draft-ietf-xcon-framework-11.txt   rfc5239.txt 
XCON Working Group M. Barnes Network Working Group M. Barnes
Internet-Draft Nortel Request for Comments: 5239 Nortel
Intended status: Standards Track C. Boulton Category: Standards Track C. Boulton
Expires: October 13, 2008 Avaya Avaya
O. Levin O. Levin
Microsoft Corporation Microsoft Corporation
April 11, 2008
A Framework for Centralized Conferencing A Framework for Centralized Conferencing
draft-ietf-xcon-framework-11
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Abstract Abstract
This document defines the framework for Centralized Conferencing. This document defines the framework for Centralized Conferencing.
The framework allows participants using various call signaling The framework allows participants using various call signaling
protocols, such as SIP, H.323, Jabber, Q.931 or ISUP, to exchange protocols, such as SIP, H.323, Jabber, Q.931 or ISDN User Part
media in a centralized unicast conference. The Centralized (ISUP), to exchange media in a centralized unicast conference. The
Conferencing Framework defines logical entities and naming Centralized Conferencing Framework defines logical entities and
conventions. The framework also outlines a set of conferencing naming conventions. The framework also outlines a set of
protocols, which are complementary to the call signaling protocols, conferencing protocols, which are complementary to the call signaling
for building advanced conferencing applications. The framework binds protocols, for building advanced conferencing applications. The
all the defined components together for the benefit of builders of framework binds all the defined components together for the benefit
conferencing systems. of builders of conferencing systems.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 4. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5. Centralized Conferencing Data . . . . . . . . . . . . . . . . 10 5. Centralized Conferencing Data . . . . . . . . . . . . . . . . 10
5.1. Conference Information . . . . . . . . . . . . . . . . . . 12 5.1. Conference Information . . . . . . . . . . . . . . . . . . 11
5.2. Conference policies . . . . . . . . . . . . . . . . . . . 12 5.2. Conference policies . . . . . . . . . . . . . . . . . . . 12
6. Centralized Conferencing Constructs and Identifiers . . . . . 13 6. Centralized Conferencing Constructs and Identifiers . . . . . 12
6.1. Conference Identifier . . . . . . . . . . . . . . . . . . 13 6.1. Conference Identifier . . . . . . . . . . . . . . . . . . 13
6.2. Conference Object . . . . . . . . . . . . . . . . . . . . 14 6.2. Conference Object . . . . . . . . . . . . . . . . . . . . 13
6.2.1. Conference Object Identifier . . . . . . . . . . . . . 16 6.2.1. Conference Object Identifier . . . . . . . . . . . . . 15
6.3. Conference User Identifier . . . . . . . . . . . . . . . . 17 6.3. Conference User Identifier . . . . . . . . . . . . . . . . 16
7. Conferencing System Realization . . . . . . . . . . . . . . . 18 7. Conferencing System Realization . . . . . . . . . . . . . . . 17
7.1. Cloning Tree . . . . . . . . . . . . . . . . . . . . . . . 18 7.1. Cloning Tree . . . . . . . . . . . . . . . . . . . . . . . 17
7.2. Ad-hoc Example . . . . . . . . . . . . . . . . . . . . . . 21 7.2. Ad Hoc Example . . . . . . . . . . . . . . . . . . . . . . 20
7.3. Advanced Example . . . . . . . . . . . . . . . . . . . . . 22 7.3. Advanced Example . . . . . . . . . . . . . . . . . . . . . 21
7.4. Scheduling a conference . . . . . . . . . . . . . . . . . 24 7.4. Scheduling a Conference . . . . . . . . . . . . . . . . . 23
8. Conferencing Mechanisms . . . . . . . . . . . . . . . . . . . 27 8. Conferencing Mechanisms . . . . . . . . . . . . . . . . . . . 26
8.1. Call Signaling . . . . . . . . . . . . . . . . . . . . . . 27 8.1. Call Signaling . . . . . . . . . . . . . . . . . . . . . . 26
8.2. Notifications . . . . . . . . . . . . . . . . . . . . . . 27 8.2. Notifications . . . . . . . . . . . . . . . . . . . . . . 26
8.3. Conference Control Protocol . . . . . . . . . . . . . . . 27 8.3. Conference Control Protocol . . . . . . . . . . . . . . . 26
8.4. Floor Control . . . . . . . . . . . . . . . . . . . . . . 27 8.4. Floor Control . . . . . . . . . . . . . . . . . . . . . . 26
9. Conferencing Scenario Realizations . . . . . . . . . . . . . . 29 9. Conferencing Scenario Realizations . . . . . . . . . . . . . . 28
9.1. Conference Creation . . . . . . . . . . . . . . . . . . . 29 9.1. Conference Creation . . . . . . . . . . . . . . . . . . . 28
9.2. Participant Manipulations . . . . . . . . . . . . . . . . 31 9.2. Participant Manipulations . . . . . . . . . . . . . . . . 30
9.3. Media Manipulations . . . . . . . . . . . . . . . . . . . 33 9.3. Media Manipulations . . . . . . . . . . . . . . . . . . . 32
9.4. Sidebar Manipulations . . . . . . . . . . . . . . . . . . 34 9.4. Sidebar Manipulations . . . . . . . . . . . . . . . . . . 33
9.4.1. Internal Sidebar . . . . . . . . . . . . . . . . . . . 36 9.4.1. Internal Sidebar . . . . . . . . . . . . . . . . . . . 35
9.4.2. External Sidebar . . . . . . . . . . . . . . . . . . . 38 9.4.2. External Sidebar . . . . . . . . . . . . . . . . . . . 37
9.5. Floor control using sidebars . . . . . . . . . . . . . . . 41 9.5. Floor Control Using Sidebars . . . . . . . . . . . . . . . 40
9.6. Whispering or Private Messages . . . . . . . . . . . . . . 43 9.6. Whispering or Private Messages . . . . . . . . . . . . . . 42
9.7. Conference Announcements and Recordings . . . . . . . . . 45 9.7. Conference Announcements and Recordings . . . . . . . . . 44
9.8. Monitoring for DTMF . . . . . . . . . . . . . . . . . . . 47 9.8. Monitoring for DTMF . . . . . . . . . . . . . . . . . . . 46
9.9. Observing and Coaching . . . . . . . . . . . . . . . . . . 47 9.9. Observing and Coaching . . . . . . . . . . . . . . . . . . 46
10. Relationships between SIP and Centralized Conferencing 10. Relationships between SIP and Centralized Conferencing
Frameworks . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Frameworks . . . . . . . . . . . . . . . . . . . . . . . . . . 49
11. Security Considerations . . . . . . . . . . . . . . . . . . . 51 11. Security Considerations . . . . . . . . . . . . . . . . . . . 50
11.1. User Authentication and Authorization . . . . . . . . . . 52 11.1. User Authentication and Authorization . . . . . . . . . . 51
11.2. Security and Privacy of Identity . . . . . . . . . . . . . 54 11.2. Security and Privacy of Identity . . . . . . . . . . . . . 53
11.3. Floor Control Server Authentication . . . . . . . . . . . 54 11.3. Floor Control Server Authentication . . . . . . . . . . . 53
12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 54 12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 53
13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 55 13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 54
14. Changes since last Version . . . . . . . . . . . . . . . . . . 55 13.1. Normative References . . . . . . . . . . . . . . . . . . . 54
15. References . . . . . . . . . . . . . . . . . . . . . . . . . . 64 13.2. Informative References . . . . . . . . . . . . . . . . . . 54
15.1. Normative References . . . . . . . . . . . . . . . . . . . 64
15.2. Informative References . . . . . . . . . . . . . . . . . . 64
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 65
Intellectual Property and Copyright Statements . . . . . . . . . . 67
1. Introduction 1. Introduction
This document defines the framework for Centralized Conferencing. This document defines the framework for Centralized Conferencing.
The framework allows participants using various call signaling The framework allows participants using various call signaling
protocols, such as SIP, H.323, Jabber, Q.931 or ISUP, to exchange protocols, such as SIP, H.323, Jabber, Q.931 or ISUP, to exchange
media in a centralized unicast conference. Other than references to media in a centralized unicast conference. Other than references to
general functionality (e.g., establishment and teardown), details of general functionality (e.g., establishment and teardown), details of
these call signaling protocols are outside the scope of this these call signaling protocols are outside the scope of this
document. document.
The Centralized Conferencing Framework defines logical entities and The Centralized Conferencing Framework defines logical entities and
naming conventions. The framework also outlines a set of naming conventions. The framework also outlines a set of
conferencing protocols, which are complementary to the call signaling conferencing protocols, which are complementary to the call signaling
protocols, for building advanced conferencing applications. protocols, for building advanced conferencing applications.
The Centralized Conferencing Framework is compatible with the The Centralized Conferencing Framework is compatible with the
functional model presented in the SIP Conferencing Framework functional model presented in the SIP Conferencing Framework
[RFC4353]. Section 10 of this document discusses the relationship [RFC4353]. Section 10 of this document discusses the relationship
between the Centralized Conferencing Framework and the SIP between the Centralized Conferencing Framework and the SIP
Conferencing framework, in the context of the Centralized Conferencing Framework, in the context of the Centralized
Conferencing model presented in this document. Conferencing model presented in this document.
2. Conventions 2. Conventions
In this document, the key words "MUST", "MUST NOT", "REQUIRED", In this document, the key words "MUST", "MUST NOT", "REQUIRED",
"SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT
RECOMMENDED", "MAY", and "OPTIONAL" are to be interpreted as RECOMMENDED", "MAY", and "OPTIONAL" are to be interpreted as
described in BCP 14, [RFC2119] and indicate requirement levels for described in BCP 14, [RFC2119] and indicate requirement levels for
compliant implementations. compliant implementations.
3. Terminology 3. Terminology
This Centralized Conferencing Framework document generalizes, when This Centralized Conferencing Framework document generalizes, when
appropriate, the SIP Conferencing Framework [RFC4353] terminology and appropriate, the SIP Conferencing Framework [RFC4353] terminology and
introduces new concepts, as listed below. Further details and introduces new concepts, as listed below. Further details and
clarification of the new terms and concepts are provided in the clarification of the new terms and concepts are provided in the
subsequent sections of this document. subsequent sections of this document.
Active conference: The term active conference refers to a conference Active conference: The term "active conference" refers to a
object that has been created and activated via the allocation of conference object that has been created and activated via the
its identifiers (e.g., conference object identifier and conference allocation of its identifiers (e.g., conference object identifier
identifier) and the associated focus. An active conference is and conference identifier) and the associated focus. An active
created based on either a system default conference blueprint or a conference is created based on either a system default conference
specific conference reservation. blueprint or a specific conference reservation.
Call Signaling protocol: The call signaling protocol is used between Call Signaling protocol: The call signaling protocol is used between
a participant and a focus. In this context, the term "call" means a participant and a focus. In this context, the term "call" means
a channel or session used for media streams. a channel or session used for media streams.
Conference blueprint: A conference blueprint is a static conference Conference blueprint: A conference blueprint is a static conference
object within a conferencing system, which describes a typical object within a conferencing system, which describes a typical
conference setting supported by the system. A conference conference setting supported by the system. A conference
blueprint is the basis for creation of dynamic conference objects. blueprint is the basis for creation of dynamic conference objects.
A system may maintain multiple blueprints. Each blueprint is A system may maintain multiple blueprints. Each blueprint is
comprised of the initial values and ranges for the elements in the comprised of the initial values and ranges for the elements in the
object, conformant to the data schemas for the conference object, conformant to the data schemas for the conference
information. information.
Conference control protocol (CCP): A conference control protocol Conference control protocol (CCP): A conference control protocol
provides the interface for data manipulation and state retrieval provides the interface for data manipulation and state retrieval
for the centralized conferencing data, represented by the for the centralized conferencing data, represented by the
conference object. conference object.
Conference factory: A conference factory is a logical entity that Conference factory: A conference factory is a logical entity that
generates unique URI(s) to identify and represent a conference generates unique URI(s) to identify and represent a conference
focus. focus.
Conference identifier (ID): A conference identifier is a call Conference identifier (ID): A conference identifier is a call
signaling protocol-specific URI that identifies a conference focus signaling protocol-specific URI that identifies a conference focus
and its associated conference instance. and its associated conference instance.
Conference information: The conference information includes Conference information: The conference information includes
definitions for basic conference features, such as conference definitions for basic conference features, such as conference
identifiers, membership, signaling, capabilities and media types, identifiers, membership, signaling, capabilities, and media types
applicable to a wide range of conferencing applications. The applicable to a wide range of conferencing applications. The
conference information also includes the media and application conference information also includes the media and application-
specific data for enhanced conferencing features or capabilities, specific data for enhanced conferencing features or capabilities,
such as media mixers. The conference information is the data type such as media mixers. The conference information is the data type
(i.e., the XML schema) for a conference object. (i.e., the XML schema) for a conference object.
Conference instance: A conference instance refers to an internal Conference instance: A conference instance refers to an internal
implementation of a specific conference, represented as a set of implementation of a specific conference, represented as a set of
logical conference objects and associated identifiers. logical conference objects and associated identifiers.
Conference object: A conference object represents a conference at a Conference object: A conference object represents a conference at a
certain stage (e.g., description upon conference creation, certain stage (e.g., description upon conference creation,
reservation, activation, etc.), which a conferencing system reservation, activation, etc.), which a conferencing system
maintains in order to describe the system capabilities and to maintains in order to describe the system capabilities and to
provide access to the services available for each object provide access to the services available for each object
independently. The conference object schema is based on the independently. The conference object schema is based on the
conference information. conference information.
Conference object identifier (ID): A conference object identifier is Conference object identifier (ID): A conference object identifier is
a URI which uniquely identifies a conference object and is used by a URI that uniquely identifies a conference object and is used by
a conference control protocol to access and modify the conference a conference control protocol to access and modify the conference
information. information.
Conference policies: Conference policies collectively refers to a Conference policies: Conference policies collectively refers to a
set of rights, permissions and limitations pertaining to set of rights, permissions, and limitations pertaining to
operations being performed on a certain conference object. operations being performed on a certain conference object.
Conference reservation: A conference reservation is a conference Conference reservation: A conference reservation is a conference
object, which is created from either a system default or client object, which is created from either a system default or client
selected blueprint. selected blueprint.
Conference state: The conference state reflects the state of a Conference state: The conference state reflects the state of a
conference instance and is represented using a specific, well- conference instance and is represented using a specific, well-
defined schema. defined schema.
Conferencing system: Conferencing system refers to a conferencing Conferencing system: Conferencing system refers to a conferencing
solution based on the data model discussed in this framework solution based on the data model discussed in this framework
document and built using the protocol specifications referenced in document and built using the protocol specifications referenced in
this framework document. this framework document.
Conference user identifier (ID): A unique identifier for a user Conference user identifier (ID): A unique identifier for a user
within the scope of a conferencing system. A user may have within the scope of a conferencing system. A user may have
multiple conference user identifiers within a conferencing system multiple conference user identifiers within a conferencing system
(e.g., to represent different roles). (e.g., to represent different roles).
Floor: Floor refers to a set of data or resources associated with a Floor: Floor refers to a set of data or resources associated with a
conference instance, for which a conference participant, or group conference instance, for which a conference participant, or group
of participants, is granted temporary access. of participants, is granted temporary access.
Floor chair: A floor chair is a floor control protocol compliant Floor chair: A floor chair is a floor control protocol compliant
client, either a human participant or automated entity, who is client, either a human participant or automated entity, who is
authorized to manage access to one floor and can grant, deny or authorized to manage access to one floor and can grant, deny, or
revoke access. The floor chair does not have to be a participant revoke access. The floor chair does not have to be a participant
in the conference instance. in the conference instance.
Focus: A focus is a logical entity that maintains the call signaling Focus: A focus is a logical entity that maintains the call signaling
interface with each participating client and the conference object interface with each participating client and the conference object
representing the active state. As such, the focus acts as an representing the active state. As such, the focus acts as an
endpoint for each of the supported signaling protocols and is endpoint for each of the supported signaling protocols and is
responsible for all primary conference membership operations responsible for all primary conference membership operations
(e.g., join, leave, update the conference instance) and for media (e.g., join, leave, update the conference instance) and for media
negotiation/maintenance between a conference participant and the negotiation/maintenance between a conference participant and the
focus. focus.
Media graph: The media graph is the logical representation of the Media graph: The media graph is the logical representation of the
flow of media for a conference. flow of media for a conference.
Media mixer: A media mixer is the logical entity with the capability Media mixer: A media mixer is the logical entity with the capability
to combine media inputs of the same type, transcode the media and to combine media inputs of the same type, transcode the media, and
distribute the result(s) to a single or multiple outputs. In this distribute the result(s) to a single or multiple outputs. In this
context, the term "media" means any type of data being delivered context, the term "media" means any type of data being delivered
over the network using appropriate transport means, such as RTP/ over the network using appropriate transport means, such as RTP/
RTCP (defined in [RFC3550]) or Message Session Relay Protocol RTP Control Protocol (RTCP) (defined in [RFC3550]) or Message
(defined in [RFC4975]). Session Relay Protocol (defined in [RFC4975]).
Role: A role provides the context for the set of conference Role: A role provides the context for the set of conference
operations that a participant can perform. A default role (e.g., operations that a participant can perform. A default role (e.g.,
standard conference participant) will always exist, providing a standard conference participant) will always exist, providing a
user with a set of basic conference operations. Based on system user with a set of basic conference operations. Based on system-
specific authentication and authorization, a user may take on specific authentication and authorization, a user may take on
alternate roles, such as conference moderator, allowing access to alternate roles, such as conference moderator, allowing access to
a wider set of conference operations. a wider set of conference operations.
Sidebar: A sidebar is a separate Conference instance that only Sidebar: A sidebar is a separate conference instance that only
exists within the context of a parent conference instance. The exists within the context of a parent conference instance. The
objective of a sidebar is to be able to provide additional or objective of a sidebar is to be able to provide additional or
alternate media only to specific participants. alternate media only to specific participants.
Whisper: A whisper involves a one-time media input to a specific
Whisper: A whisper involves a one-time media input to (a) specific
participant(s) within a specific conference instance, accomplished participant(s) within a specific conference instance, accomplished
using a sidebar. An example of a whisper would be an announcement using a sidebar. An example of a whisper would be an announcement
injected only to the conference chair or to a new participant injected only to the conference chair or to a new participant
joining a conference. joining a conference.
4. Overview 4. Overview
A centralized conference is an association of endpoints, called A centralized conference is an association of endpoints, called
conference participants, with a central endpoint, called a conference conference participants, with a central endpoint, called a conference
Focus. The Focus has direct peer relationships with the participants focus. The focus has direct peer relationships with the participants
by maintaining a separate call signaling interface with each. by maintaining a separate call signaling interface with each.
Consequently, in this centralized conferencing model, the call Consequently, in this centralized conferencing model, the call
signaling graph is always a star. signaling graph is always a star.
The most basic conference supported in this model would be an ad-hoc The most basic conference supported in this model would be an ad hoc,
unmanaged conference, which would not necessarily require any of the unmanaged conference, which would not necessarily require any of the
functionality defined within this framework. For example, it could functionality defined within this framework. For example, it could
be supported using basic SIP signaling functionality with a be supported using basic SIP signaling functionality with a
participant serving as the Focus; the SIP Conferencing Framework participant serving as the focus; the SIP Conferencing Framework
[RFC4353] together with the SIP Call Control Conferencing for User [RFC4353] together with the SIP Call Control Conferencing for User
Agents [RFC4579] documents address these types of scenarios. Agents [RFC4579] documents address these types of scenarios.
