XCON Working Group M. Barnes
Internet-Draft Nortel
Intended status: Informational L. Miniero
Expires: August 21, 2010 Meetecho
R. Presta
S P. Romano
University of Napoli
February 17, 2010
Centralized Conferencing Manipulation Protocol (CCMP) Call Flow Examples
draft-ietf-xcon-examples-03
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.
Status of this Memo
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provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on August 21, 2010.
Copyright Notice
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Copyright (c) 2010 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
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include Simplified BSD License text as described in Section 4.e of
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described in the BSD License.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
5. Working with CCMP . . . . . . . . . . . . . . . . . . . . . . 6
5.1. CCMP and the Data Model . . . . . . . . . . . . . . . . . 6
5.2. Using HTTP as a transport . . . . . . . . . . . . . . . . 8
5.3. Conference Notifications . . . . . . . . . . . . . . . . . 11
6. Conference Creation . . . . . . . . . . . . . . . . . . . . . 15
6.1. Basic Conference Creation . . . . . . . . . . . . . . . . 15
6.2. Conference Creation using Blueprints . . . . . . . . . . . 20
6.3. Conference Creation using User-Provided Conference
Information . . . . . . . . . . . . . . . . . . . . . . . 27
6.4. Cloning an Existing Conference . . . . . . . . . . . . . . 32
7. Conference Users Scenarios and Examples . . . . . . . . . . . 35
7.1. Adding a Party . . . . . . . . . . . . . . . . . . . . . . 36
7.2. Muting a Party . . . . . . . . . . . . . . . . . . . . . . 39
7.3. Conference Announcements and Recordings . . . . . . . . . 43
7.4. Monitoring for DTMF . . . . . . . . . . . . . . . . . . . 47
7.5. Entering a password-protected conference . . . . . . . . . 47
8. Sidebars Scenarios and Examples . . . . . . . . . . . . . . . 49
8.1. Internal Sidebar . . . . . . . . . . . . . . . . . . . . . 50
8.2. External Sidebar . . . . . . . . . . . . . . . . . . . . . 59
8.3. Private Messages . . . . . . . . . . . . . . . . . . . . . 65
8.4. Observing and Coaching . . . . . . . . . . . . . . . . . . 69
9. Removing Participants and Deleting Conferences . . . . . . . . 76
9.1. Removing a Party . . . . . . . . . . . . . . . . . . . . . 76
9.2. Deleting a Conference . . . . . . . . . . . . . . . . . . 79
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 80
11. Security Considerations . . . . . . . . . . . . . . . . . . . 80
12. Change Summary . . . . . . . . . . . . . . . . . . . . . . . . 81
13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 83
14. References . . . . . . . . . . . . . . . . . . . . . . . . . . 83
14.1. Normative References . . . . . . . . . . . . . . . . . . . 83
14.2. Informative References . . . . . . . . . . . . . . . . . . 83
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 84
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1. Introduction
This document provides detailed call flows for the scenarios
documented in the Framework for Centralized Conferencing (XCON
Framework) [RFC5239] and the XCON Scenarios [RFC4597]. The XCON
scenarios describe a broad range of use cases taking advantage 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 to provide an overview of the feature rich
capabilities of the XCON framework and CCMP messaging for protocol
developers, software developers and 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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Conference and Media Control Client (CMCC): as defined in the XCON
Framework. 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.ietf-mediactrl-call-flows]. A CMCC
differs from a generic Media Client in being an XCON-aware entity,
thus being able to also issue CCMP requests.
Conferencing Server (ConfS): In this document, the "Conferencing
Server" term is used interchangeably with the term Application
Server (AS) as used in the Media Control Architectural Framework
[RFC5567]. A Conferencing Server is intended to be able to act as
a Conference Control Server, as defined in the XCON framework,
i.e. it is able to handle CCMP requests and issue CCMP responses.
Media Server (MS): as defined in the Media Control Architectural
Framework [RFC5567].
4. Overview
This document provides a sampling of detailed call flows that can be
implemented based on a system realization of the XCON framework
[RFC5239] and implementation of CCMP [I-D.ietf-xcon-ccmp]. This is
intended to be a simple guide for the use of the Conference Control
Protocol between the Conferencing Server and the Conference Control
Client. The objective is to provide an informational base reference
for protocol developers, software developers and researchers.
This document focuses on the interaction between the Conference (and
Media) Control Client and the Conferencing System, specifically the
Conferencing Server. The scenarios are based on those 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. With the exception of an initial example with media
control messaging, the examples do not include the details for the
media control [I-D.ietf-mediactrl-mixer-control-package], call
signaling or binary floor control [RFC4582] protocols. This document
references the scenarios in the Media Control call flows
[I-D.ietf-mediactrl-call-flows], SIP Call Control Conferencing
[RFC4579] and binary floor control protocol documents.
The rest of this document is organized as follows. Section 5
presents an overview on CCMP, together with some implementation-
related details and related matters like HTTP transport and
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notifications. Section 6 presents the reader with examples showing
the different approaches CCMP provides to create a new conference.
Section 7 more generally addresses the different user-related
manipulations that can be achieved by means of CCMP, by presenting a
number of interesting scenarios. Section 8 addresses the several
scenarios that may involve the use of sidebars. Section 9 shows how
CCMP can be used to remove conferences and users from the system.
Finally, Section 11 provides a few details for what concerns the
Security Considerations when it comes to implementing CCMP.
5. Working with CCMP
This section aims at being a brief introduction to how the
Centralized Conferencing Manipulation Protocol (CCMP)
[I-D.ietf-xcon-ccmp] works and how it can be transported across a
network. Some words will be spent to describe a typical CCMP
interaction, by focusing on relevant aspects of the client-server
communication. Please notice that this section is by no means to be
considered as a replacement for the CCMP document, which remains a
mandatory read before approaching the following sections. It is just
conceived to help the reader take the first steps toward the actual
protocol interactions.
First of all, some lines will be devoted to the protocol by itself in
Section 5.1, together with some recommendations from an
implementation point of view. In Section 5.2, instead, an effective
CCMP interaction will be presented by exploiting HTTP as a transport.
Finally, a few words will be spent on notifications in Section 5.3.
Once done with these preliminary steps, some actual flows will be
presented and described in detail in the sections to follow.
5.1. CCMP and the Data Model
CCMP is an XML-based protocol. It has been designed as a request/
response protocol. Besides, it is completely stateless, which means
implementations can safely handle transactions indipendently from
each other.
The protocol allows for the manipulation of conference objects and
related users. By manipulation it is implied, as the document
specifies, that a Conferencing Client (briefly CMCC in all the
following sections) can create, update and remove basically
everything that is related to the objects handled by a conferencing
system. This is reflected in the allowed operations (retrieve,
create, update, delete) and the specified request types (ranging from
the manipulation of blueprints and conferences to users and
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sidebars). For instance, CCMP provides ways to:
o retrieve the list of registered and/or active conferences in the
system;
o create new conferences by exploiting to several different
approaches;
o add/remove users to/from a conference;
o update a conference with respect to all of its aspects;
and so on.
It is worthwile to note that, while CCMP acts as the means to
manipulate conference objects, its specification does not define
these objects as well. In fact, a separate document has been written
to specify how a conference object and all its components have to be
constructed: the Conference Information Data Model for Centralized
Conferencing (XCON) [I-D.ietf-xcon-common-data-model]. CCMP,
according to the request type and the related operation, carries
pieces of conference objects (or any object as a whole) according to
the aforementioned specification. This means that any implementation
aiming at being compliant with CCMP has to make sure that the
transported objects are completely compliant with the Data Model
specification and coherent with the constraints defined therein. To
make this clearer, there are elements that are mandatory in a
conference object: issuing a syntactically correct CCMP request that
carries a wrong conference object is doomed to result in a failure.
For this reason, it is suggested that the interested implementors
take special care in carefully checking the Data Model handlers as
well in order to avoid potential mistakes.
Of course, there are cases where a mandatory element in the Data
Model cannot be assigned in a conference object by a CCMP user. For
instance, a CMCC may be requesting the direct creation of a new
conference: in this case, a conference object assumes an 'entity'
element uniquely identifying the conference to be in place. Anyway,
the CMCC has no way to a priori know what the entity will be like,
considering it will only be generated by the ConfS after the request.
For scenarios like this one, the CCMP specification envisages the use
of a dedicated placeholder wildcard to make the conference object
compliant with the Data Model: the wildcard would then be replaced by
the ConfS with the right value.
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5.2. Using HTTP as a transport
[I-D.ietf-xcon-ccmp] presents several ways by which CCMP requests and
responses can be transported from a client to a server and viceversa.
Nevertheless, more focus is given on HTTP as a solution for this
transport matter, and a whole chapter is devoted in the document to
how HTTP can be used for it. This document is agnostic with respect
to the transport in use: this means that all the call flows herein
presented will just show the CCMP interactions, without talking about
how the messages could have gone across the network. Nevertheless,
the following lines will provide a brief explanation, from a more
practical point of view, of how HTTP might be exploited to carry CCMP
messages.
In case HTTP is used as a transport, the specification is very clear
with respect to how the interaction has to occur. Specifically, a
CMCC is assumed to send his request as part of an HTTP POST message,
and the Server would reply by means of an HTTP 200 message. In both
cases, the HTTP messages would have the CCMP messages as payload,
which would be reflected in the Content-Type message. Figure 1
presents a ladder diagram of such interaction, which is followed by a
dump of the exchanged HTTP messages for further analysis:
CMCC ConfS
| |
| 1. HTTP POST (CCMP request) |
|--------------------------------------------->|
| |
| |--+ Parse request,
| | | update object
| |<-+ and reply
| |
| 2. 200 OK (CCMP response) |
|<---------------------------------------------|
| |
|--+ Parse response and |
| | update local copy |
|<-+ of conference object |
| |
. .
. .
Figure 1: CCMP on HTTP
As it can be seen in the protocol dump in the following lines, the
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CMCC has issued a CCMP request (a blueprintRequest with a 'retrieve'
operation) towards the Conferencing Server (ConfS). The request has
been carried as payload of an HTTP POST (message 1.) towards a
previously known location. The mandatory 'Host' header has been
specified, and the 'Content-Type' header has been correctly set as
well (application/ccmp+xml).
The ConfS, in turn, has handled the request and replied accordingly.
The response (a blueprintResponse with a 'success' response code) has
been carried as payload of an HTTP 200 OK (message 2.). As before,
the 'Content-Type' header has been correctly set (application/
ccmp+xml).
1. CMCC -> ConfS (HTTP POST, CCMP request)
------------------------------------------
POST /Xcon/Ccmp HTTP/1.1
Content-Length: 657
Content-Type: application/ccmp+xml
Host: example.com:8080
Connection: Keep-Alive
User-Agent: Apache-HttpClient/4.0.1 (java 1.5)
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpRequest
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp"
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info">
<ccmpRequest xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-blueprint-request-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:AudioRoom@example.com</confObjID>
<operation>retrieve</operation>
<ccmp:blueprintRequest/>
</ccmpRequest>
</ccmp:ccmpRequest>
2. CMCC <- ConfS (200 to POST, CCMP response)
---------------------------------------------
HTTP/1.1 200 OK
X-Powered-By: Servlet/2.5
Server: Sun GlassFish Communications Server 1.5
Content-Type: application/ccmp+xml;charset=ISO-8859-1
Content-Length: 1652
Date: Thu, 04 Feb 2010 14:47:56 GMT
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<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpResponse
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info"
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp">
<ccmpResponse xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-blueprint-response-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:AudioRoom@example.com</confObjID>
<operation>retrieve</operation>
<response-code>success</response-code>
<ccmp:blueprintResponse>
<blueprintInfo entity="xcon:AudioRoom@example.com">
<info:conference-description>
<info:display-text>AudioRoom</info:display-text>
<info:maximum-user-count>2</info:maximum-user-count>
<info:available-media>
<info:entry label="audioLabel">
<info:type>audio</info:type>
</info:entry>
</info:available-media>
</info:conference-description>
<info:users>
<xcon:join-handling>allow</xcon:join-handling>
</info:users>
<xcon:floor-information>
<xcon:floor-request-handling>confirm
</xcon:floor-request-handling>
<xcon:conference-floor-policy>
<xcon:floor id="audioLabel"></xcon:floor>
</xcon:conference-floor-policy>
</xcon:floor-information>
</blueprintInfo>
</ccmp:blueprintResponse>
</ccmpResponse>
</ccmp:ccmpResponse>
Just for the sake of completeness, a few words will be spent about
the occurred CCMP interaction as well. In fact, despite the
simplicity of the request, this flow already provides some relevant
information on how CCMP messages are built. Specifically, both the
request and the response share a subset of the message:
o confUserID: this element, provided by the CMCC, refers to the
requester by means of his XCON-USERID; except in a few scenarios
(presented in the following sections) this element must always
contain a valid value;
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o confObjID: this element refers to the target conference object,
according to the request in place;
o operation: this element specifies the operation the CMCC wants to
perform according to the specific request type.
