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Versions: (draft-barnes-xcon-ccmp) 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 RFC 6503

XCON Working Group                                             M. Barnes
Internet-Draft                                                    Nortel
Intended status: Standards Track                              C. Boulton
Expires: May 7, 2009                                               Avaya
                                                             S P. Romano
                                                    University of Napoli
                                                          H. Schulzrinne
                                                     Columbia University
                                                        November 3, 2008


             Centralized Conferencing Manipulation Protocol
                        draft-ietf-xcon-ccmp-01

Status of this Memo

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   This Internet-Draft will expire on May 7, 2009.

Abstract

   The Centralized Conferencing Manipulation Protocol (CCMP) can create,
   retrieve, change and delete objects describing a centralized
   conference, such as state and capabilities of the conference,
   participants, and their roles.  The conference information is
   contained in XML documents and fragments conforming to the
   centralized conferencing data model schema.  CCMP is a state-less
   client-server protocol based on a request/response model.



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   Conferencing clients send requests to conference servers, which
   respond to the client with the conference information.

   This document also discusses options for using existing notification
   protocols to inform conference client about the changes in the state
   of a conference during its entire lifetime.


Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  4
   2.  Conventions  . . . . . . . . . . . . . . . . . . . . . . . . .  5
   3.  Terminology  . . . . . . . . . . . . . . . . . . . . . . . . .  5
   4.  Rationale and Motivation . . . . . . . . . . . . . . . . . . .  5
   5.  System Architecture  . . . . . . . . . . . . . . . . . . . . .  7
   6.  Conference Object and User Identifiers . . . . . . . . . . . .  9
     6.1.  Conference Object  . . . . . . . . . . . . . . . . . . . .  9
     6.2.  Conference Users and Participants  . . . . . . . . . . . .  9
   7.  Protocol Operations  . . . . . . . . . . . . . . . . . . . . . 10
     7.1.  Retrieve . . . . . . . . . . . . . . . . . . . . . . . . . 10
     7.2.  Create . . . . . . . . . . . . . . . . . . . . . . . . . . 11
     7.3.  Change . . . . . . . . . . . . . . . . . . . . . . . . . . 12
     7.4.  Delete . . . . . . . . . . . . . . . . . . . . . . . . . . 12
   8.  Protocol Operations on Conference Objects  . . . . . . . . . . 13
     8.1.  Locating a Conference Control Server . . . . . . . . . . . 14
     8.2.  Constructing a CCMP Request  . . . . . . . . . . . . . . . 15
       8.2.1.  blueprintsRequest  . . . . . . . . . . . . . . . . . . 16
       8.2.2.  confsRequest . . . . . . . . . . . . . . . . . . . . . 16
       8.2.3.  Operations Requests  . . . . . . . . . . . . . . . . . 16
     8.3.  Handling a CCMP Response . . . . . . . . . . . . . . . . . 18
       8.3.1.  blueprintsResponse . . . . . . . . . . . . . . . . . . 20
       8.3.2.  confsResponse  . . . . . . . . . . . . . . . . . . . . 20
       8.3.3.  Operation Responses  . . . . . . . . . . . . . . . . . 21
   9.  Managing sidebars  . . . . . . . . . . . . . . . . . . . . . . 25
     9.1.  Sidebars by value  . . . . . . . . . . . . . . . . . . . . 25
     9.2.  Sidebars by reference  . . . . . . . . . . . . . . . . . . 26
   10. Protocol Parameters  . . . . . . . . . . . . . . . . . . . . . 26
     10.1. Operation Parameter  . . . . . . . . . . . . . . . . . . . 26
     10.2. ConfObjID Parameter  . . . . . . . . . . . . . . . . . . . 26
     10.3. ConfUserID Parameter . . . . . . . . . . . . . . . . . . . 27
     10.4. ResponseCode Parameter . . . . . . . . . . . . . . . . . . 27
     10.5. Blueprints Parameter . . . . . . . . . . . . . . . . . . . 28
     10.6. Conference-info Parameter  . . . . . . . . . . . . . . . . 28
     10.7. User Parameter . . . . . . . . . . . . . . . . . . . . . . 29
     10.8. Users Parameter  . . . . . . . . . . . . . . . . . . . . . 29
     10.9. Sidebar Parameters . . . . . . . . . . . . . . . . . . . . 29
   11. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
     11.1. HTTP methods for realizing a RESTful CCMP  . . . . . . . . 30



