      dial-in and dial-out scenarios, a participant can of course
+      establish only a subset of the available stream (i.e., request or
+      accept the stream in one direction only, if both directions are
+      available).  The valid values are "sendrecv", "sendonly",
       "recvonly", or "inactive" as defined in SDP [3] and its later
-      revision(s).  Note that value specifies the direction from the
-      participant's point of view.
+      revision(s).  (Note that the value specifies the direction from
+      the participants' point of view.)
 
-5.3  <host-info>
+5.4  <host-info>
 
    This element contains information about the entity hosting the
    conference.  This information is set before the conference
    activation, and is rarely changed during the conference lifetime,
    unless the whole conference is moved to be hosted by another entity.
    The host information is comprised of the following elements:
 
-5.3.1  <display-text>
+5.4.1  <display-text>
 
    This element contains display text describing the entity hosting the
    conference.
 
-5.3.2  <web-page>
+5.4.2  <web-page>
 
    This element contains a URI of a web page describing either the
    conference service or the user hosting the conference.
 
-5.3.3  <uris>
+5.4.3  <uris>
 
-   This element can contain additional (to the conference URI) URIs
-   pointing to the conference host.
+   This element can contain URIs pointing to the conference host, in
+   addition to the conference URI.
 
-5.4  <conference-state>
+5.5  <conference-state>
 
    By including this element in the conference document, the server can
    inform the subscribers about the changes in the overall conference
    information.  The <conference-state> child elements are described
    below.
 
-5.4.1  <user-count>
+5.5.1  <user-count>
 
-   This element contains the current number of users in the conference.
+   The value of this element tells the recipient of the conference
+   document the overall number of users participating in the conference
+   at a certain moment.  Typically this value represents the overall
+   number of users who joined the conference by different means as
+   published through the conference document in <conf-uris>.  Note that
+   this number does not necessarily need to match and MAY exceed the
+   number of the entries in the <users> container.  For example, in
+   lecturing scenario a large conference notifications may not include
+   every participant in the <users> element, but instead report only the
+   panelists or the speakers.
 
-5.4.2  <active>
+5.5.2  <active>
 
-   This Boolean element says whether the conference is currently active
-   or not.  A conference is active if dialing into one of the
-   <conf-uris> results in successful establishment of a call signaling
-   session between the dialed user and the conference focus.
+   This Boolean element indicates whether the conference is currently
+   active or not.  A conference is active if calling one of the <conf-
+   uris> by an authorized client results in successful establishment of
+   a signaling session between the client and the focus and a successful
+   joining of the conference.
 
-5.4.3  <locked>
+5.5.3  <locked>
 
    This Boolean element says whether the conference is currently locked
    or not.  In this context, "locked" means that the conference roster
    can not be added to (although participants may leave or be removed
    from the conference).
 
-5.5  <users> of <user>
+5.6  <users> and its <user> sub-elements
 
    The <users> element is a container of <user> child elements, each
    describing a single participant in the conference.
 
    The following attributes are defined for <user> element:
 
    entity: This attribute contains the URI for the user in the
       conference.  This is a logical identifier, which corresponds to
       the call signaling authenticated identity of the participant.  The
       'entity' value MUST be unique among all participants in the
       conference.  If for some participants, the focus decides to not
-      revealing this information (due to local policies or security
+      reveal this information (due to local policies or security
       reasons, for example), the host portion of the user URI MUST use
       the .invalid top level domain (TLD) according to definitions of
       RFC 2606 [5].  The focus also MUST construct the user portion of
-      the URI such as the URI is unique among all participants of the
-      same domain.  For example,
+      the URI so that the URI is unique among all participants of the
+      same domain.  For example, the convention
 
-          "Anonymous1" <sip:anonymous1@anonymous.invalid>
+          "AnonymousX" <sip:anonymousX@anonymous.invalid>
 
-       could be used for a participant requesting privacy in accordance
+      SHOULD be used for a participant requesting privacy in accordance
       with the guidelines for generating anonymous URIs of RFC 3323
-      [15].
+      [11].  Note that in a different case, such as when used in
+      conjunction with Enhancements for Authenticated Identity
+      Management in SIP [25], the following convention can be used:
+
+          "AnonymousX" <sip:anonymousX@example.com>
 
    state: This attribute indicates whether the document contains the
       whole user information ("full"), only the information that has
       changed since the previous document ("partial"), or the user was
       removed from the conference ("deleted").
 
    The following child elements are defined for <user> element:
 
-5.5.1  <display-text>
+5.6.1  <display-text>
 
    This element is used to display the user friendly name in the
    conference.
 
-5.5.2  <associated-aors>
+5.6.2  <associated-aors>
 
-   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.
+   This element contains additional (to the 'entity') URIs being
+   associated with the <user>.  Typically, this information will be
+   manually provided by an administrator showing the logical association
+   between signaling entities otherwise independent.  For example, if
+   the 'entity' of a <user> contains a GRUU Globally Routable User URI
+   [24] or tel: URI RFC 3966 [19], it would be useful to populate this
+   field with the AOR of the person, who uses these devices, each
+   represented as an independent <user>.
 
-5.5.3  <roles>
+5.6.3  <roles>
 
-   This element is used to display the roles of the user in the
-   conference.
+   This element can contain a set of human readable strings describing
+   the roles of the user in the conference.  Note that this information
+   is applicable for human consumption only.  This specification doesn't
+   define the set of possible conferencing roles nor the semantics
+   associated with each.  It is expected that future conferencing
+   specifications will define these and the corresponding schema
+   extensions, as appropriate.
 
-5.5.4  <language>
+5.6.4  <languages>
 
-   This element contains the language preference of the user.  This
-   information can be automatically learned via call signaling or be
-   manually set per participant.
+   This element contains a list of tokens, separated by spaces, each
+   containing a language understood by the user.  This information can
+   be automatically learned via call signaling or be manually set per
+   participant.
 
-5.5.5  <cascaded-focus>
+5.6.5  <cascaded-focus>
 
    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 [19], this package allows for representation
+   conferencing framework [16], 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 [20] of each
+   subscribing to both this package and the Dialog Package [23] of each
    cascaded focus and correlating the relevant information.
 
-5.5.6  <endpoint>
+5.6.6  <endpoint>
 
    By including one or more <endpoint> elements under a parent <user>
-   element, the server can provide the desired level of details
+   element, the server can provide the desired level of detail
    (including the state, media streams, and access information) about
    the user's devices and signaling sessions taking part in the
    conference.
 
    In a conferencing system where authentication is performed per
    endpoint (rather than per user), the focus can be unaware of the
    logical association of multiple endpoints under a common user.  In
    this case, each endpoint will appear as a separate <user> with its
    own <endpoint> sub-element(s) in the conference document.
 