Besides those elements, the CMCC (in this case Alice, since the
'confUserID' has been set to 'xcon-userid:Alice@example.com') has
also provided an additional element, 'blueprintRequest'. The name of
that element varies according to the request type the CMCC is
interested into. In this specific scenario, the CMCC was interested
in acquiring details concerning a specific blueprint (identified by
its XCON-URI 'xcon:AudioRoom@example.com', as reflected in the
provided 'confObjID' target element), and so the request consisted in
an empty 'blueprintRequest' element. As it will be clearer in the
following sections, different request types may require different
elements, and as a consequence different content.
Considering the request was a 'blueprintRequest', the ConfS has
replied with a 'blueprintResponse' element. This element includes a
complete dump of the conference object (compliant with the Data
Model) describing the requested blueprint, together with an element
addressing the result of the client's request (response-
code=success).
This section won't delve in additional details for what concerns this
interaction. It is just worth noticing that this was the example of
the simplest CCMP communication that could take place between a CMCC
and a ConfS, a blueprintRequest: this scenario will be described in
more detail in Section 6.2.
5.3. Conference Notifications
[RFC5239] presents several different possible protocol interactions
between a conferencing server and a conferencing client. One of
those interactions is generically called "Notification Protocol",
implementing a notification service for all clients interested in
being informed by the server whenever something relevant happens in a
conference. While at first glance it may appear that such a
functionality should belong to a conference control protocol, such
feature has been specifically marked as out of scope in CCMP. As a
consequence, CCMP has been conceived as a request/answer protocol,
and in fact no ways to provide notifications to clients have been
introduced in the specification.
Nevertheless, the CCMP document by itself has a brief section
presenting some typical ways notifications might be managed. This
example document does not foster one rather than another, and all the
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flows will always generically present a notification being involved,
when it seems appropriate, but not providing any info on how the
notification itself has been sent to the interested clients. Anyway,
this section will briefly introduce some of the most typical ways a
notification service could be implemented and integrated with the
functionality provided by CCMP. It is by no means to be intended as
a complete list of solutions: the aim of this section is to provide
an overview of some of the possible solutions, together with
indications on how they may be integrated into a CCMP-based platform.
The first approach that comes to mind is of course the XCON Event
Package [I-D.ietf-xcon-event-package]. This specification extends
the SIP Event Package for Conference State [RFC4575] and allows for
the notification of conference notifications by means of the NOTIFY/
SUBSCRIBE mechanisms of SIP. Specifically, any SIP client who
subscribed for notifications related to a specific conference would
receive notifications via SIP describing all the changes to the
document. An example ladder diagram is presented in Figure 2: in
this figure, we assume a CMCC has updated a conference object, and
the update is notified to a previously subscribed SIP client.
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CMCC ConfS UAC
| | |
| | 1. SIP SUBSCRIBE |
| |<--------------------------|
| Handle +--| |
| new | | |
| subscription +->| 2. SIP 200 OK |
| |-------------------------->|
| | |
. . .
. . .
| | |
| 3. CCMP (add user) | |
|---------------------->| |
| |--+ Add user |
| | | to conf. |
| |<-+ object |
| 4. CCMP (success) | |
|<----------------------| |
| | 5. SIP NOTIFY (changes) |
| |-------------------------->|
| | 6. SIP 200 OK |
| |<--------------------------|
| | |
. . .
. . .
Figure 2: XCON Event Package: SIP notifications
While simple and effective, this solution has a drawback: it assumes
that all clients to be notified have a SIP stack. In fact, the
approach relies on the SIP SUBSCRIBE/NOTIFY mechanism. This means
that a client without a SIP stack would be unable to receive
notifications, in case no other means were available. Of course this
is not a desired situation in a framework as XCON which has been
conceived as being protocol-agnostic.
Considering CCMP is going to be probably most often deployed on HTTP,
another way to achieve notifications might be by exploiting some sort
of HTTP callbacks, as suggested in the CCMP specification itself.
This would allow to overcome the previous limitation, since both the
CMCC and the ConfS would already have an HTTP stack to make use of.
Using this approach, an interested web client might provide the
Conferencing System with an URL to contact whenever updates are
available: the update could be part of the notification message
itself, or it could be only implicitly referenced by the
notification. At the same time, alternative notification means could
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be exploited, e.g. by taking advantage of functionality provided by
other protocols as XMPP. Figure 3 shows an example of different
subscriptions which accordingly trigger notifications after the same
relevant event happens.
CMCC ConfS Sub1 Sub2
| | | |
| | 1. Register callback | |
| |<--------------------------| |
| Handle +--| | |
| new HTTP | | | |
| subscription +->| 2. Acknlowledge | |
| |-------------------------->| |
| | | |
| | 3. XMPP subscription |
| |<---------------------------------------|
| Handle +--| | |
| new XMPP | | | |
| subscription +->| 4. XMPP confirm subscription |
| |--------------------------------------->|
| | | |
. . . .
. . . .
| | | |
| 5. CCMP (add user) | | |
|-------------------->| | |
| |--+ Add user | |
| | | to conf. | |
| |<-+ object | |
| 6. CCMP (success) | | |
|<--------------------| | |
| | 7. HTTP POST (changes) | |
| |-------------------------->| |
| | 8. HTTP 200 OK | |
| |<--------------------------| |
| | | |
| | 9. XMPP notification | |
| |--------------------------------------->|
| | | |
. . . .
. . . .
Figure 3: Alternative means for notifications
That said, there are actually many other ways to achieve
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notifications in a conferencing system. A conferencing system may
rely on several other solutions than the ones presented as periodic
checks of a well known URL by interested clients, long polls, BOSH-
based communications, Atom/RSS feeds and the like.
6. Conference Creation
This section starts the sequence of call flows of typical XCON-
related scenarios provided in this document. Specifically, it
provides 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, call signaling and floor control protocols, where
applicable, are annotated in the flows without showing all the
details. This also applies to CCMP, whose flows are related to the
protocol alone, hiding any detail concerning the transport that may
have been used (e.g. HTTP). However, for clarification purposes,
the first example Section 6.1 provides the details of the media
control messaging along with an example of the standard annotation
used throughout the remainder of this document. In subsequent flows,
only this annotation (identified by lower case letters) is included
and the reader is encouraged to refer to the call flows in the
relevant documents for details about the other protocols. The
annotations for the call signaling are on the left side of the
conferencing server vertical bar and those for the media control
messaging are on the right side.
6.1. 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,
together with the "confUserID" associated with the requesting client
itself. 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 (the same already present
in the request) and the data for the conference object in the
"confInfo" parameter all returned in the "confResponse" message.
According to the implementation of the framework, this example may
also add the user that invoked the conference upon creation to the
conference object (e.g., "method" attribute in the "target" element
of "allowed-users-list" may be set to "dial out" for this client
based on the particular conferencing systems default). This is
exactly the case depicted in the figure, which is presented to enrich
the scenario.
The specific data for the conference object are returned in the
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"confResponse" message in the "confInfo" parameter. This allows the
client (with the appropriate authorization) to manipulate these data
and add additional participants to the conference, as well as change
the data during the conference. In addition, the client may
distribute the conferencing information to other participants
allowing them to join, the details of which are provided in
additional flows. Please notice that, according to the CCMP
specification, the return of the new conference data in the
"confInfo" parameter is not mandatory: if the "confInfo" parameter of
the successful confResponse/create is void, a following confRequest/
retrieve of the returned "confObjID" can be triggered to provide the
requesting client with the detailed conference description.
Clients that are not XCON-aware can join the conference using a
specific signaling interface such as SIP [RFC3261] or other supported
signaling protocols (being XCON agnostic with respect to them), using
the signaling interface to the conference focus as described in
[RFC4579]. However, these details are not shown in the message
flows. The message flows in this document identify the point in the
message flows at which this signaling occurs via the lower case
letter items (i.e., (a)...(x)) along with the appropriate text for
the processing done by the conferencing server.
As anticipated at the beginning of this section, this example also
shows how the conferencing system may make use of other standard
components to make available its functionality. An example of that
is the MEDIACTRL specification, which allows the conferencing system
to configure conference mixes, IVR dialogs and all sort of media-
related interactions an application like this may need. So, just to
provide the reader with some insight on these interactions, the
conferencing system also configures and starts a mixer via MEDIACTRL
as soon as the conference is created (transactions A1 and A2), and
attaches clients to it when necessary (e.g. when CMCC1 joins the
conference by means of SIP signaling, its media channels are attached
to the Media Server using MEDIACTRL in B1/B2).
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CMCC1 CMCC2 CMCCx ConfS MS
| | | | |
|(1)confRequest(confUserID, create) | |
|-------------------------------------->| |
| | (a)Create +---| |
| | |Conf | | |
| | |Object | | |
| | |& IDs +-->| |
| | | | A1. CONTROL |
| | | |+++++++++++>>|
| | | |(create conf)|--+ (b)
| | | | | | create
| | | | | | conf and
| | | | A2. 200 OK |<-+ its ID
| | | |<<+++++++++++|
| | | |(confid=Y) |
|(2)confResponse(confUserID,confObjID, | |
| create, success, | |
| version, confInfo) | |
|<--------------------------------------| |
| | | | |
| | (c) Focus +---| |
| | sets up | | |
| | signaling | | |
| | to CMCC1 +-->| |
| | | | |
| | | | B1. CONTROL |
| | | |+++++++++++>>|
| | | | (join CMCC1 |
| | | | <->confY) |
| | | | |
| | | | |--+(d) join
| | | | | | CMCC1 &
| | | | B2.200 OK |<-+ conf Y
| | | |<<+++++++++++|
| | | | |
|<<#################################################>>|
| Now the CMCC1 is mixed in the conference |
|<<#################################################>>|
| | | | |
|******CMCC1 may then manipulate conference data *****|
|****** and add addt'l users, etc. | *****|
' ' ' ' '
' ' ' ' '
' ' ' ' '
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Figure 4: Create Basic Conference - Complete flow
"Alice" "Bob"
CMCC1 CMCC2 CMCCx ConfS
| | | |
|(1)confRequest(confUserID, create) |
|-------------------------------------->|
| | | |
| | (a)Create +---|
| | |Conf | |
| | |Object | |
| | |& IDs +-->|
| | | |--+ (b) MS
| | | | | creates
| | | | | conf and
| | | |<-+ its ID
| | | | (confid=Y)
|(2)confResponse(confUserID, confObjID |
| create, success, |
| version, confInfo) |
| | | |
|<--------------------------------------|
| | | |
| | | |
| | (c) Focus +---|
| | sets up | |
| | signaling | |
| | to CMCC1 +-->|
| | | |
| | | |--+(d) MS joins
| | | | | CMCC1 &
| | | |<-+ conf Y
|<<###################################>>|
| CMCC1 is mixed in the conference |
|<<###################################>>|
| | | |
|**CMCC1 then manipulates conference****|
|** data and add addt'l users, etc. ***|
' ' ' '
' ' ' '
' ' ' '
-
Figure 5: Create Basic Conference - Annotated Flow
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1. confRequest/create message (Alice creates a default conference)
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpRequest
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp"
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info">
<ccmpRequest
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-conf-request-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<operation>create</operation>
</ccmpRequest>
</ccmp:ccmpRequest>
2. confResponse/create message ("success", created conference
object returned)
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpResponse
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info"
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp">
<ccmpResponse
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-conf-response-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:8977794@example.com</confObjID>
<operation>create</operation>
<response-code>success</response-code>
<version>1</version>
<ccmp:confResponse>
<confInfo entity="xcon:8977794@example.com">
<info:conference-description>
<info:display-text>
Default conference initiated by Alice
</info:display-text>
<info:conf-uris>
<info:entry>
<info:uri>
xcon:8977794@example.com
</info:uri>
<info:display-text>
Conference XCON-URI
</info:display-text>
</info:entry>
</info:conf-uris>
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<info:maximum-user-count>10</info:maximum-user-count>
<info:available-media>
<info:entry label="11">
<info:type>audio</info:type>
</info:entry>
</info:available-media>
<info:conference-state>
<active>false</active>
</info:conference-state>
</info:conference-description>
<info:users>
<xcon:join-handling>allow</xcon:join-handling>
<xcon:allowed-users-list>
<xcon:target uri="xcon-userid:Alice@example.com" \
method="dial-out"/>
</xcon:allowed-users-list>
</info:users>
</confInfo>
</ccmp:confResponse>
</ccmpResponse>
</ccmp:ccmpResponse>
Figure 6: Create Basic Conference (Annotated) Detailed Messaging
6.2. Conference Creation using Blueprints
The previous example showed the creation of a new conference using
default values. This means the client provided no information about
how she wanted the conference to be like. Anyway, the XCON framework
(and CCMP as a consequence) allows for the exploitation of templates.
These templates are called "conference blueprints", and are basically
conference objects with pre-defined settings except for the actual
identifiers. This means that a client might get one of these
blueprints, choose the one that more fits his needs, and use the
chosen blueprint to create a new conference.