In addition to the basic features, however, a conferencing system In addition to the basic features, however, a conferencing system
supporting the centralized conferencing model proposed in this supporting the centralized conferencing model proposed in this
framework document can offer richer functionality, by including framework document can offer richer functionality, by including
dedicated conferencing applications with explicitly defined dedicated conferencing applications with explicitly defined
capabilities, reserved recurring conferences, along with providing capabilities, reserved recurring conferences, along with providing
the standard protocols for managing and controlling the different the standard protocols for managing and controlling the different
attributes of these conferences. attributes of these conferences.
The core requirements for centralized conferencing are outlined in The core requirements for centralized conferencing are outlined in
[RFC4245]. These requirements are applicable for conferencing [RFC4245]. These requirements are applicable for conferencing
systems using various call signaling protocols, including SIP. systems using various call signaling protocols, including SIP.
Additional conferencing requirements are provided in [RFC4376], and Additional conferencing requirements are provided in [RFC4376] and
[RFC4597]. [RFC4597].
The centralized conferencing system proposed by this framework is The centralized conferencing system proposed by this framework is
built around a fundamental concept of a conference object. A built around a fundamental concept of a conference object. A
conference object provides the data representation of a conference conference object provides the data representation of a conference
during each of the various stages of a conference (e.g., creation, during each of the various stages of a conference (e.g., creation,
reservation, active, completed, etc.). A conference object is reservation, active, completed, etc.). A conference object is
accessed via the logical functional elements, with whom a accessed via the logical functional elements, with whom a
conferencing client interfaces, using the various protocols conferencing client interfaces, using the various protocols
identified in Figure 1. The functional elements defined for a identified in Figure 1. The functional elements defined for a
conferencing system described by the framework are a Conference conferencing system described by the framework are a conference
Control Server, Floor Control Server, any number of Foci and a control server, floor control server, any number of Foci, and a
Notification Service. A Conference Control Protocol (CCP) provides notification service. A conference control protocol (CCP) provides
the interface between a conference and media control client and the the interface between a conference and media control client and the
conference control server. A floor control protocol (e.g., BFCP) conference control server. A floor control protocol (e.g., Binary
provides the interface between a floor control client and the floor Floor Control Protocol (BFCP)) provides the interface between a floor
control server. A call signaling protocol (e.g., SIP, H.323, Jabber, control client and the floor control server. A call signaling
Q.931, ISUP, etc.) provides the interface between a call signaling protocol (e.g., SIP, H.323, Jabber, Q.931, ISUP, etc.) provides the
client and a Focus. A notification protocol (e.g. SIP Notify interface between a call signaling client and a focus. A
[RFC3265]) provides the interface between the conferencing client and notification protocol (e.g. SIP Notify [RFC3265]) provides the
the Notification Service. interface between the conferencing client and the notification
service.
A conferencing system can support a subset of the conferencing A conferencing system can support a subset of the conferencing
functions depicted in the conferencing system logical decomposition functions depicted in the conferencing system logical decomposition
in Figure 1 and described in this document. However, there are some in Figure 1 and described in this document. However, there are some
essential components that would typically be used by most other essential components that would typically be used by most other
advanced functions, such as the Notification Service. For example, advanced functions, such as the notification service. For example,
the notification service is used to correlate information, such as the notification service is used to correlate information, such as
list of participants with their media streams, between the various the list of participants with their media streams, between the
other components. various other components.
.................................................................... ....................................................................
. Conferencing System . . Conferencing System .
. . . .
. +-----------------------------------------------------+ . . +-----------------------------------------------------+ .
. | C o n f e r e n c e o b j e c t | . . | C o n f e r e n c e o b j e c t | .
. +-+---------------------------------------------------+ | . . +-+---------------------------------------------------+ | .
. | C o n f e r e n c e o b j e c t | | . . | C o n f e r e n c e o b j e c t | | .
. +-+---------------------------------------------------+ | | . . +-+---------------------------------------------------+ | | .
. | C o n f e r e n c e o b j e c t | | | . . | C o n f e r e n c e o b j e c t | | | .
skipping to change at page 9, line 45 skipping to change at page 8, line 45
. +----------------+ +------------+ +----------+ +------------+ . . +----------------+ +------------+ +----------+ +------------+ .
. | Conference | | Floor | | Call | |Notification| . . | Conference | | Floor | | Call | |Notification| .
. | and Media | | Control | | Signaling| | Client | . . | and Media | | Control | | Signaling| | Client | .
. | Control | | Client | | Client | | | . . | Control | | Client | | Client | | | .
. | Client | | | | | | | . . | Client | | | | | | | .
. +----------------+ +------------+ +----------+ +------------+ . . +----------------+ +------------+ +----------+ +------------+ .
. . . .
. Conferencing Client . . Conferencing Client .
.................................................................... ....................................................................
Figure 1: Conferencing System Logical Decomposition. Figure 1: Conferencing System Logical Decomposition
The media graph of a conference can be centralized, decentralized, or The media graph of a conference can be centralized, decentralized, or
any combination of both and potentially differ per media type. In any combination of both and potentially differ per media type. In
the centralized case, the media sessions are established between a the centralized case, the media sessions are established between a
media mixer controlled by the focus and each one of the participants. media mixer controlled by the focus and each one of the participants.
In the decentralized (i.e., distributed) case, the media graph is a In the decentralized (i.e., distributed) case, the media graph is a
multicast or multi-unicast mesh among the participants. multicast or multi-unicast mesh among the participants.
Consequently, the media processing (e.g., mixing) can be controlled Consequently, the media processing (e.g., mixing) can be controlled
either by the focus alone or by the participants. The concepts in either by the focus alone or by the participants. The concepts in
this framework document clearly map to a centralized media model. this framework document clearly map to a centralized media model.
The concepts can also apply to the decentralized media case, however, The concepts can also apply to the decentralized media case; however,
the details of such are left for future study. the details of such are left for future study.
Section 5 of this document provides more details on the conference Section 5 of this document provides more details on the conference
object. Section 6 defines the constructs and identifiers that MUST object. Section 6 defines the constructs and identifiers that MUST
be implemented to manage the conference objects, instances and users be implemented to manage the conference objects, instances, and users
associated with a conferencing system. Section 7 of this document associated with a conferencing system. Section 7 of this document
describes how a conferencing system is logically built using the describes how a conferencing system is logically built using the
defined high level data model and how the conference objects are defined high level data model and how the conference objects are
maintained. Section 8 describes the fundamental conferencing maintained. Section 8 describes the fundamental conferencing
mechanisms and provides a high level overview of the protocols. mechanisms and provides a high level overview of the protocols.
Section 9 then provides realizations of various conferencing Section 9 then provides realizations of various conferencing
scenarios, detailing the manipulation of the conference objects using scenarios, detailing the manipulation of the conference objects using
the defined protocols. Section 10 of this document summarizes the the defined protocols. Section 10 of this document summarizes the
relationship between this Centralized Conferencing Framework and the relationship between this Centralized Conferencing Framework and the
SIP Conferencing Framework. SIP Conferencing Framework.
skipping to change at page 11, line 38 skipping to change at page 10, line 45
| | +----------------------------------------------+ | | | | +----------------------------------------------+ | |
| | +----------------------------------------------+ | | | | +----------------------------------------------+ | |
| | | Floor controls | | | | | | Floor controls | | |
| | +----------------------------------------------+ | | | | +----------------------------------------------+ | |
| | +----------------------------------------------+ | | | | +----------------------------------------------+ | |
| | | Etc. | | | | | | Etc. | | |
| | +----------------------------------------------+ | | | | +----------------------------------------------+ | |
| +--------------------------------------------------+ | | +--------------------------------------------------+ |
+------------------------------------------------------+ +------------------------------------------------------+
Figure 2: Conference Object Type Decomposition. Figure 2: Conference Object Type Decomposition
In a system based on this conferencing framework, the same conference In a system based on this conferencing framework, the same conference
object type is used for representation of a conference during object type is used for representation of a conference during
different stages of a conference, such as expressing conferencing different stages of a conference, such as expressing conferencing
system capabilities, reserving conferencing resources or reflecting system capabilities, reserving conferencing resources, or reflecting
the state of ongoing conferences. Section 7 describes the usage the state of ongoing conferences. Section 7 describes the usage
semantics of the conference objects. The exact XML schema of the semantics of the conference objects. The exact XML schema of the
conference object, including the organization of the conference conference object, including the organization of the conference
information is detailed in a separate document information is detailed in a separate document [XCON-COMMON].
[I-D.ietf-xcon-common-data-model].
Along with the basic data model as defined in Along with the basic data model, as defined in [XCON-COMMON], the
[I-D.ietf-xcon-common-data-model], the realization of this framework realization of this framework requires a policy infrastructure. The
requires a policy infrastructure. The policies required by this policies required by this framework to manage and control access to
framework to manage and control access to the data include local, the data include local, system level boundaries associated with
system level boundaries associated with specific data elements, such specific data elements, such as the membership, and the ranges and
as the membership, and by the ranges and limitations of other data limitations of other data elements. Additional policy considerations
elements. Additional policy considerations for a system realization for a system realization based on this data model are discussed in
based on this data model are discussed in Section 5.2. Section 5.2.
5.1. Conference Information 5.1. Conference Information
There is a core set of data in the conference information that is There is a core set of data in the conference information that is
utilized in any conference, independent of the specific conference utilized in any conference, independent of the specific conference
media nature (e.g., the mixing algorithms performed, the advanced media nature (e.g., the mixing algorithms performed, the advanced
floor control applied, etc.). This core set of data in the floor control applied, etc.). This core set of data in the
conference information contains the definitions representing the conference information contains the definitions representing the
conference object capabilities, membership, roles, call signaling and conference object capabilities, membership, roles, call signaling,
media status relevant to different stages of the conference life- and media status relevant to different stages of the conference life-
cycle. This core set of conference information may be represented cycle. This core set of conference information may be represented
using the conference-type as defined in the SIP conference event using the conference-type, as defined in the SIP conference event
package [RFC4575]. Typically, participants with read-only access to package [RFC4575]. Typically, participants with read-only access to
the conference information would be interested in this core set of the conference information would be interested in this core set of
conference information only. conference information only.
In order to support more complex media manipulations and enhanced In order to support more complex media manipulations and enhanced
conferencing features, the conference information, as defined in the conferencing features, the conference information, as defined in the
data model [I-D.ietf-xcon-common-data-model], contains additional data model [XCON-COMMON], contains additional data beyond that
data beyond that defined in the SIP conference event package defined in the SIP conference event package [RFC4575]. The
[RFC4575]. The information defined in the data model information defined in the data model [XCON-COMMON] provides specific
[I-D.ietf-xcon-common-data-model] provides specific media mixing media mixing details, available floor controls, and other data
details, available floor controls and other data necessary to support necessary to support enhanced conferencing features. This
enhanced conferencing features. This information allows authorized information allows authorized clients to manipulate the mixer's
clients to manipulate the mixer's behavior via the focus, with the behavior via the focus, with the resultant distribution of the media
resultant distribution of the media to all or individual to all or individual participants. By doing so, a client can change
participants. By doing so, a client can change its own state and/or its own state and/or the state of other participants in the
the state of other participants in the conference. conference.
New centralized conferencing specifications can extend the basic New centralized conferencing specifications can extend the basic
conference-type as defined in the data model conference-type, as defined in the data model [XCON-COMMON], and
[I-D.ietf-xcon-common-data-model] and introduce additional data introduce additional data elements to be used within the conference
elements to be used within the conference information type. information type.
5.2. Conference policies 5.2. Conference policies
Conference policies collectively refers to a set of rights, Conference policies collectively refers to a set of rights,
permissions and limitations pertaining to operations being performed permissions and limitations pertaining to operations being performed
on a certain conference object. on a certain conference object.
The set of rights describes the read/write access privileges for the The set of rights describes the read/write access privileges for the
conference object as a whole. This access would usually be granted conference object as a whole. This access would usually be granted
and defined in terms of giving the read-only or read-write access to and defined in terms of giving the read-only or read/write access to
clients with certain roles in the conference. Managing this access clients with certain roles in the conference. Managing this access
would require a conferencing system have access to basic policy would require a conferencing system to have access to basic policy
information to make the decisions, but doesn't necessarily require an information to make the decisions, but doesn't necessarily require an
explicit representation in the policy model. As such, for this explicit representation in the policy model. As such, for this
framework document, the policies represented by the set of rights are framework document, the policies represented by the set of rights are
reflected in the system realization (Section 7). reflected in the system realization (Section 7).
The permissions and limits require explicit policy mechanisms and are The permissions and limits require explicit policy mechanisms and are
outside the scope of the data model [I-D.ietf-xcon-common-data-model] outside the scope of the data model [XCON-COMMON] and this framework
and this framework document. However, there are some important document. However, there are some important policy considerations
policy considerations for a conferencing system. A conferencing for a conferencing system. A conferencing system associates specific
system associates specific policies in the form of permissions and policies in the form of permissions and limitations with each user in
limitations with each user in a conferencing system. The permissions a conferencing system. The permissions may vary depending upon the
may vary depending upon the role associated with a specific role associated with a specific conference user identifier. A
conference user identifier. A conferencing system should provide a conferencing system should provide a default user role that only
default user role that only allows participation in a conference allows participation in a conference through the default signaling
through the default signaling means. means.
The conference object identifier provides access to the data The conference object identifier provides access to the data
associated with a specific conference. It is important to ensure associated with a specific conference. It is important to ensure
that elements in the data have individual policy controls to provide that elements in the data have individual policy controls to provide
flexibility in defining the various roles and specific data elements flexibility in defining the various roles and specific data elements
that may be manipulated by users with specific roles. that may be manipulated by users with specific roles.
In addition, the conference notification interface allows specific In addition, the conference notification interface allows specific
data elements to be sent to users that register for such data elements to be sent to users that register for such
notifications. It is important that the appropriate access control notifications. It is important that the appropriate access control
is provided so that only users that are authorized to view specific is provided so that only users that are authorized to view specific
data elements receive the data in the notifications. data elements receive the data in the notifications.
6. Centralized Conferencing Constructs and Identifiers 6. Centralized Conferencing Constructs and Identifiers
This section provides details of the identifiers associated with the This section provides details of the identifiers associated with the
centralized conferencing framework constructs and the identifiers centralized conferencing framework constructs and the identifiers
REQUIRED to address and manage the clients associated with a REQUIRED to address and manage the clients associated with a
conferencing system. An overview of the allocation, characteristics conferencing system. An overview of the allocation, characteristics,
and functional role of the identifiers is provided. and functional role of the identifiers is provided.
6.1. Conference Identifier 6.1. Conference Identifier
The conference identifier (conference ID) is a call signaling The conference identifier (conference ID) is a call signaling
protocol-specific URI that identifies a specific conference focus and protocol-specific URI that identifies a specific conference focus and
its associated conference instance. A conference factory is one its associated conference instance. A conference factory is one
method for generating a unique conference ID, to identify and address method for generating a unique conference ID, to identify and address
a conference focus, using a call signaling interface. Details on the a conference focus, using a call signaling interface. Details on the
use of a conference factory for SIP signaling can be found in use of a conference factory for SIP signaling can be found in
[RFC4579]. The conference identifier can also be obtained using the [RFC4579]. The conference identifier can also be obtained using the
conference control protocol or other, including proprietary, out-of- conference control protocol or other, including proprietary, out-of-
band mechanisms. To realize the centralized conferencing framework band mechanisms. To realize the centralized conferencing framework
in this document, a conferencing system is REQUIRED to support SIP as in this document, a conferencing system is REQUIRED to support SIP as
the default call signaling protocol. Other call signaling protocols the default call signaling protocol. Other call signaling protocols
(e.g., ISUP) are OPTIONAL. (e.g., ISUP) are OPTIONAL.
6.2. Conference Object 6.2. Conference Object
A Conference object provides the logical representation of a A conference object provides the logical representation of a
conference instance in a certain stage, such as a conference conference instance in a certain stage, such as a conference
blueprint representing a conferencing system's capabilities, the data blueprint representing a conferencing system's capabilities, the data
representing a conference reservation, and the conference state representing a conference reservation, and the conference state
during an active conference. Each conference object is independently during an active conference. Each conference object is independently
addressable through the conference control protocol interface addressable through the conference control protocol interface (see
[Section 8.3]. A conferencing system MUST provide a default Section 8.3). A conferencing system MUST provide a default blueprint
blueprint representing the basic capabilities provided by that representing the basic capabilities provided by that specific
specific conferencing system. conferencing system.
Figure 3 illustrates the relationships between the conference Figure 3 illustrates the relationships between the conference
identifier, the focus and the conference object ID within the context identifier, the focus, and the conference object ID within the
of a logical conference instance, with the conference object context of a logical conference instance, with the conference object
corresponding to an active conference. corresponding to an active conference.
A conference object representing a conference in the active state can A conference object representing a conference in the active state can
have multiple call signaling conference identifiers; for example, one have multiple call signaling conference identifiers; for example, one
for each call signaling protocol supported. There is a one-to-one for each call signaling protocol supported. There is a one-to-one
mapping between an active conference object and a conference focus. mapping between an active conference object and a conference focus.
The focus is addressed by explicitly associating unique conference The focus is addressed by explicitly associating unique conference
IDs for each signaling protocol supported by the active conference IDs for each signaling protocol supported by the active conference
object. object.
skipping to change at page 15, line 46 skipping to change at page 14, line 46
| +---------------+ | | | +---------------+ | |
| | | | | | | |
| | | | | | | |
v v v v v v v v
+----------------+ +--------------+ +---------------+ +----------------+ +--------------+ +---------------+
| Conferencing | | Conferencing | | Conference | | Conferencing | | Conferencing | | Conference |
| Client | | Client | | Client | | Client | | Client | | Client |
| 1 | | 2 | | X | | 1 | | 2 | | X |
+----------------+ +--------------+ +---------------+ +----------------+ +--------------+ +---------------+
Figure 3: Identifier Relationships for an Active Conference. Figure 3: Identifier Relationships for an Active Conference
6.2.1. Conference Object Identifier 6.2.1. Conference Object Identifier
In order to make each conference object externally accessible, the In order to make each conference object externally accessible, the
conferencing system MUST allocate a unique URI per distinct conferencing system MUST allocate a unique URI per distinct
conference object in the system. The conference object identifier is conference object in the system. The conference object identifier is
defined in [I-D.ietf-xcon-common-data-model]. A conferencing system defined in [XCON-COMMON]. A conferencing system allocates a
allocates a conferencing object identifier for every conference conferencing object identifier for every conference blueprint, for
blueprint, for every conference reservation and for every active every conference reservation, and for every active conference. The
conference. The distribution of the conference object identifier distribution of the conference object identifier depends upon the
depends upon the specific use case and includes a variety of specific use case and includes a variety of mechanisms, such as
mechanisms, such as the through the conference control protocol through the conference control protocol mechanism, the data model and
mechanism, the data model and conference package or out of band conference package, or out-of-band mechanisms such as email.
mechanisms such as E-Mail.