    In a different case, the focus may choose to shield the information
    about the participant's multiple endpoints and signaling sessions
    from other subscribers altogether (due to privacy policies, for
    example).  To do so, the focus MAY aggregate the multiple signaling
    sessions' information under a single <endpoint> element.  Note that
    in this case, the detailed call signaling information (represented by
    <call-info> sub-element) will not be included.
 
-5.6  <endpoint>
+5.7  <endpoint>
 
    This section describes the <endpoint> element in more detail.
 
    The following attributes are defined for <endpoint> element:
 
    entity: The server MUST generate the 'entity' key for each <endpoint>
       element included under the parent <user>, such as its value is
       unique in the user context.  In SIP terms, this can be the Contact
       URI, GRUU, etc.
 
    state: This 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 removed from the conference ("deleted").
 
    The following child elements are defined for <endpoint> element:
 
-5.6.1  <display-text>
+5.7.1  <display-text>
 
    This element contains the display text for the endpoint.
 
-5.6.2  <referred>
+5.7.2  <referred>
 
    This element contains information about the user who's action
-   resulted in this endpoint being brought into the conference (e.g.
-   the SIP user identified by this URI sent a REFER to the focus).  It
-   can contain the following sub-elements:
+   resulted in this endpoint being brought into the conference (e.g. the
+   SIP user identified by this URI sent a REFER to the focus).  It can
+   contain the following sub-elements:
 
-   when: This element contains the date and time that the endpoint was
-      referred to the conference and SHOULD be expressed in Coordinated
-      Universal Time (UTC) format.
+   when: This element of the XML dateTime type contains the date and
+      time that the endpoint was referred to the conference and SHOULD
+      be expressed in Coordinated Universal Time (UTC) format.  For
+      example,
+
+        <when>2005-03-04T20:00:00Z</when>
 
    reason: This element contains the reason the endpoint was referred to
-      the conference.
+      the conference.  It is RECOMMENDED to include the information in
+      the format defined by RFC 3326 [12].  For example,
 
+   <reason>Reason: SIP;text="Ad-hoc Invitation"</reason>
    by: This element contains the URI of the entity who caused the
-      endpoint to be referred to the conference.
+      endpoint to be referred to the conference.  In SIP case, it will
+      be populated from the Referred-By header defined in RFC 3892 [15].
 
-5.6.3  <status>
+5.7.3  <status>
 
    This element contains the status 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 signaling 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.
+      focus, but endpoint is "on-hold" for this conference, i.e. he/she
+      is neither "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 signaling 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 most active media.
 
@@ -833,388 +955,492 @@
       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 the endpoint
       (e.g., in SIP a DISCONNECT or BYE was sent to the endpoint).
 
    Note that the defined transient statuses (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.
+   alerting, etc.) could generate a lot of traffic.  Therefore
+   implementations MAY choose to generate notifications on these
+   statuses to certain participants only or not generate them at all,
+   subject to local policy.
 
-5.6.4  <joining-method>
+5.7.4  <joining-method>
 
    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 (e.g., in SIP sent
       INVITE to the focus), which resulted in successful dialog
       establishment.
 
-   dialed-out: The focus has brought the endpoint into the conference
-      (e.g., in SIP by sending a successful INVITE to the endpoint).
+   dialed-out: The focus has brought the endpoint into the
+      conference(e.g., in SIP the focus sent a successful INVITE to the
+      endpoint).
 
    focus-owner: The endpoint is the focus for this conference.  This
       status is used only when a participant's UA acts as a conference
       focus.
 
-5.6.5  <joining-info>
+5.7.5  <joining-info>
 
    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 and SHOULD be expressed in Coordinated
-      Universal Time (UTC).
+   when: This element of the XML dateTime type contains the date and
+      time that the endpoint joined the conference and SHOULD be
+      expressed in Coordinated Universal Time (UTC).
 
    reason: This element contains the reason the endpoint joined the
-      conference.
+      conference.  It is RECOMMENDED to include the information in the
+      format defined by RFC 3326 [12].  For example,
+
+   <reason>Reason: SIP;text="Ad-hoc Invitation"</reason>
 
    by: This element contains the URI of the entity who caused the
       endpoint to join the conference.
 
-5.6.6  <disconnection-method>
+5.7.6  <disconnection-method>
 
-   This element contains method by which the endpoint departed the
+   This element contains the method by which the endpoint departed the
    conference, and can assume the following values:
 
    departed: In SIP, the endpoint sent a BYE, thus leaving the
       conference.
 
-   booted: In SIP, the endpoint was sent a BYE by the focus, booting
+   booted: In SIP, the endpoint was sent a BYE by the focus, ejecting
       him/her out of the conference.  Alternatively, the endpoint tried
       to dial into to conference but was rejected by the focus due to
       local policy.
 
    failed: In SIP, 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.
 
-5.6.7  <disconnection-info>
+   busy: In SIP, the server tried to bring the endpoint into the
+      conference, but its attempt to contact the specific endpoint
+      resulted in 486 "Busy Here" final response.  Alternatively, the
+      endpoint tried to dial into the conference but the focus responded
+      with 486 response.
+
+5.7.7  <disconnection-info>
 
    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 and SHOULD be expressed in Coordinated
-      Universal Time (UTC).
+   when: This element of the XML dateTime type contains the date and
+      time that the endpoint departed the conference and SHOULD be
+      expressed in Coordinated Universal Time (UTC).
 
    reason: This element contains the reason the endpoint departed the
       conference.  When known and meaningful, it is RECOMMENDED to
       include the information as conveyed/reported by the call signaling
-      in the format defined by RFC 3326 [10].  For example,
+      in the format defined by RFC 3326 [12].  For example,
 
    <reason>Reason: SIP ;cause=415 ;text="Unsupported Media Type"</reason>
 
    by: This element contains the URI of the entity who caused the
       endpoint to depart the conference.
 
-5.6.8  <media>
+5.7.8  <media>
 
    This element contains information about a single media stream and is
    included for each media stream being established between the focus
-   and the <endpoint>.
+   and the <endpoint>.  The media stream definition can be found in SDP
+   [3].
 
    Note that if the <call-info> sub-element of the endpoint is not
    included in the document by the server, it is possible that the media
    streams listed under the common <endpoint> were established by
    separate signaling sessions.
 
-5.6.9  <call-info>
+5.7.9  <call-info>
 
    The <call-info> element provides detailed call signaling information
    for a call being maintained between the participant and the focus.
    Privacy policies MUST be consulted before revealing this information
    to other participants.
 