This section addresses exactly this scenario, and Figure 7 provides
an example of one client, "Alice", discovering the conference
blueprints available for a particular conferencing system and
creating a conference based on the desired blueprint. In particular,
Alice is interested in those blueprints suitable to represent a
"video-conference", i.e. a conference in which both audio and video
are available, so she exploits the filter mechanism envisioned by
CCMP to make a selective blueprints retrieve request. This results
in three distinct CCMP transactions.
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CMCC "Alice" ConfS
| |
| (1) blueprintsRequest |
| (confUserID,xpathFilter) |
|------------------------------>|
| |
| (2) blueprintsResponse |
| (confUserID, success, |
| blueprintsInfo) |
|<------------------------------|
| |
|--+ |
| | choose preferred |
| | blueprint from the |
| | list (blueprintName) |
|<-+ |
| |
| (3) blueprintRequest |
| (confUserID,confObjID, |
| retrieve) |
|------------------------------>|
| |
| 4) blueprintResponse |
| (confUserID,confObjID,|
| retrieve,confInfo) |
|<------------------------------|
| |
| (5) confRequest(confUserID, |
| confObjID,create) |
|------------------------------>|
| |
| (a)Create +---|
| Conf | |
| Object | |
| & IDs +-->|
| |--+ (b) MS
| | | creates
| | | conf and
| |<-+ its ID
| | (confid=Y)
|(6) confResponse |
| (confUserID, confObjID*, |
| create, success) |
|<------------------------------|
| |
| |
| |
. .
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. .
Figure 7: Client Creation of Conference using Blueprints
1. Alice first sends a "blueprintsRequest" message to the
conferencing system identified by the conference server discovery
process. This request contains the "confUserID" of the user
issuing the request (Alice's XCON-USERID) and the "xpathFilter"
parameter by which Alice specifies she desires to obtain only
blueprints providing support for both audio and video: for this
purpose, the xpath query contained in this field is: "/
conference-info[conference-description/available-media/entry/
type='audio' and conference-description/available-media/entry/
type='video'"] . Upon receipt of the "blueprintsRequest", the
conferencing system would first authenticate Alice and then
ensure that Alice has the appropriate authority based on system
policies to receive the requested kind of blueprints supported by
that system.
2. All blueprints that Alice is authorized to use are returned in a
"blueprintsResponse" message in the "blueprintsInfo" element.
3. Upon receipt of the "blueprintsResponse" containing the
blueprints, Alice determines which blueprint to use for the
conference to be created. Alice sends a "blueprintRequest"
message to get the specific blueprint as identified by the
"confObjID".
4. The conferencing system returns the "confInfo" associated with
the specific blueprint as identified by the 'confObjID' in the
"blueprintResponse" message.
5. Alice finally sends a "confRequest" with a "create" operation to
the conferencing system to create a conference reservation
cloning the chosen blueprint. This is achieved by writing the
blueprint's XCON-URI in the "confObjID" parameter.
6. Upon receipt of the "confRequest" message with a "create"
operation, the conferencing system uses the received blueprint to
clone a conference, allocating a new XCON-URI (again called
"confObjID*" in the example). The conferencing server then sends
a "confResponse" message including the new "confObjID*"
associated with the newly created conference instance. Upon
receipt of the "confResponse" message, Alice can now add other
users to the conference .
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1. blueprintsRequest message (Alice requires the list of the
available blueprints)
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpRequest xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp"
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info">
<ccmpRequest xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="xcon:ccmp-blueprints-request-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<ccmp:blueprintsRequest>
<xpathFilter>/conference-info[
conference-description/available-media/entry/type='audio' and
conference-description/available-media/entry/type='video']
</xpathFilter>
</ccmp:blueprintsRequest>
</ccmpRequest>
</ccmp:ccmpRequest>
2. blueprintsResponse message (the server provides a descriptions of
the available blueprints)
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpResponse
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info"
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp">
<ccmpResponse
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-blueprints-response-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<response-code>success</response-code>
<ccmp:blueprintsResponse>
<blueprintsInfo>
<info:entry>
<info:uri>xcon:VideoRoom@example.com</info:uri>
<info:display-text>VideoRoom</info:display-text>
<info:purpose>Video Room:
conference room with public access,
where both audio and video are available,
4 users can talk and be seen at the same time,
and the floor requests are automatically accepted.
</info:purpose>
</info:entry>
<info:entry>
<info:uri>xcon:VideoConference1@example.com</info:uri>
<info:display-text>VideoConference1</info:display-text>
<info:purpose>Public Video Conference: conference
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where both audio and video are available,
only one user can talk
</info:purpose>
</info:entry>
</blueprintsInfo>
</ccmp:blueprintsResponse>
</ccmpResponse>
</ccmp:ccmpResponse>
3. blueprintRequest/retrieve message (Alice wants the
"VideoRoom" blueprint)
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpRequest
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp"
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info">
<ccmpRequest xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-blueprint-request-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:VideoRoom@example.com</confObjID>
<operation>retrieve</operation>
<ccmp:blueprintRequest/>
</ccmpRequest>
</ccmp:ccmpRequest>
4. blueprintResponse/retrieve message ("success", "VideoRoom"
conference object returned)
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpResponse
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info"
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp">
<ccmpResponse xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-blueprint-response-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:VideoRoom@example.com</confObjID>
<operation>retrieve</operation>
<response-code>success</response-code>
<ccmp:blueprintResponse>
<blueprintInfo entity="xcon:VideoRoom@example.com">
<info:conference-description>
<info:display-text>VideoRoom</info:display-text>
<info:maximum-user-count>4</info:maximum-user-count>
<info:available-media>
<info:entry label="audioLabel">
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<info:type>audio</info:type>
</info:entry>
<info:entry label="videoLabel">
<info:type>video</info:type>
</info:entry>
</info:available-media>
</info:conference-description>
<info:users>
<xcon:join-handling>allow</xcon:join-handling>
</info:users>
<xcon:floor-information>
<xcon:floor-request-handling>confirm
</xcon:floor-request-handling>
<xcon:conference-floor-policy>
<xcon:floor id="audioLabel"></xcon:floor>
<xcon:floor id="videoLabel"></xcon:floor>
</xcon:conference-floor-policy>
</xcon:floor-information>
</blueprintInfo>
</ccmp:blueprintResponse>
</ccmpResponse>
</ccmp:ccmpResponse>
5. confRequest/create message (Alice clones the "AudioRoom" blueprint)
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpRequest
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp"
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info">
<ccmpRequest
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-conf-request-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:VideoRoom@example.com</confObjID>
<operation>create</operation>
<ccmp:confRequest/>
</ccmpRequest>
</ccmp:ccmpRequest>
6. confResponse/create message ("success", cloned conference
object returned)
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpResponse
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info"
xmlns:info="urn:ietf:params:xml:ns:conference-info"
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xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp">
<ccmpResponse
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-conf-response-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:8977794@example.com</confObjID>
<operation>create</operation>
<response-code>success</response-code>
<version>1</version>
<ccmp:confResponse>
<confInfo entity="xcon:8977794@example.com">
<info:conference-description>
<info:display-text>
New conference by Alice cloned from VideoRoom
</info:display-text>
<info:conf-uris>
<info:entry>
<info:uri>
xcon:8977794@example.com
</info:uri>
<info:display-text>
conference xcon-uri
</info:display-text>
<xcon:conference-password>
8601
</xcon:conference-password>
</info:entry>
</info:conf-uris>
<info:maximum-user-count>10</info:maximum-user-count>
<info:available-media>
<info:entry label="11">
<info:type>audio</info:type>
</info:entry>
<info:entry label="12">
<info:type>video</info:type>
</info:entry>
</info:available-media>
</info:conference-description>
<info:users>
<xcon:join-handling>allow</xcon:join-handling>
</info:users>
<xcon:floor-information>
<xcon:floor-request-handling>
confirm</xcon:floor-request-handling>
<xcon:conference-floor-policy>
<xcon:floor id="11"/>
<xcon:floor id="12"/>
</xcon:conference-floor-policy>
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</xcon:floor-information>
</confInfo>
</ccmp:confResponse>
</ccmpResponse>
</ccmp:ccmpResponse>
Figure 8: Create Conference (Blueprint) Detailed Messaging
6.3. Conference Creation using User-Provided 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 "confInfo" parameter for the
conference to be created. The request also includes the "confUserID"
of the requesting entity.
This approach allows for a client (in this example Alice) to
completely describe how the conference object should look like,
without just relying on defaults or blueprints: i.e. which media
should be available, whish should be the topic, the users allowed to
join, any scheduling-related information and so on. This can be
done, as anticipated, by providing in the creation request a full
conference object for the server to parse.
This "confInfo" parameter must comply of course with the Data Model
specification. This means that its "entity" attribute is mandatory,
and cannot be missing in the document. Nevertheless, considering in
this example the client is actually requesting the creation of a new
conference, which doesn't exist yet, this "entity" attribute cannot
be set to a valid value. This is related to an issue already
anticipated in Section 5.1. To cope with this, the CCMP protocol
fosters the use of a wildcard placeholder: this placeholder
("xcon:AUTO_GENERATE_1@example.com" in the example) has the only aim
of making the "confInfo" element compliant with the Data Model, and
would subsequently be replaced by the conferencing system with the
actual value. This means that, as soon as the conferencing system
actually creates the conference, a valid "entity" value is created
for it as well, which would take the place of the wildcard when
completing the actual conference object provided by the client.
To give a flavour of what could be added to the conference object, we
assume Alice is also interested in providing scheduling-related
information. So, in this example, Alice also specifies by the
<conference-time> element included in the "confInfo" that the
conference she wants to create has to occur on a certain date from a
certain start time to a certain stop time and has to be replicated
weekly.
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Once Alice has prepared the "confInfo" element and sent it as part of
her request to the server, if the conferencing system can support
that specific type of conference (capabilities, etc.), then the
request results in the creation of a conference. We assume the
request has been successful, and as a consequence XCON-URI in the
form of the "confObjID" parameter and the XCON-USERID in the form of
the "confUserID" parameter (again, the same as the requesting entity)
are returned in the "confResponse" message.
In this example, we choose not to return the created conference
object in the successful "confResponse" in the "confInfo" parameter.
Nevertheless, Alice could still retrieve the actual conference object
by issuing a "confRequest" with a "retrieve" operation on the
returned "confObjID". Such a request would show how, as we
anticipated at the beginning of this section, the "entity" attribute
of the conference object in "confInfo" is replaced with the actual
information (i.e. "xcon:6845432@example.com").
Just for the sake of completeness and to provide the reader with some
insight about how the CCMP conferencing server might interact with
other related components, this example also assumes that the
conference is activated upon creation: i.e., the "method" attribute
is set to "dial out" for this client based on the particular
conferencing systems default. This results (as shown in the ladder
diagram) in Alice, Bob and Carol being called by the conferencing
system. Just as before, this is not to be considered mandatory,
since it depends on the implementation choices of the framework.