When a user wishes to create or join a conference and the user does When a user wishes to create or join a conference and the user does
not have the conference object identifier for the specific not have the conference object identifier for the specific
conference, more general signaling mechanisms apply, such that a user conference, more general signaling mechanisms apply. A user may have
may have a pre-configured conference object identifier to access the a pre-configured conference object identifier to access the
conferencing system or other signaling protocols may be used and the conferencing system or other signaling protocols may be used and the
conferencing system maps those to a specific conference object conferencing system maps those to a specific conference object
identifier. Once a conference is established, a conference object identifier. Once a conference is established, a conference object
identifier is REQUIRED for the user to manipulate any of the identifier is REQUIRED for the user to manipulate any of the
conferencing data or take advantage of any of the advanced conferencing data or take advantage of any of the advanced
conferencing features. The same notion applies to users joining a conferencing features. The same notion applies to users joining a
conference using other signaling protocols. They are able to conference using other signaling protocols. They are able to
initially join a conference using any of the other signaling initially join a conference using any of the other signaling
protocols supported by the specific conferencing system, but the protocols supported by the specific conferencing system, but the
conference object identifier MUST be used to manipulate any of the conference object identifier MUST be used to manipulate any of the
conferencing data or take advantage of any of the advanced conferencing data or take advantage of any of the advanced
conferencing features. As mentioned previously, the mechanism by conferencing features. As mentioned previously, the mechanism by
which the user learns of the conference object identifier varies and which the user learns of the conference object identifier varies and
could be via the conference control protocol, using the data model could be via the conference control protocol, using the data model
and conference package or entirely out of band such as E-Mail or a and conference package or entirely out of band mechanisms such as
web interface. email or a web interface.
The conference object identifier logically maps to other protocol The conference object identifier logically maps to other protocol-
specific identifiers associated with the conference instance, such as specific identifiers associated with the conference instance, such as
the BFCP 'confid'. The mapping of the conference object identifier the BFCP 'confid'. The mapping of the conference object identifier
can be viewed to contain sensitive information in many conferencing can be viewed to contain sensitive information in many conferencing
systems. The conferencing system must ensure that the data is systems. The conferencing system must ensure that the data is
protected and that only authorized users can manipulate that protected, that only authorized users can manipulate that information
information via the conferencing control protocol and that only the via the conferencing control protocol, and that only the appropriate
appropriate users receive the information through the notification users receive the information through the notification protocol. In
protocol. In general, this information would not be expected to be general, this information would not be expected to be distributed to
distributed to the average conference participant. the average conference participant.
6.3. Conference User Identifier 6.3. Conference User Identifier
Each user within a conferencing system MUST be allocated a unique Each user within a conferencing system MUST be allocated a unique
conference user identifier. The conference user identifier is conference user identifier. The conference user identifier is
defined in [I-D.ietf-xcon-common-data-model]. The conference user defined in [XCON-COMMON]. The conference user identifier is used in
identifier is used in association with the conference object association with the conference object identifier to uniquely
identifier to uniquely identify a user within the scope of identify a user within the scope of conferencing system. There is
conferencing system. There is also a requirement for identifying also a requirement for identifying conferencing system users who may
conferencing system users who may not be participating in a not be participating in a conference instance. Examples of these
conference instance. Examples of these users would be a non users would be a non-participating 'Floor Control Chair' or 'Media
participating 'Floor Control Chair' or 'Media Policy Controller'. Policy Controller'. The conference user identifier is REQUIRED, in
The conference user identifier is REQUIRED in conference control conference control protocol requests, to uniquely determine who is
protocol requests to uniquely determine who is issuing commands, so issuing commands, so that appropriate policies can be applied to the
that appropriate policies can be applied to the requested command. requested command.
A typical mode for distributing the user identifier is out of band A typical mode for distributing the user identifier is out of band
during conferencing client configuration, thus the mechanism is during conferencing client configuration; thus, the mechanism is
outside the scope of the centralized conferencing framework and outside the scope of the centralized conferencing framework and
protocols. However, a conferencing system MUST also be capable of protocols. However, a conferencing system MUST also be capable of
allocating and distributing a user identifier during the first allocating and distributing a user identifier during the first
signaling interaction with the conferencing system, such as an signaling interaction with the conferencing system, such as an
initial request for blueprints or adding a new user to an existing initial request for blueprints or adding a new user to an existing
conference using the conference control protocol. When a user joins conference using the conference control protocol. When a user joins
a conference using a signaling specific protocol, such as SIP for a a conference using a signaling-specific protocol, such as SIP for a
dial-in conference, a conference user identifier MUST be assigned if dial-in conference, a conference user identifier MUST be assigned if
one is not already associated with that user. While this conference one is not already associated with that user. While this conference
user identifier isn't required for the participant to join the user identifier isn't required for the participant to join the
conference, it is REQUIRED to be allocated and assigned by the conference, it is REQUIRED to be allocated and assigned by the
conferencing system such that it is available for use for any conferencing system such that it is available for use for any
subsequent conference control protocol operations and/or subsequent conference control protocol operations and/or
notifications associated with that conference. For example, the notifications associated with that conference. For example, the
conference user identifier would be sent in any notifications that conference user identifier would be sent in any notifications that
may be sent to existing participants, such as the moderator, when may be sent to existing participants, such as the moderator, when
this user joins. this user joins.
skipping to change at page 18, line 8 skipping to change at page 17, line 8
Authentication and Authorization" and Section 11.2 addresses the Authentication and Authorization" and Section 11.2 addresses the
"Security and Privacy of User Identity". In addition, the "Security and Privacy of User Identity". In addition, the
conferencing system MUST ensure the appropriate access control around conferencing system MUST ensure the appropriate access control around
any internal data structure that maintains this persistent data. any internal data structure that maintains this persistent data.
This information would typically only be available to a conferencing This information would typically only be available to a conferencing
system administrator. system administrator.
7. Conferencing System Realization 7. Conferencing System Realization
Implementations based on this centralized conferencing framework can Implementations based on this centralized conferencing framework can
range from systems supporting ad-hoc conferences, with default range from systems supporting ad hoc conferences, with default
behavior only, to sophisticated systems with the ability to schedule behavior only, to sophisticated systems with the ability to schedule
recurring conferences, each with distinct characteristics, being recurring conferences, each with distinct characteristics, being
integrated with external resource reservation tools, and providing integrated with external resource reservation tools, and providing
snapshots of the conference information at any of the stages of the snapshots of the conference information at any of the stages of the
conference life-cycle. conference life-cycle.
A conference object is the logical representation of a conference A conference object is the logical representation of a conference
instance at a certain stage, such as capabilities description upon instance at a certain stage, such as capabilities description upon
conference creation, reservation, activation, etc., which a conference creation, reservation, activation, etc., which a
conferencing system maintains in order to describe the system conferencing system maintains in order to describe the system
capabilities and to provide access to the available services provided capabilities and to provide access to the available services provided
by the conferencing system. Consequently, this centralized by the conferencing system. Consequently, this centralized
conferencing framework does not mandate the actual usage of the conferencing framework does not mandate the actual usage of the
conference object, but rather defines the general cloning tree conference object, but rather defines the general cloning tree
concept and the mechanisms required for its realization, as described concept and the mechanisms required for its realization, as described
in detail in Section 7.1. in detail in Section 7.1.
Adhoc and advanced conferencing examples are provided in Section 7.2 Adhoc and advanced conferencing examples are provided in Section 7.2
and Section 7.3, with the latter providing additional description of and Section 7.3, with the latter providing additional description of
the Conference Object in terms of the stages of a conference, to the conference object in terms of the stages of a conference, to
support scheduled and other advanced conference capabilities. The support scheduled and other advanced conference capabilities. The
scheduling of a conference based on these concepts and mechanisms is scheduling of a conference based on these concepts and mechanisms is
then detailed in Section 7.4 then detailed in Section 7.4
As discussed in Section 5.2, the overall policy in terms of As discussed in Section 5.2, the overall policy in terms of
permissions and limitations is outside the scope of this framework permissions and limitations is outside the scope of this framework
document. The policies applicable to the conference object as a document. The policies applicable to the conference object as a
whole in terms of read/write access would require a conferencing whole in terms of read/write access would require a conferencing
system have access to basic policy information to make the decisions. system have access to basic policy information to make the decisions.
In the examples in this section, the policies are shown logically In the examples in this section, the policies are shown logically
skipping to change at page 19, line 16 skipping to change at page 18, line 16
being explicitly cloned from an existing parent object or being being explicitly cloned from an existing parent object or being
implicitly cloned from a default system conference blueprint. A implicitly cloned from a default system conference blueprint. A
conference blueprint is a static conference object used to describe a conference blueprint is a static conference object used to describe a
typical conference setting supported by the system. Each system can typical conference setting supported by the system. Each system can
maintain multiple blueprints, typically each describing a different maintain multiple blueprints, typically each describing a different
conferencing type using the conference information format. This conferencing type using the conference information format. This
document uses the "cloning" metaphor instead of the "inheritance" document uses the "cloning" metaphor instead of the "inheritance"
metaphor because it more closely fits the idea of object replication, metaphor because it more closely fits the idea of object replication,
rather than a data type re-usage and extension concept. rather than a data type re-usage and extension concept.
The cloning operation needs to specify whether the link between the The cloning operation needs to specify whether or not the link
parent and the child needs to be maintained in the system or not. If between the parent and child needs to be maintained in the system.
no link between the parent and the child exists, the objects become If no link between the parent and child exists, the objects become
independent and the child is not impacted by any operations on the independent and the child is not impacted by any operations on the
parent object nor subject to any limitations of the parent object. parent object nor subject to any limitations of the parent object.
Once the new object is created, it can be addressed by a unique Once the new object is created, it can be addressed by a unique
conference object URI assigned by the system, as described in conference object URI assigned by the system, as described in
Section 6.2.1. By default, the newly created object contains all the Section 6.2.1. By default, the newly created object contains all the
data existing in the parent object. The newly created object can data existing in the parent object. The newly created object can
expand the data it contains, within the schema types supported by the expand the data it contains, within the schema types supported by the
parent. It can also restrict the read/write access to its objects. parent. It can also restrict the read/write access to its objects.
However, unless the object is independent, it cannot modify the However, unless the object is independent, it cannot modify the
access restrictions imposed by the parent object. access restrictions imposed by the parent object.
Any piece of data in the child object can be independently accessed Any piece of data in the child object can be independently accessed
and, by default, can be independently modified without affecting the and, by default, can be independently modified without affecting the
parent data. parent data.
Unless the object is independent, the parent object can enforce a Unless the object is independent, the parent object can enforce a
different policy by marking certain data elements as "parent different policy by marking certain data elements as "parent
enforceable". The values of these data elements can not be changed enforceable". The values of these data elements cannot be changed by
by directly accessing the child object; neither can they be expanded directly accessing the child object, nor can they be expanded in the
in the child object alone. child object alone.
Figure 4 illustrates an example of a conference (Parent B), which is Figure 4 illustrates an example of a conference (Parent B), which is
created independent of its Parent (Parent A). Parent B creates two created independent of its Parent (Parent A). Parent B creates two
child objects, Child 1 and Child 2. Any of the data elements of child objects, Child 1 and Child 2. Any of the data elements of
Parent B can be modified (i.e. there are no "parent enforceable" data Parent B can be modified (i.e., there are no "parent enforceable"
elements) and depending upon the element, the changes will be data elements), and depending upon the element, the changes will be
reflected in Child 1 and Child 2 , whereas changes to Parent A will reflected in Child 1 and Child 2 , whereas changes to Parent A will
not impact the data elements of Parent B. Any "parent enforceable" not impact the data elements of Parent B. Any "parent enforceable"
data elements as defined by Parent B cannot be modified in the child data elements, as defined by Parent B, cannot be modified in the
objects. child objects.
+---+-----------------------+ +---+-----------------------+
| p | | | p | |
| o | P A R E N T A | | o | P A R E N T A |
| l | | | l | |
| i | C O N F E R E N C E | | i | C O N F E R E N C E |
| c | | | c | |
| i | O B J E C T | | i | O B J E C T |
| e | | | e | |
+-s-+-----------------------+ +-s-+-----------------------+
skipping to change at page 20, line 44 skipping to change at page 19, line 44
+---+-----------------------+ +---+-----------------------+ +---+-----------------------+ +---+-----------------------+
| p | | | p | | | p | | | p | |
| o | C H I L D 1 | | o | C H I L D 2 | | o | C H I L D 1 | | o | C H I L D 2 |
| l | | | l | | | l | | | l | |
| i | C O N F E R E N C E | | i | C O N F E R E N C E | | i | C O N F E R E N C E | | i | C O N F E R E N C E |
| c | | | c | | | c | | | c | |
| i | O B J E C T | | i | O B J E C T | | i | O B J E C T | | i | O B J E C T |
| e | | | e | | | e | | | e | |
+-s-+-----------------------+ +-s-+-----------------------+ +-s-+-----------------------+ +-s-+-----------------------+
Figure 4: The Cloning Tree. Figure 4: The Cloning Tree
Using the defined cloning model and its tools, the following sections Using the defined cloning model and its tools, the following sections
show examples of how different systems based on this framework can be show examples of how different systems based on this framework can be
realized. realized.
7.2. Ad-hoc Example 7.2. Ad Hoc Example
Figure 5 illustrates how an ad-hoc conference can be created and Figure 5 illustrates how an ad hoc conference can be created and
managed in a conferencing system. A client can create a conference managed in a conferencing system. A client can create a conference
by establishing a call signaling channel with a conference factory as by establishing a call signaling channel with a conference factory,
specified in Section 6.1. The conference factory can internally as specified in Section 6.1. The conference factory can internally
select one of the system supported conference blueprints based on the select one of the system supported conference blueprints based on the
requesting client privileges and the media lines included in the SDP requesting client privileges and the media lines included in the
body. Session Description Protocol (SDP) body.
The selected blueprint with its default values is copied by the The selected blueprint with its default values is copied by the
server into a newly created conference object, referred to as an server into a newly created conference object, referred to as an
'Active Conference'. At this point the conference object becomes 'Active Conference'. At this point, the conference object becomes
independent from its blueprint. A new conference object identifier, independent from its blueprint. A new conference object identifier,
a new conference identifier and a new focus are allocated by the a new conference identifier, and a new focus are allocated by the
server. server.
During the conference lifetime, an authorized client can manipulate During the conference lifetime, an authorized client can manipulate
the conference object, by performing operations such as adding the conference object, by performing operations such as adding
participants, using the Conference Control Protocol. participants, using the conference control protocol.
+---+-----------------------+ +---+-----------------------+
| p | | | p | |
| o | System Default | | o | System Default |
| l | | | l | |
| i | Conference | | i | Conference |
| c | | | c | |
| i | Blueprint | | i | Blueprint |
| e | | | e | |
+-s-+-----------------------+ +-s-+-----------------------+
skipping to change at page 22, line 4 skipping to change at page 20, line 50
V V
+---+-----------------------+ +---+-----------------------+
| p | | | p | |
| o | Active | | o | Active |
| l | | | l | |
| i | Conference | | i | Conference |
| c | | | c | |
| i | | | i | |
| e | | | e | |
+-s-+-----------------------+ +-s-+-----------------------+
Figure 5: Conference Ad-hoc Creation and Lifetime.
Figure 5: Conference Ad-hoc Creation and Lifetime
7.3. Advanced Example 7.3. Advanced Example
Figure 6 illustrates how a recurring conference can be specified Figure 6 illustrates how a recurring conference can be specified
according to system capabilities, scheduled, reserved, and managed in according to system capabilities, scheduled, reserved, and managed in
a conferencing system. A client would first query a conferencing a conferencing system. A client would first query a conferencing
system for its capabilities. This can be done by requesting a list system for its capabilities. This can be done by requesting a list
of the conference blueprints the system supports. Each blueprint of the conference blueprints the system supports. Each blueprint
contains a specific combination of capabilities and limitations of contains a specific combination of capabilities and limitations of
the conference server in terms of supported media types (e.g., audio, the conference server in terms of supported media types (e.g., audio,
video, text, or combinations of these), participant roles, maximum video, text, or combinations of these), participant roles, maximum
number of participants of each role, availability of floor control, number of participants of each role, availability of floor control,
controls available for participants, availability and type of controls available for participants, availability and type of
sidebars, the definitions and names of media streams, etc. sidebars, the definitions and names of media streams, etc.
The selected blueprint with its default values is cloned by the The selected blueprint with its default values is cloned by the
client into a newly created conference object, referred to as a client into a newly created conference object, referred to as a
conference reservation, that specifies the resources needed from the conference reservation, that specifies the resources needed from the
system for this conference instance. At this point the conference system for this conference instance. At this point, the conference
reservation becomes independent from its blueprint. The client can reservation becomes independent from its blueprint. The client can
also change the default values, within the system ranges, and add also change the default values, within the system ranges, and add
additional information, such as the list of participants and the additional information, such as the list of participants and the
conference start time, to the conference reservation. conference 'start' time, to the conference reservation.
At this point the client can ask the conference server to create new At this point, the client can ask the conference server to create new
conference reservations by attaching the conference reservation to conference reservations by attaching the conference reservation to
the request. As a result, the server can allocate the needed the request. As a result, the server can allocate the needed
resources, create the additional conference objects for the child resources, create the additional conference objects for the child
conference reservations and allocate the conference object conference reservations, and allocate the conference object
identifiers for all - the original conference reservation and for identifiers for all -- the original conference reservation and for
each child conference reservation. each child conference reservation.
From this point on, any authorized client is able to access and From this point on, any authorized client is able to access and
modify each of the conference objects independently. By default, modify each of the conference objects independently. By default,
changes to an individual child conference reservation will affect changes to an individual child conference reservation will affect
neither the parent conference reservation, from which it was created, neither the parent conference reservation, from which it was created,
nor its siblings. nor its siblings.
On the other hand, some of the conference sub-objects, such as the On the other hand, some of the conference sub-objects, such as the
maximum number of participants and the participants list, can be maximum number of participants and the participants list, can be
skipping to change at page 23, line 45 skipping to change at page 22, line 45
+-+-+---V-------------------+ | | +-+-+---V-------------------+ | |
| p | | | | | p | | | |
| o | Child Conference | | | | o | Child Conference | | |
| l | | | | | l | | | |
| i | Reservation | | | | i | Reservation | | |
| c | | | | | c | | | |
| i | | |-+ | i | | |-+
| e | |-+ | e | |-+
+-s-+-----------------------+ +-s-+-----------------------+
Figure 6: Advanced Conference Definition, Creation, and Lifetime. Figure 6: Advanced Conference Definition, Creation, and Lifetime
When the time comes to schedule the conference reservation, either When the time comes to schedule the conference reservation, either
via the system determination that the 'start' time has been reached via the system determination that the 'start' time has been reached
or via client invocation, an active conference is cloned based on the or via client invocation, an active conference is cloned based on the
conference reservation. As in the adhoc example, the active conference reservation. As in the adhoc example, the active
conference is independent from the parent and changes to the conference is independent from the parent, and changes to the
conference reservation will not impact the active conference. Any conference reservation will not impact the active conference. Any
desired changes must be targeted towards the active conference. An desired changes must be targeted towards the active conference. An
example of this interaction is shown in Section 9.1 example of this interaction is shown in Section 9.1.
7.4. Scheduling a conference 7.4. Scheduling a Conference
The capability to schedule conferences forms an important part of the The capability to schedule conferences forms an important part of the
conferencing system solution. An individual conference reservation conferencing system solution. An individual conference reservation
typically has a specified 'start' and 'end' time, with the times typically has a specified 'start' and 'end' time, with the times
being specified relative to a single specified 'fixed' time (e.g., being specified relative to a single specified 'fixed' time (e.g.,
'start' = 09.00 GMT, 'end'= 'start'+2), subject to system 'start' = 09.00 GMT, 'end'= 'start'+2), subject to system
considerations. In most advanced conferencing solutions it is considerations. In most advanced conferencing solutions, it is
possible to not only schedule an individual occurrence of a possible to not only schedule an individual occurrence of a
conference reservation, but also schedule a series of related conference reservation, but also schedule a series of related
conferences (e.g., a weekly meeting that starts on Thursday at 09.00 conferences (e.g., a weekly meeting that starts on Thursday at 09.00
GMT). GMT).