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     11.2. CCMP Detailed Message Body Examples  . . . . . . . . . . . 33
       11.2.1. Creating a New Conference  . . . . . . . . . . . . . . 33
       11.2.2. Creating a New Conference User . . . . . . . . . . . . 36
       11.2.3. Adding a User to a Conference  . . . . . . . . . . . . 36
   12. XML Schema . . . . . . . . . . . . . . . . . . . . . . . . . . 37
   13. Managing notifications . . . . . . . . . . . . . . . . . . . . 45
   14. Role based access control  . . . . . . . . . . . . . . . . . . 46
   15. IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 46
     15.1. URN Sub-Namespace Registration . . . . . . . . . . . . . . 46
     15.2. XML Schema Registration  . . . . . . . . . . . . . . . . . 47
     15.3. MIME Media Type Registration for 'application/ccmp+xml'  . 47
     15.4. DNS Registrations  . . . . . . . . . . . . . . . . . . . . 48
       15.4.1. Registration  of a Location Server Application
               Service Tag  . . . . . . . . . . . . . . . . . . . . . 48
       15.4.2. Registration of a Location Server Application
               Protocol Tag for HELD  . . . . . . . . . . . . . . . . 48
     15.5. CCMP Protocol Registry . . . . . . . . . . . . . . . . . . 49
       15.5.1. CCMP Message Types . . . . . . . . . . . . . . . . . . 49
       15.5.2. CCMP Response Codes  . . . . . . . . . . . . . . . . . 50
   16. Security Considerations  . . . . . . . . . . . . . . . . . . . 51
   17. Acknowledgments  . . . . . . . . . . . . . . . . . . . . . . . 51
   18. Changes since last Version . . . . . . . . . . . . . . . . . . 51
   19. References . . . . . . . . . . . . . . . . . . . . . . . . . . 52
     19.1. Normative References . . . . . . . . . . . . . . . . . . . 52
     19.2. Informative References . . . . . . . . . . . . . . . . . . 52
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 53
   Intellectual Property and Copyright Statements . . . . . . . . . . 55
























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1.  Introduction

   The Framework for Centralized Conferencing [RFC5239] (XCON FW)
   defines a signaling-agnostic framework, naming conventions and
   logical entities required for building advanced conferencing systems.
   The XCON FW introduces the conference object as a logical
   representation of a conference instance, representing the current
   state and capabilities of a conference.

   The Centralized Conferencing Manipulation Protocol (CCMP) defined in
   this document allows authenticated and authorized users to create,
   manipulate and delete conference objects.  Operations on conferences
   include adding and removing participants, changing their roles, as
   well as adding and removing media streams and associated end points.

   CCMP implements the client-server model within the XCON FW, with the
   conferencing client and conference control server acting as client
   and server, respectively.  CCMP is an instance of conference control
   protocol (CCP).

   CCMP can be mapped into the CRUD (Create, Read, Update, Delete)
   design pattern.  The basic CRUD operations are used to manipulate
   conference objects, which are XML documents containing the
   information characterizing a specified conference instance, be it an
   active conference or a conference blueprint used by the conference
   server to create new conference instances through a simple clone
   operation.

   CCMP can use a general-purpose protocol such as HTTP [RFC2616] to
   transfer domain-specific XML-encoded data objects defined in the
   Conference Information Data Model for Centralized Conferencing
   [I-D.ietf-xcon-common-data-model].

   CCMP follows the well-known REST (REpresentational State Transfer)
   architectural style [REST] This document describes how the CCMP
   specification maps onto the REST philosophy, by specifying resource
   URIs, resource formats, methods supported at each URI and status
   codes that have to be returned when a certain method is invoked on a
   specific URI.

   Section 4 motivates the design of CCMP, followed by the system
   architecture in Section 5.  Section 6 discusses the primary keys in
   the conference object carried in the protocol.  An overview of the
   operations associated with each protocol request and response is
   provided in Section 7, with the sequence of protocol requests and
   responses discussed in Section 8 and examples provided in Section 11.
   The protocol parameters are detailed in Section 10.  Section 12
   provides the XML schema.



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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.