    The <sip> sub-element contains the SIP dialog identifier of the
    endpoint's dialog with the focus.  The element includes sub-elements
    <display-text>, <call-id>, <to-tag>, <from-tag>.
 
    In future, the <call-info> element can be expanded to include call
    signaling protocol information for other protocols besides SIP.
 
-5.7  <media>
+5.8  <media>
 
    This section describes the <media> element in more detail.
 
    A single 'id' attribute is defined for this element.  This is the
    media stream identifier being generated by the server such as its
    value is unique in the endpoint context.  This attribute is the key
    to refer to a particular media stream in the conference document.
 
    The following child elements are defined for <media>:
 
-5.7.1  <display-text>
+5.8.1  <display-text>
 
-   This element contains the display text for the media stream.
+   This element contains the display text for the media stream.  The
+   value of this element corresponds to the SDP description media
+   attribute ("i") defined in SDP [3].
 
-5.7.2  <type>
+5.8.2  <type>
 
    This element contains the media type for the media stream.  The value
    of this element MUST be one of the values registered for "media" of
    SDP [3] and its later revision(s).
 
-5.7.3  <label>
+5.8.3  <label>
 
    The <label> element 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 SDP "label" media attribute
-   defined in [22].
+   defined in [17], which is exchanged between a participant and a focus
+   over the signaling connection between them.
 
-5.7.4  <src-id>
+   If the <available-media> information (described in Section 5.3.4) is
+   included in the conference document, the value of this element MUST
+   be equal to the 'label' value of the corresponding media stream
+   <entry> in the <available-media> container.
+
+5.8.4  <src-id>
 
    The <src-id> element, if applicable, carries the information about
-   the actual source of the media.  For example, for RTP/RTCP [11] media
-   streams, the value MUST contain the SSRC value generated by the
-   endpoint for the stream it sends.
+   the actual source of the media.  For example, for Real-Time Transport
+   Protocol (RTP) / Real-Time Control Protocol (RTCP) [13] media
+   streams, the value MUST contain the synchronization source (SSRC)
+   identifier value generated by the endpoint for the stream it sends.
+
+   When an RTP mixer generates a contributing source (CSRC) identifiers'
+   list according to RTP/RTCP [13], 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.  A quote from
+   RFC 3550: "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)."
 
-   When an RTP mixer generates a CSRC list according to RTP/RTCP [11],
-   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.  A quote from RFC 3550: "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)."
    If an RTP mixer compliant to the above is used, participants can
    perform an SSRC to user mapping and identify "a current speaker".
 
-5.7.5  <status>
+5.8.5  <status>
 
    The element <status> indicates the status in both directions of the
    media stream and has the values "sendrecv", "sendonly", "recvonly",
    or "inactive" as defined in SDP [3] and its later revision(s).  Note
    that value specifies the direction from the participant's point of
    view.  For example, a muted participant's stream will have the value
    of "recvonly".
 
-5.8  <sidebars-by-ref>
+5.9  Sidebars
+
+   If a participant in the main conference joins a sidebar, a new <user>
+   element representing the user is created either as a part of a
+   separate sub-conference referenced from the <sidebars-by-ref> element
+   or under one of the <sidebar-by-val> elements as described below.
+
+   Note that the <user> in the main roster is not being deleted, but its
+   media statuses can be updated to reflect the effect being caused by
+   his/her participation in the sidebar.  The display of this
+   information can vary among subscribers to the same conference
+   information, subject to local policies and to the subscriber role
+   both in the sidebar and in the main conference.
+
+5.9.1  <sidebars-by-ref>
 
    This element contains a set of <entry> child elements each containing
    a sidebar conference URI.  The recipient of the information can then
    subscribe to sidebar information independently from the main
    conference package subscription.
 
-5.9  <sidebar-by-val>
+5.9.2  <sidebar-by-val>
 
    This element contains a set of <entry> child elements each containing
    information about a single sidebar.  By using this element of
    conference-type, the server can include a full or a partial
    description of each sidebar (as a sub-conference) in the body of the
    main conference document.
 