To be able to achieve such functionality, a conferencing system needs To be able to achieve such functionality, a conferencing system needs
to be able to appropriately schedule and maintain conference to be able to appropriately schedule and maintain conference
reservations that form part of a recurring conference. The mechanism reservations that form part of a recurring conference. The mechanism
proposed in this document makes use of the 'Internet Calendaring and proposed in this document makes use of the "Internet Calendaring and
Scheduling Core Object' specification defined in [RFC2445] in union Scheduling Core Object" specification defined in [RFC2445] in union
with the concepts introduced in Section 5 for the purpose of with the concepts introduced in Section 5 for the purpose of
achieving advanced conference scheduling capability. achieving advanced conference scheduling capability.
Figure 7 illustrates a simplified view of a client interacting with a Figure 7 illustrates a simplified view of a client interacting with a
conferencing system. The client is using the Conference Control conferencing system. The client is using the conference control
Protocol to add a new conference reservation to the conferencing protocol to add a new conference reservation to the conferencing
system by interfacing with the conference control server. A CCP system by interfacing with the conference control server. A CCP
request contains a valid conference reservation and reference by request contains a valid conference reservation and reference by
value to an 'iCal' object which contains scheduling information about value to an "iCal" object that contains scheduling information about
the conference (e.g., start time, end time). the conference (e.g., 'start' time, 'end' time).
+--------------+ +-------Conferencing System-----------------+ +--------------+ +-------Conferencing System-----------------+
| Generic ICAL | | | | Generic ICAL | | |
| Resource | | ..Conference Instance.... | | Resource | | ..Conference Instance.... |
+--------------+ | . . +-----------+| +--------------+ | . . +-----------+|
^ ^ | . +-------------------+ . | Conference|| ^ ^ | . +-------------------+ . | Conference||
| | | . |Conference Objects |<--| Control || | | | . |Conference Objects |<--| Control ||
| ----------------->. +-------------------+ . | Server || | ----------------->. +-------------------+ . | Server ||
| | . . +-----------+| | | . . +-----------+|
| | ......................... ^ | | | ......................... ^ |
skipping to change at page 25, line 47 skipping to change at page 24, line 47
| Conferencing| | Conferencing|
| Client | | Client |
+-------------+ +-------------+
Figure 7: Resource Scheduling Figure 7: Resource Scheduling
A CCP request to create a new conference reservation is validated, A CCP request to create a new conference reservation is validated,
including the associated iCal object, and the resultant conference including the associated iCal object, and the resultant conference
reservation is created. The conference reservation is uniquely reservation is created. The conference reservation is uniquely
represented within the conferencing system by a conference object represented within the conferencing system by a conference object
identifier (e.g., xcon:hd87928374) as introduced in Section 6.2.1 and identifier (e.g., xcon:hd87928374), as introduced in Section 6.2.1
defined in [I-D.ietf-xcon-common-data-model]. This unique URI is and defined in [XCON-COMMON]. This unique URI is returned to the
returned to the client and can be used to reference the conference client and can be used to reference the conference reservation, if
reservation, if any future manipulations are required (e.g., alter any future manipulations are required (e.g., alter 'start' time),
start time), using a CCP request. using a CCP request.
The previous example explains how a client creates a basic conference The previous example explains how a client creates a basic conference
reservation using an iCal reference in association with a conference reservation using an iCal reference in association with a conference
control protocol. Figure 7 can also be applied when explaining how a control protocol. Figure 7 can also be applied when explaining how a
series of conferences are scheduled in the system. The description series of conferences are scheduled in the system. The description
is almost identical with the exception that the iCal definition that is almost identical with the exception that the iCal definition that
is included in a CCP request represents a series of recurring is included in a CCP request represents a series of recurring
conference instances (e.g., conference start time, end time, occur conference instances (e.g., conference 'start' time, 'end' time,
weekly). The conferencing system will treat this request the same as occur weekly). The conferencing system will treat this request the
the first example. The CCP request will be validated, along with the same as the first example. The CCP request will be validated, along
associated iCal object, and the conference reservation is created. with the associated iCal object, and the conference reservation is
The conference reservation and its conference object ID created for created. The conference reservation and its conference object ID,
this example represent the entire series of recurring conference created for this example, represent the entire series of recurring
instances rather than a single Conference. If the client uses the conference instances rather than a single Conference. If the client
conference object ID provided and a CCP request to adjust the uses the conference object ID provided and a CCP request to adjust
conference reservation, every conference instance in the series will the conference reservation, every conference instance in the series
be altered. This includes all future occurrences, such as a will be altered. This includes all future occurrences, such as a
conference scheduled as an infinite series, subject to the conference scheduled as an infinite series, subject to the
limitations of the available calendaring interface. limitations of the available calendaring interface.
A conferencing system that supports the scheduling of a series of A conferencing system that supports the scheduling of a series of
conference instances should also be able to support manipulation conference instances should also be able to support manipulation
within a specific range of the series. A good example is a within a specific range of the series. A good example is a
conference reservation that has been scheduled to occur every Monday conference reservation that has been scheduled to occur every Monday
at 09.00 GMT. For the next three weeks only, the meeting has been at 09.00 GMT. For the next three weeks only, the meeting has been
altered to occur at 10.00 GMT in an alternative venue. With Figure 7 altered to occur at 10.00 GMT in an alternative venue. With Figure 7
in mind, the client will construct a CCP request whose purpose is to in mind, the client will construct a CCP request whose purpose is to
skipping to change at page 26, line 45 skipping to change at page 25, line 45
will contain all the required changes to the conference reservation will contain all the required changes to the conference reservation
(e.g., change of venue). (e.g., change of venue).
The conferencing system matches the incoming CCP request to the The conferencing system matches the incoming CCP request to the
existing conference reservation but identifies that the associated existing conference reservation but identifies that the associated
iCal object only refers to a range of the existing series. The iCal object only refers to a range of the existing series. The
conferencing system creates a child, by cloning the original conferencing system creates a child, by cloning the original
conference reservation, to represent the altered conference instances conference reservation, to represent the altered conference instances
within the series. The cloned child object is not independent of the within the series. The cloned child object is not independent of the
original parent object, thus preventing any potential conflicts in original parent object, thus preventing any potential conflicts in
scheduling (e.g., a change to the whole series 'start time'). The scheduling (e.g., a change to the whole series ''start' time'). The
cloned conference reservation, representing the altered series of cloned conference reservation, representing the altered series of
conference instances, has its own associated conference object ID conference instances, has its own associated conference object ID
which is returned to the client using a CCP response. This that is returned to the client using a CCP response. This conference
conference object ID is then used by the client to make any future object ID is then used by the client to make any future alterations
alterations on the newly defined sub-series. This process can be on the newly defined sub-series. This process can be repeated any
repeated any number of times as the newly returned conference object number of times as the newly returned conference object ID
ID representing an altered (cloned) series of conference instances, representing an altered (cloned) series of conference instances, can
can itself be manipulated using a CCP request for the newly created itself be manipulated using a CCP request for the newly created
conference object ID . This provides a flexible approach to the conference object ID . This provides a flexible approach to the
scheduling of recurring conference instances. scheduling of recurring conference instances.
8. Conferencing Mechanisms 8. Conferencing Mechanisms
8.1. Call Signaling 8.1. Call Signaling
The focus is the central component of the conference. Participants The focus is the central component of the conference. Participants
interface with the focus using an appropriate call signaling protocol interface with the focus using an appropriate call signaling protocol
(CSP). Participants request to establish or join a conference using (CSP). Participants request to establish or join a conference using
the CSP. After checking the applicable policies, a focus then either the CSP. After checking the applicable policies, a focus then either
accepts the request, sends a progress indication related to the accepts the request, sends a progress indication related to the
status of the request (e.g., for a parked call while awaiting status of the request (e.g., for a parked call while awaiting
moderator approval to join) or rejects that request using the call moderator approval to join), or rejects that request using the call
signaling interface. signaling interface.
During an active conference, a Conference Control Protocol can be During an active conference, a conference control protocol can be
used to affect the conference state. For example, CCP requests to used to affect the conference state. For example, CCP requests to
add and delete participants are communicated to the focus and checked add and delete participants are communicated to the focus and checked
against the conference policies. If approved, the participants are against the conference policies. If approved, the participants are
added or deleted using the call signaling to/from the focus. added or deleted using the call signaling to/from the focus.
8.2. Notifications 8.2. Notifications
A conferencing system is responsible for implementing a Conference A conferencing system is responsible for implementing a conference
Notification Service. The Conference Notification Service provides notification service. The conference notification service provides
updates about the conference instance state to authorized parties, updates about the conference instance state to authorized parties,
including participants. A model for notifications using SIP is including participants. A model for notifications using SIP is
defined in [RFC3265] with the specifics to support conferencing defined in [RFC3265] with the specifics to support conferencing
defined in [RFC4575]. defined in [RFC4575].
The conference user identifier and associated role are used by the The conference user identifier and associated role are used by the
conferencing system to filter the notifications such that they conferencing system to filter the notifications such that they
contain only information that is allowed to be sent to that user. contain only information that is allowed to be sent to that user.
8.3. Conference Control Protocol 8.3. Conference Control Protocol
skipping to change at page 28, line 5 skipping to change at page 27, line 4
The conference control protocol provides for data manipulation and The conference control protocol provides for data manipulation and
state retrieval for the centralized conferencing data, represented by state retrieval for the centralized conferencing data, represented by
the conference object. The details of the conference control the conference object. The details of the conference control
protocol are provided in separate documents. protocol are provided in separate documents.
8.4. Floor Control 8.4. Floor Control
A floor control protocol allows an authorized client to manage access A floor control protocol allows an authorized client to manage access
to a specific floor and to grant, deny or revoke access of other to a specific floor and to grant, deny or revoke access of other
conference users to that floor. Floor control is not a mandatory conference users to that floor. Floor control is not a mandatory
mechanism for a conferencing system implementation but provides mechanism for a conferencing system implementation, but it provides
advanced media input control features for conference users. A advanced media input control features for conference users. A
mechanism for floor control within a conferencing system is defined mechanism for floor control within a conferencing system is defined
in the Binary Floor Control Protocol specification [RFC4582]. in the "Binary Floor Control Protocol (BFCP)" specification
[RFC4582].
Within this framework, a client supporting floor control needs to Within this framework, a client supporting floor control needs to
obtain information for connecting to a floor control server to enable obtain information for connecting to a floor control server to enable
it to issue floor requests. This connection information can be it to issue floor requests. This connection information can be
retrieved using information provided by mechanisms such as retrieved using information provided by mechanisms such as
negotiation using the SDP[RFC4566] offer/answer[RFC3264] exchange on negotiation using the SDP [RFC4566] offer/answer [RFC3264] exchange
the signaling interface with the focus. Section 11.3 provides a on the signaling interface with the focus. Section 11.3 provides a
discussion of client authentication of a floor control server. discussion of client authentication of a floor control server.
As well as the client to the floor control server connection As well as the client to the floor control server connection
information, a client wishing to interact with a floor control server information, a client wishing to interact with a floor control server
requires access to additional information. This information requires access to additional information. This information
associates floor control interactions with the appropriate floor associates floor control interactions with the appropriate floor
instance. Once a connection has been established and authenticated instance. Once a connection has been established and authenticated
(see [RFC4582] for authentication details), a specific floor control (see [RFC4582] for authentication details), a specific floor control
message requires detailed information to uniquely identify a message requires detailed information to uniquely identify a
conference, a user and a floor. conference, a user, and a floor.
The conference is uniquely identifed by the conference object ID per The conference is uniquely identified by the conference object ID per
Section 6.2.1. This conference object ID must be included in all Section 6.2.1. This conference object ID must be included in all
floor control messages. When the SDP model is used as described in floor control messages. When the SDP model is used as described in
[RFC4583] this identifier maps to the 'confid' SDP attribute. [RFC4583], this identifier maps to the 'confid' SDP attribute.
Each authorized user associated with a conference object is uniquely Each authorized user associated with a conference object is uniquely
represented by a conference user ID per Section 6.3. This conference represented by a conference user ID per Section 6.3. This conference
user ID must be included in all floor control messages. When using user ID must be included in all floor control messages. When using
SDP offer/answer exchange to negotiate a Floor control connection SDP offer/answer exchange to negotiate a floor control connection
with the focus using the call signaling protocol, the unique with the focus using the call signaling protocol, the unique
conference user identifier is contained in the 'userid' SDP conference user identifier is contained in the 'userid' SDP
attribute, as defined in [RFC4583] attribute, as defined in [RFC4583].
A media session within a conferencing system can have any number of A media session within a conferencing system can have any number of
floors (0 or more) that are represented by the conference identifier. floors (0 or more) that are represented by the conference identifier.
When using SDP offer/answer exchange to negotiate a floor control When using SDP offer/answer exchange to negotiate a floor control
connection with the focus using the call signaling interface, the connection with the focus using the call signaling interface, the
unique conference identifier is contained in the 'floorid' SDP unique conference identifier is contained in the 'floorid' SDP
attribute, as defined in [RFC4583] e.g., a=floorid:1 m-stream:10 . attribute, as defined in [RFC4583], e.g., a=floorid:1 m-stream:10 .
Each 'floorid' attribute, representing a unique floor, has an Each 'floorid' attribute, representing a unique floor, has an
'm-stream' tag containing one or more identifiers. The identifiers 'm-stream' tag containing one or more identifiers. The identifiers
represent individual SDP media sessions (as defined using 'm=' from represent individual SDP media sessions (as defined using 'm=' from
SDP) using the SDP 'Label' attribute as defined in [RFC4574]. SDP) using the SDP 'Label' attribute, as defined in [RFC4574].
9. Conferencing Scenario Realizations 9. Conferencing Scenario Realizations
This section addresses how advanced conferencing scenarios, many of This section addresses how advanced conferencing scenarios, many of
which have been described in [RFC4597], are realized using this which have been described in [RFC4597], are realized using this
centralized conferencing framework. The objective of this section is centralized conferencing framework. The objective of this section is
to further illustrate the model, mechanisms and protocols presented to further illustrate the model, mechanisms, and protocols presented
in the previous sections and also serves to validate that the model, in the previous sections and also serves to validate that the model,
mechanisms and protocols are sufficient to support advanced mechanisms, and protocols are sufficient to support advanced
conferencing scenarios. conferencing scenarios.
The scenarios provide a high level primitive view of the necessary The scenarios provide a high level primitive view of the necessary
operations and general logic flow. The details shown in the operations and general logic flow. The details shown in the
scenarios are for illustrative purposes only and don't necessarily scenarios are for illustrative purposes only and don't necessarily
reflect the actual structure of the conference control protocol reflect the actual structure of the conference control protocol
messages nor the detailed data, including states, which are defined messages nor the detailed data, including states, which are defined
in separate documents. It should be noted that not all entities in separate documents. It should be noted that not all entities
impacted by the request are shown in the diagram (e.g., Focus), but impacted by the request are shown in the diagram (e.g., focus), but
rather the emphasis is on the new entities introduced by this rather the emphasis is on the new entities introduced by this
centralized conferencing framework. centralized conferencing framework.
9.1. Conference Creation 9.1. Conference Creation
There are different ways to create a conference. A participant can There are different ways to create a conference. A participant can
create a conference using call signaling means only, such as SIP and create a conference using call signaling means only, such as SIP
detailed in [RFC4579]. For a conferencing client to have more detailed in [RFC4579]. For a conferencing client to have more
flexibility in defining the charaterisitics and capabilities of a flexibility in defining the characteristics and capabilities of a
conference, a conferencing client would implement a conference conference, a conferencing client would implement a conference
control protocol client. By using a conference control protocol, the control protocol client. By using a conference control protocol, the
client can determine the capabilities of a conferencing system and client can determine the capabilities of a conferencing system and
its various resources. its various resources.
Figure 8 provides an example of one client "Alice" determining the Figure 8 provides an example of one client "Alice" determining the
conference blueprints available for a particular conferencing system conference blueprints available for a particular conferencing system
and creating a conference based on the desired blueprint. and creating a conference based on the desired blueprint.
+--------------------------------+ +--------------------------------+
skipping to change at page 30, line 43 skipping to change at page 29, line 43
| |CCP Request <add, | V | | |CCP Request <add, | V |
| |reservationConfObjID, | +-----------+ +------------+| | |reservationConfObjID, | +-----------+ +------------+|
| Client |-------------------------->|Conference | |Active || | Client |-------------------------->|Conference | |Active ||
| | confID,confUserID> | |Control |~~~>|Conference || | | confID,confUserID> | |Control |~~~>|Conference ||
| |<--------------------------|Server | | || | |<--------------------------|Server | | ||
| |CCP Response | | | +------------+| | |CCP Response | | | +------------+|
+--------+ <activeConfObjID, | | | | +--------+ <activeConfObjID, | | | |
confID> | +-----------+ | confID> | +-----------+ |
+--------------------------------+ +--------------------------------+
Figure 8: Client Creation of Conference using Blueprints Figure 8: Client Creation of Conference Using Blueprints
Upon receipt of the Conference Control Protocol request for Upon receipt of the conference control protocol request for
blueprints, the conferencing system would first authenticate "Alice" blueprints, the conferencing system would first authenticate "Alice"
(and allocate a conference user identifier, if necessary) and then (and allocate a conference user identifier, if necessary) and then
ensure that "Alice" has the appropriate authority based on system ensure that "Alice" has the appropriate authority based on system
policies to receive any blueprints supported by that system. Any policies to receive any blueprints supported by that system. Any
blueprints that "Alice" is authorized to use are returned in a blueprints that "Alice" is authorized to use are returned in a
response, along with the conference user ID. response, along with the conference user ID.
Upon receipt of the Conference Control Protocol response containing Upon receipt of the conference control protocol response containing
the blueprints, "Alice" determines which blueprint to use for the the blueprints, "Alice" determines which blueprint to use for the
conference to be created. "Alice" creates a conference object based conference to be created. "Alice" creates a conference object based
on the blueprint (i.e., clones) and modifies applicable fields, such on the blueprint (i.e., clones) and modifies applicable fields, such
as membership list and start time. "Alice" then sends a request to as membership list and 'start' time. "Alice" then sends a request to
the conferencing system to create a conference reservation based upon the conferencing system to create a conference reservation based upon
the updated blueprint. the updated blueprint.
Upon receipt of the Conference Control Protocol request to "reserve" Upon receipt of the conference control protocol request to "reserve"
a conference based upon the blueprint in the request, the a conference based upon the blueprint in the request, the
conferencing system ensures that the blueprint received is a valid conferencing system ensures that the blueprint received is a valid
blueprint (i.e. the values of the various field are within range). blueprint (i.e., the values of the various field are within range).