3.  Terminology

   In additon to the terms defined in the Framework for Centralized
   Conferencing [RFC5239], this document uses the following terms and
   acronyms:

   CRUD:  CRUD stands for Create/Read/Update/Delete and indicates a
      design pattern supporting creating, retrieving, updating and
      destroying objects.
   REST:  REpresentational State Transfer (REST) is an architectural
      style, i.e., a coordinated set of architectural constraints.  REST
      is based on the consideration that a software architecture can
      often be specified as an appropriate configuration of components,
      data and connectors, all coordinated through constraining their
      mutual relationships.  Coordination and constraints help achieve a
      desired set of architectural properties.  [REST]
   SOAP:  Simple Object Access Protocol defined in
      [W3C.REC-soap12-part1-20030624] and
      [W3C.REC-soap12-part2-20030624].
   W3C:  World Wide Web Consortium, the organization that developed the
      SOAP and WSDL specifications referenced within this document.


4.  Rationale and Motivation

   This document specifies the basic operations that can create,
   retrieve, modify and delete conference-related information in a
   centralized conference.  The core set of objects includes conference
   blueprints, the conference itself, users, and sidebars.

   The operations on these objects can be implemented in at least two
   different ways, namely as remote procedure calls and by defining
   resources.  A remote procedure call (RPC) mechanism could use SOAP
   (Simple Object Access Protocol[W3C.REC-soap12-part1-20030624][W3C.REC
   -soap12-part2-20030624]), where conferences and the other objects are
   modeled as services with associated operations.  Conferences and
   other objects are selected by their own local identifiers, such as
   email-like names for users.  This approach has the advantage that it
   can easily define atomic operations that have well-defined error



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   conditions.

   Alternatively, conference objects can be modeled as resources
   identified by URIs, with the basic CRUD operations mapped to the HTTP
   methods POST/PUT for creating objects, GET for reading objects,
   PATCH/POST/PUT for changing objects and DELETE for deleting them.
   Many of the objects, such as conferences, already have a natural
   URIs.

   In both approaches, servers will have to recreate their internal
   state representation of the object with each update request, checking
   parameters and triggering function invocations.  In the SOAP
   approach, it would be possible to describe a separate operation for
   each atomic element, but that would greatly increase the complexity
   of the protocol.  The coarser-grained approach in CCMP does require
   that the server process XML elements in updates that have not changed
   and that there can be multiple changes in one update.

   We assume that each update operation is atomic and either succeeds or
   fails as a whole.  Thus, a server has to first check all parameters,
   before making any changes to the internal representation of the
   conference object.  For example, it would be undesirable to change
   the <subject> of the conference, but then detect an invalid URI in
   one of the <service-uris> and abort the remaining updates.

   Because multiple clients can modify the same conference objects,
   clients need to obtain the current object and then update the whole
   object.

   Editor's Note: Do we need locking, using WebDAV or floor control?
   Otherwise, changes made by user A could get lost when user B wants to
   modify some other parameter.  For example, A changes the subject, B
   adds the a service URI.

   In summary, a REST-style approach must ensure sure that all
   operations can be mapped to HTTP operations, while all SOAP
   operations would use a single HTTP verb.  While the RESTful approach
   requires the use of a URI for each object, SOAP can use any token.

   For CCMP, the resource (REST) model appears more attractive, since
   the conference operations fit the CRUD approach.

   It is likely that implementations and future standardization work
   will add more conference attributes and parameters.  There are three
   types of extensions.  The first and simplest type of extension adds
   elements to the overall conference description, media descriptions or
   descriptions of users.  The XML namespace mechanism makes such
   extensions relatively easy, although implementations still have to



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   deal with implementations that may not understand the new namespaces.
   The CCMP "blueprintsRequest" message allows clients to determine the
   capabilities of a specific server, reflected by the specific
   blueprints supported by that server.

   A second type of extension replaces the conference, user or media
   objects with completely new schema definitions, i.e., the namespaces
   for these objects themselves differ from the basic one defined in
   this document.  As long as the OPTIONS request remains available and
   keeps to a mutually-understood definition, a compatible client and
   server will be able to bootstrap themselves into using these new
   objects.

   Finally, it is conceivable that new object types are needed beyond
   the core conference, user and media objects and their children.
   These would also be introduced by namespaces and new URIs.


