XCON Working Group M. Barnes
Internet-Draft Nortel
Intended status: Informational C. Boulton
Expires: January 8, 2009 Avaya
L. Miniero
S P. Romano
University of Napoli
July 7, 2008
Centralized Conferencing Manipulation Protocol (CCMP) Call Flow Examples
draft-barnes-xcon-examples-00.txt
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Abstract
This document provides detailed call flows for the scenarios
documented in the Centralized Conferencing (XCON) Framework and the
XCON Scenarios. The call flows document the use of the interface
between a conference control client and a conference control server
using the Centralized Conferencing Manipulation Protocol (CCMP). The
objective is to provide a base reference for both protocol
researchers and developers.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.1. A Practical Approach . . . . . . . . . . . . . . . . . . . 5
4.1.1. Conferencing Control Client Overview . . . . . . . . . 5
4.1.2. Conferencing Control Server Overview . . . . . . . . . 5
5. Conference Creation . . . . . . . . . . . . . . . . . . . . . 6
5.1. Basic Conference Creation . . . . . . . . . . . . . . . . 6
5.2. Basic Conference Creation for a specific instance of
Conference Information . . . . . . . . . . . . . . . . . . 8
5.3. Basic Conference Creation - Cloning an existing
Conference . . . . . . . . . . . . . . . . . . . . . . . . 9
5.4. Conference Creation using Blueprints . . . . . . . . . . . 11
6. General Conference scenarios and examples . . . . . . . . . . 14
6.1. Conference Announcements and Recordings . . . . . . . . . 14
6.2. Monitoring for DTMF . . . . . . . . . . . . . . . . . . . 15
6.3. Adding a Party . . . . . . . . . . . . . . . . . . . . . . 15
6.4. Joining a Conference . . . . . . . . . . . . . . . . . . . 16
6.5. Muting a Party . . . . . . . . . . . . . . . . . . . . . . 17
6.6. Internal Sidebar . . . . . . . . . . . . . . . . . . . . . 18
6.7. External Sidebar . . . . . . . . . . . . . . . . . . . . . 19
6.8. Floor control using sidebars . . . . . . . . . . . . . . . 21
6.9. Whispering or Private Messages . . . . . . . . . . . . . . 22
6.10. Observing and Coaching . . . . . . . . . . . . . . . . . . 23
7. Removing participants and deleting conferences . . . . . . . . 24
7.1. Removing a Party . . . . . . . . . . . . . . . . . . . . . 25
7.2. Deleting a Conference . . . . . . . . . . . . . . . . . . 26
8. Additional Conference Scenarios and Examples . . . . . . . . . 26
8.1. Chat . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
8.1.1. Basic Chat Operations . . . . . . . . . . . . . . . . 27
8.1.2. Additional Operations . . . . . . . . . . . . . . . . 31
8.1.3. Advanced Operations . . . . . . . . . . . . . . . . . 33
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 36
10. Security Considerations . . . . . . . . . . . . . . . . . . . 36
11. Change Summary . . . . . . . . . . . . . . . . . . . . . . . . 36
12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 36
13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 36
13.1. Normative References . . . . . . . . . . . . . . . . . . . 36
13.2. Informative References . . . . . . . . . . . . . . . . . . 37
Appendix A. IM Chat and Conferencing Identifier Relationships . . 39
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 41
Intellectual Property and Copyright Statements . . . . . . . . . . 43
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1. Introduction
This document provides detailed call flows for the scenarios
documented in the Centralized Conferencing (XCON) Framework [RFC5239]
and the XCON Scenarios [RFC4597]. The XCON scenarios describe a
broad range of use cases making use of the advanced conferencing
capabilities provided by a system realization of the XCON framework.
The call flows document the use of the interface between a conference
control client and a conference control server using the Centralized
Conferencing Manipulation Protocol (CCMP)[I-D.ietf-xcon-ccmp].
Due to the broad range of functionality provided by the XCON
Framework and the flexibility of the CCMP messaging, these call flows
should not be considered inclusive of all the functionality that can
provided by the XCON Framework and protocol implementations. These
flows represent a sample in order to provide an overview of the
feature rich capabilities of the XCON framework and CCMP messaging.
The objective is to provide some concrete examples for both
implementors and protocol researchers.
2. Conventions
In this document, the key words "MUST", "MUST NOT", "REQUIRED",
"SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT
RECOMMENDED", "MAY", and "OPTIONAL" are to be interpreted as
described in BCP 14, RFC 2119 [RFC2119] and indicate requirement
levels for compliant implementations. In this document, these key
words are used when describing normative functionality based on the
XCON Framework and CCMP.
Note that due to RFC formatting conventions, this document often
splits message details whose content would exceed 72 characters. A
backslash character marks where this line folding has taken place.
This backslash and its trailing CRLF and whitespace would not appear
in the actual protocol contents.
3. Terminology
This document uses the same terminology as found in the referenced
documents, with the following terms and abbreviations used in the
call flows. Also, note that the term "call flows" is used in a very
generic sense in this document since the media is not limited to
voice. The calls supported by the XCON framework and CCMP can
consist of media such as text, voice and video, including multiple
media types in a single active conference.
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Conferencing and Media Client Client (CMCC): This client may be an
integral part of a User Agent Client (UAC) per [RFC3261]. In the
flows in this document, the CMCC is logically equivalent to the
use of UAC as the client notation in the media control call flows
[I-D.miniero-mediactrl-escs].
Conferencing Server (ConfS): In this document, the conferencing
server is used interchangeably with the term Application Server
(AS) in the Media Control framework
[I-D.ietf-mediactrl-architecture] to simplify the call flows.
However, these need not be the same entities in an implementation.
Media Server (MS): Media Server. Per its definition in the Media
Control Architecture.
4. Overview
This document provides a sampling of detailed call flows that can be
implemented based on a system realization of [RFC5239] and
implementation of [I-D.ietf-xcon-ccmp]. This is intended to be a
simple guide on the use of the conference control protocol between
the Conference Server and the Conference Control Client. It is
expected that this document provides a helpful base reference for
other implementors and protocol researchers.
This document focuses on the interaction between the Conference (and
Media) Control Client and the Conferencing system, specifically the
Conference Server. The initial scenarios chosen are based on the
ones described in the XCON framework, many of which are based on the
advanced conferencing capabilities described in the XCON scenarios.
Additional scenarios have been added to provide examples of other
real life scenarios that are anticipated to be supported by the
framework and to document the conference control that complements
some of the Media Control Call Flows [I-D.miniero-mediactrl-escs].
Rather than repeat the details associated with the media control,
this document references the media control call flow examples
[I-D.miniero-mediactrl-escs] by Figure title to aid the user in
finding the flows in that document. This approach was taken rather
than integrating the two documents due to dependencies in completing
working group items and because the messages for the two protocols
provide fairly discrete operations. In addition, the scenarios for
which floor control are used also do not include details of the
Binary Floor Control Protocol (BFCP) [RFC4582], but rather refer to
that document for further details for clients that also implement
BFCP for floor control.
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In the following sections some approaches and choices by which one
can implement the XCON framework and the related protocols are
described. This provides the context for the ordering of the flows.
The physical client can implement all the client side protocols in a
single device or the protocols might exist in multiple places, such
as a separate device supporting the media interface and another for
conference control (e.g., video along with a web based interface for
conference control). This section should not be considered a
mandatory approach to the implementation of the XCON framework. It
is only meant to ease the understanding of how the framework works
from a practical point of view.
4.1. A Practical Approach
This section provides a logical overview of an implementation
approach for a a conference control client and conference server
implementing CCMP. This section is not normative, however, it's
anticipated that it gives an implementor an idea of the overall
general functionality that can be implemented to support the XCON
framework and CCMP.
4.1.1. Conferencing Control Client Overview
A basic conferencing control client can integrate all the
functionality including media, conference and floor control into a
single client. However, this diagram is focused on the processing
directly associated with CCMP, with annotations/callouts when media
control or floor interaction might be necessary or would be allowed.