The conferencing system determines the appropriate read/write access The conferencing system determines the appropriate read/write access
of any users to be added to a conference based on this blueprint of any users to be added to a conference based on this blueprint
(using membership, roles, etc.). The conferencing system uses the (using membership, roles, etc.). The conferencing system uses the
received blueprint to clone a conference reservation. The received blueprint to clone a conference reservation. The
conferencing system also reserves or allocates a conference ID to be conferencing system also reserves or allocates a conference ID to be
used for any subsequent protocol requests from any of the members of used for any subsequent protocol requests from any of the members of
the conference. The conferencing system maintains the mapping the conference. The conferencing system maintains the mapping
between this conference ID and the conference object ID associated between this conference ID and the conference object ID associated
with the reservation through the conference instance. with the reservation through the conference instance.
skipping to change at page 32, line 6 skipping to change at page 31, line 6
9.2. Participant Manipulations 9.2. Participant Manipulations
There are different ways to affect a participant state in a There are different ways to affect a participant state in a
conference. A participant can join and leave the conference using conference. A participant can join and leave the conference using
call signaling means only, such as SIP. This kind of operation is call signaling means only, such as SIP. This kind of operation is
called "1st party signaling" and does not affect the state of other called "1st party signaling" and does not affect the state of other
participants in the conference. participants in the conference.
Limited operations for controlling other conference participants (a Limited operations for controlling other conference participants (a
so called "3rd party control") through the Focus, using call so called "3rd party control") through the focus, using call
signaling only, may also be available for some signaling protocols. signaling only, may also be available for some signaling protocols.
For example, "Conferencing for SIP User Agents" [RFC4579] shows how For example, "Conferencing for SIP User Agents" [RFC4579] shows how
SIP with REFER can be used to achieve this functionality. SIP with REFER can be used to achieve this functionality.
In order to perform richer conference control a user client needs to In order to perform richer conference control, a user client needs to
implement a conference control protocol client. By using a implement a conference control protocol client. By using a
conference control protocol, the client can affect its own state, conference control protocol, the client can affect its own state, the
state of other participants, and state of various resources (such as state of other participants, and the state of various resources (such
media mixers) which may indirectly affect the state of any of the as media mixers) that may indirectly affect the state of any of the
conference participants. conference participants.
Figure 9 provides an example of one client "Alice" impacting the Figure 9 provides an example of one client "Alice" impacting the
state of another client "Bob". This example assumes an established state of another client "Bob". This example assumes an established
conference. In this example, "Alice" wants to add "Bob" to the conference. In this example, "Alice" wants to add "Bob" to the
conference. conference.
+--------------------------------+ +--------------------------------+
| Conferencing System | | Conferencing System |
"Alice" | +---------+--+| "Alice" | +---------+--+|
skipping to change at page 32, line 43 skipping to change at page 31, line 43
"Carol" | ' ' '| "Carol" | ' ' '|
+--------+ NOTIFY <"Bob"="added"> |+------------+ ' ' '| +--------+ NOTIFY <"Bob"="added"> |+------------+ ' ' '|
| |<-------------------------|Notification|<~~~| || | |<-------------------------|Notification|<~~~| ||
| Client |. . ||Service | +-------+ || | Client |. . ||Service | +-------+ ||
+--------+--+ . || | |"Bob" | || +--------+--+ . || | |"Bob" | ||
| |<----------------------| | +-------+----+| | |<----------------------| | +-------+----+|
| Client |NOTIFY <"Bob"="added">|+------------+ | | Client |NOTIFY <"Bob"="added">|+------------+ |
+--------+ +--------------------------------+ +--------+ +--------------------------------+
"Bob" "Bob"
Figure 9: Client Manipulation of Conference - Add a party Figure 9: Client Manipulation of Conference - Add a Party
Upon receipt of the Conference Control Protocol request to "add" a Upon receipt of the conference control protocol request to "add" a
party ("Bob") in the specific conference as identified by the party ("Bob") in the specific conference as identified by the
conference object ID, the conferencing system ensures that "Alice" conference object ID, the conferencing system ensures that "Alice"
has the appropriate authority based on the policies associated with has the appropriate authority based on the policies associated with
that specific conference object to perform the operation. The that specific conference object to perform the operation. The
conferencing system must also determine whether "Bob" is already a conferencing system must also determine whether "Bob" is already a
user of this conferencing system or whether he is a new user. user of this conferencing system or whether he is a new user.
If "Bob" is a new user for this conferencing system, a Conference If "Bob" is a new user for this conferencing system, a Conference
User Identifier is created for Bob. Based upon the addressing User Identifier is created for Bob. Based upon the addressing
information provided for "Bob" by "Alice", the call signaling to add information provided for "Bob" by "Alice", the call signaling to add
"Bob" to the conference is instigated through the Focus. "Bob" to the conference is instigated through the focus.
Once the call signaling indicates that "Bob" has been successfully Once the call signaling indicates that "Bob" has been successfully
added to the specific conference, per updates to the state, and added to the specific conference, per updates to the state, and
depending upon the policies, other participants (including "Bob") may depending upon the policies, other participants (including "Bob") may
be notified of the addition of "Bob" to the conference via the be notified of the addition of "Bob" to the conference via the
Conference Notification Service. conference notification service.
9.3. Media Manipulations 9.3. Media Manipulations
There are different ways to manipulate the media in a conference. A There are different ways to manipulate the media in a conference. A
participant can change its own media streams by, for example, sending participant can change its own media streams by, for example, sending
re-INVITE with new SDP content using SIP only. This kind of re-INVITE with new SDP content using SIP only. This kind of
operation is called "1st party signaling" and they do not affect the operation is called "1st party signaling" and they do not affect the
state of other participants in the conference. state of other participants in the conference.
In order to perform richer conference control a user client needs to In order to perform richer conference control, a user client needs to
implement a conference control protocol client. By using a implement a conference control protocol client. By using a
conference control protocol, the client can manipulate the state of conference control protocol, the client can manipulate the state of
various resources, such as media mixers, which may indirectly affect various resources, such as media mixers, which may indirectly affect
the state of any of the conference participants. the state of any of the conference participants.
Figure 10 provides an example of one client "Alice" impacting the Figure 10 provides an example of one client "Alice" impacting the
media state of another client "Bob". This example assumes an media state of another client "Bob". This example assumes an
established conference. In this example, the client, "Alice" whose established conference. In this example, the client, "Alice" whose
Role is "moderator" of the conference, wants to mute "Bob" on a Role is "moderator" of the conference, wants to mute "Bob" on a
medium-size multi-party conference, as his device is not muted (and medium-size multi-party conference, as his device is not muted (and
skipping to change at page 34, line 25 skipping to change at page 33, line 25
"Carol" | ' ' '| "Carol" | ' ' '|
+--------+ NOTIFY <"Bob"=mute"> |+------------+ ' ' '| +--------+ NOTIFY <"Bob"=mute"> |+------------+ ' ' '|
| |<-------------------------|Notification|<~~~| || | |<-------------------------|Notification|<~~~| ||
| Client |. . ||Service | +-------+ || | Client |. . ||Service | +-------+ ||
+--------+--+ . || | |"Bob" | || +--------+--+ . || | |"Bob" | ||
| |<----------------------| | +-------+----+| | |<----------------------| | +-------+----+|
| Client | NOTIFY <"Bob"=mute">|+------------+ | | Client | NOTIFY <"Bob"=mute">|+------------+ |
+--------+ +--------------------------------+ +--------+ +--------------------------------+
"Bob" "Bob"
Figure 10: Client Manipulation of Conference - Mute a party Figure 10: Client Manipulation of Conference - Mute a Party
Upon receipt of the Conference Control Protocol request to "mute" a Upon receipt of the conference control protocol request to "mute" a
party ("Bob") in the specific conference as identified by the party ("Bob") in the specific conference as identified by the
conference object ID, the Conference Server ensures that "Alice" has conference object ID, the conference server ensures that "Alice" has
the appropriate authority based on the policies associated with that the appropriate authority based on the policies associated with that
specific conference object to perform the operation. "Bob's" status specific conference object to perform the operation. "Bob's" status
is marked as "recvonly" and the conference object is updated to is marked as "recvonly" and the conference object is updated to
reflect that "Bob's" media is not to be "mixed" with the conference reflect that "Bob's" media is not to be "mixed" with the conference
media. media.
Depending upon the policies, other participants (including "Bob") may Depending upon the policies, other participants (including "Bob") may
be notified of this change via the Conference Notification Service. be notified of this change via the conference notification service.
9.4. Sidebar Manipulations 9.4. Sidebar Manipulations
A sidebar can be viewed as a separate Conference instance that only A sidebar can be viewed as a separate Conference instance that only
exists within the context of a parent conference instance. Although exists within the context of a parent conference instance. Although
viewed as an independent conference instance, it can not exist viewed as an independent conference instance, it can not exist
without a parent. A sidebar is created using the same mechanisms without a parent. A sidebar is created using the same mechanisms
employed for a standard conference as described in Section 7.1. employed for a standard conference, as described in Section 7.1.
A conference object representing a sidebar is created by cloning the A conference object representing a sidebar is created by cloning the
parent associated with the existing conference and updating any parent associated with the existing conference and updating any
information specific to the sidebar. A sidebar conference object is information specific to the sidebar. A sidebar conference object is
implicitly linked to the parent conference object (i.e. it is not an implicitly linked to the parent conference object (i.e., it is not an
independent object) and is associated with the parent conference independent object) and is associated with the parent conference
object identifier as shown in Figure 11. A conferencing system object identifier, as shown in Figure 11. A conferencing system
manages and enforces the parent and appropriate localized manages and enforces the parent and appropriate localized
restrictions on the sidebar conference object (e.g., no members from restrictions on the sidebar conference object (e.g., no members from
outside the parent conference instance can join, sidebar conference outside the parent conference instance can join, sidebar conference
can not exist if parent conference is terminated, etc.). can not exist if parent conference is terminated, etc.).
+--------------+ +--------------+
| Conference | | Conference |
| Object | | Object |
| Identifier | | Identifier |
+--------------+ +--------------+
skipping to change at page 35, line 29 skipping to change at page 34, line 29
| |
+---------------------+---------------------+ +---------------------+---------------------+
| | | | | |
+-------+-------+ +-------+-------+ +-------+-------+ +-------+-------+ +-------+-------+ +-------+-------+
| Sidebar | | Sidebar | | Sidebar | | Sidebar | | Sidebar | | Sidebar |
| Conference | | Conference | | Conference | | Conference | | Conference | | Conference |
| Object | | Object | | Object | | Object | | Object | | Object |
| Identifier | | Identifier | | Identifier | | Identifier | | Identifier | | Identifier |
+-------+-------+ +-------+-------+ +---------------+ +-------+-------+ +-------+-------+ +---------------+
Figure 11: Conference Object Mapping. Figure 11: Conference Object Mapping
Figure 11 illustrates the relationship between a conference object Figure 11 illustrates the relationship between a conference object
and associated Sidebar conference objects within a conferencing and associated sidebar conference objects within a conferencing
system. Each Sidebar conference object has a unique conference system. Each sidebar conference object has a unique conference
object Identifier as described in Section 6.2.1. The main conference object identifier, as described in Section 6.2.1. The main
object identifier acts as a top level identifier for associated conference object identifier acts as a top level identifier for
sidebars. associated sidebars.
A sidebar conference object Identifier follows many of the concepts A sidebar conference object identifier follows many of the concepts
outlined in the cloning tree model described in Section 7.1. A outlined in the cloning tree model described in Section 7.1. A
Sidebar conference object contains a subset of members from the sidebar conference object contains a subset of members from the
original Conference object. Properties of the sidebar conference original conference object. Properties of the sidebar conference
object can be manipulated by a Conference Control Protocol using the object can be manipulated by a Conference Control Protocol using the
unique conference object identifier for the sidebar. It is also unique conference object identifier for the sidebar. It is also
possible for the top level conference object to enforce policy on the possible for the top level conference object to enforce policy on the
sidebar object (similar to parent enforceable as discussed in sidebar object (similar to parent enforceable, as discussed in
Section 7.1). Section 7.1).
9.4.1. Internal Sidebar 9.4.1. Internal Sidebar
Figure 12 provides an example of one client "Alice" involved in Figure 12 provides an example of one client "Alice" involved in
active conference with "Bob" and "Carol". "Alice" wants to create a active conference with "Bob" and "Carol". "Alice" wants to create a
sidebar to have a side discussion with "Bob" while still viewing the sidebar to have a side discussion with "Bob" while still viewing the
video associated with the main conference. Alternatively, the audio video associated with the main conference. Alternatively, the audio
from the main conference could be maintained at a reduced volume. from the main conference could be maintained at a reduced volume.
"Alice" initiates the sidebar by sending a request to the "Alice" initiates the sidebar by sending a request to the
skipping to change at page 38, line 4 skipping to change at page 36, line 51
| | | |Conference || | | | |Conference ||
| +-----------+ +-------+ || | +-----------+ +-------+ ||
| |"Alice"| || | |"Alice"| ||
"Bob" | | | || "Bob" | | | ||
+--------+ NOTIFY <"Bob"=added> |+------------+ +-------+ || +--------+ NOTIFY <"Bob"=added> |+------------+ +-------+ ||
| |<-------------------------|Notification|<~~~| | || | |<-------------------------|Notification|<~~~| | ||
| Client | ||Service | |"Bob" | || | Client | ||Service | |"Bob" | ||
+--------+ || | +-------+----+| +--------+ || | +-------+----+|
|+------------+ | |+------------+ |
+--------------------------------+ +--------------------------------+
Figure 12: Client Creation of a Sidebar Conference
Upon receipt of the Conference Control Protocol request to "reserve" Figure 12: Client Creation of a Sidebar Conference
Upon receipt of the conference control protocol request to "reserve"
a new sidebar conference, based upon the active conference received a new sidebar conference, based upon the active conference received
in the request, the conferencing system uses the received active in the request, the conferencing system uses the received active
conference to clone a conference reservation for the sidebar. As conference to clone a conference reservation for the sidebar. As
discussed previously, the sidebar reservation is NOT independent of discussed previously, the sidebar reservation is NOT independent of
the active conference (i.e., parent). The conferencing system also the active conference (i.e., parent). The conferencing system also
reserves or allocates a conference ID to be used for any subsequent reserves or allocates a conference ID to be used for any subsequent
protocol requests from any of the members of the conference. The protocol requests from any of the members of the conference. The
conferencing system maintains the mapping between this conference ID conferencing system maintains the mapping between this conference ID
and the conference object ID associated with the sidebar reservation and the conference object ID associated with the sidebar reservation
through the conference instance. through the conference instance.
Upon receipt of the conference control protocol response to reserve Upon receipt of the conference control protocol response to reserve
the conference, "Alice" can now create an active conference using the conference, "Alice" can now create an active conference using
that reservation or create additional reservations based upon the that reservation or create additional reservations based upon the
existing reservations. In this example, "Alice" wants only "Bob" to existing reservations. In this example, "Alice" wants only "Bob" to
be involved in the sidebar, thus she manipulates the membership. be involved in the sidebar, thus she manipulates the membership.
"Alice" also only wants the video from the original conference and "Alice" also only wants the video from the original conference and
wants the audio to be restricted to the participants in the sidebar. wants the audio to be restricted to the participants in the sidebar.
Alternatively, "Alice" could manipulate the media values to recieve Alternatively, "Alice" could manipulate the media values to receive
the audio from the main conference at a reduced volume. "Alice" the audio from the main conference at a reduced volume. "Alice"
sends a conference control protocol request to update the information sends a conference control protocol request to update the information
in the reservation and to create an active conference. in the reservation and to create an active conference.
Upon receipt of the conference control protocol request to update the Upon receipt of the conference control protocol request to update the
reservation and to create an active conference for the sidebar, as reservation and to create an active conference for the sidebar, as
identified by the conference object ID, the conferencing system identified by the conference object ID, the conferencing system
ensures that "Alice" has the appropriate authority based on the ensures that "Alice" has the appropriate authority based on the
policies associated with that specific conference object to perform policies associated with that specific conference object to perform
the operation. The conferencing system must also validate the the operation. The conferencing system must also validate the
skipping to change at page 38, line 47 skipping to change at page 37, line 45
"Bob" is already a user of this conferencing system. "Bob" is already a user of this conferencing system.
Depending upon the policies, the initiator of the request (i.e., Depending upon the policies, the initiator of the request (i.e.,
"Alice") and the participants in the sidebar (i.e., "Bob") may be "Alice") and the participants in the sidebar (i.e., "Bob") may be
notified of his addition to the sidebar via the conference notified of his addition to the sidebar via the conference
notification service. notification service.
9.4.2. External Sidebar 9.4.2. External Sidebar
Figure 13 provides an example of one client "Alice" involved in an Figure 13 provides an example of one client "Alice" involved in an
active conference with "Bob", "Carol", "David" and "Ethel". "Alice" active conference with "Bob", "Carol", "David", and "Ethel". "Alice"
gets an important text message via a whisper from "Bob" that a gets an important text message via a whisper from "Bob" that a
critical customer needs to talk to "Alice", "Bob" and "Ethel". critical customer needs to talk to "Alice", "Bob", and "Ethel".
"Alice" creates a sidebar to have a side discussion with the customer "Alice" creates a sidebar to have a side discussion with the customer
"Fred" including the participants in the current conference with the "Fred" including the participants in the current conference with the
exception of "Carol" and "David", who remain in the active exception of "Carol" and "David", who remain in the active
conference. "Alice" initiates the sidebar by sending a request to conference. "Alice" initiates the sidebar by sending a request to
the conferencing system to create a conference reservation based upon the conferencing system to create a conference reservation based upon
the active conference object. "Alice", "Bob" and "Ethel" would the active conference object. "Alice", "Bob", and "Ethel" would
remain on the roster of the main conference in a hold state. Whether remain on the roster of the main conference in a hold state. Whether
or not the hold state of these participants is visible to other or not the hold state of these participants is visible to other
participants depends upon the individual and local policy. participants depends upon the individual and local policy.
+--------------------------------+ +--------------------------------+
| Conferencing System | | Conferencing System |
| +---------+--+| | +---------+--+|
| |policies | || | |policies | ||
| +---------+ || | +---------+ ||
| |Active || | |Active ||
skipping to change at page 40, line 19 skipping to change at page 39, line 17
| Client |<-------------------------|Notification|<~~~+-------+ || | Client |<-------------------------|Notification|<~~~+-------+ ||
+--------+ "Ethel"=added, ||Service | |"Ethel"| || +--------+ "Ethel"=added, ||Service | |"Ethel"| ||
"Fred"=added,> || | +-------+ || "Fred"=added,> || | +-------+ ||
"Ethel" +---| | |"Fred" | || "Ethel" +---| | |"Fred" | ||
+--------+ NOTIFY <"Bob"=added,| |+------------+ +-------+----+| +--------+ NOTIFY <"Bob"=added,| |+------------+ +-------+----+|
| Client | <--------------------+ +--------------------------------+ | Client | <--------------------+ +--------------------------------+
+--------+ "Ethel"=added,"Fred"=added,> +--------+ "Ethel"=added,"Fred"=added,>
Figure 13: Client Creation of an External Sidebar Figure 13: Client Creation of an External Sidebar
Upon receipt of the Conference Control Protocol request to "reserve" Upon receipt of the conference control protocol request to "reserve"
a new sidebar conference, based upon the active conference received a new sidebar conference, based upon the active conference received
in the request, the conferencing system uses the received active in the request, the conferencing system uses the received active
conference to clone a conference reservation for the sidebar. As conference to clone a conference reservation for the sidebar. As
discussed previously, the sidebar reservation is NOT independent of discussed previously, the sidebar reservation is NOT independent of
the active conference (i.e., parent). The conferencing system also the active conference (i.e., parent). The conferencing system also
reserves or allocates a conference ID to be used for any subsequent reserves or allocates a conference ID to be used for any subsequent
protocol requests from any of the members of the conference. The protocol requests from any of the members of the conference. The
conferencing system maintains the mapping between this conference ID conferencing system maintains the mapping between this conference ID
and the conference object ID associated with the sidebar reservation and the conference object ID associated with the sidebar reservation
through the conference instance. through the conference instance.