5.  System Architecture

   CCMP supports the framework for centralized conferencing.  Figure 1
   depicts a subset of the 'Conferencing System Logical Decomposition'
   architecture from the framework for centralized conferencing
   document.  It illustrates the role that CCMP assumes within the
   overall centralized architecture.


























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   ........................................................
   .  Conferencing System                                 .
   .                                                      .
   .        +---------------------------------------+     .
   .        |   C O N F E R E N C E   O B J E C T   |     .
   .      +-+-------------------------------------+ |     .
   .      |   C O N F E R E N C E   O B J E C T   | |     .
   .    +-+-------------------------------------+ | |     .
   .    |   C O N F E R E N C E   O B J E C T   | | |     .
   .    |                                       | | |     .
   .    |                                       | |-+     .
   .    |                                       |-+       .
   .    +---------------------------------------+         .
   .                        ^                             .
   .                        |                             .
   .                        v                             .
   .               +-------------------+                  .
   .               | Conference Control|                  .
   .               | Server            |                  .
   .               +-------------------+                  .
   .                        ^                             .
   .........................|..............................
                            |
                            |Conference
                            |Control
                            |Protocol
                            |
                            |
   .........................|..............................
   .                        V                             .
   .                +----------------+                    .
   .                | Conference     |                    .
   .                | Control        |                    .
   .                | Client         |                    .
   .                +----------------+                    .
   .                                                      .
   .  Conferencing Client                                 .
   ........................................................


                  Figure 1: Conference Client Interaction

   CCMP serves as the Conference Control Protocol, allowing the
   conference control client to interface with the conference object
   maintained by the conferencing system, as represented in Figure 1.
   Conference Control is one part of functionality for advanced
   conferencing supported by a conferencing client.  Other functions are
   discussed in the framework for centralized conferencing document and



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   related documents.


6.  Conference Object and User Identifiers

   This section provides an overview of the conference object and
   conference users which are key protocol elements for creating the
   CCMP requests and responses.  The identifiers used in CCMP for the
   conference object (XCON-URI) and conference user (XCON-USERID) are
   introduced in the XCON framework and defined in the XCON data model
   [I-D.ietf-xcon-common-data-model].

6.1.  Conference Object

   Conference objects feature a simple dynamic inheritance-and-override
   mechanism.  Conference objects are linked into a tree, where each
   tree node inherits attributes from its parent node.  The roots of
   these inheritance trees are also known as "blueprints".  Nodes in the
   inheritance tree can be active conferences or simply descriptions
   that do not currently have any resources associated with them.  An
   object can mark certain of its properties as unalterable, so that
   they cannot be overridden.

   The schema for the conference object is defined in the XCON data
   model.  Conference objects are uniquely identified by the XCON-URI.
   A client MAY specify a parent element that indicates the parent from
   which the conference is to inherit values.  When creating
   conferences, the XCON-URI included by the client is only a
   suggestion.  To avoid identifier collisions and to conform to local
   server policy, the conference control server MAY choose a different
   identifier.

6.2.  Conference Users and Participants

   Each conference can have zero or more users.  All conference
   participants are users, but some users may have only administrative
   functions and do not contribute or receive media.  Users are added
   one user at a time to simplify error reporting.  Users are inherited
   as well, so that it is easy to set up a conference that has the same
   set of participants or a common administrator.  The Conference
   Control Server creates individual users, assigning them a unique
   Conference User Identifier (XCON-USERID).

   A variety of elements defined in the common <conference-info> element
   as specified in the XCON data model are used to determine how a
   specific user expects and is allowed to join a conference as a
   participant, or users with specific privileges (e.g., observer).  For
   example, the <method> attribute defines how the caller joins the



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   conference, with a set of defined XML elements, namely <dial-in> for
   users that are allowed to dial in and <dial-out> for users that the
   conference focus will be trying to reach. <dial-in> is the default.

   If the conference is currently active, dial-out users are contacted
   immediately; otherwise, they are contacted at the start of the
   conference.  The conference control server assigns a unique
   Conference User Identifier (XCON-USERID) to each user.  The
   conference control server uses the XCON-USERID to change or delete
   <user> elements.  Depending upon policies and privileges, specific
   users MAY also manipulate <user> elements.