It's entirely an implementation choice how a client might implement
those interactions, however, it's recommended that the implementor
consider the possible distributed nature of the various control
protocols.
(Figure not available yet).
Figure 1: Conferencing Control Client CCMP State Diagram
4.1.2. Conferencing Control Server Overview
A conferencing system can integrate all the functionality including
conference control, floor control and even Application Server
functionality to support media control into a single client.
However, this diagram is focused on the processing directly
associated with CCMP, with annotations/callouts when media control or
floor interaction might be necessary or would be allowed. It's
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entirely an implementation choice how a client might implement those
interactions, however, it's recommended that the implementor consider
the possible distributed nature of the various control protocols.
(Figure not available yet).
Figure 2: Conference Server CCMP State Diagram
5. Conference Creation
This section provides the details associated with the various ways in
which a conference can be created using CCMP and the XCON framework
constructs. As previously mentioned the details of the media control
and floor control protocols, where applicable, are annotated in the
flows without showing all the details. However, for clarification
purposes, the first example Section 5.1 provides the details of the
media control messaging along with an example of the standard
annotation used throughout the remainder of this document. [Editors'
Note: should we add the call control signaling (i.e., SIP) to the
annotated example, as well. There is already a reference to the call
control signaling in the text description - is that sufficient?]
The term conferenceing server (ConfS) is shown in the diagrams in
this document as opposed to the more generic application server (AS)
in the media control flow document [I-D.miniero-mediactrl-escs].
Also, note that the term conferencing and media control client (CMCC)
in these call flows may be an integral part of a User Agent Client
(UAC) per [RFC3261], which is the client notation used in the media
control call flow document. However, in the context of XCON, the
conferencing and media control client can be independent of the call
signaling client.
5.1. Basic Conference Creation
The simplest manner in which a conference can be created is
accomplished by the client sending a "confRequest" message with the
"create" operation as the only parameter to the conference server.
This results in the creation of a default conference, with an XCON-
URI in the form of the "confObjID" parameter, the XCON-UserID in the
form of the "confUserID" parameter and the data for the conference
object in the "conference-info" parameter all returned in the
"confResponse" message. This example also activates the conference
upon creation, thus the call signaling interactions to add the CMCC
to the conference are completed prior to returning the confResponse
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message. The media interactions handled when the confResponse
message is sent.
CMCC ConfS MS
| | |
|(1) confRequest(create) | |
|----------------------->| |
| |1.CONTROL (create conference)|
| |+++++++++++++++++++++++++++>>|
| | |--+(a)create
| | | | conf and
| | 2. 200 OK (with confID)|<-+ its ID
| |<<+++++++++++++++++++++++++++|
| |--+ |
| | | (b)Setup call signaling |
| | | and media to CMCC |
|(2)confResponse(create,\|<-+ via Focus |
|<-----------------------| |
| confObjID, confUserID,\| |
| conference-info) | |
| | |
| |3.CONTROL(join CMCC<->confID)|
| |+++++++++++++++++++++++++++>>|
| | |--+ (c) join
| | | | CMCC &
| |4. 200 OK |<-+ confID
| |<<+++++++++++++++++++++++++++|
| | |
| | |
|<<##################################################>>|
| Now the CMCC is mixed in the conference |
|<<##################################################>>|
. . .
. . .
Figure 3: Create Basic Conference - Complete flow
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CMCC ConfS
| |
| (1) confRequest(create) |
|------------------------------>|
| |--+
| | |(a) Create conf
| | | and ID
| | |(b) Setup call
| | | signaling and
| | | media interface
| | | to CMCC
| (2) confResponse(create,\ |<-+ via Focus
|<------------------------------|
| confObjID, confUserID,\ |--+
| conference-info) | |(c) Join CMCC
| | | and media
| |<-+
| |
. .
. .
Figure 4: Create Basic Conference - Annotated Flow
(CCMP Messaging details not available yet).
Figure 5: Create Basic Conference (Annotated) Detailed Messaging
5.2. Basic Conference Creation for a specific instance of Conference
Information
A conference can also be created by the client sending a
"confRequest" message with the "create" operation, along with the
desired data in the form of the "conference-info" parameter for the
conference to be created. An example where this approach might be
applicable would be in the case where a conference user might need to
use a different conferencing system than is typically used (e.g., one
that is more geographically appropriate for some participants that
perhaps do not support advanced conferencing functionality). If the
specific conferencing system can support that specific type of
conference (capabilities, etc.), then the request results in the
creation of a conference. In this success case, an XCON-URI in the
form of the "confObjID" parameter and the XCON-UserID in the form of
the "confUserID" parameter are returned in the "confResponse"
message. The "conference-info" is not returned unless changes have
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been made, in which case the "responseCode" is "modified". This
example also activates the conference upon creation, thus the call
signaling interactions to add the CMCC to the conference are
completed prior to returning the confResponse message. The media
interactions handled when the confResponse message is sent.
CMCC "Alice" ConfS
| |
| (1) confRequest(create,\ |
|------------------------------>|(a') Validate user/
| conference-info) | conference-info data
| |--+
| | |(a) Create conf
| | | and ID
| | |(b) Setup call
| | | signaling and
| | | media interface
| | | to CMCC
| |<-+
| (2) confResponse(create,\ |
|<------------------------------|
| confObjID, confUserID) |--+
| | | (c) Join CMCC
| | | and media
| |<-+
| |
. .
. .
Figure 6: Create Basic Conference from user provided conference-info
(CCMP Messaging details not available yet).
Figure 7: Create Basic Conference Detailed Messaging
5.3. Basic Conference Creation - Cloning an existing Conference
A client can also create another conference by cloning an existing
conference, such as an active conference or conference reseravation.
In this example, the client sends a "confRequest" message with the
"create" operation, along with a specific "confObjID", from which a
new conference is to be created by cloning an existing conference.
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An example of how a client can create a conference based on a
blueprint is provided in Section 5.4. The manner by which a client
in this example might learn about a conference reservation or active
conferences is similar to the first step in the blueprint example,
with the exception of specifying querying for different types of
conference objects supported by the specific conferencing system.
For example, in this example, the client clones a conference
reservation, thus the client would include the appropriate
"confObjState" parameter. [Note: we don't currently have this
parmeter in the XML schema in CCMP, BUT this functionality is
documented in the text.]
If the conferencing system can support a new instance of the specific
type of conference(capabilities, etc.), then the request results in
the creation of a conference, with an XCON-URI in the form of the
"confObjID" parameter to reflect the newly cloned conference object
and the XCON-UserID in the form of the "confUserID" parameter
returned in the "confResponse" message. The "conference-info" is not
returned unless there had been changes, in which case the
"responseCode" is "modified". This example also activates the
conference upon creation, thus the call signaling interactions to add
the CMCC to the conference are completed prior to returning the
confResponse message. The media interactions handled when the
confResponse message is sent.
CMCC "Alice" ConfS
| |
| (1) confRequest(create,\ |
|------------------------------>|(a') Validate user
| confObjID, child) | and confObjID
| |--+
| | |(a) Create conf
| | | and ID
| | |(b) Setup call
| | | signaling and
| | | media interface
| | | to CMCC
| |<-+
| (2) confResponse(create,\ |
|<------------------------------|
| confObjID, confUserID) |--+
| | | (c) Join CMCC
| | | and media
| |<-+
| |
. .
. .
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Figure 8: Create Basic Conference - Clone
1. "Alice" sends a confRequest message to clone a conference based
on an existing conference reservation. "Alice" indicates this
conference should be a "child" of the parent conference represented
by the "confObjID" in the request.
2. Upon receipt of the confRequest message containing a "create"
operation and "confObjID", the conferencing system ensures that the
"confObjID" received is valid. The conferencing system determines
the appropriate read/write access of any users to be added to a
conference based on this confObjID(using membership, roles, etc.).
The conferencing system uses the received confObjID to clone a
conference reservation. The conferencing system also reserves or
allocates a new confObjID to be used for the cloned conference
object. Any subsequent protocol requests from any of the members of
the conference. The conferencing system maintains the mapping
between this conference ID and the parent conference object ID
associated with the reservation through the conference instance.