Upon receipt of the conference control protocol response to reserve Upon receipt of the conference control protocol response to reserve
the conference, "Alice" can now create an active conference using the conference, "Alice" can now create an active conference using
that reservation or create additional reservations based upon the that reservation or create additional reservations based upon the
existing reservations. In this example, "Alice" wants only "Bob" and existing reservations. In this example, "Alice" wants only "Bob" and
"Ethel", along with the new participant "Fred" to be involved in the "Ethel", along with the new participant "Fred" to be involved in the
sidebar, thus she manipulates the membership. "Alice" sets the media sidebar; thus, she manipulates the membership. "Alice" sets the
such that the participants in the sidebar don't receive any media media such that the participants in the sidebar don't receive any
from the main conference. "Alice" sends a conference control media from the main conference. "Alice" sends a conference control
protocol request to update the information in the reservation and to protocol request to update the information in the reservation and to
create an active conference. create an active conference.
Upon receipt of the conference control protocol request to update the Upon receipt of the conference control protocol request to update the
reservation and to create an active conference for the sidebar, as reservation and to create an active conference for the sidebar, as
identified by the conference object ID, the conferencing system identified by the conference object ID, the conferencing system
ensures that "Alice" has the appropriate authority based on the ensures that "Alice" has the appropriate authority based on the
policies associated with that specific conference object to perform policies associated with that specific conference object to perform
the operation. The conferencing system must also validate the the operation. The conferencing system must also validate the
updated information in the reservation, ensuring whether members like updated information in the reservation, ensuring whether members like
"Fred" are already a user of this conferencing system or whether he "Fred" are already a user of this conferencing system or whether he
is a new user. Since "Fred" is a new user for this conferencing is a new user. Since "Fred" is a new user for this conferencing
system, a conference user identifier is created for "Fred". Based system, a conference user identifier is created for "Fred". Based
upon the addressing information provided for "Fred" by "Alice", the upon the addressing information provided for "Fred" by "Alice", the
call signaling to add "Fred" to the conference is instigated through call signaling to add "Fred" to the conference is instigated through
the Focus. the focus.
Depending upon the policies, the initiator of the request (i.e., Depending upon the policies, the initiator of the request (i.e.,
"Alice") and the participants in the sidebar (i.e., "Bob" and "Alice") and the participants in the sidebar (i.e., "Bob" and
"Ethel") may be notified of his addition to the sidebar via the "Ethel") may be notified of his addition to the sidebar via the
conference notification service. conference notification service.
9.5. Floor control using sidebars 9.5. Floor Control Using Sidebars
Floor control with sidebars can be used to realize conferencing Floor control with sidebars can be used to realize conferencing
scenario such as an analyst briefing. In this scenario, the scenarios such as an analyst briefing. In this scenario, the
conference call has a panel of speakers who are allowed to talk in conference call has a panel of speakers who are allowed to talk in
the main conference. The other participants are the analysts, who the main conference. The other participants are the analysts, who
are not allowed to speak unless they have the floor. To request are not allowed to speak unless they have the floor. To request
access to the floor, they have to join a new sidebar with the access to the floor, they have to join a new sidebar with the
moderator and ask their question. The moderator can also whisper to moderator and ask their question. The moderator can also whisper to
each analyst what their status/position in the floor control queue, each analyst what their status/position in the floor control queue,
similar to the example in Figure 15 similar to the example in Figure 15.
Figure 14 provides an example of the configuration involved for this Figure 14 provides an example of the configuration involved for this
type of conference. As in the previous sidebar examples, there is type of conference. As in the previous sidebar examples, there is
the main conference along with a sidebar. "Alice" and "Bob" are the the main conference along with a sidebar. "Alice" and "Bob" are the
main participants in the conference, with "A1", "A2" and "A3" main participants in the conference, with "A1", "A2", and "A3"
representing the analysts. The sidebar remains active throughout the representing the analysts. The sidebar remains active throughout the
conference, with the moderator, "Carol", serving as the chair. As conference, with the moderator, "Carol", serving as the chair. As
discussed previously, the sidebar conference is NOT independent of discussed previously, the sidebar conference is NOT independent of
the active conference (i.e., parent). The analysts are provided the the active conference (i.e., parent). The analysts are provided the
conference object ID associated with the active sidebar when they conference object ID associated with the active sidebar when they
join the main conference. The conferencing system also allocates a join the main conference. The conferencing system also allocates a
conference ID to be used for any subsequent manipulations of the conference ID to be used for any subsequent manipulations of the
sidebar conference. The conferencing system maintains the mapping sidebar conference. The conferencing system maintains the mapping
between this conference ID and the conference object ID associated between this conference ID and the conference object ID associated
with the active sidebar conference through the conference instance. with the active sidebar conference through the conference instance.
skipping to change at page 42, line 50 skipping to change at page 41, line 50
| |Active || | |Active ||
| |Sidebar || | |Sidebar ||
"A1" | |Conference || "A1" | |Conference ||
+--------+ Floor Granted <"A1", |+------------+ +-------+ || +--------+ Floor Granted <"A1", |+------------+ +-------+ ||
| |<-------------------------|Floor Ctrl |<~~~|"Carol"| || | |<-------------------------|Floor Ctrl |<~~~|"Carol"| ||
| Client | activeSideConfObjID,||Server | +-------+ || | Client | activeSideConfObjID,||Server | +-------+ ||
+--------+ confID > || | |"A1" | || +--------+ confID > || | |"A1" | ||
|+------------+ +-------+----+| |+------------+ +-------+----+|
+--------------------------------+ +--------------------------------+
Figure 14: Floor Control with sidebars Figure 14: Floor Control with Sidebars
When "A1" wishes to ask a question, he sends a Floor Request message When "A1" wishes to ask a question, he sends a Floor Request message
to the floor control server. Upon receipt of the request, the floor to the floor control server. Upon receipt of the request, the floor
control server notifies the moderator, "Carol" of the active sidebar control server notifies the moderator, "Carol" of the active sidebar
conference, whose serving as the floor chair. Note, that this conference, who's serving as the floor chair. Note, that this
signaling flow is not shown in the diagram. Since no other analysts signaling flow is not shown in the diagram. Since no other analysts
have yet requested the floor, "Carol" indicates to the floor control have yet requested the floor, "Carol" indicates to the floor control
server that "A1" may be granted the floor. server that "A1" may be granted the floor.
9.6. Whispering or Private Messages 9.6. Whispering or Private Messages
The case of private messages can be handled as a sidebar with just The case of private messages can be handled as a sidebar with just
two participants, similar to the example in section Section 9.4.1, two participants, similar to the example in Section 9.4.1, but rather
but rather than using audio within the sidebar, "Alice" could add an than using audio within the sidebar, "Alice" could add an additional
additional text based media stream to the sidebar. The other text based media stream to the sidebar. The other context, referred
context, referred to as whisper, in this document refers to to as whisper, in this document refers to situations involving one
situations involving one time media targetted to specific user(s). time media targeted to specific user(s). An example of a whisper
An example of a whisper would be an announcement injected only to the would be an announcement injected only to the conference chair or to
conference chair or to a new participant joining a conference. a new participant joining a conference.
Figure 15 provides an example of one user "Alice" whose chairing a Figure 15 provides an example of one user "Alice" who's chairing a
fixed length conference with "Bob" and "Carol". The configuration is fixed length conference with "Bob" and "Carol". The configuration is
such that only the chair is providing a warning when there is only 10 such that only the chair is providing a warning when there are only
minutes left in the conference. At that time, "Alice" is moved into 10 minutes left in the conference. At that time, "Alice" is moved
a sidebar created by the conferencing system and only "Alice" into a sidebar created by the conferencing system and only "Alice"
receives the announcement. receives the announcement.
+--------------------------------+ +--------------------------------+
| Conferencing System | | Conferencing System |
| +---------+--+| | +---------+--+|
| |policies | || | |policies | ||
| +---------+ || | +---------+ ||
| |Active || | |Active ||
| |Conference || | |Conference ||
| +-------+ || | +-------+ ||
skipping to change at page 45, line 4 skipping to change at page 43, line 51
| | |~~~>+ \ / || | | |~~~>+ \ / ||
| | | | \ / || | | | | \ / ||
| +-----------+ |Sid\bar / || | +-----------+ |Sid\bar / ||
"Alice" | |Conf\re/ce || "Alice" | |Conf\re/ce ||
+--------+ NOTIFY <"Alice"=removed,|+------------+ +-----\/+ || +--------+ NOTIFY <"Alice"=removed,|+------------+ +-----\/+ ||
| |<-------------------------|Notification|<~~~| /\| || | |<-------------------------|Notification|<~~~| /\| ||
| Client | activeSideConfObjID,||Service | |"Ali/ce\ || | Client | activeSideConfObjID,||Service | |"Ali/ce\ ||
+--------+ confID > || | +---/---+\---+| +--------+ confID > || | +---/---+\---+|
|+------------+ / \ | |+------------+ / \ |
+--------------------------------+ +--------------------------------+
Figure 15: Whisper
When the conferencing system determines that there is only 10 minutes Figure 15: Whisper
left in the conference which "Alice" is chairing, rather than When the conferencing system determines that there are only 10
minutes left in the conference which "Alice" is chairing, rather than
creating a reservation as was done for the sidebar in Section 9.4.1, creating a reservation as was done for the sidebar in Section 9.4.1,
the conferencing system directly creates an active sidebar the conferencing system directly creates an active sidebar
conference, based on the active conference associated with "Alice". conference, based on the active conference associated with "Alice".
As discussed previously, the sidebar conference is NOT independent of As discussed previously, the sidebar conference is NOT independent of
the active conference (i.e., parent). The conferencing system also the active conference (i.e., parent). The conferencing system also
allocates a conference ID to be used for any subsequent manipulations allocates a conference ID to be used for any subsequent manipulations
of the sidebar conference. The conferencing system maintains the of the sidebar conference. The conferencing system maintains the
mapping between this conference ID and the conference object ID mapping between this conference ID and the conference object ID
associated with the active sidebar conference through the conference associated with the active sidebar conference through the conference
instance. instance.
Immediately upon creation of the active sidebar conference, the Immediately upon creation of the active sidebar conference, the
announcement media is provided to "Alice". Depending upon the announcement media is provided to "Alice". Depending upon the
policies, Alice may be notified of her addition to the sidebar via policies, "Alice" may be notified of her addition to the sidebar via
the conference notification service. "Alice" continues to receive the conference notification service. "Alice" continues to receive
the media from the main conference. the media from the main conference.
Upon completion of the announcement, "Alice" is removed from the Upon completion of the announcement, "Alice" is removed from the
siebar and the sidebar conference is deleted. Depending upon the sidebar, and the sidebar conference is deleted. Depending upon the
policies, "Alice" may be notified of her removal from the sidebar via policies, "Alice" may be notified of her removal from the sidebar via
the conference notification service. the conference notification service.
9.7. Conference Announcements and Recordings 9.7. Conference Announcements and Recordings
Each participant can require a different type of announcement and/or Each participant can require a different type of announcement and/or
recording service from the system. For example, "Alice", the recording service from the system. For example, "Alice", the
conference chair, could be listening to a roll call while "Bob" may conference chair, could be listening to a roll call while "Bob" may
be using a telephony user interface to create a sidebar. Some be using a telephony user interface to create a sidebar. Some
announcements would apply to all the participants such as "This announcements would apply to all the participants such as "This
conference will end in 10 minutes". Recording is often required to conference will end in 10 minutes". Recording is often required to
capture the names of participants as they join a conference, capture the names of participants as they join a conference,
typically after the participant has entered an access code as typically after the participant has entered an access code, as
discussed in Section 9.8. These recorded names are then announced to discussed in Section 9.8. These recorded names are then announced to
all the participants as the new participant is added to the active all the participants as the new participant is added to the active
conference. conference.
An example of a conferencing recording and announcement , along with An example of a conferencing recording and announcement , along with
collecting the DTMF, within the context of this framework, is shown collecting the dual tone multi-frequency (DTMF), within the context
in Figure 16. of this framework, is shown in Figure 16.
+--------------------------------+ +--------------------------------+
| Conferencing System | | Conferencing System |
"Alice" | +-----------+ | "Alice" | +-----------+ |
+--------+ | |Conference | | +--------+ | |Conference | |
| |CCP Request < | |Control | | | |CCP Request < | |Control | |
| Client |--------------------------->| |Server | | | Client |--------------------------->| |Server | |
| |Bob's Conference ID, | | | | | |Bob's Conference ID, | | | |
+--------+ Join > | | | | +--------+ Join > | | | |
| | | | | | | |
skipping to change at page 46, line 49 skipping to change at page 45, line 49
| |<-------------------------|Notification| +-------+ || | |<-------------------------|Notification| +-------+ ||
| Client | activeSideConfObjID,||Service |<~~~|"Alice"| || | Client | activeSideConfObjID,||Service |<~~~|"Alice"| ||
+--------+ confID > || | +-------+----+| +--------+ confID > || | +-------+----+|
|+------------+ | |+------------+ |
~~~Announcement provided to All Parties~~~ ~~~Announcement provided to All Parties~~~
| | | |
+--------------------------------+ +--------------------------------+
Figure 16: Recording and Announcements Figure 16: Recording and Announcements
Upon receipt of the Conference Control Protocol request from "Alice" Upon receipt of the conference control protocol request from "Alice"
to join "Bob's" conference, the conferencing system maps the to join "Bob's" conference, the conferencing system maps the
identifier received in the request to the conference object identifier received in the request to the conference object
representing "Bob's" active conference. The conferencing system representing "Bob's" active conference. The conferencing system
determines that a password is required for this specific conference, determines that a password is required for this specific conference;
thus an announcement asking "Alice" to enter the password is provided thus, an announcement asking "Alice" to enter the password is
to "Alice". Once "Alice" enters the password, it is validated provided to "Alice". Once "Alice" enters the password, it is
against the policies associated with "Bob's" active conference. The validated against the policies associated with "Bob's" active
conferencing system then connects to a server which prompts and conference. The conferencing system then connects to a server that
records "Alice's" name. The conferencing system must also determine prompts and records "Alice"'s name. The conferencing system must
whether "Alice" is already a user of this conferencing system or also determine whether "Alice" is already a user of this conferencing
whether she is a new user. system or whether she is a new user.
If "Alice" is a new user for this conferencing system, a conference If "Alice" is a new user for this conferencing system, a conference
user identifier is created for "Alice". Based upon the addressing user identifier is created for "Alice". Based upon the addressing
information provided by "Alice", the call signaling to add "Alice" to information provided by "Alice", the call signaling to add "Alice" to
the conference is instigated through the Focus. the conference is instigated through the focus.
Once the call signaling indicates that "Alice" has been successfully Once the call signaling indicates that "Alice" has been successfully
added to the specific conference, per updates to the state, and added to the specific conference, per updates to the state, and
depending upon the policies, other participants (e.g., "Bob") are depending upon the policies, other participants (e.g., "Bob") are
notified of the addition of "Alice" to the conference via the notified of the addition of "Alice" to the conference via the
conference notification service and an announcement is provided to conference notification service, and an announcement is provided to
all the participants indicating that "Alice" has joined the all the participants indicating that "Alice" has joined the
conference. conference.
9.8. Monitoring for DTMF 9.8. Monitoring for DTMF
The conferencing system also needs the capability to monitor for DTMF The conferencing system also needs the capability to monitor for DTMF
from each individual participant. This would typically be used to from each individual participant. This would typically be used to
enter the identifier and/or access code for joining a specific enter the identifier and/or access code for joining a specific
conference. conference.
skipping to change at page 47, line 45 skipping to change at page 46, line 45
elements, is shown in Figure 16. elements, is shown in Figure 16.
9.9. Observing and Coaching 9.9. Observing and Coaching
The capability to observe a conference allows a participant with the The capability to observe a conference allows a participant with the
appropriate authority to listen to the conference, typically without appropriate authority to listen to the conference, typically without
being an active participant and often as a hidden participant. When being an active participant and often as a hidden participant. When
such a capability is available on a conferencing system, there is such a capability is available on a conferencing system, there is
often an announcement provided to each participant as they join the often an announcement provided to each participant as they join the
conference indicating the call may be monitored. This capability is conference indicating the call may be monitored. This capability is
useful in the context of conferences which might be experiencing useful in the context of conferences, which might be experiencing
technical difficulties, thus allowing a technician to listen in to technical difficulties, thus allowing a technician to listen in to
evaluate the type of problem. evaluate the type of problem.
This capability could also apply to call center applications as it This capability could also apply to call center applications as it
provides a mechanism for a supervisor to observe how the agent is provides a mechanism for a supervisor to observe how the agent is
handling a particular call with a customer. This scenario can be handling a particular call with a customer. This scenario can be
handled by a supervisor adding themselves to the existing active handled by a supervisor adding themselves to the existing active
conference, with a listen only audio media path. Whether the agent conference, with a listen only audio media path. Whether the agent
is aware of when the supervisor joins the call should be is aware of when the supervisor joins the call should be
configurable. configurable.
Taking the supervisor capability one step further introduces a Taking the supervisor capability one step further introduces a
scenario whereby the agent can hear the supervisor, as well as the scenario whereby the agent can hear the supervisor, as well as the
customer. The customer can still only hear the agent. This scenario customer. The customer can still only hear the agent. This scenario
would involve the creation of a sidebar involving the agent and the would involve the creation of a sidebar involving the agent and the
supervisor. Both the agent and supervisor receive the audio from the supervisor. Both the agent and supervisor receive the audio from the
main conference. When the agent speaks, it is heard by the customer main conference. When the agent speaks, it is heard by the customer
in the main conference. When the supervisor speaks, it is heard only in the main conference. When the supervisor speaks, it is heard only
by the agent in the sidebar conference. by the agent in the sidebar conference.
An example of observing and coaching is shown in figure Figure 17. An example of observing and coaching is shown in Figure 17. In this
In this example, call center agent "Bob" is involved in a conference example, call center agent "Bob" is involved in a conference with
with customer "Carol". Since "Bob" is a new agent and "Alice" sees customer "Carol". Since "Bob" is a new agent and "Alice" sees that
that he has been on the call with "Carol" for longer than normal, she he has been on the call with "Carol" for longer than normal, she
decides to observe the call and coach "Bob" as necessary. decides to observe the call and coach "Bob" as necessary.