   In many conferences, users can dial in if they know the XCON-URI and
   an access code shared by all conference participants.  In this case,
   the system is typically not aware of the call signaling URL.  Thus,
   the initial <user> element does not have an entity attribute and the
   default type of <dial-in> is used to support this type of user.  For
   this case, the server assigns a locally-unique URI, such as a
   locally-scoped tel URI.  The conference control server assigns a
   unique Conference User Identifier (XCON-USERID) to these users when
   they dial-in to join the conference.  If the user supports the
   notification event package [I-D.ietf-xcon-event-package], they can
   receive their XCON-USERID, thus allowing them to also manipulate the
   <user> attribute, including the entity attribute, in the conference
   object.


7.  Protocol Operations

   The primary function of the protocol defined within this document is
   to provide a conference control client with the ability to carry out
   operations on a conference object as a whole and on specific elements
   within a conference object.  This section describes the four basic
   operations on a conference object: retrieve, create, change and
   delete.  The recommended HTTP method for each of the basic operations
   is described.  The XCON-URI as discussed in Section 6.1 is the
   primary target for each of these operations.  The normative protocol
   details as to the applicability of each of the operations for the
   various CCMP requests and responses are provided in Section 8.

7.1.  Retrieve

   The "retrieve" operation is used by a client to query a system for a
   specific template in the form of a blueprint prior to the creation of
   a conference.  In this case, the "retrieve" operation often follows a
   "blueprintsRequest" operation, although a conferencing control client
   may be pre-configured to perform the "retrieve" operation on a
   specific blueprint.



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   The "retrieve" operation is also used to get the current
   representation of a specific conference object (or specific
   parameters in the conference object) for a conference reservation or
   an active conference.  The unique conference identifier (XCON-URI) is
   included in the CCMP request.

   The "retrieve" operation returns the XML document describing the
   conference object in its current state including all inherited values
   or the specific parameters per the specific request type.  Elements
   may be marked by attributes, in particular, whether they are specific
   to this instance or have been inherited from the parent node.

   In the case of a RESTful implementation of the protocol, HTTP GET
   MUST be used on XCON-URIs, so that clients can obtain data about
   conference objects in the form of XML data model documents.

7.2.  Create

   The "create" operation is used by a client to create and reserve a
   conference object or a new conference user.  The creation of a
   conference object can be explicit by requesting it to be created
   based upon a specific blueprint, based on an existing conference
   object (e.g., cloning a conference reservation or active conference
   object) or based on the data included in the request.  In the first
   two cases, a specific XCON-URI MUST be included in the request.

   When the creation of a conference object is implicit, with no
   conference object for a blueprint or existing conference specified
   and no data included in the request (i.e., an "empty" request sent to
   a specific conference server), the creation and reservation of the
   conference instance is based on the default conference object.  The
   default conference object is specific to a conference control server
   and its specification is outside the scope of this document.

   A client may first send a request with "retrieve" operation in order
   to obtain all the data as defined in
   [I-D.ietf-xcon-common-data-model] for the specific blueprint or
   existing conference object.  This would allow the client to modify
   the data prior to sending the request with the "create" operation.
   In this case, the request would also include all the data.  If the
   client wants to create the new conference by cloning the blueprint or
   existing conference object, there would be no data included in the
   request.  The client may later modify this data by sending a request
   with a "change" operation.

   When creating conferences, any XCON-URI included by the client is
   considered as the target conference object from which the new
   conference is to be created.  To avoid identifier collisions and to



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   conform to local server policy, the conference control server
   typically chooses a different identifier for the newly created
   conference object.  The identifier is returned in the response.

   In addition, the conference description MAY contain a calendar
   element, in the iCal format in XML rendition defined in CPL [RFC3880]
   or (preferable, if available as stable reference) xCal
   [I-D.royer-calsch-xcal].  This description indicates when the
   conference is active.

   The "create" operation may also be used to create a new conference
   user with the "userRequest" message.  In this case, the
   "userResponse" to this operation includes an XCON-USERID.

   In the case of a RESTful implementation of the protocol, HTTP PUT
   MUST be used to create a new object as identified by the XCON-URI or
   XCON-USERID.

7.3.  Change

   The "change" operation updates the conference object as referenced by
   the XCON-URI included in the request.  A request which attempts to
   change a non-existing object is an error, as is a request which
   attempts to change a parameter that is inherited from a protected
   element.