(CCMP Messaging details not available yet).
Figure 9: Create Basic Conference (Clone) Detailed Messaging
5.4. Conference Creation using Blueprints
Figure 10 provides an example of one client "Alice" determining the
conference blueprints available for a particular conferencing system
and creating a conference based on the desired blueprint.
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CMCC "Alice" ConfS
| |
| (1) optionsRequest |
|------------------------------>|
| |
| (2) optionsResponse |
|<------------------------------|
|--+ |
| | choose preferred |
| | blueprint from the |
| | list (blueprintName) |
|<-+ |
| (3) confRequest(create,\ |
|------------------------------>|(a')Validate user
| blueprintName, | and confObjID
| confObjID, child) |--+
| | |(a)Create conf
| | | and ID
| |<-+
| (4) confResponse(create,\ |
|<------------------------------|
| confObjID, confUserID) |
| |
| |
| |
. .
. .
Figure 10: Client Creation of Conference using Blueprints
1. "Alice" first sends an "optionsRequest" message to the
conferencing system identified by the conference server discovery
process (details TBD). Upon receipt of the "optionsRequest", the
conferencing system would first authenticate "Alice" (and allocate a
conference user identifier, if necessary) and then ensure that
"Alice" has the appropriate authority based on system policies to
receive any blueprints supported by that system. Any blueprints that
"Alice" is authorized to use are returned in a "optionsResponse"
message in the "blueprints" attribute, along with the "confUserID"
parameter.
2. Upon receipt of the "optionsResponse" containing the blueprints,
"Alice" determines which blueprint to use for the conference to be
created. "Alice" creates a conference object based on the blueprint
(i.e., clones) and modifies applicable fields, such as membership
list and start time.
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3. "Alice" then sends a "confRequest" with a "create" operation to
the conferencing system to create a conference reservation based upon
the updated blueprint, including the appropriate "blueprintName" and
associated "confObjID".
Note: This conference is created as independent of the parent
(blueprint), but there are no hard and fast requirements as to
whether conference from blueprints are always independent or whether
the conferences cloned from conference reservations or active
conferences are also children. The protocol is flexible enough to
allow all the variations, thus any limitations would be specific to a
conferencing system.
Upon receipt of the "confRequest" message with a "create" operation
and an "action" to "reserve" a conference based upon the blueprint in
the request, the conferencing system ensures that the blueprint
received is a valid blueprint (i.e. the values of the various field
are within range). [Note: we don't currently have this "action"
field defined for the "confRequest" message.] The conferencing
system determines the appropriate read/write access of any users to
be added to a conference based on this blueprint (using membership,
roles, etc.). The conferencing system uses the received blueprint to
clone a conference reservation. The conferencing system also
reserves or allocates a conference ID to be used for any subsequent
CCMP requests from any of the members of the conference. The
conferencing system maintains the mapping between this conference ID
and the "confObjID" associated with the reservation through the
conference instance.
4. The conferencing server then sends a "confResponse" message
including the "confObjID" associated with the reserved conference.
Upon receipt of the "confResponse" message, "Alice" can now create an
active conference using that reservation or create additional
reservations based upon the existing reservation.
5. In this example, "Alice" has reserved a meetme conference bridge.
Thus, "Alice" provides the conference information, including the
necessary "confObjID", to desired participants. Note, that this
interface is entirely outside the scope of the XCON framework,
protocols and this document. When the first participant, "Alice" in
this example, then requests to be added to the conference by sending
a "userRequest" ....
6. Upon receipt of the "userRequest" message, the conference is
activated and the focus is created. The focus is associated with the
"confObjID" received in the request. Any participants that have the
authority to manipulate the conference would receive the "confObjID"
in any responses. The conference server then sends "userResponse"
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message....
(CCMP Messaging details not available yet).
Figure 11: Create Conference (Blueprint) Detailed Messaging
6. General Conference scenarios and examples
The following scenarios are based on those documented in the XCON
framework. The examples assume that a conference has already been
correctly established, with media, if applicable, per one of the
examples in Section 5.
6.1. Conference Announcements and Recordings
In this example, as shown in Figure 12 "Alice" is joining "Bob"'s
conference that requires that she first enter a pass code. After
successfully entering the passcode, an announcement prompts "Alice to
speak her name so it can be recorded. When "Alice" is added to the
active conference, the recording is played back to all the existing
participants.
(Figure not available yet).
Figure 12: Recording and Announcements
1. Upon receipt of the userRequest from "Alice" to be added to
"Bob's" conference, the conferencing system maps the identifier
received in the request to the conference object representing "Bob's"
active conference. The conferencing system determines that a
password is required for this specific conference, thus an
announcement asking "Alice" to enter the password is provided to
"Alice". Once "Alice" enters the password, it is validated against
the policies associated with "Bob's" active conference. The
conferencing system then connects to a server which prompts and
records "Alice's" name. The conferencing system must also determine
whether "Alice" is already a user of this conferencing system or
whether she is a new user.
2. "Alice" is a new user for this conferencing system, so a
conference user identifier is created for "Alice". Based upon the
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addressing information provided by "Alice", the call signaling to add
"Alice" to the conference is instigated through the Focus. In
addition, "Alice" is sent a userResponse message which includes the
"confUserID" assigned by the conferencing system for "Alice". This
would allow "Alice" to later perform operations on the conference (if
she were to have the appropriate policies), including registering for
event notifications associated with the conference.
3. Once the call signaling indicates that "Alice" has been
successfully added to the specific conference, per updates to the
state, and depending upon the policies, other participants (e.g.,
"Bob") are notified of the addition of "Alice" to the conference via
the conference notification service and an announcement is provided
to all the participants indicating that "Alice" has joined the
conference.
(CCMP Messaging details not available yet).
Figure 13: Announcement Messaging Details
6.2. Monitoring for DTMF
The conferencing system also needs the capability to monitor for DTMF
from each individual participant. This would typically be used to
enter the identifier and/or access code for joining a specific
conference.
An example of DTMF monitoring, within the context of the framework
elements, is shown in Figure 12.
6.3. Adding a Party
Figure 14 provides an example of one client "Alice" impacting the
state of another client "Bob". This example assumes an established
conference. In this example, "Alice" wants to add "Bob" to the
conference.
To do.
Figure 14: Client Manipulation of Conference - Add a party
1. Upon receipt of the Conference Control Protocol request to "add"
a party ("Bob") in the specific conference as identified by the
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conference object ID, the conferencing system ensures that "Alice"
has the appropriate authority based on the policies associated with
that specific conference object to perform the operation. The
conferencing system must also determine whether "Bob" is already a
user of this conferencing system or whether he is a new user.
2. If "Bob" is a new user for this conferencing system, a Conference
User Identifier is created for Bob. Based upon the addressing
information provided for "Bob" by "Alice", the call signaling to add
"Bob" to the conference is instigated through the Focus.
3. Once the call signaling indicates that "Bob" has been
successfully added to the specific conference, per updates to the
state, and depending upon the policies, other participants (including
"Bob") may be notified of the addition of "Bob" to the conference via
the Conference Notification Service.
(CCMP Messaging details not available yet).
Figure 15: Add Party Message Details
6.4. Joining a Conference
Figure 16 provides an example of one client "Duck" joining an active
conference with "Alice", "Bob" and "Claire" as participants. Using
SIP as a call control protocol such as SIP, "Duck" joins the
conference without using any CCMP messaging since the required
interactions are specific to the conferencing system via a trigger
from the focus upon receipt of the SIP message. The the conferencing
system does the following to join "Duck" to the active conference:
adds "Duck" as a user, authorizes "Duck" to join the conference,
modifies the appropriate conference data, and provides the
notifications to the participants that have registered for such.
To do.