Alice Bob Carol ConfS
| | | |
| | | |
|(1)confRequest(confUserID, | |
| create, confInfo) | |
| | | |
|-------------------------------------->|
| | | |
| | (a)Create +---|
| | |Conf | |
| | |Object | |
| | |& IDs +-->|
| | | |--+ (b) MS
| | | | | creates
| | | | | conf and
| | | |<-+ its ID
| | | | (confid=Y)
|(2)confResponse(confUserID | |
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| confObjID, create, | |
| success, version) | |
|<--------------------------------------|
| | | |
| | (c) Focus +---|
| | sets up | |
| | signaling | |
| | to Alice +-->|
| | | |
| | | |--+(d) MS joins
| | | | | Alice &
| | | |<-+ conf Y
| | | |
| | | |
|<<###################################>>|
| Alice is mixed in the conference |
|<<###################################>>|
| | | |
| | (e)Focus +---|
| | sets up | |
| | signaling | |
| | to Bob | |
| | | +-->|
| | | |
| | | |--+(f)MS joins
| | | | | Bob &
| | | |<-+ conf Y
| | | |
| |<<###################>>|
| | Bob is mixed too |
| |<<###################>>|
| | | |
| | (g )Focus +---|
| | sets up | |
| | signaling | |
| | to Carol | |
| | CMCCx +-->|
| | | |
| | | |--+(h)MS joins
| | | | | CMCCx &
| | | |<-+ conf Y
| | | |
| | |<<#######>>|
| | |Carol mixed|
| | |<<#######>>|
| | | |
| | | |
| | | |
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|<***All parties connected to conf Y***>|
| | | |
| | | |
" " " "
" " " "
" " " "
Figure 9: Create Basic Conference from user provided conference-info
1. confRequest/create message (Alice proposes a conference object
to be created - direct creation)
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpRequest
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp"
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info">
<ccmpRequest
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-conf-request-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<operation>create</operation>
<ccmp:confRequest>
<confInfo entity="xcon:AUTO_GENERATE_1@example.com">
<info:conference-description>
<info:display-text>
Dial-out conference initiated by Alice
</info:display-text>
<info:maximum-user-count>10</info:maximum-user-count>
<info:available-media>
<info:entry label="AUTO_GENERATE_2">
<info:type>audio</info:type>
</info:entry>
</info:available-media>
<xcon:conference-time>
<xcon:entry>
<xcon:base>
BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Mozilla.org/NONSGML \
Mozilla Calendar V1.0//EN
BEGIN:VEVENT
DTSTAMP: 20100127T140728Z
UID: 20100127T140728Z-345FDA-alice@example.com
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ORGANIZER:MAILTO:alice@example.com
DTSTART:20100127T143000Z
RRULE:FREQ=WEEKLY
DTEND: 20100127T163000Z
END:VEVENT
END:VCALENDAR
</xcon:base>
<xcon:mixing-start-offset \
required-participant="moderator">
2010-01-27T14:29:00Z
</xcon:mixing-start-offset>
<xcon:mixing-end-offset \
required-participant="participant">
2010-01-27T16:31:00Z</xcon:mixing-end-offset>
<xcon:must-join-before-offset>
2010-01-27T15:30:00Z
</xcon:must-join-before-offset>
</xcon:entry>
</xcon:conference-time>
</info:conference-description>
<info:users>
<xcon:join-handling>allow</xcon:join-handling>
<xcon: allowed-users-list>
<xcon:target uri="xcon-userid:alice@example.com"
method="dial-out"/>
<xcon:target uri="sip:bob83@example.com"
method="dial-out"/>
<xcon:target uri="sip:carol@example.com"
method="dial-out"/>
</xcon:allowed-users-list>
</info:users>
</confInfo>
</ccmp:confRequest>
</ccmpRequest>
</ccmp:ccmpRequest>
2. confResponse/create message ("success")
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpResponse
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info"
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp">
<ccmpResponse
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-conf-response-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
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<confObjID>xcon:6845432@example.com</confObjID>
<operation>create</operation>
<response-code>success<response-code>
<version>1</version>
</ccmpResponse>
</ccmp:ccmpResponse>
Figure 10: Create Basic Conference Detailed Messaging
6.4. Cloning an Existing Conference
A client can also create another conference by cloning an existing
conference, such as an active conference or conference reservation.
This approach can be seen as a logical extension of the creation of a
new conference using a blueprint: the difference is that, instead of
cloning the pre-defined settings listed in a blueprint, the settings
of an existing conference would be cloned.
In this example, the client sends a "confRequest" message with the
"create" operation, along with the "confUserID" and a specific
"confObjID", from which a new conference is to be created by cloning
an existing conference.
An example of how a client can create a conference based on a
blueprint is provided in Section 6.2. 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 (i.e., an inactive conference).
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 a new
value in the "confObjID" parameter to reflect the newly cloned
conference object returned in the "confResponse" message.
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Alice ConfS
| |
|(1)confRequest(confUserID, |
| confObjID, create) |
|------------------------------>|
| (a)Create +---|
| Conf | |
| Object | |
| & IDs +-->|
| |--+ (b) MS
| | | creates
| | | conf and
| |<-+ its ID
| | (confid=Y)
| |
|(2)confResponse(confUserID, |
| confObjID*,create, |
| success, version, |
| confInfo) |
| |
|<------------------------------|
| |
Figure 11: Create Basic Conference - Clone
1. Alice, a conferencing system client, sends a confRequest message
to clone a conference based on an existing conference
reservation. Alice indicates this conference should be cloned
from the specified 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"
(called "confObjID*" in Figure 11) to be used for the cloned
conference object. This new identifier is of course different
from the one associated with the conference to be cloned, since
it represents a different conference object. Any subsequent
protocol requests from any of the members of the conference must
use this new identifier. The conferencing system maintains the
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mapping between this conference ID and the parent conference
object ID associated with the reservation through the conference
instance, and this mapping is explicitly addressed through the
"cloning-parent" element of the "conference-description" in the
new conference object.
1. confRequest/create message
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpRequest
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp"
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info">
<ccmpRequest
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-conf-request-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:6845432@example.com</confObjID>
<operation>create</operation>
</ccmpRequest>
</ccmp:ccmpRequest>
2. confResponse/create message ("success", created conference
object returned)
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpResponse
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info"
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp">
<ccmpResponse
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-conf-response-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:8977794@example.com</confObjID>
<operation>create</operation>
<response-code>success</response-code>
<version>1</version>
<ccmp:confResponse>
<confInfo entity="xcon:8977794@example.com">
<info:conference-description>
<info:display-text>
New conference by Alice cloned from 6845432
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</info:display-text>
<xcon:cloning-parent>
xcon:6845432@example.com
</xcon:cloning-parent>
<info:maximum-user-count>10</info:maximum-user-count>
<info:available-media>
<info:entry label="11">
<info:type>audio</info:type>
</info:entry>
</info:available-media>
</info:conference-description>
<info:users>
<xcon:join-handling>allow</xcon:join-handling>
<xcon: allowed-users-list>
<xcon:target uri="sip:alice@example.com"
method="dial-out"/>
<xcon:target uri="sip:bob83@example.com"
method="dial-out"/>
<xcon:target uri="sip:carol@example.com"
method="dial-out"/>
</xcon:allowed-users-list>
</info:users>
<xcon:floor-information>
<xcon:floor-request-handling>
confirm</xcon:floor-request-handling>
<xcon:conference-floor-policy>
<xcon:floor id="11"/>
</xcon:conference-floor-policy>
</xcon:floor-information>
</confInfo>
</ccmp:confResponse>
</ccmpResponse>
</ccmp:ccmpResponse>
Figure 12: Create Basic Conference (Clone) Detailed Messaging
7. Conference Users Scenarios and Examples
Section 6 showed examples describing the several different ways a
conference might be created using CCMP. This section instead focuses
on user-related scenarios, i.e. typical scenarios that may occur
during the lifetime of a conference, like adding new users and
handling their media. 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
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applicable, per one of the examples in Section 6.
7.1. Adding a Party
In this example, Alice wants to add Bob to an established conference.
In the following example we assume Bob is a new user of the system,
which means Alice also needs to provide some details about him. In
fact, the case of Bob already present as a user in the conferencing
system is much easier to address, and will be discussed later on.
"Alice" "Bob"
CMCC1 CMCC2 CMCCx ConfS
| | | |
|(1) userRequest(confUserID,| |
| confObjID, create, | |
| userInfo) | | |
|-------------------------------------->|
| | | |
| | (a) Create +---|
| | | Bob | |
| | | as a | |
| | | user +-->|
| | | |
|(2) userResponse(confUserID,confObjID |
| create,success,userInfo) |
|<--------------------------------------|
| | | |
| | | (b) Focus |
| | | sets up |
| | | signaling |
| | | to Bob |
| |<----------------------|
| | | |
| | | (c) Notify|
| | | ("Bob just|
| | | joined") |
| | |<----------|
| | | |
' ' ' '
' ' ' '
' ' ' '
Figure 13: Client Manipulation of Conference - Add a party
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1. Alice sends a userRequest message with an operation of "create"
to add Bob to the specific conference as identified by the
"confObjID". The "create" operation also makes sure that Bob is
created as a user in the whole conferencing system. This is done
by adding a "userInfo" element describing Bob as a user. This is
needed in order to let the conferencing system be aware of Bob's
characteristics. In case Bob was already a registered user,
Alice would just have referenced him through his XCON-USERID in
the "entity" attribute of the "userInfo" field, without providing
additional data. In fact, that data (including, for instance,
Bob's SIP-URI to be used subsequently for dial-out) would be
obtained by referencing the extant registration. The conference
server ensures that Alice has the appropriate authority based on
the policies associated with that specific conference object to
perform the operation. As mentioned before, a new Conference
User Identifier is created for Bob, and the "userInfo" is used to
update the conference object accordingly. As already seen in
Section 6.3, a placeholder wildcard
("xcon-userid:AUTO_GENERATE@example.com" in the CCMP messages
below) is used for the "entity" attribute of the "userInfo"
element, to be replaced by the actual XCON-USERID later on;
2. Bob is successfully added to the conference object, and an XCON-
USERID is allocated for him ("xcon-userid:Bob@example.com"); this
identifier is reported in the response as part of the "entity"
element of the returned "userInfo";
3. In the presented example, the call signaling to add Bob to the
conference is instigated through the Focus as well. We again
remind that this is implementation specific. In fact, a
conferencing system may accomplish different actions after the
user creation, just as it may do nothing at all. Among the
possible actions, for instance Bob may be added as a <target>
element to the <allowed-users-list> element, whose joining
"method" may be either "dial-in" or "dial-out". Besides, out-of-
band notification mechanisms may be involved as well, e.g. to
notify Bob via mail of the new conference, including details as
the date, password, expected participants and so on (see
Section 5.3).
To conclude the overview on this scenario, once Bob has been
successfully added to the specified conference, per updates to the
state, and depending upon the policies, other participants
(including Bob himself) may be notified of the addition of Bob to
the conference via the Conference Notification Service in use.
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1. userRequest/create message (Alice adds Bob)
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpRequest xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp"
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info">
<ccmpRequest xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-user-request-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:8977878@example.com</confObjID>
<operation>create</operation>
<ccmp:userRequest>
<userInfo entity="xcon-userid:AUTO_GENERATE@example.com">
<info:display-text>Bob</info:display-text>
<info:associated-aors>
<info:entry>
<info:uri>mailto:bob.depippis@example.com</info:uri>
<info:display-text>Bob's email</info:display-text>
</info:entry>
</info:associated-aors>
<info:endpoint entity="sip:bob83@example.com">
<info:display-text>Bob's laptop</info:display-text>
</info:endpoint>
</userInfo>
</ccmp:userRequest>
</ccmpRequest>
</ccmp:ccmpRequest>
2. userResponse/create message ("success": a new XCON-USERID is
created for Bob and he is added to the conference)
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpResponse xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp"
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info">
<ccmpResponse xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-user-response-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:8977878@example.com</confObjID>
<operation>create</operation>
<response-code>success</response-code>
<version>10</version>
<ccmp:userResponse>
<userInfo entity="xcon-userid:Bob@example.com">
<info:display-text>Bob</info:display-text>
<info:associated-aors>
<info:entry>
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<info:uri>mailto:bob.depippis@example.com</info:uri>
<info:display-text>Bob's email</info:display-text>
</info:entry>
</info:associated-aors>
<info:endpoint entity="sip:bob83@example.com">
<info:display-text>Bob's laptop</info:display-text>
</info:endpoint>
</userInfo>
</ccmp:userResponse>
</ccmpResponse>
</ccmp:ccmpResponse>
Figure 14: Add Party Message Details
7.2. Muting a Party
This section provides an example of the muting of a party in an
active conference. We assume that the user to mute has already been
added to the conference. The document only addresses muting and not
unmuting as well, since it would involve an almost identical CCMP
message flow anyway. Although, in case that any external floor
control is involved, whether or not a particular conference client
can actually mute/unmute itself must be considered by the
conferencing system.
Please notice that interaction between CCMP and floor control
should be carefully considered. In fact, handling CCMP- and BFCP-
based media control has to be considered as multiple layers: i.e.,
a participant may have the BFCP floor granted, but be muted by
means of CCMP. If so, he would still be muted in the conference,
and would only be unmuted if both the protocols allowed for this.
Figure 15 provides an example of one client, "Alice", impacting the
media state of another client, "Bob". This example assumes an
established conference. In this example, 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. BFCP floor
control is assumed not to be involved.
From a protocol point of view, muting/unmuting an user basically
consists in updating the conference object by modifying the settings
related to the target user's media streams. Specifically, Bob's
"userInfo" must be updated by modifying its audio <endpoint>
information (e.g. setting it to "recvonly" in case of muting),
identified by the right media id.
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"Alice" "Bob"
CMCC1 CMCC2 CMCCx ConfS MS
| | | | |
|(1) userRequest(confUserID,| | |
| confObjID, update, | | |
| userInfo) | | | |
|--------------------------------------->| |
| | | | Mute Bob |
| | | |----------------->|
| | | | 200 OK |
| | | |<-----------------|
| | | | |
| |<====== XXX Bob excluded from mix XXX ====>|
| | | | |
| | (a) Update +---| |
| | Bob in | | |
| | Data Model | | |
| | (muted) +-->| |
| | | | |
| (2)userResponse(confUserID,confObjID, | |
| update,success,version) | |
|<---------------------------------------| |
| | | | |
| | | (b) Notify | |
| | | ("Bob is | |
| | | muted") | |
| | |<-----------| |
| | | | |
' ' ' ' '
' ' ' ' '
' ' ' ' '
Figure 15: Client Manipulation of Conference - Mute a party
1. Alice sends a userRequest message with an "update" operation and
the userInfo with the "status" field in the "media" element for
Bob set to "revconly". The Conference Server ensures that Alice
has the appropriate authority based on the policies associated
with that specific conference object to perform the operation and
updates the "userInfo" in the conference object reflecting 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 to enforce the decision. An example describing a
possible way of dealing with such a situation using the Media
Server Control architecture is described in
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[I-D.ietf-mediactrl-call-flows], at "Simple Bridging: Framework
Transactions (2)".