 6.  XML 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: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 imports the xml:language definition
       -->
-        <xs:import namespace="http://www.w3.org/XML/1998/namespace" schemaLocation="http://www.w3.org/2001/03/xml.xsd" />
+      <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="users" type="users-type" minOccurs="0"/>
-      	   <xs:element name="sidebars-by-ref" type="uris-type" minOccurs="0"/>
-      	   <xs:element name="sidebars-by-val" type="sidebars-by-val-type" minOccurs="0"/>
-      	   <xs:any namespace="##other" processContents="lax" minOccurs="0" maxOccurs="unbounded"/>
+        <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="users"
+         type="users-type" minOccurs="0"/>
+        <xs:element name="sidebars-by-ref"
+         type="uris-type" minOccurs="0"/>
+        <xs:element name="sidebars-by-val"
+         type="sidebars-by-val-type" minOccurs="0"/>
+        <xs:any namespace="##other" processContents="lax"
+         minOccurs="0" maxOccurs="unbounded"/>
          </xs:sequence>
-         <xs:attribute name="entity" type="xs:anyURI" use="required"/>
-         <xs:attribute name="state" type="state-type" use="optional" default="full"/>
-         <xs:attribute name="version" type="xs:unsignedInt" use="optional"/>
+       <xs:attribute name="entity"
+        type="xs:anyURI" use="required"/>
+       <xs:attribute name="state"
+        type="state-type" use="optional" default="full"/>
+       <xs:attribute name="version"
+        type="xs:unsignedInt" use="optional"/>
          <xs:anyAttribute namespace="##other"/>
       </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>
-      	   <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="conf-uris" type="uris-type" minOccurs="0"/>
-      	   <xs:element name="service-uris" type="uris-type" minOccurs="0"/>
-      	   <xs:element name="maximum-user-count" type="xs:unsignedInt" minOccurs="0"/>
-      	   <xs:element name="available-media" type="conference-media-type" minOccurs="0"/>
-    	   <xs:any namespace="##other" processContents="lax" minOccurs="0" maxOccurs="unbounded"/>
+        <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="conf-uris"
+         type="uris-type" minOccurs="0"/>
+        <xs:element name="service-uris"
+         type="uris-type" minOccurs="0"/>
+        <xs:element name="maximum-user-count"
+         type="xs:unsignedInt" minOccurs="0"/>
+        <xs:element name="available-media"
+         type="conference-media-type" minOccurs="0"/>
+        <xs:any namespace="##other" processContents="lax"
+         minOccurs="0" maxOccurs="unbounded"/>
          </xs:sequence>
          <xs:anyAttribute namespace="##other"/>
       </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:any namespace="##other" processContents="lax" minOccurs="0" maxOccurs="unbounded"/>
+        <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:any namespace="##other" processContents="lax"
+
+         minOccurs="0" maxOccurs="unbounded"/>
          </xs:sequence>
          <xs:anyAttribute namespace="##other"/>
       </xs:complexType>
       <!--
          CONFERENCE STATE TYPE
       -->
       <xs:complexType name="conference-state-type">
          <xs:sequence>
-               <xs:element name="user-count" type="xs:unsignedInt" minOccurs="0"/>
-      	   <xs:element name="active" type="xs:boolean" minOccurs="0"/>
-      	   <xs:element name="locked" type="xs:boolean" minOccurs="0"/>
-      	   <xs:any namespace="##other" processContents="lax" minOccurs="0" maxOccurs="unbounded"/>
+        <xs:element name="user-count" type="xs:unsignedInt"
+         minOccurs="0"/>
+        <xs:element name="active" type="xs:boolean"
+         minOccurs="0"/>
+        <xs:element name="locked" type="xs:boolean"
+         minOccurs="0"/>
+        <xs:any namespace="##other" processContents="lax"
+         minOccurs="0" maxOccurs="unbounded"/>
          </xs:sequence>
          <xs:anyAttribute namespace="##other"/>
       </xs:complexType>
       <!--
          CONFERENCE MEDIA TYPE
       -->
       <xs:complexType name="conference-media-type">
          <xs:sequence>
-      	   <xs:element name="entry" type="conference-medium-type" maxOccurs="unbounded"/>
+        <xs:element name="entry" type="conference-medium-type"
+         maxOccurs="unbounded"/>
          </xs:sequence>
       <xs:anyAttribute namespace="##other"/>
       </xs:complexType>
       <!--
          CONFERENCE MEDIUM TYPE
       -->
       <xs:complexType name="conference-medium-type">
          <xs:sequence>
-       	   <xs:element name="display-text" type="xs:string"/>
-      	   <xs:element name="type" type="xs:string" minOccurs="0"/>
-      	   <xs:element name="status" type="media-status-type" minOccurs="0"/>
-      	   <xs:any namespace="##other" processContents="lax" minOccurs="0" maxOccurs="unbounded"/>
+        <xs:element name="display-text" type="xs:string"
+         minOccurs="0"/>
+        <xs:element name="type" type="xs:string"/>
+        <xs:element name="status" type="media-status-type"
+         minOccurs="0"/>
+        <xs:any namespace="##other" processContents="lax"
+         minOccurs="0" maxOccurs="unbounded"/>
          </xs:sequence>
-         <xs:attribute name="label" type="xs:string" use="required"/>
+       <xs:attribute name="label" type="xs:string"
+        use="required"/>
          <xs:anyAttribute namespace="##other"/>
       </xs:complexType>
-
       <!--
          URIs TYPE
       -->
       <xs:complexType name="uris-type">
          <xs:sequence>
-      	   <xs:element name="entry" type="uri-type" maxOccurs="unbounded"/>
+        <xs:element name="entry" type="uri-type"
+         maxOccurs="unbounded"/>
          </xs:sequence>
-         <xs:attribute name="state" type="state-type" use="optional" default="full"/>
+       <xs:attribute name="state" type="state-type"
+        use="optional" default="full"/>
          <xs:anyAttribute namespace="##other"/>
       </xs:complexType>
-
       <!--
          URI TYPE
       -->
       <xs:complexType name="uri-type">
          <xs:sequence>
       	   <xs:element name="uri" type="xs:anyURI"/>
-      	   <xs:element name="display-text" type="xs:string" minOccurs="0"/>
-      	   <xs:element name="purpose" type="xs:string" minOccurs="0"/>
-      	   <xs:element name="modified" type="execution-type" minOccurs="0"/>
-      	   <xs:any namespace="##other" processContents="lax" minOccurs="0" maxOccurs="unbounded"/>
+        <xs:element name="display-text" type="xs:string"
+         minOccurs="0"/>
+        <xs:element name="purpose" type="xs:string"
+         minOccurs="0"/>
+        <xs:element name="modified" type="execution-type"
+         minOccurs="0"/>
+        <xs:any namespace="##other" processContents="lax"
+         minOccurs="0" maxOccurs="unbounded"/>
          </xs:sequence>
-
          <xs:anyAttribute namespace="##other"/>
       </xs:complexType>
-
       <!--
          KEWORDS TYPE
       -->
       <xs:simpleType name="keywords-type">
              <xs:list itemType="xs:string"/>
       </xs:simpleType>
-
       <!--
          USERS TYPE
       -->
       <xs:complexType name="users-type">
          <xs:sequence>
-             <xs:element name="user" type="user-type" minOccurs="0" maxOccurs="unbounded"/>