Figure 16: Client Joining an Active Conference
1. Upon receipt of the SIP request to "join" a party ("Duck") to the
specific conference as identified by the Focus. The conferencing
system determines the appropriate conference object ID. The
conferencing system then determines whether "Bob" is already a user
of this conferencing system or whether he is a new user. If "Bob" is
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a new user for this conferencing system, a Conference User Identifier
is created for Bob. Based upon the addressing information provided
for "Bob" by "Alice", the call signaling to add "Bob" to the
conference is instigated through the Focus.
2. Once the call signaling indicates that "Duck" has been
successfully added to the specific conference, per updates to the
state, and depending upon the policies, other participants (including
"Duck") may be notified of the addition of "Duck" to the conference
via the Conference Notification Service.
(CCMP Messaging details not available yet).
Figure 17: Join Message Details
6.5. Muting a Party
This section provides an example of the muting of a party in an
active conference. The unmuting would involve the identical CCMP
message flow. Although, in the case that floor control is involved,
whether or not a particular conference client can unmute themselves
must be considered by the conferencing system.
Figure 18 provides an example of one client "Alice" impacting the
media state of another client "Bob". This example assumes an
established conference. In this example, the client, "Alice" whose
Role is "moderator" of the conference, wants to mute "Bob" on a
medium-size multi-party conference, as his device is not muted (and
he's obviously not listening to the call) and background noise in his
office environment is disruptive to the conference.
(To be added).
Figure 18: Client Manipulation of Conference - Mute a party
1. Upon receipt of the Conference Control Protocol request to "mute"
a party ("Bob") in the specific conference as identified by the
conference object ID, the Conference Server ensures that "Alice" has
the appropriate authority based on the policies associated with that
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specific conference object to perform the operation. "Bob"'s status
is marked as "recvonly" and the conference object is updated to
reflect that "Bob"s media is not to be "mixed" with the conference
media. In case the Conference Server relies on a remote Media Server
for its multimedia functionality, it subsequently changes "Bob"'s
media profile accordingly by means of the related protocol
interaction with the MS. An example describing a possible way of
dealing with such a situation using the Media Server Control
architecture is described in [I-D.miniero-mediactrl-escs], at "Simple
Bridging: Framework Transactions (2)".
2...x. Depending upon the policies, other participants (including
"Bob") may be notified of this change via the Conference Notification
Service.
(CCMP Messaging details not available yet).
Figure 19: Mute Message Details
6.6. Internal Sidebar
Figure 20 provides an example of one client "Alice" involved in
active conference with "Bob" and "Carol". "Alice" wants to create a
sidebar to have a side discussion with "Bob" while still viewing the
video associated with the main conference. Alternatively, the audio
from the main conference could be maintained at a reduced volume.
"Alice" initiates the sidebar by sending a request to the
conferencing system to create a conference reservation based upon the
active conference object. "Alice" and "Bob" would remain on the
roster of the main conference, such that other participants could be
aware of their participation in the main conference, while an
internal-sidebar conference is occurring.
(To be added).
Figure 20: Client Creation of a Sidebar Conference
1. Upon receipt of the Conference Control Protocol request to
"reserve" a new sidebar conference, based upon the active conference
received in the request, the conferencing system uses the received
active conference to clone a conference reservation for the sidebar.
The sidebar reservation is NOT independent of the active conference
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(i.e., parent). The conferencing system also reserves or allocates a
conference ID to be used for any subsequent protocol requests from
any of the members of the conference.
2. Upon receipt of the conference control protocol response to
reserve the conference, "Alice" can now create an active conference
using that reservation or create additional reservations based upon
the existing reservations. In this example, "Alice" wants only "Bob"
to be involved in the sidebar, thus she manipulates the membership.
"Alice" also only wants the video from the original conference and
wants the audio to be restricted to the participants in the sidebar.
Alternatively, "Alice" could manipulate the media values to recieve
the audio from the main conference at a reduced volume. "Alice"
sends a conference control protocol request to update the information
in the reservation and to create an active conference.
3. Upon receipt of the conference control protocol request to update
the reservation and to create an active conference for the sidebar,
as identified by the conference object ID, the conferencing system
ensures that "Alice" has the appropriate authority based on the
policies associated with that specific conference object to perform
the operation. The conferencing system must also validate the
updated information in the reservation, ensuring that a member like
"Bob" is already a user of this conferencing system.
4...x. Depending upon the policies, the initiator of the request
(i.e., "Alice") and the participants in the sidebar (i.e., "Bob") may
be notified of his addition to the sidebar via the conference
notification service.
(CCMP Messaging details not available yet).
Figure 21: Internal Sidebar Messaging Details
6.7. External Sidebar
Figure 22 provides an example of one client "Alice" involved in an
active conference with "Bob", "Carol", "David" and "Ethel". "Alice"
gets an important text message via a whisper from "Bob" that a
critical customer needs to talk to "Alice", "Bob" and "Ethel".
"Alice" creates a sidebar to have a side discussion with the customer
"Fred" including the participants in the current conference with the
exception of "Carol" and "David", who remain in the active
conference. "Alice" initiates the sidebar by sending a request to
the conferencing system to create a conference reservation based upon
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the active conference object. "Alice", "Bob" and "Ethel" would
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
participants depends upon the individual and local policy.
(To be Detailed).
Figure 22: Client Creation of an External Sidebar
1. Upon receipt of the Conference Control Protocol request to
"reserve" a new sidebar conference, based upon the active conference
received in the request, the conferencing system uses the received
active conference to clone a conference reservation for the sidebar.
The sidebar reservation is NOT independent of the active conference
(i.e., parent). The conferencing system also reserves or allocates a
conference ID to be used for any subsequent protocol requests from
any of the members of the conference. The conferencing system
maintains the mapping between this conference ID and the conference
object ID associated with the sidebar reservation through the
conference instance.
2. Upon receipt of the conference control protocol response to
reserve the conference, "Alice" wants only "Bob" and "Ethel", along
with the new participant "Fred" to be involved in the sidebar, thus
she manipulates the membership. "Alice" sets the media in the
conference-info such that the participants in the sidebar don't
receive any media from the main conference.
3. "Alice" sends a conference control protocol request to update the
information in the reservation and to create an active conference.
4. Upon receipt of the conference control protocol request to update
the reservation and to create an active conference for the sidebar
the conferencing system ensures that "Alice" has the appropriate
authority based on the policies associated with that specific
conference object to perform the operation. The conferencing system
also validates the updated information in the reservation. Since
"Fred" is a new user for this conferencing system, a conference user
identifier is created for "Fred". Based upon the addressing
information provided for "Fred" by "Alice", the call signaling to add
"Fred" to the conference is instigated through the Focus.
5...x. Depending upon the policies, the initiator of the request
(i.e., "Alice") and the participants in the sidebar (i.e., "Bob" and
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"Ethel") may be notified of his addition to the sidebar via the
conference notification service.
(CCMP Messaging details not available yet).
Figure 23: External Sidebar Messaging Details
6.8. Floor control using sidebars
Floor control with sidebars can be used to realize conferencing
scenario such as an analyst briefing. In this scenario, the
conference call has a panel of speakers who are allowed to talk in
the main conference. The other participants are the analysts, who
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
moderator and ask their question. The moderator can also whisper to
each analyst what their status/position in the floor control queue,
similar to the example in Figure 26. It should be noted that other
mechanisms which don't make use of sidebars could be used for floor
control such as those detailed in BFCP. [Editor's note: Should we
add detailed flows for BFCP to this document and show additional
floor control scenarios?
Figure 24 provides an example of the configuration involved for this
type of conference. As in the previous sidebar examples, there is
the main conference along with a sidebar. "Alice" and "Bob" are the
main participants in the conference, with "A1", "A2" and "A3"
representing the analysts. The sidebar remains active throughout the
conference, with the moderator, "Carol", serving as the chair. As
discussed previously, the sidebar conference is NOT independent of
the active conference (i.e., parent). The analysts are provided the
conference object ID associated with the active sidebar when they
join the main conference. The conferencing system also allocates a
conference ID to be used for any subsequent manipulations of the
sidebar conference. The conferencing system maintains the mapping
between this conference ID and the conference object ID associated
with the active sidebar conference through the conference instance.