2. A userResponse message with a response-code of "success" is then
sent to Alice. Depending upon the policies, the conference
server may notify other participants (including Bob) of this
update via any Conference Notification Service that may be in
use.
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1. userRequest/update message (Alice mutes Bob)
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpRequest xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp"
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info">
<ccmpRequest xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-user-request-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:8977878@example.com</confObjID>
<operation>update</operation>
<ccmp:userRequest>
<userInfo entity="xcon-userid:Bob@example.com">
<info:endpoint entity="sip:bob83@example.com">
<info:media id="1">
<info:label>123</info:label>
<info:status>recvonly</info:status>
</info:media>
</info:endpoint>
</userInfo>
</ccmp:userRequest>
</ccmpRequest>
</ccmp:ccmpRequest>
2. userResponse/update message ("success")
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpResponse xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp"
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info">
<ccmpResponse xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-user-response-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:8977878@example.com</confObjID>
<operation>update</operation>
<response-code>success</response-code>
<version>7</version>
<ccmp:userResponse/>
</ccmpResponse>
</ccmp:ccmpResponse>
Figure 16: Mute Message Details
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7.3. Conference Announcements and Recordings
This section deals with features that are typically required in a
conferencing system, that are public announcements (e.g. to notify
vocally that a new user joined a conference) and name recording.
While this is not strictly CCMP-related (the CCMP signaling is
actually the same as the one seen in Section 7.1) it is an
interesting scenario to address to see how the several components of
an XCON-compliant architecture interact with each other to make it
happen.
In this example, as shown in Figure 17 Alice is joining Bob's
conference that requires that she first enters a pass code. After
successfully entering the pass code, 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. A very similar example is presented in Figure 33 of
[I-D.ietf-mediactrl-call-flows].
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CMCC "Alice" ConfS MS
| | |
|(1)userRequest(confObjID, | |
| create,userInfo) | |
|--------------------------->| |
| |--+ Alice is |
| | | new in the |
| |<-+ system (create |
| | confUserID) |
| ConfS handles +--| |
| SIP signaling | | |
| (Alice<->ConfS<->MS) +->| |
| | |
| |--+ A password is |
| | | required for |
| |<-+ that conference |
| | |
| | Request IVR menu (PIN) |
| |--------------------------->|
| | |
|<========= MS gets PIN from Alice through DTMF =========>|
| | |
| | Provided PIN is... |
| |<---------------------------|
| Check +--| |
| PIN | | |
| +->| |
| |--+ Alice must |
| | | record her |
| |<-+ name |
| | |
| | Request name recording |
| |--------------------------->|
| | |
|<========= MS records Alice's audio RTP (name) =========>|
| | |
| | Audio recording |
| |<---------------------------|
| Complete +--| |
| creation | | |
| of Alice +->| |
| | |
| | |
| (2)userResponse(confUserID,| |
| confObjID, create, | |
| success, version) | |
|<---------------------------| |
| | |
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Figure 17: Recording and Announcements
1. Upon receipt of the userRequest from Alice to be added to Bob's
conference, the conferencing system determines that a password is
required for this specific conference. Thus an announcement
asking Alice to enter the password is sent back. This may be
achieved by means of typical IVR functionality. 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. In this case, Alice is a new user for this
conferencing system, so a Conference User Identifier (i. e. an
XCON-USERID) is created for Alice. Based upon the contact
information provided by Alice, the call signaling to add Alice to
the conference is instigated through the Focus.
2. The conference server sends Alice a userResponse message which
includes the "confUserID" assigned by the conferencing system to
her. 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. 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.
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1. userRequest/create message (Alice - a new conferencing system
client - enters Bob's conference)
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpRequest
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp"
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info">
<ccmpRequest xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-user-request-message-type">
<confObjID>xcon:bobConf@example.com</confObjID>
<operation>create</operation>
<ccmp:userRequest>
<userInfo entity="xcon-userid:AUTO_GENERATE@example.com">
<info:associated-aors>
<info:entry>
<info:uri>
mailto:Alice83@example.com
</info:uri>
<info:display-text>email</info:display-text>
</info:entry>
</info:associated-aors>
<info:endpoint entity="sip:alice_789@example.com"/>
</userInfo>
</ccmp:userRequest>
</ccmpRequest>
</ccmp:ccmpRequest>
2.userResponse/create ("success": Alice is provided with a new
xcon-userid and is added to the conference)
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpResponse
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp"
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info">
<ccmpResponse xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-user-response-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:bobConf@example.com</confObjID>
<operation>create</operation>
<response-code>success</response-code>
<version>5</version>
<ccmp:userResponse/>
</ccmpResponse>
</ccmp:ccmpResponse>
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Figure 18: Announcement Messaging Details
7.4. Monitoring for DTMF
Conferencing systems often also need 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. This feature is often also exploited to achieve
interaction between participants and the conference system for non-
XCON-aware user agents (e.g. using DTMF tones to get muted/unmuted).
An example of DTMF monitoring, within the context of the framework
elements, is shown in Figure 17. A typical way for the conferencing
system to be aware of all the DTMF interactions within the context of
conferences it is responsible for, is making use of the MEDIACTRL
architecture for what regards media manipulation. Examples in that
sense (specifically for what concerns DTMF interception in conference
instances) are presented in [I-D.ietf-mediactrl-call-flows].
7.5. Entering a password-protected conference
Some conferences may envision a password to be provided by a user who
wants to manipulate the relative conference objects (e.g. join,
update, delete) via CCMP. Such a password would be included in the
<conference-password> element related to the conference XCON-URI in
the appropriate <conference-uris> entry and must be then included in
the apposite "conference-password" field in the CCMP request
addressed to that conference.
In the following CCMP transactions, it is depicted a scenario in
which Alice, a conferencing system client, attempts to join a
password-protected conference.
1. Alice sends a userRequest message with a "create" operation to
add herself in the conference with XCON-URI
"xcon:8977777@example.com" (written in the "confObjID"
parameter). Alice provides her XCON-USERID via the "confUserID"
field of the userRequest and leaves out the "userInfo" one
(first-party join). In this first attempt, she doesn't insert
any password parameter.
2. Upon receipt the userRequest/create message, the conferencing
server detects that the indicated conference is not joinable
without providing the relative pass code. Then a userResponse
message with "confPasswordRequired" response-code is returned to
Alice to indicate that her join has been refused and that she has
to recast her request including the appropriate conference
password in order to participate.
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3. After getting the pass code through out-of-band mechanisms, Alice
provides it in the proper "password" request field of a new
userRequest/create message and sends the updated request back to
the server.
4. The conferencing server checks the provided password and then
adds Alice to the protected conference. After that, a
userResponse with a "success" response-code is sent to Alice.
1. userRequest/create message (Alice tries to enter the conference
without providing the password)
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpRequest
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp"
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info">
<ccmpRequest xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-user-request-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:8977794@example.com</confObjID>
<operation>create</operation>
<ccmp:userRequest/>
</ccmpRequest>
</ccmp:ccmpRequest>
2. userResponse/create message ("passwordRequired")
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpResponse
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp"
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info">
<ccmpResponse xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-user-response-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:8977794@example.com</confObjID>
<operation>create</operation>
<ccmp:response-code>confPasswordRequired</ccmp:response-code>
<ccmp:userResponse/>
</ccmpResponse>
</ccmp:ccmpResponse>
3. userRequest/create message (Alice provides the password)
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<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpRequest
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp"
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info">
<ccmpRequest xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-user-request-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:8977794@example.com</confObjID>
<operation>create</operation>
<conference-password>8601</conference-password>
<ccmp:userRequest/>
</ccmpRequest>
</ccmp:ccmpRequest>
4. userResponse/create message ("success")
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpResponse
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp"
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info">
<ccmpResponse xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-user-response-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:8977794@example.com</confObjID>
<operation>create</operation>
<response-code>success</response-code>
<version>10</version>
<ccmp:userResponse/>
</ccmpResponse>
</ccmp:ccmpResponse>
Figure 19: Password-protected conference join messages details
8. Sidebars Scenarios and Examples
While creating conferences and manipulating users and their media may
be considered enough for many scenarios, there may be cases when a
more complex management is needed.
In fact, a feature typically required in conferencing systems is the
ability to create sidebars. A sidebar is basically a child
conference that usually includes a subset of the participants of the
parent conference, and a subset of its media as well. Sidebars are
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typically required whenever some of the participants in a conference
want to discuss privately about something, without interfering with
the main conference.
This section deals with some scenarios that typically envisage the
use of a sidebar, like whispering, private messages and coaching
scenarios. The first subsections, anyway, present some examples of
how a generic sidebar can be created, configured and managed.
8.1. Internal Sidebar
Figure 20 provides an example of one client, "Alice", involved in an
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. Besides, Bob decides that he is not
interested in still receiving the conference audio in background (not
even at a lower volume as Alice configured) and so modifies the
sidebar in order to make that stream inactive for him.
Alice Bob ConfS
| | |
|(1) sidebarByValRequest(confUserID, |
| confObjID,create) |
|--------------------------------------------->|
| | |
| | (a) Create +---|
| | sidebar-by-val | |
| | (new conf obj | |
| | cloned from +-->|
| | confObjID) | Sidebar now has
| | | id confObjID*
|(2) sidebarByValResponse(confUserID, | (parent mapping
| (confObjID*, create, success, | conf<->sidebar)
| version, sidebarByValInfo) |
|<---------------------------------------------|
| | |
|(3) sidebarByValRequest |
| (confUserID, confObjID*, |
| update,sidebarByValInfo) |
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|--------------------------------------------->|
| | |
| | (b) Update +---|
| | sidebar-by-val | |
| | (media, users | |
| | etc.) +-->|
| | | Sidebar is
| | | modified
|(4) sidebarByValResponse(confUserID, |
| confObjID*, update, |
| success, version) |
|<---------------------------------------------|
| | |
| |(5) userRequest |
| | (confUserID', |
| | confObjID*, |
| | update,userInfo)|
| |---------------------->|
| | |
| | (c) Update +---|
| | user settings | |
| | (Bob's media) | |
| | +-->|
| | | Sidebar is modified
| | | (original audio
| | | inactive for Bob)
| |(6) userResponse |
| | (confUserID', |
| | confObjID*,update|
| | success,version) |
| |<----------------------|
| | |
" " "
" " "
" " "
Figure 20: Client Creation of a Sidebar Conference
1. Upon receipt of CCMP sidebarByValRequest message to create a new
sidebar-conference based upon the confObjID received in the
request, the conferencing system uses the confObjID 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 allocates a new XCON-URI for that
sidebar to be used for any subsequent protocol requests from any
of the members of the conference. The new sidebar identifier
("confObjID*" in Figure 20) is returned in the response message
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confObjID parameter.
2. The relationship information is provided in the
sidebarByValResponse message, specifically in the <sidebar-
parent> element. A dump of the complete representation of the
main/parent conference is provided below as well to show how the
cloning process for the creation of the sidebar could take place.
3. Upon receipt of the sidebarByValResponse message 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
so that only the two of them appear in the <allowed-users-list>
section. Alice also wants both audio and video from the original
conference to be available in the sidebar. For what concerns the
media belonging to the sidebar itself, Alice wants the audio to
be restricted to the participants in the sidebar (that is, Bob
and herself). Additionally, Alice manipulates the media values
to receive the audio from the main conference at a reduced
volume, so that the communication between her and Bob isn't
affected. Alice sends a sidebarByValRequest message with an
operation of "update" along with the "sidebarByValInfo"
containing the aforementioned sidebar modifications.
4. Upon receipt of the sidebarByValRequest to update the sidebar
reservation, the conference server ensures that Alice has the
appropriate authority based on the policies associated with that
specific conference object to perform the operation. The
conference server must also validate the updated information in
the reservation, ensuring that a member like Bob is already a
user of this conference server. Once the data for the confObjID
is updated, the conference server sends a sidebarByValResponse to
Alice. 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.
5. At this point, Bob sends a userRequest message to the conference
server with an operation of "update" to completely disable the
background audio from the parent conference, since it prevents
him from understanding what Alice says in the sidebar.
6. Notice that Bob's request only changes the media perspective for
Bob. Alice keeps on receiving both the audio from Bob and the
background from the parent conference. This request may be
relayed by the conference server to the Media Server handling the
mixing, if present. Upon completion of the change, the
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conference server sends a "userResponse" message to Bob.
Depending upon the policies, the initiator of the request (i.e.,
Bob) and the participants in the sidebar (i.e., Alice) may be
notified of this change via the conference notification service.