   During the lifetime of a conference, this operation is used by a
   conference control client to manipulate a conference object.  This
   includes the ability to manipulate specific elements in the
   conference object through element specific requests such as
   "userRequest" or "sideBarRequest", etc.

   Upon receipt of a "change" operation, the conference control server
   updates the specific elements in the referenced conference object.
   Object properties that are not explicitly changed, remain as-is.
   This approach allows a conference control client to manipulate
   objects created by another application even if the manipulating
   application does not understand all object properties.

   In the case of a RESTful implementation of the protocol, either HTTP
   PATCH or HTTP POST MUST be used to change the conference object
   identified by the XCON-URI.

7.4.  Delete

   This conference control operation is used to delete the current
   representation of a conference object or a specific parameter in the
   conference object and requires the unique conference identifier



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   (XCON-URI) be provided by the client.

   A request which attempts to delete a conference object that is being
   referenced by a child object is an error.

   In case of a RESTful implementation of the protocol, HTTP DELETE MUST
   be used to delete conference objects and parameters within conference
   objects identified by the XCON-URI.


8.  Protocol Operations on Conference Objects

   The primary function of CCMP is to provide a conference control
   client with the ability to carry out specific operations (Section 7)
   on a conference object through the protocol requests and responses.
   In case of a RESTful implementation of the protocol, the CCMP
   requests (Section 8.2)and responses (Section 8.3) MUST be represented
   as HTTP requests and responses.  The basic CCMP request/response
   pairs defined in this document are:

   blueprintsRequest/blueprintsResponse:  The blueprintsRequest is used
      to ascertain the list of blueprints available at the conference
      server.  The blueprintsResponse returns a list of the requested
      blueprints, in the form of XCON URIs.
   confsRequest/confsResponse:  The confsRequest is used to ascertain
      conference reservations and active conferences supported by the
      server.  The confsResponse returns a list of the requested types
      of conference objects (i.e.  Conference Reservations and/or Active
      Conferences) supported by the specific conference server.
   blueprintRequest/blueprintResponse:  The blueprintRequest is used to
      request an operation on a specific blueprint.
   confRequest/confResponse:  The confRequest is used to request an
      operation on the conference object as a whole.
   userRequest/userResponse:  The userRequest is used to request an
      operation on the "user" element in the conference object.
      [Editor's Note: we may want to add more discrete user requests/
      responses as this is a very broad parameter]
   usersRequest/usersResponse:  This usersRequest is used to manipulate
      the "users" element in the conference object, including parameters
      such as the allowed-users-list, join-handling, etc.
   sidebarRequest/sidebarResponse:  This sidebarRequest is used to
      retrieve the information related to a sidebar or to create, change
      or delete a specific sidebar.  [Editor's Note: the data model
      defines a byVal and byRef sidebar type.  Rather than define two
      root operations, the preference is to have these two types
      reflected by a parameter in the request.]

   With respect to the above mentioned operations, we remark that the



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   difference between "blueprintsRequest" and "confsRequest" only exists
   at the semantic level.  They both ask for a list of XCON-URIs and
   they have exactly the same format.  The returned XCON-URIs, though,
   represent blueprints in the former case, real (i.e. either active or
   reserved) conferences in the latter.  The fact that blueprints and
   conferences share the same representation (a conference object
   compliant with the XCON data model) is a mere coincidence.  The same
   holds for "confRequest/blueprintRequest", which aim at managing,
   respectively, a specific conference object and a specific blueprint.

   To simplify operations, a conference control server treats certain
   parameters as suggestions (e.g., for the "create" and "change"
   operations), as noted in the object description.  If the conference
   control server cannot set the parameter to the values desired, it
   picks the next best value, according to local policy and returns the
   values selected in the response.  If the client is not satisfied with
   these values, it simply deletes the object.

   As illustrated above, along with the protocol requests and responses
   for manipulating the conference object, there are also querying
   mechanisms ("blueprintsRequest"/"blueprintsResponse" and
   "confsRequest/confsResponse") to get information about either
   blueprints or scheduled/active conferences supported by the server.
   Any elements with namespaces not understood by the server are to be
   ignored by the server.  This allows a client to include optional
   elements in requests without having to tailor its request to the
   capabilities of each server.