+--------------------------------+ +--------------------------------+
| Conferencing System | | Conferencing System |
| +---------+--+| | +---------+--+|
| |policies | || | |policies | ||
| +---------+ || | +---------+ ||
| |Active || | |Active ||
| |Conference || | |Conference ||
"Alice" | | || "Alice" | | ||
skipping to change at page 50, line 4 skipping to change at page 48, line 51
| | | |Conference || | | | |Conference ||
| +-----------+ +-------+ || | +-----------+ +-------+ ||
| |"Alice"| || | |"Alice"| ||
"Bob" | | | || "Bob" | | | ||
+--------+ NOTIFY <"Bob"=added, |+------------+ +-------+ || +--------+ NOTIFY <"Bob"=added, |+------------+ +-------+ ||
| |<-------------------------|Notification|<~~~| | || | |<-------------------------|Notification|<~~~| | ||
| Client | "chair"="Alice" ||Service | |"Bob" | || | Client | "chair"="Alice" ||Service | |"Bob" | ||
+--------+ || | +-------+----+| +--------+ || | +-------+----+|
|+------------+ | |+------------+ |
+--------------------------------+ +--------------------------------+
Figure 17: Supervisor Creating a Sidebar for Observing/Coaching
Upon receipt of the Conference Control Protocol request from "Alice" Figure 17: Supervisor Creating a Sidebar for Observing/Coaching
Upon receipt of the conference control protocol request from "Alice"
to "reserve" a new sidebar conference, based upon the active to "reserve" a new sidebar conference, based upon the active
conference received in the request, the conferencing system uses the conference received in the request, the conferencing system uses the
received active conference to clone a conference reservation for the received active conference to clone a conference reservation for the
sidebar. The conferencing system also reserves or allocates a sidebar. The conferencing system also reserves or allocates a
conference ID to be used for any subsequent protocol requests from conference ID to be used for any subsequent protocol requests from
any of the members of the conference. The conferencing system any of the members of the conference. The conferencing system
maintains the mapping between this conference ID and the conference maintains the mapping between this conference ID and the conference
object ID associated with the sidebar reservation through the object ID associated with the sidebar reservation through the
conference instance. conference instance.
Upon receipt of the conference control protocol response to reserve Upon receipt of the conference control protocol response to reserve
the conference, "Alice" can now create an active conference using the conference, "Alice" can now create an active conference using
that reservation or create additional reservations based upon the that reservation or create additional reservations based upon the
existing reservations. In this example, "Alice" wants only "Bob" to existing reservations. In this example, "Alice" wants only "Bob" to
be involved in the sidebar, thus she manipulates the membership. be involved in the sidebar; thus, she manipulates the membership.
"Alice" also wants the audio to be received by herself and "Bob" from "Alice" also wants the audio to be received by herself and "Bob" from
the original conference, but wants any outgoing audio from herself to the original conference, but wants any outgoing audio from herself to
be restricted to the participants in the sidebar, whereas "Bob's" be restricted to the participants in the sidebar, whereas "Bob's"
outgoing audio should go to the main conference, so that both "Alice" outgoing audio should go to the main conference, so that both "Alice"
and the customer "Carol" hear the same audio from "Bob". "Alice" and the customer "Carol" hear the same audio from "Bob". "Alice"
sends a conference control protocol request to update the information sends a conference control protocol request to update the information
in the reservation and to create an active conference. in the reservation and to create an active conference.
Upon receipt of the conference control protocol request to update the Upon receipt of the conference control protocol request to update the
reservation and to create an active conference for the sidebar, as reservation and to create an active conference for the sidebar, as
identified by the conference object ID, the conferencing system identified by the conference object ID, the conferencing system
ensures that "Alice" has the appropriate authority based on the ensures that "Alice" has the appropriate authority based on the
policies associated with that specific conference object to perform policies associated with that specific conference object to perform
the operation. Based upon the addressing information provided for the operation. Based upon the addressing information provided for
"Bob" by "Alice", the call signaling to add "Bob" to the sidebar with "Bob" by "Alice", the call signaling to add "Bob" to the sidebar with
the appropriate media characteristics is instigated through the the appropriate media characteristics is instigated through the
Focus. focus.
"Bob" is notified of his addition to the sidebar via the conference "Bob" is notified of his addition to the sidebar via the conference
notification service, thus he is aware that "Alice" the supervisor is notification service; thus, he is aware that "Alice", the supervisor,
available for coaching him through this call. is available for coaching him through this call.
10. Relationships between SIP and Centralized Conferencing Frameworks 10. Relationships between SIP and Centralized Conferencing Frameworks
The SIP Conferencing Framework [RFC4353] provides an overview of a The SIP Conferencing Framework [RFC4353] provides an overview of a
wide range of centralized conferencing solutions known today in the wide range of centralized conferencing solutions known today in the
conferencing industry. The document introduces a terminology and conferencing industry. The document introduces a terminology and
logical entities in order to systemize the overview and to show the logical entities in order to systemize the overview and to show the
common core of many of these systems. The logical entities and the common core of many of these systems. The logical entities and the
listed scenarios in the SIP Conferencing Framework are used to listed scenarios in the SIP Conferencing Framework are used to
illustrate how SIP [RFC3261] can be used as a signaling means in illustrate how SIP [RFC3261] can be used as a signaling means in
skipping to change at page 51, line 17 skipping to change at page 50, line 16
define new conference control protocols to be used by the general define new conference control protocols to be used by the general
conferencing system. It uses only basic SIP [RFC3261], the SIP conferencing system. It uses only basic SIP [RFC3261], the SIP
Conferencing for User Agents [RFC4579], and the SIP Conference Conferencing for User Agents [RFC4579], and the SIP Conference
Package [RFC4575] for basic SIP conferencing realization. Package [RFC4575] for basic SIP conferencing realization.
This centralized conferencing framework document defines a particular This centralized conferencing framework document defines a particular
centralized conferencing system and the logical entities implementing centralized conferencing system and the logical entities implementing
it. It also defines a particular data model and refers to the set of it. It also defines a particular data model and refers to the set of
protocols (beyond call signaling means) to be used among the logical protocols (beyond call signaling means) to be used among the logical
entities for implementing advanced conferencing features. The entities for implementing advanced conferencing features. The
purpose of the XCON working group and this framework is to achieve purpose of the XCON Working Group and this framework is to achieve
interoperability between the logical entities from different vendors interoperability between the logical entities from different vendors
for controlling different aspects of advanced conferencing for controlling different aspects of advanced conferencing
applications. applications.
The logical entities defined in the two frameworks are not intended The logical entities defined in the two frameworks are not intended
to be mapped one-to-one. The two frameworks differ in the to be mapped one-to-one. The two frameworks differ in the
interpretation of the internal conferencing system decomposition and interpretation of the internal conferencing system decomposition and
the corresponding operations. Nevertheless, the basic SIP [RFC3261], the corresponding operations. Nevertheless, the basic SIP [RFC3261],
the SIP Conferencing for User Agents [RFC4579], and the SIP the SIP Conferencing for User Agents [RFC4579], and the SIP
Conference Package [RFC4575] are fully compatible with both Framework Conference Package [RFC4575] are fully compatible with both framework
documents. The basis for compatibility is provided by including the documents. The basis for compatibility is provided by including the
basic data elements defined in [RFC4575] in the Conference basic data elements defined in [RFC4575] in the Conference
Information Data Model for Centralized Conferencing (XCON) Information Data Model for Centralized Conferencing (XCON)
[I-D.ietf-xcon-common-data-model]. User agents that only support [XCON-COMMON]. User agents that only support [RFC4579] and do not
[RFC4579] and do not support the Conferencing Control Protocol are support the Conferencing Control Protocol are still provided basic
still provided basic SIP conferencing, but cannot take advantage of SIP conferencing, but cannot take advantage of any of the advanced
any of the advanced features. features.
11. Security Considerations 11. Security Considerations
There are a wide variety of potential attacks related to There are a wide variety of potential attacks related to
conferencing, due to the natural involvement of multiple endpoints conferencing, due to the natural involvement of multiple endpoints
and the many, often user-invoked, capabilities provided by the and the many, often user-invoked, capabilities provided by the
conferencing system. Examples of attacks include the following: an conferencing system. Examples of attacks include the following: an
endpoint attempting to listen to conferences in which it is not endpoint attempting to listen to conferences in which it is not
authorized to participate, an endpoint attempting to disconnect or authorized to participate, an endpoint attempting to disconnect or
mute other users, and theft of service by an endpoint in attempting mute other users, and theft of service by an endpoint in attempting
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There are several issues surrounding security of this conferencing There are several issues surrounding security of this conferencing
framework. One set of issues involves securing the actual protocols framework. One set of issues involves securing the actual protocols
and the associated authorization mechanisms. This first set of and the associated authorization mechanisms. This first set of
issues should be addressed in the specifications specific to the issues should be addressed in the specifications specific to the
protocols described in Section 8 and policy control. The protocols protocols described in Section 8 and policy control. The protocols
used for manipulation and retrieval of confidential information need used for manipulation and retrieval of confidential information need
to support a confidentiality and integrity mechanism. Similar to support a confidentiality and integrity mechanism. Similar
requirements apply for the floor control protocols. Section 11.3 requirements apply for the floor control protocols. Section 11.3
discusses an approach for client authentication of a floor control discusses an approach for client authentication of a floor control
server. It is RECOMMENDED that all the protocols that interface with server. It is RECOMMENDED that all the protocols that interface with
the conferencing system implement TLS. the conferencing system implement Transport Layer Security (TLS).
There are also security issues associated with the authorization to There are also security issues associated with the authorization to
perform actions on the conferencing system to invoke specific perform actions on the conferencing system to invoke specific
capabilities. Section 5.2 discusses the policies associated with the capabilities. Section 5.2 discusses the policies associated with the
conference object to ensure that only authorized entities are able to conference object to ensure that only authorized entities are able to
manipulate the data to access the capabilities. Another set of manipulate the data to access the capabilities. Another set of
issues involves the privacy and security of the identity of a user in issues involves the privacy and security of the identity of a user in
the conference, which is discussed in Section 11.2. the conference, which is discussed in Section 11.2.
A final issue is related to Denial of Service (DoS) attacks on the A final issue is related to Denial of Service (DoS) attacks on the
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Many policy authorization decisions are based on the identity of the Many policy authorization decisions are based on the identity of the
user or the role that a user may have. Conferencing systems user or the role that a user may have. Conferencing systems
typically require authentication of users to validate their identity. typically require authentication of users to validate their identity.
There are several ways that a user might authenticate its identity to There are several ways that a user might authenticate its identity to
the system. For users joining a conference using one of the call the system. For users joining a conference using one of the call
signaling protocols, the user authentication mechanisms for the signaling protocols, the user authentication mechanisms for the
specific protocol often suffice. For the case of users joining the specific protocol often suffice. For the case of users joining the
conference via SIP signaling or using the conference control conference via SIP signaling or using the conference control
protocol, TLS is RECOMMENDED. protocol, TLS is RECOMMENDED.
The conferencing system may also know (e.g., out of band mechanisms) The conferencing system may also know (e.g., out-of-band mechanisms)
about specific users and assign passwords to allow these users to be about specific users and assign passwords to allow these users to be
authorized. In some cases (e.g., PSTN users), additional authorized. In some cases (e.g., Public Switched Telephone Network
authorization may be required to allow the user to participate in the (PSTN) users), additional authorization may be required to allow the
conference. This may be in the form of an Interactive Voice Response user to participate in the conference. This may be in the form of an
(IVR) system or other means. The users may also be authorized by Interactive Voice Response (IVR) system or other means. The users
knowing a particular conference ID and a Personal Identification may also be authorized by knowing a particular conference ID and a
(PIN) for it. Sometimes, a PIN is not required and the conference ID Personal Identification (PIN) for it. Sometimes, a PIN is not
is used as a shared secret. required and the conference ID is used as a shared secret.
In the cases where a user is authorized via multiple mechanisms, it In the cases where a user is authorized via multiple mechanisms, it
is up to the conferencing system to correlate (if desired) the is up to the conferencing system to correlate (if desired) the
authorization of the call signaling interface with other authorization of the call signaling interface with other
authorization mechanisms. A conferencing system can avoid the authorization mechanisms. A conferencing system can avoid the
problem with multiple mechanisms by restricting the methods by which problem with multiple mechanisms by restricting the methods by which
a conference can be joined. For example, many conferencing systems a conference can be joined. For example, many conferencing systems
that provide a web interface for conferences correlate the PSTN call that provide a web interface for conferences correlate the PSTN call
signaling by forcing a dial-out mode for joining the conference. signaling by forcing a dial-out mode for joining the conference.
Thus, there is only the need for a single PIN or password to join the Thus, there is only the need for a single PIN or password to join the
conference. conference.
When a conferencing system presents the identity of authorized users, When a conferencing system presents the identity of authorized users,
it may choose to provide information about the way the identity was it may choose to provide information about the way the identity was
proven or verified by the system. A user may also come as a proven or verified by the system. A user may also come as a
completely unauthenticated user into the system - this fact needs completely unauthenticated user into the system -- this fact needs
also be communicated to interested parties. also to be communicated to interested parties.
When guest users interact with the system, it is often in the context When guest users interact with the system, it is often in the context
of a particular conference. In this case, the user may provide a PIN of a particular conference. In this case, the user may provide a PIN
or a password that is specific to the conferences and authorizes the or a password that is specific to the conferences and authorizes the
user to take on a certain role in that conference. The guest user user to take on a certain role in that conference. The guest user
can then perform actions that are allowed to any user with that role. can then perform actions that are allowed to any user with that role.
The term password refers to the usual, reasonable sized and hard to The term password refers to the usual, reasonable sized and hard to
predict shared secret. Today users often have passwords containing predict shared secret. Today, users often have passwords containing
up to 30 bits (8-16 characters). PIN is a special password case - a up to 30 bits (8-16 characters) of entropy. A PIN is a special
shared secret that is only numeric and often contains a fairly small password case -- a shared secret that is only numeric and often
number of bits (often as few as 10 bits or 3 digits). When contains a fairly small number of bits (often as few as 10 bits or 3
conferencing systems are used for audio on the PSTN, there is often a digits). When conferencing systems are used for audio on the PSTN,
need to authenticate using a PIN. Typically if the user fails to there is often a need to authenticate using a PIN. Typically, if the
provide the correct PIN a few times in a row, the PSTN call is user fails to provide the correct PIN a few times in a row, the PSTN
disconnected. The rate of making the calls and getting to the point call is disconnected. The rate of making the calls and getting to
to enter a PIN makes it fairly hard to do an exhaustive search of the the point to enter a PIN makes it fairly hard to do an exhaustive
PIN space even for 4 digit PINs. When using a high speed interface search of the PIN space even for 4 digit PINs. When using a high
to connect to a conferencing system, it is often possible to do speed interface to connect to a conferencing system, it is often
thousands of attempts per second and the PIN space could quickly be possible to do thousands of attempts per second and the PIN space
searched. Because of this, it is not appropriate to use PINs for could quickly be searched. Because of this, it is not appropriate to
authorization on any of the interfaces that provide fast queries or use PINs for authorization on any of the interfaces that provide fast
many simultaneous queries. queries or many simultaneous queries.
Once a user is authenticated and authorized through the various Once a user is authenticated and authorized through the various
mechanisms available on the conferencing system, a conference user mechanisms available on the conferencing system, a conference user
identifier is associated with any signaling specific user identifiers identifier is associated with any signaling specific user identifiers
that may have been used for authentication and authorization. This that may have been used for authentication and authorization. This
conference user identifier may be provided to a specific user through conference user identifier may be provided to a specific user through
the conference notification interface and will be provided to users the conference notification interface and will be provided to users
that interact with the conferencing system using the conference that interact with the conferencing system using the conference
control protocol. This conference user identifier is required for control protocol. This conference user identifier is required for
any subsequent operations on the conference object. any subsequent operations on the conference object.
11.2. Security and Privacy of Identity 11.2. Security and Privacy of Identity
This conferencing system has an idea of the identity of a user but This conferencing system has an idea of the identity of a user, but
this does not mean it can reveal this identity to other users, due to this does not mean it can reveal this identity to other users, due to
privacy considerations. Users can select various options for privacy considerations. Users can select various options for
revealing their identity to other users. A user can be "hidden" such revealing their identity to other users. A user can be "hidden" such
that other users can not see they are participants in the conference, that other users can not see they are participants in the conference,
or they can be "anonymous" such that users can see that another user "anonymous" such that users can see that another user is there, but
is there, but not see the identity of the user, or they can be not see the identity of the user, or they can be "public" where other
"public" where other users can see their identity. If there are users can see their identity. If there are multiple "anonymous"
multiple "anonymous" users, other parties will be able to see them as users, other parties will be able to see them as independent
independent "anonymous" parties and will be able to tell how many "anonymous" parties and will be able to tell how many "anonymous"
"anonymous" parties are in the conference. Note, that the visibility parties are in the conference. Note, that the visibility to other
to other participants is dependent on their roles. For example, participants is dependent on their roles. For example, users'
users' visibility (including "anonymous" and "hidden") may be identity (including "anonymous" and "hidden") may be displayed to the
displayed to the moderator or administrator, subject to a moderator or administrator, subject to a conferencing system's local
conferencing system's local policies. "Hidden" status is often used policies. "Hidden" status is often used by automated or machine
by automated or machine participants of a conference (e.g., call participants of a conference (e.g., call recording) and is also used
recording) and is also used in many call center situations. in many call center situations.
Since a conferencing system based on this framework allocates a Since a conferencing system based on this framework allocates a
unique conference user identifer for each user of the conferencing unique conference user identifier for each user of the conferencing
system, it is not necessary to distribute any signaling specific user system, it is not necessary to distribute any signaling specific user
identifier to other users or participants. Access to any signaling identifier to other users or participants. Access to any signaling
specific user identifiers can be controlled by applying the specific user identifiers can be controlled by applying the
appropriate access control to the signaling specific user identifiers appropriate access control to the signaling specific user identifiers
in the data schema. in the data schema.
11.3. Floor Control Server Authentication 11.3. Floor Control Server Authentication
The floor control protocol contains mechanisms that clients can use The floor control protocol contains mechanisms that clients can use
to authenticate servers and that servers can use to authenticate to authenticate servers, and that servers can use to authenticate
clients, as described in section 9 of [RFC4582]. The precise clients, as described in Section 9 of [RFC4582]. The precise
mechanisms used for such authentication can vary depending on the mechanisms used for such authentication can vary depending on the
call control protocol used. Clients using call control protocols call control protocol used. Clients using call control protocols
that employ an SDP offer/answer model, such as SIP, use the mechanism that employ an SDP offer/answer model, such as SIP, use the mechanism
described in section 8 of [RFC4583]. Clients using other call described in Section 8 of [RFC4583]. Clients using other call
control protocols make use of the mechanisms described in the BFCP control protocols make use of the mechanisms described in the BFCP
Connection Establishment document [RFC5018]. Connection Establishment document [RFC5018].
12. IANA Considerations 12. Acknowledgements
This document requires no action on the part of IANA.
13. Acknowledgements
This document is a result of architectural discussions among IETF This document is a result of architectural discussions among IETF
XCON working group participants. The authors would like to thank XCON Working Group participants. The authors would like to thank
Henning Schulzrinne for the "Conference Object Tree" proposal and Henning Schulzrinne for the "Conference Object Tree" proposal and
general feedback, Cullen Jennings for providing input for the general feedback, Cullen Jennings for providing input for the
"Security Considerations" section and Keith Lantz, Dave Morgan, Oscar "Security Considerations" section, and Keith Lantz, Dave Morgan,
Novo, Roni Even, Umesh Chandra, Avshalom Houri, Sean Olson, Rohan Oscar Novo, Roni Even, Umesh Chandra, Avshalom Houri, Sean Olson,
Mahy, Brian Rosen, Pierre Tane, Bob Braudes and Gregory Sperounes and Rohan Mahy, Brian Rosen, Pierre Tane, Bob Braudes, Gregory Sperounes,
Gonzalo Camarillo for their reviews and constructive input. In and Gonzalo Camarillo for their reviews and constructive input. In
addition, the authors would like to thank Scott Brim for his gen-art addition, the authors would like to thank Scott Brim for his gen-art
review comments and Kurt Zeilenga for his secdir review comments. review comments and Kurt Zeilenga for his secdir review comments.