-      	   <xs:any namespace="##other" processContents="lax" minOccurs="0" maxOccurs="unbounded"/>
-
+        <xs:element name="user" type="user-type"
+         minOccurs="0" maxOccurs="unbounded"/>
+        <xs:any namespace="##other" processContents="lax"
+         minOccurs="0" maxOccurs="unbounded"/>
          </xs:sequence>
-         <xs:attribute name="state" type="state-type" use="optional" default="full"/>
+       <xs:attribute name="state" type="state-type"
+        use="optional" default="full"/>
          <xs:anyAttribute namespace="##other"/>
       </xs:complexType>
       <!--
          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:any namespace="##other" processContents="lax" minOccurs="0" maxOccurs="unbounded"/>
+        <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="languages" type="user-languages-type"
+         minOccurs="0"/>
+        <xs:element name="cascaded-focus" type="xs:anyURI"
+         minOccurs="0"/>
+        <xs:element name="endpoint" type="endpoint-type"
+         minOccurs="0" maxOccurs="unbounded"/>
+        <xs:any namespace="##other" processContents="lax"
+         minOccurs="0" maxOccurs="unbounded"/>
          </xs:sequence>
          <xs:attribute name="entity" type="xs:anyURI"/>
-         <xs:attribute name="state" type="state-type" use="optional" default="full"/>
+       <xs:attribute name="state" type="state-type"
+        use="optional" default="full"/>
          <xs:anyAttribute namespace="##other"/>
       </xs:complexType>
-
       <!--
          USER ROLES TYPE
       -->
       <xs:complexType name="user-roles-type">
          <xs:sequence>
-      	   <xs:element name="entry" type="xs:string" maxOccurs="unbounded"/>
+        <xs:element name="entry" type="xs:string"
+         maxOccurs="unbounded"/>
          </xs:sequence>
          <xs:anyAttribute namespace="##other"/>
       </xs:complexType>
-
+      <!--
+         USER LANGUAGES TYPE
+      -->
+      <xs:simpleType name="user-languages-type">
+       <xs:list itemType="xs:language"/>
+      </xs:simpleType>
       <!--
          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="status" type="endpoint-status-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="call-info" type="call-type" minOccurs="0"/>
-      	   <xs:any namespace="##other" processContents="lax" minOccurs="0" maxOccurs="unbounded"/>
+        <xs:element name="display-text" type="xs:string"
+         minOccurs="0"/>
+        <xs:element name="referred" type="execution-type"
+         minOccurs="0"/>
+        <xs:element name="status" type="endpoint-status-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="call-info" type="call-type"
+         minOccurs="0"/>
+        <xs:any namespace="##other" processContents="lax"
+         minOccurs="0" maxOccurs="unbounded"/>
          </xs:sequence>
          <xs:attribute name="entity" type="xs:string"/>
-         <xs:attribute name="state" type="state-type" use="optional" default="full"/>
+       <xs:attribute name="state" type="state-type"
+        use="optional" default="full"/>
          <xs:anyAttribute namespace="##other"/>
       </xs:complexType>
-
       <!--
          ENDPOINT STATUS TYPE
       -->
       <xs:simpleType name="endpoint-status-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"/>
@@ -1235,77 +1462,85 @@
       	</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:enumeration value="busy"/>
       	</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: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 namespace="##other"/>
       </xs:complexType>
-
      <!--
          CALL TYPE
       -->
       <xs:complexType name="call-type">
          <xs:choice>
       	   <xs:element name="sip" type="sip-dialog-id-type"/>
-      	   <xs:any namespace="##other" processContents="lax" minOccurs="0" maxOccurs="unbounded"/>
+        <xs:any namespace="##other" processContents="lax"
+         minOccurs="0" maxOccurs="unbounded"/>
          </xs:choice>
          <xs:anyAttribute namespace="##other"/>
       </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="display-text" type="xs:string"
+         minOccurs="0"/>
       	   <xs:element name="call-id" type="xs:string"/>
       	   <xs:element name="from-tag" type="xs:string"/>
       	   <xs:element name="to-tag" type="xs:string"/>
-      	   <xs:any namespace="##other" processContents="lax" minOccurs="0" maxOccurs="unbounded"/>
+        <xs:any namespace="##other" processContents="lax"
+         minOccurs="0" maxOccurs="unbounded"/>
          </xs:sequence>
          <xs:anyAttribute namespace="##other"/>
       </xs:complexType>
-
       <!--
          MEDIA TYPE
       -->
       <xs:complexType name="media-type">
          <xs:sequence>
-   	   <xs:element name="display-text" type="xs:string" minOccurs="0"/>
-      	   <xs:element name="type" type="xs:string" minOccurs="0"/>
-      	   <xs:element name="label" type="xs:string" minOccurs="0"/>
-     	         <xs:element name="src-id" type="xs:string" minOccurs="0"/>
-      	   <xs:element name="status" type="media-status-type" minOccurs="0"/>
-      	   <xs:any namespace="##other" processContents="lax" minOccurs="0" maxOccurs="unbounded"/>
+        <xs:element name="display-text" type="xs:string"
+         minOccurs="0"/>
+        <xs:element name="type" type="xs:string"
+         minOccurs="0"/>
+        <xs:element name="label" type="xs:string"
+         minOccurs="0"/>
+        <xs:element name="src-id" type="xs:string"
+         minOccurs="0"/>
+        <xs:element name="status" type="media-status-type"
+         minOccurs="0"/>
+        <xs:any namespace="##other" processContents="lax"
+         minOccurs="0" maxOccurs="unbounded"/>
          </xs:sequence>
-         <xs:attribute name="id" type="xs:string" use="required"/>
+       <xs:attribute name="id" type="xs:string"
+        use="required"/>
          <xs:anyAttribute namespace="##other"/>
       </xs:complexType>
-
       <!--
          MEDIA STATUS TYPE
       -->
       <xs:simpleType name="media-status-type">
       	<xs:restriction base="xs:string">
       		<xs:enumeration value="recvonly"/>
       		<xs:enumeration value="sendonly"/>
       		<xs:enumeration value="sendrecv"/>
       		<xs:enumeration value="inactive"/>
       	</xs:restriction>
@@ -1303,40 +1538,44 @@
          MEDIA STATUS TYPE
       -->
       <xs:simpleType name="media-status-type">
       	<xs:restriction base="xs:string">
       		<xs:enumeration value="recvonly"/>
       		<xs:enumeration value="sendonly"/>
       		<xs:enumeration value="sendrecv"/>
       		<xs:enumeration value="inactive"/>
       	</xs:restriction>
       </xs:simpleType>
-
        <!--
          SIDEBARS BY VAL TYPE
        -->
       <xs:complexType name="sidebars-by-val-type">
          <xs:sequence>
-      	   <xs:element name="entry" type="conference-type" minOccurs="0" maxOccurs="unbounded"/>
+         <xs:element name="entry" type="conference-type"
+          minOccurs="0" maxOccurs="unbounded"/>
          </xs:sequence>
-         <xs:attribute name="state" type="state-type" use="optional" default="full"/>
+        <xs:attribute name="state" type="state-type"
+         use="optional" default="full"/>
          <xs:anyAttribute namespace="##other"/>
       </xs:complexType>
+
       </xs:schema>
 