That said, let's consider the following conference object:
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<info:conference-info
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp"
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info"
entity="xcon:8977878@example.com">
<info:conference-description>
<info:display-text>MAIN CONFERENCE</info:display-text>
<info:conf-uris>
<info:entry>
<info:uri>sip:8977878@example.com</info:uri>
<info:display-text>conference sip uri</info:display-text>
</info:entry>
</info:conf-uris>
<info:available-media>
<info:entry label="123">
<info:display-text>main conference audio</info:display-text>
<info:type>audio</info:type>
<info:status>sendrecv</info:status>
</info:entry>
<info:entry label="456">
<info:display-text>main conference video</info:display-text>
<info:type>video</info:type>
<info:status>sendrecv</info:status>
<xcon:controls>
<xcon:video-layout>single-view</xcon:video-layout>
</xcon:controls>
</info:entry>
</info:available-media>
</info:conference-description>
<info:conference-state>
<info:active>true</info:active>
</info:conference-state>
<info:users>
<info:user entity="xcon-userid:Alice@example.com">
<info:display-text>Alice</info:display-text>
<info:endpoint entity="sip:Alice@example.com">
<info:media id="1">
<info:label>123</info:label>
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<info:status>sendrecv</info:status>
</info:media>
<info:media id="2">
<info:label>456</info:label>
<info:status>sendrecv</info:status>
</info:media>
</info:endpoint>
</info:user>
<info:user entity="xcon-userid:Bob@example.com">
<info:display-text>Bob</info:display-text>
<info:endpoint entity="sip:bob83@example.com">
<info:media id="1">
<info:label>123</info:label>
<info:status>sendrecv</info:status>
</info:media>
<info:media id="2">
<info:label>456</info:label>
<info:status>sendrecv</info:status>
</info:media>
</info:endpoint>
</info:user>
<info:user entity="xcon-userid:Carol@example.com">
<info:display-text>Carol</info:display-text>
<info:endpoint entity="sip:carol@example.com">
<info:media id="1">
<info:label>123</info:label>
<info:status>sendrecv</info:status>
</info:media>
<info:media id="2">
<info:label>456</info:label>
<info:status>sendrecv</info:status>
</info:media>
</info:endpoint>
</info:user>
</info:users>
</info:conference-info>
Figure 21: Conference with Alice, Bob and Carol
This is the representation of the conference the sidebar is going to
be created in. As such, it will be used by the conferencing system
in order to create the new conference object associated with the
sidebar. In fact, the sidebar creation happens through a cloning of
the parent conference. Once the sidebar is created, an "update"
makes sure that the sidebar is customized as needed. The following
protocol dump makes the process clearer.
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1. sidebarByValRequest/create message (Alice creates an
internal sidebar)
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpRequest xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp"
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info">
<ccmpRequest xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-sidebarByVal-request-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:8977878@example.com</confObjID>
<operation>create</operation>
<ccmp:sidebarByValRequest/>
</ccmpRequest>
</ccmp:ccmpRequest>
2. sidebarByValResponse/create message ("success", sidebar returned)
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpResponse
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info"
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp">
<ccmpResponse xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-sidebarByVal-response-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:8974545@example.com</confObjID>
<operation>create</operation>
<response-code>success</response-code>
<version>1</version>
<ccmp:sidebarByValResponse>
<sidebarByValInfo entity="xcon:8974545@example.com">
<info:conference-description>
<info:display-text>
SIDEBAR CONFERENCE registered by Alice
</info:display-text>
<xcon:sidebar-parent>
xcon:8977878@example.com
</xcon:sidebar-parent>
<info:available-media>
<info:entry label="123">
<info:display-text>
main conference audio
</info:display-text>
<info:type>audio</info:type>
<info:status>sendrecv</info:status>
</info:entry>
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<info:entry label="456">
<info:display-text>
main conference video
</info:display-text>
<info:type>video</info:type>
<info:status>sendrecv</info:status>
</info:entry>
</info:available-media>
</info:conference-description>
<info:conference-state>
<info:active>false</info:active>
</info:conference-state>
<info:users>
<xcon:allowed-users-list>
<xcon:target method="dial-in"
uri="xcon-userid:Alice@example.com"/>
<xcon:target method="dial-in"
uri="xcon-userid:Bob@example.com"/>
<xcon:target method="dial-in"
uri="xcon-userid:Carol@example.com"/>
</xcon:allowed-users-list>
</info:users>
</sidebarByValInfo>
</ccmp:sidebarByValResponse>
</ccmpResponse>
</ccmp:ccmpResponse>
3. sidebarByValRequest/update message (Alice updates the
created sidebar)
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpRequest
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info"
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp">
<ccmpRequest xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-sidebarByVal-request-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:8974545@example.com</confObjID>
<operation>update</operation>
<ccmp:sidebarByValRequest>
<sidebarByValInfo entity="xcon:8974545@example.com">
<info:conference-description>
<info:display-text>
private sidebar Alice - Bob
</info:display-text>
<info:available-media>
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<info:entry label="123">
<info:display-text>
main conference audio
</info:display-text>
<info:type>audio</info:type>
<info:status>recvonly</info:status>
<xcon:controls>
<xcon:gain>-60</xcon:gain>
</xcon:controls>
</info:entry>
<info:entry label="456">
<info:display-text>
main conference video
</info:display-text>
<info:type>video</info:type>
<info:status>recvonly</info:status>
</info:entry>
<info:entry label="AUTO_GENERATE_1">
<info:display-text>
sidebar audio
</info:display-text>
<info:type>audio</info:type>
<info:status>sendrecv</info:status>
</info:entry>
<info:entry label="AUTO_GENERATE_2">
<info:display-text>
sidebar video
</info:display-text>
<info:type>video</info:type>
<info:status>sendrecv</info:status>
</info:entry>
</info:available-media>
</info:conference-description>
<info:users>
<xcon:allowed-users-list>
<xcon:target method="dial-out"
uri="xcon-userid:Alice@example.com"/>
<xcon:target method="dial-out"
uri="xcon-userid:Bob@example.com"/>
</xcon:allowed-users-list>
</info:users>
</sidebarByValInfo>
</ccmp:sidebarByValRequest>
</ccmpRequest>
</ccmp:ccmpRequest>
4. sidebarByValResponse/update message ("success", sidebar's
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updates accepted)
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpResponse
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info"
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp">
<ccmpResponse xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-sidebarByVal-response-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:8974545@example.com</confObjID>
<operation>update</operation>
<response-code>success</response-code>
<version>2</version>
<ccmp:sidebarByValResponse/>
</ccmpResponse>
</ccmp:ccmpResponse>
5. userRequest/update message (Bob updates his media)
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpRequest
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info"
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp">
<ccmpRequest xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-user-request-message-type">
<confUserID>xcon-userid:Bob@example.com</confUserID>
<confObjID>xcon:8974545@example.com</confObjID>
<operation>update</operation>
<ccmp:userRequest>
<userInfo entity="xcon-userid:Bob@example.com">
<info:endpoint entity="sip:bob83@example.com">
<info:media id="1">
<info:display-text>
main conference audio
</info:display-text>
<info:label>123</info:label>
<info:status>inactive</info:status>
</info:media>
</info:endpoint>
</userInfo>
</ccmp:userRequest>
</ccmpRequest>
</ccmp:ccmpRequest>
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6. userResponse/update message ("success", Bob's preferences setted)
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpResponse xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp"
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info">
<ccmpResponse xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-user-response-message-type">
<confUserID>xcon-userid:Bob@example.com</confUserID>
<confObjID>xcon:8974545@example.com</confObjID>
<operation>update</operation>
<response-code>success</response-code>
<version>3</version>
<ccmp:userResponse/>
</ccmpResponse>
</ccmp:ccmpResponse>
Figure 22: Internal Sidebar Messaging Details
8.2. External Sidebar
Figure 23 provides an example of a different approach towards
sidebar. In this scenario, one client, "Alice", is 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. The difference
from the previous scenario is that Fred is not part of the parent
conference: this means that different policies might be involved,
considering that Fred may access information coming from the parent
conference, in case the sidebar was configured accordingly. For this
reason, in this scenario we assume that Alice disables all the media
from the original (parent) conference within the sidebar. This means
that, while in the previous example Alice and Bob still heard the
audio from the main conference in background, this time no background
is made available. Alice initiates the sidebar by sending a request
to the conferencing system to create a conference reservation based
upon 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.
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Alice Bob ConfS
| | |
|(1) sidebarByRefRequest(confUserID, |
| confObjID, create) |
|--------------------------------------------->|
| | |
| | (a) Create +---|
| | sidebar-by-ref | |
| | (new conf obj | |
| | cloned from +-->|
| | confObjID) | Sidebar now has
| | | id confObjID*
|(2) sidebarByRefResponse(confUserID, | (parent mapping
| confObjID*, create, success, | conf<->sidebar)
| version, sidebarByRefInfo) |
|<---------------------------------------------|
| | |
|(3) sidebarByRefRequest(confUserID, |
| confObjID*,update,sidebarByRefInfo) |
|--------------------------------------------->|
| | |
| | (b) Create +---|
| | new user for | |
| | Fred | |
| | +-->|
| | |
| | (c) Update +---|
| | sidebar-by-ref | |
| | (media, users | |
| | policy, etc.) +-->|
| | | Sidebar is modified:
| | | no media from the
| | | parent conference is
| | | available to anyone
|(4) sidebarByRefResponse(confUserID, |
| confObjID*, update, |
| success, version) |
|<---------------------------------------------|
| | |
| | Notify (Fred |
| | added to |
| | sidebar users) |
| |<----------------------|
| | |
" " "
" " "
" " "
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Figure 23: Client Creation of an External Sidebar
1. Upon receipt of the "sidebarByRefRequest" message to create a new
sidebar conference, based upon the active conference specified by
"confObjID" in the request, the conferencing system uses that
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, as
before, allocates a conference ID (confObjID*) to be used for any
subsequent protocol requests toward the sidebar reservation. The
mapping between the sidebar conference ID and the one associated
with the main conference is mantained by the conferencing system
and it is gathered from the c<sidebar-parent> element in the
sidebar conference object.
2. Upon receipt of the "sidebarByRefResponse" message, which
acknowledges the successful creation of the sidebar object, Alice
decides that only Bob and Ethel, along with the new participant
Fred are to be involved in the sidebar. Thus she manipulates the
membership accordingly. Alice also sets the media in the
"conference-info" such that the participants in the sidebar don't
receive any media from the main conference. All these settings
are provided to the conferencing system by means of a new
"sidebarByRefRequest" message, with an "update" operation.
3. Alice sends the aforementioned "sidebarByRefRequest" to update
the information in the reservation and to create an active
conference. Upon receipt of the "sidebarByRefRequest" with an
operation of "update", 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.
Specifically, Fred is added to the conference by only providing
his SIP URI. Based upon the contact information provided for
Fred by Alice, the call signaling to add Fred to the conference
may be instigated through the Focus (e.g. if Fred had a "dial-
out" method set as the target for him) at the actual activation
of the sidebar.
4. The conference server sends a "sidebarByRefResponse" message and,
depending upon the policies, the initiator of the request (i.e.,
Alice) and the participants in the sidebar (i.e., Bob and Ethel)
may be notified of his addition to the sidebar via the conference
notification service.