   A conference client must first discover the conference control server
   as described in Section 8.1.  The conference control server is the
   recipient of the CCMP requests.

8.1.  Locating a Conference Control Server

   If a conference control client is not pre-configured to use a
   specific conference control server for the requests, the client MUST
   first discover the conference control server before it can send any
   requests.  The result of the discovery process, is the address of the
   server supporting conferencing.  In this document, the result is an
   http: or https: URI, which identifies a conference server.

   This document proposes the use of DNS to locate the conferencing
   server.  U-NAPTR resolution for conferencing takes a domain name as
   input and produces a URI that identifies the conferencing server.
   This process also requires an Application Service tag and an
   Application Protocol tag, which differentiate conferencing-related
   NAPTR records from other records for that domain.




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   Section 15.4.1 defines an Application Service tag of "XCON", which is
   used to identify the centralized conferencing (XCON) server for a
   particular domain.  The Application Protocol tag "CCMP", defined in
   Section 15.4.2, is used to identify an XCON server that understands
   the CCMP protocol.

   The NAPTR records in the following example Figure 2 demonstrate the
   use of the Application Service and Protocol tags.  Iterative NAPTR
   resolution is used to delegate responsibility for the conferencing
   service from "zonea.example.com." and "zoneb.example.com." to
   "outsource.example.com.".



             zonea.example.com.
             ;;       order pref flags
             IN NAPTR 100   10   ""  "XCON:CCMP" (     ; service
             ""                                        ; regex
             outsource.example.com.                    ; replacement
             )
             zoneb.example.com.
             ;;       order pref flags
             IN NAPTR 100   10   ""  "XCON:CCMP" (     ; service
             ""                                        ; regex
             outsource.example.com.                    ; replacement
             )
             outsource.example.com.
             ;;       order pref flags
             IN NAPTR 100   10   "u"  "XCON:CCMP" (    ; service
             "!*.!https://confs.example.com/!"         ; regex
             .                                         ; replacement
             )


             Figure 2: Sample XCON:CCMP Service NAPTR Records

   Details for the "XCON" Application Service tag and the "CCMP"
   Application Protocol tag are included in Section 15.4.

8.2.  Constructing a CCMP Request

   Construction of a valid CCMP request is based upon the operations
   defined in Section 7, depending upon the function and associated
   information desired by the conference control client.  The next two
   sections provide details of the "blueprintsRequest" and
   "confsRequest" messages, which differ from the other CCMP messages in
   that they are only used to ask the conference system for general
   information (blueprints and conferences).  Subsequent sections



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   summarize the CCMP requests related to the specific operations in
   Section 7.

8.2.1.  blueprintsRequest

   The "blueprintsRequest" is used by a client to query a system for its
   capabilities in terms of types of conferences supported and isn't
   targeted toward a particular conference object.  Detailed information
   about a specific blueprint, can be subsequently obtained through the
   blueprintRequest operation, which is used to retrieve a whole XCON
   blueprint (in the form of a conference object) available at the
   server.

   The "blueprintsResponse" returns the XML namespaces that the server
   understands and the namespaces to be used in responses that it
   requires the client to understand.  Within the conferencing system,
   the namespaces correlate with blueprints, as specified in the XCON
   framework.  The blueprints are comprised of conference information
   initialized to specific values and ranges.  Each blueprint has a
   corresponding XCON-URI.

8.2.2.  confsRequest

   The "confsRequest" is used by a client to query a system for
   information about reserved/active conferences and isn't targeted
   toward a particular conference object.  Detailed information about a
   specific conference, can be subsequently obtained through the
   confRequest operation, which can be used to retrieve a whole XCON
   conference (in the form of a conference object) available at the
   server.

   The "confsResponse" returns the XCON-URIs of all reserved and active
   conferences currently hosted by the server.

8.2.3.  Operations Requests

   Construction of other valid CCMP requests is based upon the
   operations defined in Section 7, depending upon the function and
   associated information desired by the conference control client.  The
   following table summarizes specific request type and processing for
   each of the "operations".  A value of "N/A" indicates the specific
   operation is not valid for the specific CCMP request.  Following the
   table examples for each of the HTTP operations for each of the
   request types is provided.