The analysts are permanently muted while in the main conference. The
analysts are moved to the sidebar when they wish to speak. Only one
analyst is given the floor at a given time. All participants in the
main conference receive audio from the sidebar conference, as well as
audio provided by the panelists in the main conference.
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(To Be added).
Figure 24: Floor Control with sidebars
1. "A1" wishes to ask a question, so he sends a Floor Request
message to the floor control server.
2. Upon receipt of the request, the floor control server notifies
the moderator, "Carol" of the active sidebar conference, whose
serving as the floor chair.
3. Since no other analysts have yet requested the floor, "Carol"
indicates to the floor control server that "A1" may be granted the
floor.
(CCMP Messaging details not available yet).
Figure 25: Floor Control Messaging Details
6.9. Whispering or Private Messages
The case of private messages can be handled as a sidebar with just
two participants, similar to the example in section Section 6.6, but
rather than using audio within the sidebar, "Alice" could add an
additional text based media stream to the sidebar. The other
context, referred to as whisper, in this document refers to
situations involving one time media targetted to specific user(s).
An example of a whisper would be an announcement injected only to the
conference chair or to a new participant joining a conference.
Figure 26 provides an example of one user "Alice" whose chairing a
fixed length conference with "Bob" and "Carol". The configuration is
such that only the chair is providing a warning when there is only 10
minutes left in the conference. At that time, "Alice" is moved into
a sidebar created by the conferencing system and only "Alice"
receives the announcement.
(To Be completed).
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Figure 26: Whisper
1. When the conferencing system determines that there is only 10
minutes left in the conference which "Alice" is chairing, the
conferencing system directly creates an active sidebar conference,
based on the active conference associated with "Alice". This sidebar
conference is NOT independent of the active conference (i.e.,
parent). The conferencing system also allocates a conference ID to
be used for any subsequent manipulations of the sidebar conference.
2. Immediately upon creation of the active sidebar conference, the
announcement media is provided to "Alice". Depending upon the
policies, Alice may be notified of her addition to the sidebar via
the conference notification service. "Alice" continues to receive
the media from the main conference.
3. Upon completion of the announcement, "Alice" is removed from the
siebar and the sidebar conference is deleted.
4. "Alice" is notified of her removal from the sidebar via the
conference notification service.
(CCMP Messaging details not available yet).
Figure 27: Whisper Messaging Details
6.10. Observing and Coaching
An example of observing and coaching is shown in figure Figure 28.
In this example, call center agent "Bob" is involved in a conference
with customer "Carol". Since "Bob" is a new agent and "Alice" sees
that he has been on the call with "Carol" for longer than normal, she
decides to observe the call and coach "Bob" as necessary.
(Figure not available yet).
Figure 28: 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
conference received in the request, the conferencing system uses the
received active conference to clone a conference reservation for the
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sidebar. The conferencing system also reserves or allocates a
conference ID to be used for any subsequent protocol requests from
any of the members of the conference. The conferencing system
maintains the mapping between this conference ID and the conference
object ID associated with the sidebar reservation through the
conference instance.
Upon receipt of the conference control protocol response to reserve
the conference, "Alice" can now create an active conference using
that reservation or create additional reservations based upon the
existing reservations. In this example, "Alice" wants only "Bob" to
be involved in the sidebar, thus she manipulates the membership.
"Alice" also wants the audio to be received by herself and "Bob" from
the original conference, but wants any outgoing audio from herself to
be restricted to the participants in the sidebar, whereas "Bob's"
outgoing audio should go to the main conference, so that both "Alice"
and the customer "Carol" hear the same audio from "Bob". "Alice"
sends a conference control protocol request to update the information
in the reservation and to create an active conference.
Upon receipt of the conference control protocol request to update the
reservation and to create an active conference for the sidebar, as
identified by the conference object ID, the conferencing system
ensures that "Alice" has the appropriate authority based on the
policies associated with that specific conference object to perform
the operation. Based upon the addressing information provided for
"Bob" by "Alice", the call signaling to add "Bob" to the sidebar with
the appropriate media characteristics is instigated through the
Focus.
"Bob" is notified of his addition to the sidebar via the conference
notification service, thus he is aware that "Alice" the supervisor is
available for coaching him through this call.
(CCMP Messaging details not available yet).
Figure 29: Coaching and Observing Messaging details
7. Removing participants and deleting conferences
The following scenarios detail the basic operations associated with
removing participants from conferences and entirely deleting
conferences. The examples assume that a conference has already been
correctly established, with media, if applicable, per one of the
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examples in Section 5.
7.1. Removing a Party
Figure 30 provides an example of one client "Alice" removing another
participant "Bob" from a conference. This example assumes an
established conference with "Alice", "Bob", "Claire" and "Duck". In
this example, "Alice" wants to remove "Bob" from the conference so
that the group can continue in the same conference without "Bob"'s
participation.
(Figure not available yet).
Figure 30: Client Manipulation of Conference - Remove a party
1. Upon receipt of the confUsersRequest message, with a "change"
operation to remove "Bob" from the "allowed-users-list" for the
conference identified by the "confObjID" in the request, the
conferencing system ensures that "Alice" has the appropriate
authority based on the policies associated with that specific
conference object to perform the operation.
2. Based upon the addressing and media information in the conference
object for "Bob" in the "user" element, the conferencing system
instigates the process to remove "Bob" (e.g., the call signaling to
remove "Bob" from the conference is instigated through the Focus).
In addition, the "conference-info" in the conference object is
modified to remove "Bob" from the "users" list.
3. Once the call signaling indicates that "Bob" has been
successfully removed from the specific conference, per updates to the
state, and depending upon the policies, other participants (including
"Bob") may be notified of the removal of "Bob" from the conference
via the Conference Notification Service.
(CCMP Messaging details not available yet).
Figure 31: Removing a Participant Messaging Details
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7.2. Deleting a Conference
Details to be added.
(Figure not available yet).
Figure 32: Deleting a conference
(Text description to be added).
(CCMP Messaging details not available yet).
Figure 33: Deleting a Conference Messaging Details
8. Additional Conference Scenarios and Examples
The following are additional scenarios making use of the XCON
framework and associated protocols. In some cases, these examples
make use of some of the building block scenarios detailed in the
previous example sections, in which case the appropriate scenario is
referenced rather than duplicating details. In addition, in cases
where the scenarios make use of other protocols, as in the previous
section, the appropriate reference in the form of a title to the
specific flow in the appropriate protocol document is included.
8.1. Chat
The chat functionality described in this section of the document
allows clients that use the XCON framework and protocols for other
media types (e.g. voice/video) to utilize the same conference control
mechanisms and conferencing system to establish, update and delete a
conference instance associated with an Instant Messaging (IM) chat
session, independent of the IM chat protocol. In some cases(e.g.,
Message Session Relay Protocol (MSRP) chat), this would provide
additional capabilities, such as sidebars. This approach also allows
the conferencing system to provide a natural interworking point for
various IM protocols, the details of the interworking are outside the
scope of this document.
An IM client wishing to join a conference uses standardized
centralized conferencing mechanisms for creating and joining a
conference, as identified in the previous sections. The request to
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send an IM to an IM media session is specific to the IM protocol
(e.g., MSRP SEND), just as there is specific media control messaging
for other types of sessions. An IM client connecting to a
conferencing system has a 1:1 relationship with the IM media
signaling entity in the conferencing system. This relationship is
referred to as an IM session. Further details of the correlation of
the IM session identifiers with the XCON session identifiers is
provided in Appendix A. The IM media signaling entity is responsible
for distribution of all the messages to the other participants.
As with the other example conferences created, each IM session is
logically associated with a specific conference. The conference
itself has a specific identifier in the form of the XCON-URI, which
is passed in the "confObjID" element in the CCMP messages. This
provides the relevant association between IM session and a
centralized conference.
An IM client wishing to delete a chat room uses standardized
mechanisms for deleting a conference instance, such as those detailed
in Section 7.2.