14. Changes since last Version 13. References
NOTE TO THE RFC-Editor: Please remove this section prior to
publication as an RFC.
Changes from WG 10 to 11 (addressing IESG DISCUSSes from SEC ADs):
1) Added normative language in Construct and Identifier section to
define what must be implemented to support the framework. In
addition, specified SIP being the default mandatory to implement call
signaling protocol to realize the framework (to address
interoperability concerns). Thus, added back the RFC 2119 reference.
2) Clarified security issues around multiple methods for user
authentication/authorization in security section and how the
conferencing system manages the mapping to the conference user
Identifier.
3) Clarified security for the Conference object identifier and its
mapping to signaling protocol specific identifiers.
4) Added additional detail on compatibility with SIPPING
conferencing.
Changes from WG 09 to 10 (gen-art, secdir and initial IESG review
comments):
1) Abstract and Section 1: removed "along with a high level
conferencing data model."
2) Section 5.2.1: removed confusing unclear 2nd sentence since it
really added no value(Scott Brim's comment from gen-art review) and
changed the tense of the 3rd sentence (editor's comment)
3) Updates to security section based on secdir (Kurt Zeilenga) and
IESG (Tim Polk) comments
3a) Section 10. Added a fourth paragraph about DoS attacks at the
end of that section just prior to 10.1
3b) Section 10.1. Clarifying Authentication versus Authorization
3bi) Renamed section: OLD: Authorization NEW: User Authentication and
Authorization
3bii) First paragraph: expanded acronyms and clarified text. Added
2nd sentence (removed last sentence) and moved 4th and 5th sentences
to the end
3biii) 3rd paragraph (change "authenticates" to "authorizes")
3biv) 4th paragraph: Reworded to add detail about the number of
digits/characters associated with specific numbers of bits in first
two sentences
4) Updated references (gen-art review comment):
draft-ietf-simple-message-sessions => RFC 4975,
draft-ietf-xcon-bfcp-connection => RFC 5018
5) Updated Chris' affiliation.
Changes from WG 08 to 09 (chair PROTO review comments):
1) Changed Intended Status to standards track.
2) Updated IANA section per 1).
3) Removed normative language (i.e., "must" in CAPS in section 10)
4) Updated section 10.3 (Floor Control authentication) to be more
general based on changes to the final BFCP authentication mechanism.
5) Miscellaneous editorial nits - it is amazing after all these
reviews, how many were still there!
Changes from WG 07 to 08 (post-WGLC comments, reflecting IETF-68
discussions on policy):
1) added Intended Status as Informational.
2) Removed data model from Title and clarified reference to data
model in this document as "high level data model". Renamed section 5
from "Centralized Conferencing Data Model" to "Centralized
Conferencing Data".
3) Deleted Conventions section with reference to 2119.
4) Moved terminology to just after intro, before overview.
5) Changed "Common Conference Information" to "Conference
Information".
6) Removed references to policies as an integral part of data model:
updated text discussing policies in section 5 and section 5.2, with
section 7 text changed to be consistent with the updated text in
section 5 and 5.2.
7) Removal of references to individual conference-URI and Userid
documents, bringing some background back into the framework, since
those identifiers are defined in the data model.
8) Miscellaneous editorial nits.
Changes from WG 06 to 07 (WGLC comments):
1) Section 4: Added definition for Conference User Identifier,
including concept of a single user having multiple identifiers.
2) Section 9: Clarified text to indicate that details of message
flows are illustrative and exact states, etc. will be defined by the
detailed data model, etc.
3) Section 9.4.1: Clarified that "Alice" and "Bob" remain in roster
of main conference while in sidebar.Clarified text that Bob must
already be a user of the conferencing system for internal sidebar
scenario.
4) Section 9.4.1/9.4.2: Clarified text in last paragraph to indicated
that notifications may also go to the initial requestor.
5) Section 9.5: Clarified text to explicitly state that sidebar
participants also receive the audio from the main conference.
6) Fixed Editorial nits including updating references to published
RFC numbers and miscellaneous typos.
Changes from WG 05 to 06:
1) Section 9.4.2: Added a statement that whether the hold state is
visible to other participants is subject to user and local policy.
2) Fixed Editorial nits including updating references to published
RFC numbers, adding references for userid and uri definitions,
removing unused references, fixing names in detailed scenarios
(section 9.4.2: "Frank" -> "Fred", section 9.5: "Alice" -> "Carol" as
moderator), aligning with data model (section 9.5: "allowed to join"
list -> "allowed-users-list") and miscellaneous typos.
Changes from WG 04 to 05:
1) Removed all references to "Conference Template":
Section 4:
- Updated "Common Conference Information" definition, merging details
from "Conference Template" definition, which was removed.
- In definition of "conference blueprint"
- In definition of "conference object"
- Removed definition of "Registered conference document"
Section 5:
- 1st paragraph. Reworded.
- Figure2: added "boxes" for all the data listed in the Conference
Template type in the diagram.
- Paragraph following Figure 2. Reworded.
Section 5.1/5.2: Merged 5.2 into section 5.1 and reworded
appropriately.
Section 7.1: Second paragraph, 3rd sentence.
Section 7.3:
- Second paragraph, 2nd and 3rd sentences. Deleted. Remaining
sentence merged with 1st paragraph
- Third paragraph. Deleted.
Section 8.4, 1st paragraph. Removed Editor's note containing
reference to alternative proposal for floor control using templates.
Section 9.3, 1st paragraph after Figure 10.
2) Section 4:
- Sidebar. Clarified definition.
- Whisper. Added definition.
3) Section 5, last paragraph, added reference to
draft-ietf-xcon-common-data-model.
4) Section 8.3. Deleted Editor's note. Deleted subsections
containing details of separate protocol proposals.
5) Section 9.4. Sidebar. Added another example - an external
sidebar (i.e. one involving a participant not in the main conference
and with no media from the main conference).
6) New section 9.5. Floor control with sidebars.
7) Section 9.5 (new 9.6) Whisper. Added more detail and an example
diagram.
8) Section 9.8. (new 9.9) Observing a Conference. Added more details
to example, including concept of coaching and added a corresponding
diagram.
9) Removed Appendix A and Appendix B and updated references to these.
The content will be in separate documents (references TBD).
10) Updated references. Changed drafts to RFCs as appropriate and
removed unused references.
Changes from WG 03 to 04:
- Editorial nits and clarifications.
- Section 4. Template: Removed reference to "user interface
abstractions".
- Section 5.2. Conference Template: deleted references to user
interface abstraction (1st paragraph, last phrase and 4th paragraph).
- Section 9.6. Conference Announcements and Recording: text
expanded. Moved discussion of DTMF to a new section.
- Added two new sections 9.7 (DTMF) and 9.8 (Observing a Conference),
with some initial text.
Changes from WG 02 to 03:
- Updated the definition of Blueprint (per DP 4/4.1 discussions)
- Added definition for Sidebar.
- Section 5.2 Added text indicating that adding new elements or
modifying elements requires the definition of a new template. (per
DP4.2 conclusion).
- Section 7.3. Added text reiterating that the blueprint comprises
both the common conference information and a template (per DP4/4.1
discussions.
- Section 7.3. Added text per resolution of DP 4.3 indicating that a
blueprint is common conference information + one template and that
multiple templates is FFS.
- Section 8.3 - Updated Conference Control Protocol section to
include the protocols on the table for WG discussion as of 31 Dec
2005 deadline.
- Section 9.4 - Sidebars - added Ascii art to show FW interactions
- Section 9.5 - Whisper - Added some text, reflecting past WG
discussions. Basic definition and further details/example still
needed.
- Section 9.6 - Conf Anncs and Recordings - Added some basic text.
Further details/example still needed.
Changes from WG 01 to 02:
- Editorial nits -i.e. consistent terminology, capatilization, etc.
- Revamped abstract and introduction
- Global removal of XCON as a qualifier (we had previously done this
in a previous version with all the identifiers).
- Global change of "call control signalling" to "call signaling"
- Moved the terminology section after the Overview section:
- - Modified the definitions to be more concise and per some of
Henning's recommendations.
- - Added definitions for blueprint and conference reservation.
- Clarified the definition of policy and added more explicit text as
to how policy is accomplished via the data model and system
realization (section 4.3 and 6.1)
- Removed the Editor's note/text in section 4 about the options for
the schema; added a reference to a TBD schema document.
- Section 5:
- - clarified the identifiers. Kept the logical definition as
"identifiers", although most will be realized as URIs.
- - deleted the section on conference instance.
- - removed the term "umbrella" from sections conference User and
conference object identifier sections
- - moved alot of detail from Conference User Identifier and
conference Object Identifier sections into appendices, and added
additional detail, that will become the basis for separate documents.
- In section 6:
- - added a bit of explanation as to the intent of the cloning tree
model - it's not implementation binding, but rather to illustrate the
data model and context for the protocol interactions.
- - removed the term copying altogether. Cloning is the model and
the idea is that the cloned object contains data indentical to the
parent when it was created (whether it gets "copied" or whatever from
the parent is an implementation issue).
- - introduce the blueprint concept in section 6.1 prior to its
implied usage in 6.2 and 6.3.
- - removed the usage of the term occurrence (which is just a child
reservation).
- Removed security related details from Floor Control section and
moved those to the security section. As a result removed most of the
editorial notes from the front of the Floor control section and
integrated the remaining ones inline into that section, where the
resolution should be documented.
- Section 8:
- - Added new example 8.1 - conference creation
- - Added a placeholder for a more detailed example to the sidebar
section to show a sidebar which has some media specifically
associated with the sidebar (i.e. audio), yet still use the main
conference for other media (visual presentation).
- Section 11: As a result of adding additional information to the
security section, divided this section into subsections for clarity.
Changes from WG 00 to 01::
- Section 2 (Conventions and Terminology). Slight modifications to
definitions of Call (control) signaling, Conference Identifier,
Conference Instance, Conference Object.
- Section 2 (Conventions and Terminology).Renaming of term
"Registered Template Definition" to "Registered Conference Document"
(per agreement at interim meeting).
- Section 3 (Next to the last paragraph on the media model).
Clarified the text such that it doesn't read that the focus performs
media mixing. Changed "focus" to "media mixer controlled by the
focus" in the 2nd sentence and "performed" to "controlled" in the
4th.
- Section 5. Rearranged the sub-sections a bit for better flow.
First describe the Conference ID, then the Conference Instance,
followed by the Conference Object, with the Conference Object
Identifier described in a subsection of the Conference Object
section. Added a diagram showing the relationship between Conference
Identifier/Focus and Conference Object Identifier, within the context
of a Conference Instance to the Conference Object section.
- Section 6.1 (Cloning Tree). Rewording to clarify which operations
apply to independent objects (and non-independent).
- Section 6.3 (Advanced Example). Added additional text with regards
to future conferences, introducing the concept of infinite series
(which would be limited by calendaring interface).
- Section 7.3 (Conference Control Protocol). Updated to include
reference to SOAP option.
- Section 8.3 (sidebars) - reworded 1st paragraph to be more explicit
about the XCON FW constructs used.
Changes from individual 02 to WG 00:
- few minor editorial changes
- Section 2. Removed second sentence of definition of Conference ID,
as that's now included/described in context in new Identifier
section.
- Section 3. Clarified that TBD in Figure 1 is "Conference Control
Protocol" (per Keith's comment to be more explicit).
- Section 4.1. Identifiers. Moved this to a new section (
Section 6).
- New section for Identifiers ( Section 6), thus all section
references beyond 4 are incremented in the new version.
- Section 4. Since section 4.1 was removed, section 4.2 became the
body text for section 4.
- Section 4.2. Added "Floor Information" to Figure 2 as part of
Common Conference Information, also added "Floor Control" to
Conference Template (per text and Cullen's draft).
- Section 4.5. Conference policies. Reworded to not introduce new
terms, but use the general terms identified in the 1st paragraph.
- Section 5.2. Removed "Instance" from "Active Conference Instance"
in Figure 4.
- Section 5.3. Added text clarifying that templates are retrieved
from server (not central repository) (per DP3 conclusion).
- Section 5.4. Added text that there is a single time and that the
times are all relative the one time (per DP1 conclusion).
- Section 5.4. Added text clarifying that changes to a series impact
"all future occurrences (per DP1 discussion/conclusion).
- Section 6.3 - Added subsections for discussion of CSCP and NETCONF
as the CCP.
- Section 6.4 - Floor Control. Removed Editor's notes 2 and 3.
Condensed the text only slightly, but added explicit references to
new identifier section.
- Section 6.4.1 Moved to new Identifier section ( Section 6)
- Section 7.1 - moved example to 7.2. Included a new (more
appropriate example) in 7.1, although this may be too basic.
- Section 7.3 - added some proposed text for Sidebars.
15. References
15.1. Normative References 13.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
15.2. Informative References 13.2. Informative References
[RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session [RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP:
Description Protocol", RFC 4566, July 2006. Session Description Protocol", RFC 4566, July 2006.
[RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, [RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G.,
A., Peterson, J., Sparks, R., Handley, M., and E. Johnston, A., Peterson, J., Sparks, R., Handley, M.,
Schooler, "SIP: Session Initiation Protocol", RFC 3261, and E. Schooler, "SIP: Session Initiation Protocol",
June 2002. RFC 3261, June 2002.
[RFC3264] Rosenberg, J. and H. Schulzrinne, "An Offer/Answer Model [RFC3264] Rosenberg, J. and H. Schulzrinne, "An Offer/Answer
with Session Description Protocol (SDP)", RFC 3264, Model with Session Description Protocol (SDP)",
June 2002. RFC 3264, June 2002.
[RFC3265] Roach, A., "Session Initiation Protocol (SIP)-Specific [RFC3265] Roach, A., "Session Initiation Protocol (SIP)-Specific
Event Notification", RFC 3265, June 2002. Event Notification", RFC 3265, June 2002.
[RFC3550] Schulzrinne, H., Casner, S., Frederick, R., and V. [RFC3550] Schulzrinne, H., Casner, S., Frederick, R., and V.
Jacobson, "RTP: A Transport Protocol for Real-Time Jacobson, "RTP: A Transport Protocol for Real-Time
Applications", STD 64, RFC 3550, July 2003. Applications", STD 64, RFC 3550, July 2003.
[RFC2445] Dawson, F. and Stenerson, D., "Internet Calendaring and [RFC2445] Dawson, F. and Stenerson, D., "Internet Calendaring
Scheduling Core Object Specification (iCalendar)", and Scheduling Core Object Specification (iCalendar)",
RFC 2445, November 1998. RFC 2445, November 1998.
[RFC4245] Levin, O. and R. Even, "High-Level Requirements for [RFC4245] Levin, O. and R. Even, "High-Level Requirements for
Tightly Coupled SIP Conferencing", RFC 4245, Tightly Coupled SIP Conferencing", RFC 4245,
November 2005. November 2005.
[RFC4353] Rosenberg, J., "A Framework for Conferencing with the [RFC4353] Rosenberg, J., "A Framework for Conferencing with the
Session Initiation Protocol (SIP)", RFC 4353, Session Initiation Protocol (SIP)", RFC 4353,
February 2006. February 2006.
[RFC4575] Rosenberg, J., Schulzrinne, H., and O. Levin, "A Session [RFC4575] Rosenberg, J., Schulzrinne, H., and O. Levin, "A
Initiation Protocol (SIP) Event Package for Conference Session Initiation Protocol (SIP) Event Package for
State", RFC 4575, August 2006. Conference State", RFC 4575, August 2006.
[RFC4376] Koskelainen, P., Ott, J., Schulzrinne, H., and X. Wu, [RFC4376] Koskelainen, P., Ott, J., Schulzrinne, H., and X. Wu,
"Requirements for Floor Control Protocols", RFC 4376, "Requirements for Floor Control Protocols", RFC 4376,
February 2006. February 2006.
[RFC4597] Even, R. and N. Ismail, "Conferencing Scenarios", [RFC4597] Even, R. and N. Ismail, "Conferencing Scenarios",
RFC 4597, August 2006. RFC 4597, August 2006.
[RFC4579] Johnston, A. and O. Levin, "Session Initiation Protocol [RFC4579] Johnston, A. and O. Levin, "Session Initiation
(SIP) Call Control - Conferencing for User Agents", Protocol (SIP) Call Control - Conferencing for User
BCP 119, RFC 4579, August 2006. Agents", BCP 119, RFC 4579, August 2006.
[RFC4582] Camarillo, G., Ott, J., and K. Drage, "The Binary Floor [RFC4582] Camarillo, G., Ott, J., and K. Drage, "The Binary
Control Protocol (BFCP)", RFC 4582, November 2006. Floor Control Protocol (BFCP)", RFC 4582,
November 2006.
[RFC4574] Levin, O. and G. Camarillo, "The Session Description [RFC4574] Levin, O. and G. Camarillo, "The Session Description
Protocol (SDP) Label Attribute", RFC 4574, August 2006. Protocol (SDP) Label Attribute", RFC 4574,
August 2006.
[RFC4583] Camarillo, G., "Session Description Protocol (SDP) Format [RFC4583] Camarillo, G., "Session Description Protocol (SDP)
for Binary Floor Control Protocol (BFCP) Streams", Format for Binary Floor Control Protocol (BFCP)
RFC 4583, November 2006. Streams", RFC 4583, November 2006.
[I-D.ietf-xcon-common-data-model] [XCON-COMMON] Novo, O., Camarillo, G., Morgan, D., and R. Even,
Novo, O., Camarillo, G., Morgan, D., and R. Even,
"Conference Information Data Model for Centralized "Conference Information Data Model for Centralized
Conferencing (XCON)", draft-ietf-xcon-common-data-model-10 Conferencing (XCON)", Work in Progress, March 2008.
(work in progress), March 2008.
[RFC4975] Campbell, B., Mahy, R., and C. Jennings, "The Message [RFC4975] Campbell, B., Mahy, R., and C. Jennings, "The Message
Session Relay Protocol (MSRP)", RFC 4975, September 2007. Session Relay Protocol (MSRP)", RFC 4975,
September 2007.
[RFC5018] Camarillo, G., "Connection Establishment in the Binary [RFC5018] Camarillo, G., "Connection Establishment in the Binary
Floor Control Protocol (BFCP)", RFC 5018, September 2007. Floor Control Protocol (BFCP)", RFC 5018,
September 2007.
Authors' Addresses Authors' Addresses
Mary Barnes Mary Barnes
Nortel Nortel
2201 Lakeside Blvd 2201 Lakeside Blvd
Richardson, TX Richardson, TX
Email: mary.barnes@nortel.com EMail: mary.barnes@nortel.com
Chris Boulton Chris Boulton
Avaya Avaya
Building 3 Building 3
Wern Fawr Lane Wern Fawr Lane
St Mellons St Mellons
Cardiff, South Wales CF3 5EA Cardiff, South Wales CF3 5EA
Email: cboulton@avaya.com EMail: cboulton@avaya.com
Orit Levin Orit Levin
Microsoft Corporation Microsoft Corporation
One Microsoft Way One Microsoft Way
Redmond, WA 98052 Redmond, WA 98052
Email: oritl@microsoft.com EMail: oritl@microsoft.com
Full Copyright Statement Full Copyright Statement
Copyright (C) The IETF Trust (2008). Copyright (C) The IETF Trust (2008).
This document is subject to the rights, licenses and restrictions This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors contained in BCP 78, and except as set forth therein, the authors
retain all their rights. retain all their rights.
This document and the information contained herein are provided on an This document and the information contained herein are provided on an
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