 7.  Examples
 
 7.1  Basic Example
 
-   The following is an example conference information document:
+   The following is an example of a full conference information
+   document:
 
-   <conference-info entity="sips:conf233@example.com" state="partial" version="5" >
+   <conference-info entity="sips:conf233@example.com"
+    state="full" version="1">
    <!--
       CONFERENCE INFO
    -->
       <conference-description>
    	<subject>Agenda: This month's goals</subject>
    	<service-uris>
    		<entry>
    			<uri> http://sharepoint/salesgroup/</uri>
    			<purpose>web-page</purpose>
    		</entry>
@@ -1335,33 +1574,30 @@
    -->
       <conference-description>
    	<subject>Agenda: This month's goals</subject>
    	<service-uris>
    		<entry>
    			<uri> http://sharepoint/salesgroup/</uri>
    			<purpose>web-page</purpose>
    		</entry>
    	</service-uris>
       </conference-description>
-
    <!--
       CONFERENCE STATE
    -->
       <conference-state>
    	<user-count>33</user-count>
       </conference-state>
-
-      <users>
       <!--
-
-          USER
+     USERS
       -->
+    <users>
    	<user entity="sip:bob@example.com" state="full">
    		<display-text>Bob Hoskins</display-text>
    		<!--
    	  		ENDPOINTS
    		-->
    		<endpoint entity="sip:bob@pc33.example.com">
    			<display-text>Bob's Laptop</display-text>
    			<status>disconnected</status>
    			<disconnection-method>departed</disconnection-method>
    			<disconnection-info>
@@ -1370,37 +1606,33 @@
    				<by>sip:mike@example.com</by>
    			</disconnection-info>
    			<!--
    	  			MEDIA
    			-->
    			<media id="1">
    				<display-text>main audio</display-text>
    				<type>audio</type>
    				<label>34567</label>
    				<src-id>432424</src-id>
-
    				<status>sendrecv</status>
    			</media>
    		</endpoint>
    	</user>
-
       <!--
-
    	USER
       -->
-          <user entity="sip:alice@example.net" state="full">
+     <user entity="sip:alice@example.com" state="full">
           		<display-text>Alice</display-text>
           		<!--
    			ENDPOINTS
    		-->
-   	 	<endpoint entity="sip:4kfk4j392jsu@example.net;grid=433kj4j3u" call="1">
-
+      <endpoint entity="sip:4kfk4j392jsu@example.com;grid=433kj4j3u">
    	 		<status>connected</status>
    	 		<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 id="1">
@@ -1404,74 +1636,68 @@
    	  			MEDIA
     			-->
     			<media id="1">
    				<display-text>main audio</display-text>
    				<type>audio</type>
      				<label>34567</label>
     				<src-id>534232</src-id>
     				<status>sendrecv</status>
     			</media>
           		</endpoint>
-
           </user>
       </users>
-
    </conference-info>
 
 7.2  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 URIs and
+   The following is an example of a partial conference information
+   document.  In this example, there are 32 participants in a voice
+   conference.  The user Bob has been ejected 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 URIs 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 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 goals</subject>
    		<free-text>We will start strict on time</free-text>
-
-   		<keywords>sales, meeting, weekly</keywords>
+     <keywords>sales meeting weekly</keywords>
    		<conf-uris>
    			<entry>
    				<uri>tel:+18005671234</uri>
    				<display-text>TTI Bridge</display-text>
    				<purpose>participation</purpose>
-
    			</entry>
-
    			<entry>
    				<uri>h323:conf545@h323.example.com</uri>
    				<purpose>participation</purpose>
    			</entry>
    			<entry>
       	<uri>http://real.streaming.com/54634/live.ram</uri>
    				<purpose>streaming</purpose>
    			</entry>
-
    		</conf-uris>
    		<service-uris>
    			<entry>
    				<uri>http://sharepoint/salesgroup/</uri>
    				<purpose>web-page</purpose>
    			</entry>
    			<entry>
    	<uri>http://quicktime.com/54634/recording.mov</uri>
    				<display-text>Quicktime</display-text>
-
    				<purpose>recording</purpose>
    			</entry>
    		</service-uris>
    		<maximum-user-count>100</maximum-user-count>
    		<available-media>
    			<entry label="34567">
    				<display-text>main audio</display-text>
    				<type>audio</type>
    				<status>sendrecv</status>
    			</entry>
@@ -1513,22 +1736,21 @@
    			<display-text>Bob Hoskins</display-text>
    			<associated-aors>
    				<entry>
    					<uri>mailto:bob@example.com</uri>
    					<display-text>email</display-text>
    				</entry>
    			</associated-aors>
    			<roles>
    				<entry>participant</entry>
    			</roles>
-   			<language>en</language>
-
+      <languages>en</languages>
    		<!--
    	  	ENDPOINTS
    		-->
    			<endpoint entity="sip:bob@pc33.example.com">
    				<display-text>Bob's Laptop</display-text>
    				<referred>
    					<when>2005-03-04T20:00:00Z</when>
    					<reason>expert required</reason>
    					<by>sip:mike@example.com</by>
    				</referred>
@@ -1528,57 +1750,55 @@
    			<endpoint entity="sip:bob@pc33.example.com">
    				<display-text>Bob's Laptop</display-text>
    				<referred>
    					<when>2005-03-04T20:00:00Z</when>
    					<reason>expert required</reason>
    					<by>sip:mike@example.com</by>
    				</referred>
    				<status>disconnecting</status>
    				<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 id="1">
+        <display-text>main audio</display-text>
+        <type>audio</type>
+        <label>34567</label>
+        <src-id>432424</src-id>
+        <status>sendrecv</status>
+       </media>
+   <!--
    	  		CALL INFO
    			-->
    				<call-info>
    					<sip>
    					   <display-text>full info</display-text>
    					   <call-id>hsjh8980vhsb78</call-id>
    					   <from-tag>vav738dvbs</from-tag>
    					   <to-tag>8954jgjg8432</to-tag>
    					</sip>
    				</call-info>
-   			<!--
-   	  		MEDIA
-   			-->
-   				<media id="1">
-   					<display-text>main audio</display-text>
-   					<type>audio</type>
-   					<label>34567</label>
-   					<src-id>432424</src-id>
-   					<status>sendrecv</status>
-   				</media>
    			</endpoint>
    		</user>
    	</users>
-
    	<!--
    	SIDEBARS BY REFERENCE
    	-->
    	<sidebars-by-ref state="partial">
    		<entry>
    			<uri>sips:conf233@example.com; grid=45</uri>
    			<display-text>sidebar with Carol</display-text>
    		</entry>
    		<entry>
    			<uri>sips:conf233@example.com; grid=21</uri>
@@ -1575,113 +1795,144 @@
    	<!--
    	SIDEBARS BY REFERENCE
    	-->
    	<sidebars-by-ref state="partial">
    		<entry>
    			<uri>sips:conf233@example.com; grid=45</uri>
    			<display-text>sidebar with Carol</display-text>
    		</entry>
    		<entry>
    			<uri>sips:conf233@example.com; grid=21</uri>
-   			<display-text>private sidebar with Peter</display-text>
+      <display-text>private with Peter</display-text>
    		</entry>
    	</sidebars-by-ref>
-
    	<!--
    	SIDEBARS BY VALUE
    	-->
    	<sidebars-by-val state="partial">
-   		<entry entity="sips:conf233@example.com; grid=77" state="partial">
-
+     <entry entity="sips:conf233@example.com;grid=77"
+      state="partial">
    			<users>
-   				<user entity="sip:bob@example.com"></user>
-   				<user entity="sip:mark@example.com"></user>
-   				<user entity="sip:dan@example.com"></user>
+       <user entity="sip:bob@example.com"/>
+       <user entity="sip:mark@example.com"/>
+       <user entity="sip:dan@example.com"/>
    			</users>
    		</entry>
    	</sidebars-by-val>
-
    </conference-info>
 
 8.  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.
+   Subscriptions to conference state information can reveal very
+   sensitive information.  For this reason, it is RECOMMENDED a focus
+   use a strong means for authentication, conference information
+   protection, and apply comprehensive authorization rules when using
+   the conference notification mechanism defined in this document.  The
+   following sections will discuss each of these aspects in more detail.
 