8.1.1. Basic Chat Operations
This section provides details of the realization of the Multi-party
IM (chat) within the context of the centralized conferencing
framework. A brief discussion and diagrams are provided for
creating, joining, and deleting a chat based conference. The
discovery of chat rooms available on a specific conferencing system
is inherent in the blueprint capability provided by the conferencing
system. The objective of this section is to further illustrate the
model, mechanisms and protocols presented in the previous sections
and also serves to validate that the model, mechanisms and protocols
are sufficient to support IM chat.
It should be noted that not all entities impacted by the request are
shown in the diagram (e.g., Focus), but rather the emphasis is on the
new entities introduced by this centralized conferencing framework.
[Editor's Note: Ideally, this section will be updated with details
once the protocol is agreed.]
8.1.1.1. Creating a Chat Room
There are different ways to create a conference. A participant can
create a conference using call signaling means only, such as SIP, as
detailed in [RFC4579]. For a conferencing client to have more
flexibility in defining the charaterisitics and capabilities of a
chat based conference, a conferencing client would implement a
conference control protocol client. By using a conference control
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protocol, the client can determine the capabilities of a conferencing
system and its various resources.
Figure 34 provides an example of one client "Alice" determining the
conference blueprints available to support various types of chat
rooms for a particular conferencing system and creating a chat based
conference using the desired blueprint.
Details to be added.
Figure 34: Client Creation of Chat room
Upon receipt of the Conference Control Protocol request for
blueprints associated with chat rooms, the conferencing system would
first authenticate "Alice" (and allocate a conference user
identifier, if necessary) and then ensure that "Alice" has the
appropriate authority based on system policies to receive any chat
room based blueprints supported by that system. Any blueprints that
"Alice" is authorized to use are returned in a response, along with
the conference user ID.
Upon receipt of the Conference Control Protocol response containing
the blueprints, "Alice" determines which blueprint to use for the
conference to be created. "Alice" creates a conference object based
on the blueprint (i.e., clones) and modifies applicable fields, such
as membership list, topic details, and start time. "Alice" then
sends a request to the conferencing system to create a conference
reservation based upon the updated blueprint.
Upon receipt of the Conference Control Protocol request to "create" a
conference based upon the blueprint in the request, the conferencing
system ensures that the blueprint received is a valid blueprint (i.e.
the values of the various field are within range). The conferencing
system determines the appropriate read/write access of any users to
be added to a conference based on this blueprint (using membership,
roles, etc.). The conferencing system uses the received blueprint to
clone a conference reservation. The conferencing system also
reserves or allocates a conference ID to be used for any subsequent
protocol requests from any of the members of the conference. The
conferencing system maintains the mapping between this conference ID
and the conference object ID associated with the reservation through
the conference instance.
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Upon receipt of the conference control protocol response to reserve
the conference, "Alice" now creates an active chat room using that
reservation. "Alice" provides the conference information, including
the necessary conference ID, to desired participants to allow them to
join the chat room. "Alice" may also add other users to the chat
room. When the first participant, including "Alice", requests to be
added to the conference, an active conference and focus are created.
The focus is associated with the conference ID received in the
request.
(CCMP Messaging details not available yet.
Plan is to reference detailed flows in
previous sections and add MSRP messaging
in the example.)
Figure 35: Chatroom Creation Messaging Details
8.1.1.2. Joining a Chat Room
A participant can join and leave the conference using call signaling
means only, such as SIP. However, in order to perform richer
conference control a user client can implement a conference control
protocol client. By using a conference control protocol, the client
can affect its own state and the state of other participants,
depending upon policies, which may indirectly affect the state of any
of the conference participants.
In the example in section Section 8.1.1.1, "Alice" has reserved a
chat room . "Alice" has also already joined the conference and made
the chat room active. "Alice" can either add additional participants
to the chat room or provide the conference information, including the
necessary conference ID, to desired participants and allow them to
request to join themselves. Any participants that have the authority
to manipulate the conference would receive the conference object
identifier of the active conference object in the response to their
request to join.
Figure 36 provides an example of "Bob" joining the chat room using
the conference ID provided by "Alice" (e.g., in an IM).
Details to be added.
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Figure 36: Joining a chat room
Upon receipt of the Conference Control Protocol request to "add" a
party ("Bob") in the specific conference as identified by the
conference object ID, the conferencing system must determine whether
"Bob" is already a user of this conferencing system or whether he is
a new user. If "Bob" is a new user for this conferencing system, a
Conference User Identifier is created for Bob. The conferencing
system must also ensure that "Bob" has the appropriate authority
based on the policies associated with that specific conference object
to perform the operation.
Once "Bob" has been successfully added to the chat room, a response
is sent to "Bob". Depending upon the policies, other participants
(including "Bob") may be notified of the addition of "Bob" to the
conference via the Conference Notification Service.
(CCMP Messaging details not available yet.
Plan is to reference detailed flows in
previous sections as appropriate and add MSRP messaging
in the example.)
Figure 37: Chatroom Join Messaging Details
8.1.1.3. Deleting a Chat Room
Depending upon the conferencing system policies and policies specific
to the chat room, the creator of the chat would typically be the
participant authorized to delete the chat room.
In the example in section Section 8.1.1.1, "Alice" has created a chat
room and provided the conference information, including the necessary
conference ID, to desired participants and allow them to request to
join themselves. "Bob" and others are participants in the chat.
Figure 38 provides an example of "Alice" later deleting this same
chat room.
Details to be added.
Figure 38: Deleting a chat room
Upon receipt of the Conference Control Protocol request to "delete"
the specific chat room as identified by the conference object ID, the
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conferencing system must determine whether "Alice" has the authority
to delete this conference. Since "Alice" is the creator of the
conference, the "delete" operation is performed, with the appropriate
signaling sent to the participants, including a response to "Alice"
indicating that the chat room has been deleted.
One step in the deletion of the chat room may include notifitying the
participants (including "Bob") that they have been removed via the
Conference Notification Service.
(CCMP Messaging details not available yet.
Plan is to reference detailed flows in
previous sections and add MSRP messaging
in the example.)
Figure 39: Chatroom Deletion Messaging Details
8.1.2. Additional Operations
This section discusses additional operations or features required to
provide chat room functionality. Most of the operations are not
explicitly specified in the centralized conferencing framework.
However, some of the features and operations are achievable using
data maintained by a conferencing system based on the framework.
8.1.2.1. Nicknames
Nicknames allow a user to define a text string that uniquely
identifies the user within a particular chatroom without necessarily
reflecting any protocol specific identity (e.g., SIP URI, Conference
User Indentifier, etc.). It is also important to note that the
functionality to provide nicknames is not limited to users involved
in chatrooms, thus it should be a general feature of the conferencing
system. However, the mechanism to allow a user to negotiate a
nickname with a conferencing system is additional functionality
beyond the centralized conferencing framework, and thus is described
in [ref:TBD].
Within a conferencing system, all nicknames should map to a
conference user identifier. There may be multiple nicknames
associated with a single conference user identifier (e.g., a user
that has different nicknames for different chat rooms and/or voice/
video conferences).
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8.1.2.2. Logging
A common chat feature involves logging the history of a chat room.
This provides a record of a chat room that can be used when a user
first joins a chat room as discussed in Section 8.1.2.3. It can also
be used to provide a complete capture of a specific chat room
session. The centralized conferencing framework does not fully
describe the role of recording or logging of active conferences.
However, this functionality can be realized with the manipulation of
the appropriate elements in the data model using the general
conference control protocol operations. One approach for
implementing this function would be to have it be based on specific
manipulation of the conference by a user with the appropriate
permissions (e.g., CHANGE operation to start and stop recording).
Another mechanism for implementing this function would be to have a
specific user as part of the conference to perform this function, by
defining a specific role such as "observer" and having the media
proxied to a logging device.