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1. sidebarByRefRequest/create message (Alice creates an
external sidebar)
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpRequest xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp"
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info">
<ccmpRequest xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-sidebarByRef-request-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:8977878@example.com</confObjID>
<operation>create</operation>
<ccmp:sidebarByRefRequest/>
</ccmpRequest>
</ccmp:ccmpRequest>
2. sidebarByRefResponse/create message ("success", created
sidebar returned)
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpResponse
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info"
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp">
<ccmpResponse xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-sidebarByRef-response-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:8971212@example.com</confObjID>
<operation>create</operation>
<response-code>success</response-code>
<version>1</version>
<ccmp:sidebarByRefResponse>
<sidebarByRefInfo entity="xcon:8971212@example.com">
<info:conference-description>
<info:display-text>
SIDEBAR CONFERENCE registered by Alice
</info:display-text>
<xcon:sidebar-parent>
xcon:8977878@example.com
</xcon:sidebar-parent>
<info:available-media>
<info:entry label="123">
<info:display-text>
main conference audio
</info:display-text>
<info:type>audio</info:type>
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<info:status>sendrecv</info:status>
</info:entry>
<info:entry label="456">
<info:display-text>
main conference video
</info:display-text>
<info:type>video</info:type>
<info:status>sendrecv</info:status>
</info:entry>
</info:available-media>
</info:conference-description>
<info:conference-state>
<info:active>false</info:active>
</info:conference-state>
<info:users>
<xcon:allowed-users-list>
<xcon:target method="dial-in"
uri="xcon-userid:Alice@example.com"/>
<xcon:target method="dial-in"
uri="xcon-userid:Bob@example.com"/>
<xcon:target method="dial-in"
uri="xcon-userid:Carol@example.com"/>
<xcon:target method="dial-in"
uri="xcon-userid:David@example.com"/>
<xcon:target method="dial-in"
uri="xcon-userid:Ethel@example.com"/>
</xcon:allowed-users-list>
</info:users>
</sidebarByRefInfo>
</ccmp:sidebarByRefResponse>
</ccmpResponse>
</ccmp:ccmpResponse>
3. sidebarByRefRequest/update message (Alice updates the sidebar)
<ccmp:ccmpRequest
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info"
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp">
<ccmpRequest xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-sidebarByRef-request-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:8971212@example.com</confObjID>
<operation>update</operation>
<ccmp:sidebarByRefRequest>
<sidebarByRefInfo entity="xcon:8971212@example.com">
<info:conference-description>
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<info:display-text>
sidebar with Alice, Bob, Ethel & Fred
</info:display-text>
<info:available-media>
<info:entry label="123">
<info:display-text>
main conference audio
</info:display-text>
<info:type>audio</info:type>
<info:status>inactive</info:status>
</info:entry>
<info:entry label="456">
<info:display-text>
main conference video
</info:display-text>
<info:type>video</info:type>
<info:status>inactive</info:status>
</info:entry>
<info:entry label="AUTO_GENERATE_1">
<info:display-text>
sidebar audio
</info:display-text>
<info:type>audio</info:type>
<info:status>sendrecv</info:status>
</info:entry>
<info:entry label="AUTO_GENERATE_2">
<info:display-text>
sidebar video
</info:display-text>
<info:type>video</info:type>
<info:status>sendrecv</info:status>
<xcon:controls>
<xcon:video-layout>
single-view
</xcon:video-layout>
</xcon:controls>
</info:entry>
</info:available-media>
</info:conference-description>
<info:conference-state>
<info:active>false</info:active>
</info:conference-state>
<info:users>
<xcon:allowed-users-list>
<xcon:target method="dial-out"
uri="xcon-userid:Alice@example.com"/>
<xcon:target method="dial-out"
uri="xcon-userid:Bob@example.com"/>
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<xcon:target method="dial-out"
uri="sip:fred@example.com"/>
</xcon:allowed-users-list>
</info:users>
</sidebarByRefInfo>
</ccmp:sidebarByRefRequest>
</ccmpRequest>
</ccmp:ccmpRequest>
4. sidebarByRefResponse/update message ("success", sidebar updated)
<ccmp:ccmpResponse
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info"
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp">
<ccmpResponse xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-sidebarByref-response-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:8971212@example.com</confObjID>
<operation>update</operation>
<response-code>success</response-code>
<version>2</version>
<ccmp:sidebarByRefResponse/>
</ccmpResponse>
</ccmp:ccmpResponse>
Figure 24: External Sidebar Messaging Details
8.3. Private Messages
The case of private messages can be handled as a sidebar with just
two participants, similarly to the example in Section 8.1. Unlike
the previous example, rather than using audio within the sidebar,
Alice could just add an additional text based media stream to the
sidebar in order to convey her textual messages to Bob, while still
viewing and listening to the main conference.
In this scenario, Alice requests to the conferencing system the
creation of a private chat room within the main conference context
(presented in Figure 21) in which the involved partecipants are just
Bob and herself. This can be achieved through the following CCMP
transaction (Figure 25).
1. Alice forwards a sidebarByValRequest/create to the Conferencing
Control Server with the main conference XCON-URI in the
"confObjID" parameter and the desired sidebar conference object
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in the "sidebarByValInfo" field. In this way, a sidebar creation
using user-provided conference information is requested to the
conferencing system. Please note that, unlike the previous
sidebar examples, in this case a comnpletely new conference
object to describe the sidebar is provided: there is no cloning
involved, while the "confObjID" still enforces the parent-child
relationship between the main conference and the to-be-created
sidebar.
2. The Conference Control Server, after checking Alice's rights and
validating the conference-object carried in the request, creates
the required sidebar-by-val conference and a new XCON-URI for it.
Instead of cloning the main conference object, as envisioned in
Section 8.1 and Section 8.2, the sidebar is created on the basis
of the user provided conference information (as anticipated
before). However, the parent relationship between the main
conference and the newly created sidebar is still mantained by
the conferencing system (as a consequence of the chosen CCMP
request message type - the sidebarByVal one) and it is reflected
by the <sidebar-parent> element in the "sidebarByValInfo" element
returned in the sidebarByValResponse message. Please notice
that, according to the CCMP specification, the return of the
created sidebar data in this kind of "success" response is not
mandatory.
1. sidebarByValRequest/create message (Alice creates a private
chat room between Bob and herself)
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpRequest
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info"
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp">
<ccmpRequest xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-sidebarByVal-request-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:8977878@example.com</confObjID>
<operation>create</operation>
<ccmp:sidebarByValRequest>
<sidebarByValInfo entity="xcon:AUTO_GENERATE_1@example.com">
<info:conference-description>
<info:display-text>
private textual sidebar alice - bob
</info:display-text>
<info:available-media>
<info:entry label="123">
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<info:display-text>
main conference audio
</info:display-text>
<info:type>audio</info:type>
<info:status>recvonly</info:status>
</info:entry>
<info:entry label="456">
<info:display-text>
main conference video
</info:display-text>
<info:type>video</info:type>
<info:status>recvonly</info:status>
</info:entry>
<info:entry label="AUTO_GENERATE_2">
<info:display-text>
sidebar text
</info:display-text>
<info:type>text</info:type>
<info:status>sendrecv</info:status>
</info:entry>
</info:available-media>
</info:conference-description>
<info:users>
<xcon:allowed-users-list>
<xcon:target method="dial-out"
uri="xcon-userid:Alice@example.com"/>
<xcon:target method="dial-out"
uri="xcon-userid:Bob@example.com"/>
</xcon:allowed-users-list>
</info:users>
</sidebarByValInfo>
</ccmp:sidebarByValRequest>
</ccmpRequest>
</ccmp:ccmpRequest>
2. sidebarByValResponse/create message ("success", sidebar returned)
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpResponse
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info"
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp">
<ccmpResponse xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-sidebarByVal-response-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:8974545@example.com</confObjID>
<operation>create</operation>
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<response-code>success</response-code>
<version>1</version>
<ccmp:sidebarByValResponse>
<sidebarByValInfo entity="xcon:8974545@example.com">
<info:conference-description>
<info:display-text>
private textual sidebar alice - bob
</info:display-text>
<xcon:sidebar-parent>
xcon:8977878@example.com
</xcon:sidebar-parent>
<info:available-media>
<info:entry label="123">
<info:display-text>
main conference audio
</info:display-text>
<info:type>audio</info:type>
<info:status>recvonly</info:status>
</info:entry>
<info:entry label="456">
<info:display-text>
main conference video
</info:display-text>
<info:type>video</info:type>
<info:status>recvonly</info:status>
</info:entry>
<info:entry label="789">
<info:display-text>
sidebar text
</info:display-text>
<info:type>text</info:type>
<info:status>sendrecv</info:status>
</info:entry>
</info:available-media>
</info:conference-description>
<info:users>
<xcon:allowed-users-list>
<xcon:target method="dial-out"
uri="xcon-userid:Alice@example.com"/>
<xcon:target method="dial-out"
uri="xcon-userid:Bob@example.com"/>
</xcon:allowed-users-list>
</info:users>
</sidebarByValInfo>
</ccmp:sidebarByValResponse>
</ccmpResponse>
</ccmp:ccmpResponse>
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Figure 25: Sidebar for Private Messages scenario
8.4. Observing and Coaching
Observing and Coaching is one of the most interesting sidebars-
related scenarios. In fact, it envisages two different interactions
that have to be properly coordinated.
An example of observing and coaching is shown in figure Figure 27.
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. Of course the
conferencing system must make sure that the customer Carol is not
aware of the presence of the coach Alice. This makes the use of a
sidebar necessary for the success of the scenario.
Consider the following as the conference document associated with the
video conference involving Bob (the call agent) and Carol (the
customer) (Figure 26):
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<info:conference-info
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp"
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info"
entity="xcon:8978383@example.com">
<info:conference-description>
<info:display-text>
CUSTOMER SERVICE conference
</info:display-text>
<info:conf-uris>
<info:entry>
<info:uri>sip:8978383@example.com</info:uri>
<info:display-text>conference sip uri</info:display-text>
</info:entry>
</info:conf-uris>
<info:available-media>
<info:entry label="123">
<info:display-text>service audio</info:display-text>
<info:type>audio</info:type>
<info:status>sendrecv</info:status>
</info:entry>
<info:entry label="456">
<info:display-text>service video</info:display-text>
<info:type>video</info:type>
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<info:status>sendrecv</info:status>
<xcon:controls>
<xcon:video-layout>single-view</xcon:video-layout>
</xcon:controls>
</info:entry>
</info:available-media>
</info:conference-description>
<info:conference-state>
<info:active>true</info:active>
</info:conference-state>
<info:users>
<info:user entity="xcon-userid:bob@example.com">
<info:display-text>Bob - call agent</info:display-text>
<info:endpoint entity="sip:bob@example.com">
<info:media id="1">
<info:label>123</info:label>
<info:status>sendrecv</info:status>
</info:media>
<info:media id="2">
<info:label>456</info:label>
<info:status>sendrecv</info:status>
</info:media>
</info:endpoint>
</info:user>
<info:user entity="xcon-userid:carol@example.com">
<info:display-text>Carol - customer</info:display-text>
<info:endpoint entity="sip:carol@example.com">
<info:media id="1">
<info:label>123</info:label>
<info:status>sendrecv</info:status>
</info:media>
<info:media id="2">
<info:label>456</info:label>
<info:status>sendrecv</info:status>
</info:media>
</info:endpoint>
</info:user>
</info:users>
</info:conference-info>
Figure 26: A call-center conference object example
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Alice Bob ConfS
| | |
|(1) sidebarByRefRequest(confUserID, |
| confObjID, create) |
|--------------------------------------------->|
| | |
| | (a) Create +---|
| | sidebar-by-ref | |
| | (new conf obj | |
| | cloned from +-->|
| | confObjID) | Sidebar now has
| | | id confObjID*
|(2) sidebarByRefResponse(confUserID, | (parent mapping
| confObjID*, create, success, | conf<->sidebar)
| version, sidebarByRefInfo) |
|<---------------------------------------------|
| | |
|(3) sidebarByRefRequest(confUserID, |
| confObjID*,update,sidebarByRefInfo) |
|--------------------------------------------->|
| | |
| | (b) Update +---|
| | sidebar-by-val | |
| | (media, users | |
| | policy, etc.) +-->|
| | | Sidebar is modified:
| | | unilateral sidebar
| | | audio, Carol excluded
| | | from the sidebar
|(4) sidebarByRefResponse(confUserID, |
| confObjID*, update, |
| success, version) |
|<---------------------------------------------|
| | |
| | Notify (Bob |
| | he's been added to |
| | sidebar users) |
| |<----------------------|
| | |
" " "
" " "
" " "
Figure 27: Supervisor Creating a Sidebar for Observing/Coaching
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1. Upon receipt of the sidbarByRefRequest/create from Alice to
"create" a new sidebar conference from the confObjID received in
the request, the conferencing system uses the received active
conference to clone a conference reservation for the sidebar.
The conferencing system also 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 confObjID associated with the
sidebar reservation through the conference instance. The
conference server sends a sidebarByRefResponse message with the
new confObjID and relevant sidebarByRefInfo.
2. Upon receipt of the sidebarByRefResponse message, Alice
manipulates the data received in the sidebarByRefInfo in the
response. Alice wants only Bob to be involved in the sidebar,
thus she updates the <allowed-users-list> to include only Bob and
herself. 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 sidebarByRefRequest message
with an "update" operation including the updated sidebar
information.
3. Upon receipt of the sidebarByRefRequest message with an "update"
operation, the conferencing system ensures that Alice has the
appropriate authority based on the policies associated with that
specific conference object to perform the operation. In order to
request the insertion of a further media stream in the sidebar
(i.e. in this example an audio stream from Alice to Bob), the
requestor has to provide a new <entry> element in the <available-
media> field of the "sidebarByRefInfo". The mandatory "label"
attribute of that new entry is filled with a dummy value
"AUTO_GENERATE_1", but it will contain the real server-generated
media stream identifier when the media stream is effectively
allocated on the server side. Similarly, the mandatory "id"
attribute in <media> element referring to the new sidebar audio
stream under both Alice's and Bob's <endpoint> contains a
wildcard value, respectively "AUTO_GENERATE_2" and
"AUTO_GENERATE_3": those values will be replaced with the
appropriated server-generated identifiers upon the creation of
the referred media stream. We are assuming the conferencing
control server is able to recognize those dummy values as place-
holders.
4. After validating the data, the conference server sends a
sidebarByRefResponse message. Based upon the contact information
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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.