-   Since the data in notifications is sensitive as well, end-to-end SIP
-   encryption mechanisms using S/MIME SHOULD be used to protect it.
+8.1  Connection Security
+
+   It is RECOMMENDED that a focus authenticate a conference package
+   subscriber using the normal SIP authentication mechanisms, such as
+   Digest as defined in Section 22 of RFC 3261 [8].
+
+   The mechanism used for conveying the conference information MUST
+   ensure integrity and SHOULD ensure confidentially of the information.
+   In order to achieve these, an end-to-end SIP encryption mechanism,
+   such as S/MIME described in Section 26.2.4 of RFC 3261 [8], SHOULD be
+   used.
+
+   If strong end-to-end security means (such as above) is not available,
+   it is RECOMMENDED that a focus use mutual hop-by-hop TLS
+   authentication and encryption mechanisms described in Section 26.2.2
+   "SIPS URI Scheme" and Section 26.3.2.2 "Interdomain Requests" of RFC
+   3261 [8].
+
+8.2  Authorization Considerations
+
+   Generally speaking, conference applications are very concerned about
+   authorization decisions.  Mechanisms for establishing and enforcing
+   such authorization rules are a central concept throughout the SIP
+   conferencing framework [16].  Because most of the information about a
+   conference can be presented using the conference package, many of the
+   authorization rules directly apply to this specification.  As a
+   result, a notification server MUST be capable of generating distinct
+   conference information views to different subscribers, subject to a
+   subscriber's role in a conference, personal access rights, etc. - all
+   subject to local authorization policies and rules.
 
    Since a focus provides participant 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 [15].  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 Section 5.5
-   of this document MUST be followed.
+   described in RFC 3323 [11].  For a participant requesting privacy, no
+   identity information SHOULD be revealed by the focus in any included
+   URI (e.g. the Address of Record, Contact, or GRUU).  For these cases,
+   the anonymous URI generation method outlined in Section 5.6 of this
+   document MUST be followed.
 
 9.  IANA Considerations
 
    This document registers a SIP event package, a new MIME type,
    application/conference-info+xml, a new XML namespace, a new XML
    schema, and creates a  sub-registry "URI purposes" under the
    existing registry: http://www.iana.org/assignments/sip-parameters.
 
 9.1  conference Event Package Registration
 
    This specification registers an event package, based on the
-   registration procedures defined in RFC 3265 [9].  The following is
+   registration procedures defined in RFC 3265 [10].  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.
+   Published Document: RFC XXXX (Note to RFC Editor: Please, fill in
+      XXXX with the RFC number of this specification).
+   Person to Contact: IETF SIPPING Working Group <sipping@ietf.org>, as
+      designated by the IESG <iesg@ietf.org>
 
 9.2  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 [7]
    Encoding considerations: Same as encoding considerations of
       application/xml as specified in RFC 3023 [7]
    Security considerations: See Section 10 of RFC 3023 [7] and Section 8
       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
+      File Extension: .xml
       Macintosh file type code: "TEXT"
-   Personal and email address for further information: Jonathan
-      Rosenberg, <jdrosen@jdrosen.net>
+   Personal and email address for further information: IETF SIPPING
+      Working Group <sipping@ietf.org>, as designated by the IESG
+      <iesg@ietf.org>
    Intended usage: COMMON
-   Author/Change controller: The IETF
+   Author/Change controller: IETF SIPPING Working Group
+      <sipping@ietf.org>, as designated by the IESG <iesg@ietf.org>
 
 9.3  URN Sub-Namespace Registration for
     urn:ietf:params:xml:ns:conference-info
 
    This section registers a new XML namespace, as per the guidelines in
-   RFC 3688 [13].
+   RFC 3688 [21].
 
    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>
+   Registrant Contact: IETF SIPPING Working Group <sipping@ietf.org>, as
+      designated by the IESG <iesg@ietf.org>
    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"/>
@@ -1692,37 +1943,37 @@
      <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
 
 9.4  XML Schema Registration
 
    This specification registers a schema, as per the guidelines in RFC
-   3688 [13].
+   3688 [21].
       URI: please assign
-      Registrant Contact: IETF, SIPPING Working Group
-      (sipping@ietf.org), Jonathan Rosenberg (jdrosen@jdrosen.net)
+      Registrant Contact: IETF SIPPING Working Group <sipping@ietf.org>,
+      as designated by the IESG <iesg@ietf.org>
       XML: The XML can be found as the sole content of Section 6
 
 9.5  URI Purposes Sub-registry Establishment
 
    This document instructs the IANA to create a new sub-registry "URI
    purposes" under the already existing registry:
    http://www.iana.org/assignments/sip-parameters.
 
    The purpose of a URI is an XML element, encoded in the conference
    event package [RFC XXXX - substitute with the number assigned to this
    draft].  The value of the <purpose> element indicates the intended
    usage of the URI in the context of the conference event package and
-   is defined in sections Section 5.2.1 and Section 5.2.2 of this
+   is defined in sections Section 5.3.1 and Section 5.3.2 of this
    specification.
 
    This sub-registry is defined as a table that contains the following
    three columns:
 
    Value: The token under registration
    Description: A descriptive text defining the intended usage of the
       URI
    Document: A reference to the document defining the registration
 
@@ -1741,116 +1992,132 @@
    event         The URI can be used to subscribe    [RFC XXXX]
                  to the conference event package
 
    recording     The URI can be used to access the   [RFC XXXX]
                  recorded conference data
 
    web-page      The URI can be used to access a     [RFC XXXX]
                  web page that contains additional
                  information of the conference
 
-   New values of the "URI purposes" are registered by the IANA when a
-   specification becomes available and according to the definition of
+   New values of the "URI purposes" are registered by the IANA when
+   specification is approved, according to the IETF Consensus policy in
    RFC 2434 [4].  The IANA Considerations section of the specification
    MUST include the following information:
 
    Value: The value of the <purpose> element to be registered
+
    Description: A short description of the intended usage of the URI
 
+   Security Considerations: A brief discussion of any security issues
+      associated with the new URI purpose usage, and methods of handling
+      them
+
 10.  Acknowledgements
 
    The authors would like to thank Dan Petrie, Sean Olson, Alan
    Johnston, Rohan Mahy, Cullen Jennings, Brian Rosen, Roni Even, and
    Miguel Garcia for their comments and inputs.
 