8.1.2.3. History
A common chat feature allows users to view the past history of chat
rooms. This operation is common when a user first joins a chat room
that is underway. A user is often offered the option to review a
specific number of past messages. Conferencing systems that maintain
the history associated with specific chat rooms through logging, as
described in Section 8.1.2.2, should provide a mechanism, using the
conference identifier, to access the specific information requested
by a user based on a specific timestamp. The user request for the
information and the rendering of the information is specific to the
user's session based messaging protocol and may not be supported by
all the messaging protocols.
8.1.2.4. Indicating Alternate Venue
Another chat room feature provides the details of an alternate chat
room venue for previously active chat rooms that have been closed,
with a related topic. While not detailed in the centralized
conferencing framework, this functionality can be accomplished by
creating the new chat room as a child or sibling of the previous chat
room and providing the Active chat conference object identifier to
any valid users that attempt to join a previous chat room. The
information about the new chat room can also be provided at the end
of a chat room that is being de-activated at the end of the session.
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8.1.3. Advanced Operations
This section provides details of the realization of advanced chat
features, such as sidebars and private messages, within the context
of the centralized conferencing framework. As with Section 8.1.1,
the objective of this section is to further illustrate the model,
mechanisms and protocols presented in the previous sections and also
serves to validate that the model, mechanisms and protocols are
sufficient to support advance IM chat features.
8.1.3.1. Text Sidebar
The concept of a 'sidebar' in conferencing system is fully described
in the Sidebar section and related subsections within the
Conferencing Scenarios Realization section of the centralized
conferencing framework document [RFC5239]. The creation,
manipulation and deletion of sidebars for chat rooms follows the same
principles.
A conference object representing a sidebar is created by cloning the
parent associated with the existing conference and updating any
information specific to the sidebar. A sidebar conference object is
implicitly linked to the parent conference object (i.e. it is not an
independent object) and is associated with the parent conference
object identifier. A conferencing system manages and enforces the
parent and appropriate localized restrictions on the sidebar
conference object (e.g., no members from outside the parent
conference instance can join, sidebar conference can not exist if
parent conference is terminated, etc.).
Figure 40 provides an example of one client "Alice" involved in
active chat room with "Bob" and "Carol". "Alice" wants to create a
sidebar to have a side discussion with "Bob" while still receiving
the session based messaging associated with the main chat room.
Whether the text is interleaved with the main chat or whether a
separate window is created for the sidebar is implementation
specific. "Alice" initiates the sidebar by sending a request to the
conferencing system to create a conference chat reservation based
upon the active chat conference object. "Alice" and "Bob" would
remain on the roster of the main conference, such that other
participants could be aware of their participation in the main
conference, while the text sidebar conference is occurring.
Details to be added.
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Figure 40: Client Creation of a Sidebar Conference
Upon receipt of the Conference Control Protocol request to "reserve"
a new sidebar chat conference, based upon the active chat conference
received in the request, the conferencing system uses the received
active chat conference to clone a conference chat reservation for the
sidebar. As discussed previously, the sidebar reservation is NOT
independent of the active conference (i.e., parent). The
conferencing system also reserves or allocates a conference ID to be
used for any subsequent protocol requests from any of the members of
the conference. The conferencing system maintains the mapping
between this conference ID and the conference object ID associated
with the sidebar reservation through the conference instance.
Upon receipt of the conference control protocol response to reserve
the conference, "Alice" can now create an active chat conference
using that reservation or create additional reservations based upon
the existing reservations. In this example, "Alice" wants only "Bob"
to be involved in the sidebar, thus she manipulates the membership.
"Alice" also only wants the text from the original conference, but
wants the text within the sidebar to be restricted to the
participants in the sidebar. "Alice" sends a conference control
protocol request to update the information in the reservation and to
create an active conference.
Upon receipt of the conference control protocol request to update the
reservation and to create an active chat conference for the sidebar,
as identified by the conference object ID, the conferencing system
ensures that "Alice" has the appropriate authority based on the
policies associated with that specific conference object to perform
the operation. The conferencing system must also validate the
updated information in the reservation, ensuring that a member like
"Bob" is already a user of this conferencing system.
Depending upon the policies, the initiator of the request (i.e.,
"Alice") and the participants in the sidebar (i.e., "Bob") may be
notified of his addition to the sidebar via the conference
notification service.
(CCMP Messaging details not available yet.
Plan is to reference detailed flows in
previous sections.)
Figure 41: Chatroom Sidebar Messaging Details
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8.1.3.2. Private Message
The case of private messages can be handled as a sidebar with just
two participants, identical to the example in section
Section 8.1.3.1. The other context, referred to as whisper, in this
document refers to situations involving one time media targetted to
specific user(s). An example of a whisper would be a text message
injected only to the conference chair or to a new participant joining
a conference.
Figure 42 provides an example of one user "Alice" who's chairing a
fixed length conference with "Bob" and "Carol". The configuration is
such that only the chair is providing a warning when there is only 10
minutes left in the conference. At that time, "Alice" is moved into
a sidebar created by the conferencing system and only "Alice"
receives that text message announcing the 10 minute warning.
Details to be added.
Figure 42: Whisper
When the conferencing system determines that there is only 10 minutes
left in the conference which "Alice" is chairing, rather than
creating a reservation as was done for the sidebar in
Section 8.1.3.1, the conferencing system directly creates an active
chat sidebar conference, based on the active chat conference
associated with "Alice". As discussed previously, the sidebar
conference is NOT independent of the active conference (i.e.,
parent). The conferencing system also allocates a conference ID to
be used for any subsequent manipulations of the sidebar chat
conference. The conferencing system maintains the mapping between
this conference ID and the conference object ID associated with the
active sidebar conference through the conference instance.
Immediately upon creation of the active chat sidebar conference, the
text announcement is provided to "Alice". Depending upon the
policies, Alice may be notified of her addition to the sidebar via
the conference notification service. "Alice" continues to receive
the text messages from the main conference.
Upon delivery of the text announcement, "Alice" is removed from the
sidebar and the sidebar conference is deleted. Depending upon the
policies, "Alice" may be notified of her removal from the sidebar via
the conference notification service.
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(CCMP Messaging details not available yet.
Plan is to reference detailed flows in
previous sections.)
Figure 43: Chatroom Sidebar Messaging Details
9. IANA Considerations
This document has no IANA considerations.
10. Security Considerations
The security considerations applicable to the implementation of these
call flows is documented in the XCON Framework, with additional
security considerations documented in the CCMP document. Where
applicable, statements with regards to the necessary security are
discussed in particular flows, however, since this is only an
informational document, readers are strongly recommended to carefully
consider the security considerations defined in the XCON Framework
and the CCMP document.
11. Change Summary
The following are the major changes between the 00 and the 01
versions of the draft:
o TBD based on WG feedback.
12. Acknowledgements
The detailed content for this document is derived from the prototype
work of Lorenzo Miniero, Simon Pietro-Romano, Tobia Castaldi and
their colleagues at the University of Napoli.
13. References
13.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
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[RFC5239] Barnes, M., Boulton, C., and O. Levin, "A Framework for
Centralized Conferencing", RFC 5239, June 2008.
[I-D.ietf-xcon-ccmp]
Barnes, M., Boulton, C., Romano, S., and H. Schulzrinne,
"Centralized Conferencing Manipulation Protocol",
draft-ietf-xcon-ccmp-00 (work in progress), June 2008.
13.2. Informative References
[RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,
A., Peterson, J., Sparks, R., Handley, M., and E.
Schooler, "SIP: Session Initiation Protocol", RFC 3261,
June 2002.
[RFC3264] Rosenberg, J. and H. Schulzrinne, "An Offer/Answer Model
with Session Description Protocol (SDP)", RFC 3264,
June 2002.
[RFC3550] Schulzrinne, H., Casner, S., Frederick, R., and V.
Jacobson, "RTP: A Transport Protocol for Real-Time
Applications", STD 64, RFC 3550, July 2003.
[RFC4574] Levin, O. and G. Camarillo, "The Session Description
Protocol (SDP) Label Attribute", RFC 4574, August 2006.
[RFC4145] Yon, D. and G. Camarillo, "TCP-Based Media Transport in
the Session Description Protocol (SDP)", RFC 4145,
September 2005.