1. sidebarByRefRequest/create message (Alice as coach creates a sidebar)
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpRequest xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp"
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info">
<ccmpRequest xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-sidebarByRef-request-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:8978383@example.com</confObjID>
<operation>create</operation>
<ccmp:sidebarsByRefRequest/>
</ccmpRequest>
</ccmp:ccmpRequest>
2. sidebarByRefResponse/create message ("success")
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpResponse
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info"
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp">
<ccmpResponse xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-sidebarByRef-response-message-type">
<confUserID>xcon-userid:alice@example.com</confUserID>
<confObjID>xcon:8971313@example.com</confObjID>
<operation>create</operation>
<ccmp:response-code>success</ccmp:response-code>
<version>1</version>
<ccmp:sidebarByRefResponse>
<sidebarByRefInfo entity="xcon:8971313@example.com">
<info:conference-description>
<info:display-text>
SIDEBAR CONFERENCE registered by alice
</info:display-text>
<xcon:sidebar-parent>
xcon:8971313@example.com
</xcon:sidebar-parent>
<info:available-media>
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<info:entry label="123">
<info:display-text>
main conference audio
</info:display-text>
<info:type>audio</info:type>
<info:status>sendrecv</info:status>
</info:entry>
<info:entry label="456">
<info:display-text>
main conference video
</info:display-text>
<info:type>video</info:type>
<info:status>sendrecv</info:status>
</info:entry>
</info:available-media>
</info:conference-description>
<info:conference-state>
<info:active>false</info:active>
</info:conference-state>
<info:users>
<xcon:allowed-users-list>
<xcon:target method="dial-in"
uri="xcon-userid:alice@example.com"/>
<xcon:target method="dial-in"
uri="xcon-userid:bob@example.com"/>
<xcon:target method="dial-in"
uri="xcon-userid:carol@example.com"/>
</xcon:allowed-users-list>
</info:users>
</sidebarByRefInfo>
</ccmp:sidebarByRefResponse>
</ccmpResponse>
</ccmp:ccmpResponse>
3. sidebarByRefRequest/update message (Alice introduces unilateral
sidebar audio and excludes Carol from the sidebar)
<ccmp:ccmpRequest
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info"
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp">
<ccmpRequest xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-sidebarByRef-request-message-type">
<confUserID>xcon-userid:alice@example.com</confUserID>
<confObjID>xcon:8971313@example.com</confObjID>
<operation>update</operation>
<ccmp:sidebarByRefRequest>
<sidebarByRefInfo entity="xcon:8971313@example.com">
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<info:conference-description>
<info:display-text>
Coaching sidebar Alice and Bob
</info:display-text>
<info:available-media>
<info:entry label="AUTO_GENERATE_1">
<info:display-text>
Alice-to-Bob audio
</info:display-text>
<info:type>audio</info:type>
<info:status>sendrecv</info:status>
</info:entry>
</info:available-media>
</info:conference-description>
<info:conference-state>
<info:active>false</info:active>
</info:conference-state>
<info:users>
<xcon:allowed-users-list>
<xcon:target method="dial-in"
uri="xcon-userid:alice@example.com"/>
<xcon:target method="dial-out"
uri="xcon-userid:bob@example.com"/>
</xcon:allowed-users-list>
<user entity="xcon-userid:Alice@example.com>
<info:endpoint entity="sip:Alice@example.com">
<info:media id="AUTO_GENERATE_2">
<info:label>AUTO_GENERATE_1</info:label>
<info:status>sendonly</info:status>
</info:media>
</info:endpoint>
</user>
<user entity="xcon-userid:Bob@example.com>
<info:endpoint entity="sip:Bob@example.com">
<info:media id="AUTO_GENERATE_3">
<info:label>AUTO_GENERATE_1</info:label>
<info:status>recvonly</info:status>
</info:media>
</info:endpoint>
</user>
</info:users>
</sidebarByRefInfo>
</ccmp:sidebarByRefRequest>
</ccmpRequest>
</ccmp:ccmpRequest>
4. sidebarByRefRequest/update message ("success")
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<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpResponse
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info"
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp">
<ccmpResponse xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-sidebarByRef-response-message-type">
<confUserID>xcon-userid:alice@example.com</confUserID>
<confObjID>xcon:8971313@example.com</confObjID>
<operation>update</operation>
<ccmp:response-code>success</ccmp:response-code>
<version>2</version>
<ccmp:sidebarByRefResponse/>
</ccmpResponse>
</ccmp:ccmpResponse>
Figure 28: Coaching and Observing Messaging details
9. 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
examples in Section 6.
9.1. Removing a Party
Figure 29 provides an example of a 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.
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Alice Bob Claire ConfS
| | | |
|(1) userRequest(confUserID,| |
| confObjID, delete,| |
| userInfo) | |
|-------------------------------------->|
| | | |
| | | (a) Focus |
| | | tears down|
| | | signaling |
| | | to Bob |
| |<----------------------|
| | |
| | (b)Deletes+---|
| | | Bob | |
| | | as a | |
| | | user +-->|
| | | in |
| | | confObj |
| | | |
|(2) userResponse(confUserID,confObjID, |
| delete,success,version) |
|<--------------------------------------|
| | | |
| | | |
| | | (c) Notify|
| | | ("Bob just|
| | | left") |
| | |<----------|
| | | |
' ' ' '
' ' ' '
' ' ' '
Figure 29: Client Manipulation of Conference - Remove a party
1. Alice sends a userRequest message, with a "delete" operation.
The conference server 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 contact and media information in the conference
object for Bob in the "userInfo" element, the conferencing system
starts the process to remove Bob (e.g., the call signaling to
remove Bob from the conference is instigated through the Focus).
The conference server updates the data in the conference object,
thus removing Bob from the <users> list. After updating the
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data, the conference server sends a userResponse message to
Alice. Depending upon the policies, other participants (e.g.
"Claire") may be notified of the removal of Bob from the
conference via the Conference Notification Service.
1. userRequest/delete message (Alice deletes Bob):
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpRequest
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp"
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info">
<ccmpRequest xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-user-request-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:8977794@example.com</confObjID>
<operation>delete</operation>
<ccmp:userRequest>
<userInfo entity="xcon-userid:Bob@example.com"/>
</ccmp:userRequest>
</ccmpRequest>
</ccmp:ccmpRequest>
2. userResponse/delete message ("success")
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpResponse
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp"
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info">
<ccmpResponse xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-user-response-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:8977794@example.com</confObjID>
<operation>delete</operation>
<response-code>success</response-code>
<version>17</version>
<ccmp:userResponse/>
</ccmpResponse>
</ccmp:ccmpResponse>
Figure 30: Removing a Participant Messaging Details
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9.2. Deleting a Conference
In this section, an example of a successful conference deletion is
provided (Figure 31).
Alice ConfS
| |
|(1)confRequest(confUserID, |
| confObjID, delete) |
|------------------------------>|
| (a)Delete +---|
| Conf | |
| Object | |
| +-->|
| |--+ (b) MS
| | | removes related
| | | mixer instances and
| |<-+ their participants
| | (SIP signaling as well)
| |
|(2)confResponse(confUserID, |
| confObjID,delete, |
| success) |
| |
|<------------------------------|
| |
Figure 31: Deleting a conference
1. The conferencing system client "Alice" sends a confRequest
message with a "delete" operation to be performed on the
conference identified by the XCON-URI carried in the "confObjID"
parameter. The conference server, on the basis of the
"confUserID" included in the receipt request, ensures that Alice
has the appropriate authority to fulfill the operation.
2. After validating Alice's rights, the conferencing server
instigates the process to delete the conference object,
disconnetting participants and removing associated resources such
as mixer instances. Then, the conference server returns a
confResponse message to Alice with "success" as "response-code"
and the deleted conference XCON-URI in the "confObjID" field.
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1. confRequest/delete message (Alice deletes a conference)
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpRequest
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp"
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info">
<ccmpRequest xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-conf-request-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:8977794@example.com</confObjID>
<operation>delete</operation>
<ccmp:confRequest/>
</ccmpRequest>
</ccmp:ccmpRequest>
2. confResponse/delete message ("success")
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ccmp:ccmpResponse
xmlns:info="urn:ietf:params:xml:ns:conference-info"
xmlns:ccmp="urn:ietf:params:xml:ns:xcon:ccmp"
xmlns:xcon="urn:ietf:params:xml:ns:xcon-conference-info">
<ccmpResponse xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="ccmp:ccmp-conf-response-message-type">
<confUserID>xcon-userid:Alice@example.com</confUserID>
<confObjID>xcon:8977794@example.com</confObjID>
<operation>delete</operation>
<response-code>success</response-code>
<ccmp:confResponse/>
</ccmpResponse>
</ccmp:ccmpResponse>
Figure 32: Deleting a Conference Messaging Details
10. IANA Considerations
This document has no IANA considerations.
11. Security Considerations
The security considerations applicable to the implementation of these
call flows is documented in the XCON Framework, with additional
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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.
12. Change Summary
NOTE TO THE RFC-EDITOR: Please remove this section prior to
publication as an RFC.
The following are the major changes between the 02 and the 03
versions of the draft:
o updated the call flows in order to take into account the changes
on CCMP;
o added a completely new introductory section, addressing the
protocol in general, the data model constraints, transport-related
information, and notifications in a practical way;
o reorganized the chapters, grouping user-related scenarios in an
users section, and doing the same for sidebars;
o added more verbose text to almost every section of the document;
The following are the major changes between the 01 and the 02
versions of the draft:
o updated the call flows in order to take into account the new
versioning mechanism of the CCMP;
o clarified, per agreement in Stockholm, that cloning from a
blueprint does not need a cloning-parent to be made available in
the response;
o clarified that BFCP and CCMP-based media control are neither in
conflict nor one the wrapper of the other; they act at different
levels, and when both are involved, it is required that both grant
a resource before it can be used by an interested participant;
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o changed all the domains involved in the flows to make them
compliant with [RFC2606];
o clarified that a successful creation of a new conference object
may or may not contain the whole confInfo object in the response;
in case it doesn't, a retrieve of the updated object can be
achieved by issuing a confRequest/retrieve;
o clarified that the scenario in Section 7.3 only involves CCMP in
adding the user to a conference; this includes requiring the use
of a password only in adding the user to the conference object;
the actual request for PIN/Password when joining thw conference is
handled by means of out-of-band mechanisms (in this case at the
media level, with the help of the MEDIACTRL framework);
o added and corrected Sidebars-related scenarios;
o added flows for some previously missing scenarios: Private
Message/Whisper, Coaching Scenario, Removing a Party, Deleting a
Conference;
o
The following are the major changes between the 00 and the 01
versions of the draft:
o Updates to reflect change of CCMP to HTTP transport model.
The following are the major changes between the individual 01 version
to the WG 00:
o Updates to reflect most recent version of CCMP, including
parameter names, etc.
o Added protocol details to many of the examples.
o Editorial: Simplifying intro, terms, etc.
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13. 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.
14. References
14.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[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-05 (work in progress), December 2009.
14.2. Informative References
[RFC2606] Eastlake, D. and A. Panitz, "Reserved Top Level DNS
Names", BCP 32, RFC 2606, June 1999.
[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.
[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.
[RFC4575] Rosenberg, J., Schulzrinne, H., and O. Levin, "A Session
Initiation Protocol (SIP) Event Package for Conference
State", RFC 4575, August 2006.
[I-D.ietf-xcon-event-package]
Camarillo, G., Srinivasan, S., Even, R., and J.
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Urpalainen, "Conference Event Package Data Format
Extension for Centralized Conferencing (XCON)",
draft-ietf-xcon-event-package-01 (work in progress),
September 2008.
[I-D.ietf-xcon-common-data-model]
Novo, O., Camarillo, G., Morgan, D., and J. Urpalainen,
"Conference Information Data Model for Centralized
Conferencing (XCON)", draft-ietf-xcon-common-data-model-16
(work in progress), February 2010.
[I-D.ietf-mediactrl-call-flows]
Amirante, A., Castaldi, T., Miniero, L., and S. Romano,
"Media Control Channel Framework (CFW) Call Flow
Examples", draft-ietf-mediactrl-call-flows-03 (work in
progress), February 2010.
[RFC5567] Melanchuk, T., "An Architectural Framework for Media
Server Control", RFC 5567, June 2009.
[I-D.ietf-mediactrl-mixer-control-package]
McGlashan, S., Melanchuk, T., and C. Boulton, "A Mixer
Control Package for the Media Control Channel Framework",
draft-ietf-mediactrl-mixer-control-package-10 (work in
progress), January 2010.
[I-D.boulton-xcon-session-chat]
Barnes, M., Boulton, C., and S. Loreto, "Chatrooms within
a Centralized Conferencing (XCON) System",
draft-boulton-xcon-session-chat-04 (work in progress),
July 2009.
Authors' Addresses
Mary Barnes
Nortel
2201 Lakeside Blvd
Richardson, TX
Email: mary.barnes@nortel.com
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Lorenzo Miniero
Meetecho
Via Carlo Poerio 89/a
Napoli 80121
Italy
Email: lorenzo@meetecho.com
Roberta Presta
University of Napoli
Via Claudio 21
Napoli 80125
Italy
Email: roberta.presta@unina.it
Simon Pietro Romano
University of Napoli
Via Claudio 21
Napoli 80125
Italy
Email: spromano@unina.it
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