 11.  References
 
 11.1  Normative References
 
    [1]   Bradner, S., "Key words for use in RFCs to Indicate Requirement
          Levels", BCP 14, RFC 2119, March 1997.
 
    [2]   Moats, R., "URN Syntax", RFC 2141, May 1997.
 
    [3]   Handley, M. and V. Jacobson, "SDP: Session Description
          Protocol", RFC 2327, April 1998.
 
    [4]   Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA
-         Considerations Section in RFCs", BCP 26, RFC 2434, October
-         1998.
+         Considerations Section in RFCs", BCP 26, RFC 2434,
+         October 1998.
 
    [5]   Eastlake, D. and A. Panitz, "Reserved Top Level DNS Names",
          BCP 32, RFC 2606, June 1999.
 
    [6]   Moats, R., "A URN Namespace for IETF Documents", RFC 2648,
          August 1999.
 
-   [7]   Murata, M., St. Laurent, S. and D. Kohn, "XML Media Types",
+   [7]   Murata, M., St. Laurent, S., and D. Kohn, "XML Media Types",
          RFC 3023, January 2001.
 
    [8]   Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A.,
-         Peterson, J., Sparks, R., Handley, M. and E. Schooler, "SIP:
+         Peterson, J., Sparks, R., Handley, M., and E. Schooler, "SIP:
          Session Initiation Protocol", RFC 3261, June 2002.
 
-   [9]   Roach, A., "Session Initiation Protocol (SIP)-Specific Event
+   [9]   Rosenberg, J. and H. Schulzrinne, "An Offer/Answer Model with
+         Session Description Protocol (SDP)", RFC 3264, June 2002.
+
+   [10]  Roach, A., "Session Initiation Protocol (SIP)-Specific Event
          Notification", RFC 3265, June 2002.
 
-   [10]  Schulzrinne, H., Oran, D. and G. Camarillo, "The Reason Header
+   [11]  Peterson, J., "A Privacy Mechanism for the Session Initiation
+         Protocol (SIP)", RFC 3323, November 2002.
+
+   [12]  Schulzrinne, H., Oran, D., and G. Camarillo, "The Reason Header
          Field for the Session Initiation Protocol (SIP)", RFC 3326,
          December 2002.
 
-   [11]  Schulzrinne, H., Casner, S., Frederick, R. and V. Jacobson,
+   [13]  Schulzrinne, H., Casner, S., Frederick, R., and V. Jacobson,
          "RTP: A Transport Protocol for Real-Time Applications", STD 64,
          RFC 3550, July 2003.
 
-   [12]  Yergeau, F., "UTF-8, a transformation format of ISO 10646",
+   [14]  Yergeau, F., "UTF-8, a transformation format of ISO 10646",
          STD 63, RFC 3629, November 2003.
 
-   [13]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
-         January 2004.
+   [15]  Sparks, R., "The Session Initiation Protocol (SIP) Referred-By
+         Mechanism", RFC 3892, September 2004.
 
-11.2  Informative References
+   [16]  Rosenberg, J., "A Framework for Conferencing with the Session
+         Initiation Protocol",
+         draft-ietf-sipping-conferencing-framework-05 (work in
+         progress), May 2005.
 
-   [14]  Schulzrinne, H., Rao, A. and R. Lanphier, "Real Time Streaming
-         Protocol (RTSP)", RFC 2326, April 1998.
+   [17]  Levin, O. and G. Camarillo, "The SDP (Session Description
+         Protocol) Label Attribute",
+         draft-ietf-mmusic-sdp-media-label-01 (work in progress),
+         January 2005.
 
-   [15]  Peterson, J., "A Privacy Mechanism for the Session Initiation
-         Protocol (SIP)", RFC 3323, November 2002.
+11.2  Informative References
 
-   [16]  Camarillo, G., Eriksson, G., Holler, J. and H. Schulzrinne,
-         "Grouping of Media Lines in the Session Description Protocol
-         (SDP)", RFC 3388, December 2002.
+   [18]  Schulzrinne, H., Rao, A., and R. Lanphier, "Real Time Streaming
+         Protocol (RTSP)", RFC 2326, April 1998.
 
-   [17]  Schulzrinne, H., "The tel URI for Telephone Numbers", RFC 3966,
+   [19]  Schulzrinne, H., "The tel URI for Telephone Numbers", RFC 3966,
          December 2004.
 
-   [18]  Levin, O., "H.323 Uniform Resource Locator (URL) Scheme
+   [20]  Levin, O., "H.323 Uniform Resource Locator (URL) Scheme
          Registration", RFC 3508, April 2003.
 
-   [19]  Rosenberg, J., "A Framework for Conferencing with the Session
-         Initiation Protocol",
-         Internet-Draft draft-ietf-sipping-conferencing-framework-04,
-         February 2005.
+   [21]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
+         January 2004.
 
-   [20]  Rosenberg, J., "An INVITE Inititiated Dialog Event Package for
+   [22]  Saint-Andre, P., "A Uniform Resource Identifier (URI) Scheme
+         for the Extensible Messaging and  Presence Protocol (XMPP)",
+         draft-saintandre-xmpp-uri-08 (work in progress), December 2004.
+
+   [23]  Rosenberg, J., "An INVITE Inititiated Dialog Event Package for
          the Session Initiation  Protocol (SIP)",
-         Internet-Draft draft-ietf-sipping-dialog-package-05, November
-         2004.
+         draft-ietf-sipping-dialog-package-06 (work in progress),
+         April 2005.
 
-   [21]  Rosenberg, J., "Obtaining and Using Globally Routable User
+   [24]  Rosenberg, J., "Obtaining and Using Globally Routable User
          Agent (UA) URIs (GRUU) in the  Session Initiation Protocol
-         (SIP)", Internet-Draft draft-ietf-sip-gruu-03, February 2005.
+         (SIP)", draft-ietf-sip-gruu-03 (work in progress),
+         February 2005.
 
-   [22]  Levin, O. and G. Camarillo, "The SDP (Session Description
-         Protocol) Label Attribute",
-         Internet-Draft draft-ietf-mmusic-sdp-media-label-01, January
-         2005.
+   [25]  Peterson, J. and C. Jennings, "Enhancements for Authenticated
+         Identity Management in the Session Initiation  Protocol (SIP)",
+         draft-ietf-sip-identity-05 (work in progress), May 2005.
 
 Authors' Addresses
 
    Jonathan Rosenberg
    Cisco Systems
    600 Lanidex Plaza
    Parsippany, NJ  07054
    US
 
    Phone: +1 973 952-5000