[RFC4579] Johnston, A. and O. Levin, "Session Initiation Protocol
(SIP) Call Control - Conferencing for User Agents",
BCP 119, RFC 4579, August 2006.
[RFC4597] Even, R. and N. Ismail, "Conferencing Scenarios",
RFC 4597, August 2006.
[RFC4582] Camarillo, G., Ott, J., and K. Drage, "The Binary Floor
Control Protocol (BFCP)", RFC 4582, November 2006.
[RFC5018] Camarillo, G., "Connection Establishment in the Binary
Floor Control Protocol (BFCP)", RFC 5018, September 2007.
[I-D.ietf-xcon-event-package]
Camarillo, G., Srinivasan, S., Even, R., and J.
Urpalainen, "Conference Event Package Data Format
Extension for Centralized Conferencing (XCON)",
draft-ietf-xcon-event-package-00 (work in progress),
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February 2008.
[I-D.ietf-xcon-common-data-model]
Novo, O., Camarillo, G., Morgan, D., and R. Even,
"Conference Information Data Model for Centralized
Conferencing (XCON)", draft-ietf-xcon-common-data-model-11
(work in progress), June 2008.
[I-D.miniero-mediactrl-escs]
Amirante, A., Castaldi, T., Miniero, L., and S. Romano,
"Media Control Channel Framework (CFW) Call Flow
Examples", draft-miniero-mediactrl-escs-02 (work in
progress), June 2008.
[I-D.ietf-mediactrl-architecture]
Melanchuk, T., "An Architectural Framework for Media
Server Control", draft-ietf-mediactrl-architecture-03
(work in progress), April 2008.
[I-D.ietf-mediactrl-sip-control-framework]
Boulton, C., Melanchuk, T., and S. McGlashan, "Media
Control Channel Framework",
draft-ietf-mediactrl-sip-control-framework-02 (work in
progress), April 2008.
[I-D.boulton-mmusic-sdp-control-package-attribute]
Boulton, C., "A Session Description Protocol (SDP) Control
Package Attribute",
draft-boulton-mmusic-sdp-control-package-attribute-02
(work in progress), February 2008.
[I-D.boulton-ivr-control-package]
Boulton, C., Melanchuk, T., and S. McGlashan, "A Basic
Interactive Voice Response (IVR) Control Package for the
Media Control Channel Framework",
draft-boulton-ivr-control-package-06 (work in progress),
February 2008.
[I-D.boulton-conference-control-package]
Boulton, C., Melanchuk, T., McGlashan, S., and A.
Shiratzky, "A Conference Control Package for the Media
Control Channel Framework",
draft-boulton-conference-control-package-04 (work in
progress), February 2008.
[I-D.miniero-bfcp-control-package]
Miniero, L., Amirante, A., Castaldi, T., and S. Romano, "A
Binary Floor Control Protocol (BFCP) Control Package for
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the Session Initiation Protocol (SIP)",
draft-miniero-bfcp-control-package-00 (work in progress),
February 2008.
[RFC2810] Kalt, C., "Internet Relay Chat: Architecture", RFC 2810,
April 2000.
[RFC3920] Saint-Andre, P., Ed., "Extensible Messaging and Presence
Protocol (XMPP): Core", RFC 3920, October 2004.
[RFC4353] Rosenberg, J., "A Framework for Conferencing with the
Session Initiation Protocol (SIP)", RFC 4353,
February 2006.
[RFC4975] Campbell, B., Mahy, R., and C. Jennings, "The Message
Session Relay Protocol (MSRP)", RFC 4975, September 2007.
[I-D.ietf-simple-chat]
Niemi, A., Garcia-Martin, M., and G. Sandbakken, "Multi-
party Instant Message (IM) Sessions Using the Message
Session Relay Protocol (MSRP)", draft-ietf-simple-chat-02
(work in progress), February 2008.
Appendix A. IM Chat and Conferencing Identifier Relationships
When referring to IM session ID's this document is making reference
to the locally (at conferencing system) generated session ID used for
IM session signaling identification. In the case of MSRP, this
session ID is inserted into the local path SDP attribute. An
important concept is the creation and management of IM sessions. It
is important that each IM session created, as identified by a unique
IM session ID, is explicitly tied to an associated conference,
represented by the conference identifier, represented by the
"confObjID" in the protocol and data model. This provides the
relevant association between IM session and a centralized conference.
A generic example representation is illustrated by the rows contained
in Figure 44.
-------------------------------------------
| Conference Identifier |
-------------------------------------------
| IM Session ID=8asjdhk |
| IM Session ID=38iuhds |
| IM Session ID=djiowid |
| IM Session ID=389hewu |
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-------------------------------------------
Figure 44: Simple Session Association
When a user joins a conference instance through the signaling
protocol, it is allocated an appropriate conference user identifer
either through authentication or system allocation. The conference
user identifer MUST be used in conjunction with an IM session
identifier to internally represent a participant in a conference
instance. Figure 44 is then expanded to look like Figure 45. Again
a row in the table representing a single entry.
----------------------------------------------------------------
| Conference Identifier |
----------------------------------------------------------------
| IM Session ID=8asjdhk | confUserID=839ULjj |
| IM Session ID=38iuhds | confUserID=0283hHu |
| IM Session ID=djiowid | confUserID=ncH37H |
| IM Session ID=389hewu | confUserID=pakdjjH |
----------------------------------------------------------------
Figure 45: Advanced Session Association
A more complex session association is necessary due to potential for
a user to have multiple IM sessions in a single conference instance,
such as multi-lingual conference support. In an example with SIP and
MSRP, the conference representation in Figure 45 allows for such
functionality when separate SIP dialogs represent MSRP sessions.
This process becomes complex when multiple SDP MSRP media sessions
(m=) are defined in a single payload. This internal representation
now needs expanding to enable a conferencing system to explicitly
associate a media session (m=). This involves including the media
label, as defined in [RFC4574], to maintain the internal conference
association. An example is illustrated in Figure 46.
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---------------------------------------------------------------------
| Conference Identifier |
---------------------------------------------------------------------
| MSRP Session ID=8asjdhk | Conf User ID=839ULjj | Label=iede3 |
| MSRP Session ID=38iuhds | Conf User ID=0283hHu | Label=8heus |
| MSRP Session ID=838unaH | Conf User ID=0283hHu | Label=3cnu7 |
| MSRP Session ID=djiowid | Conf User ID=ncH37Hs | Label=jd38J |
| MSRP Session ID=389hewu | Conf User ID=pakdj7H | Label=U83hd |
| MSRP Session ID=Ko03jdk | Conf User ID=pakdj7H | Label=ehy3h |
---------------------------------------------------------------------
Figure 46: Advanced Session Association + Media Label
In Figure 46, conference user identifiers '0283hHu' and 'pakdj7H'
appear twice. The combination of multiple conference user
identifiers and a unique MSRP session ID enables the conference
system to clearly identify a specific MSRP instance. The
representation also includes the media label, as defined in
[RFC4574],for identification purposes. This added property, which is
extracted from the SDP media line, enables clear identification when
multi SDP media (m=) lines appear in the same SDP payload.
A client MUST include the media label attribute defined in [RFC4574]
when including multiple MSRP sessions in the same SDP payload. Even
in the simplest conferencing system, where users are allowed to enter
anonymously, the internal representation described in this section
should be observed. In this case, the conferencing system would
still internally create a conference user identifier for participant
reference purposes.
Authors' Addresses
Mary Barnes
Nortel
2201 Lakeside Blvd
Richardson, TX
Email: mary.barnes@nortel.com
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Chris Boulton
Avaya
Building 3
Wern Fawr Lane
St Mellons
Cardiff, South Wales CF3 5EA
Email: cboulton@avaya.com
Lorenzo Miniero
University of Napoli
Via Claudio 21
Napoli 80125
Italy
Email: lorenzo.miniero@unina.it
Simon Pietro Romano
University of Napoli
Via Claudio 21
Napoli 80125
Italy
Email: spromano@unina.it
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