   Editors' Notes:





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   1.  Sidebars need additional consideration - e.g., due to the byVal
       and byRef options, it's messy.  Operations approach may need
       additional consideration (or we need separate request types).

   +---------------+------------+------------+------------+------------+
   | Operation     |  Retrieve  |   Create   |   Change   |   Delete   |
   | (HTTP method) |    (GET)   |    (PUT)   |  (PATCH or |  (DELETE)  |
   | ------------- |            |            |    POST)   |            |
   | Request Type  |            |            |            |            |
   +---------------+------------+------------+------------+------------+
   | blueprintsReq |  Gets list |     N/A    |     N/A    |     N/A    |
   | uest          |     of     |            |            |            |
   |               |  available |            |            |            |
   |               | blueprints |            |            |            |
   | ------------- | ---------- | ---------- | ---------- | ---------- |
   | confsRequest  |  Gets list |     N/A    |     N/A    |     N/A    |
   |               |  of active |            |            |            |
   |               |     or     |            |            |            |
   |               |  reserved  |            |            |            |
   |               |    confs   |            |            |            |
   | ------------- | ---------- | ---------- | ---------- | ---------- |
   | blueprintRequ |   Gets a   |  Creates a |  Changes a |  Deletes a |
   | est           |  specific  |  blueprint |  blueprint |  blueprint |
   |               |  blueprint |   (needs   |   (needs   |   (needs   |
   |               |            |    admin   |    admin   |    admin   |
   |               |            | privileges | privileges | privileges |
   |               |            | )          | )          | )          |
   | ------------- | ---------- | ---------- | ---------- | ---------- |
   | confRequest   |    Gets    |   Creates  |   Changes  |   Deletes  |
   |               | conference | conference | conference | conference |
   |               |   object   |   object   |   object   |  Object as |
   |               |            |            |            |   a whole  |
   | ------------- | ---------- | ---------- | ---------- | ---------- |
   | userRequest   |   Gets a   |  Creates a |  Modifies  |  Deletes a |
   |               |  specific  |  user and  |     the    |    user    |
   |               |    user    | associated |  specified | element as |
   |               |   element  | XCON-UserI |    user    |   a whole  |
   |               |            | D          |   element  |            |
   | ------------- | ---------- | ---------- | ---------- | ---------- |
   | usersRequest  |   Gets a   |     N/A    |  Modifies  |  Deletes a |
   |               |  specific  |            |     the    |    users   |
   |               |    users   |            |  specified | element as |
   |               |   element  |            |    users   |   a whole  |
   |               |            |            |   element  |            |
   | ------------- | ---------- | ---------- | ---------- | ---------- |






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   | sidebarReques |   Gets a   |  Creates a | Modifies a | Removes/de |
   | t             |   sidebar  |     new    | sidebar by | l etes the |
   |               | element by | sidebar by |     Val    |    entire  |
   |               |  Val or by |     Val    |            |  sidebar b |
   |               |     Ref    |            |            | y    Val   |
   +---------------+------------+------------+------------+------------+

            Table 1: Request Type Operation Specific Processing

   The following provides HTTP examples for each of the valid operations
   for each request type in the above table Table 1

   o  blueprintsRequest: GET /blueprints
   o  confsRequest: GET /confs
   o  blueprintRequest
      *  GET /blueprint/blueprintId
      *  PUT /blueprint/blueprintId
      *  POST /blueprint/blueprintId
      *  DELETE /blueprint/blueprintId
   o  confRequest
      *  GET /confs/confObjId
      *  PUT /confs/confObjId
      *  POST /confs/confObjId
      *  DELETE /confs/confObjId
   o  userRequest
      *  GET /user/confUserId
      *  PUT /user/confUserId
      *  POST /user/confUserId
      *  DELETE /user/confUserId
   o  usersRequest
      *  GET /confs/confObjId/users
      *  POST /confs/confObjId/users
      *  DELETE /confs/confObjId/users
   o  sidebarRequest
      *  By val: GET /confs/confObjId/sidebars/entityAttribute
      *  By val: N/A (use a "confRequest" message with a "change"
         operation for this)
      *  By val: N/A (use a "confRequest" message with a "change"
         operation for this)
      *  By val: N/A (use a "confRequest" message with a "change"
         operation for this)
      *  By ref: GET /sidebars/sidebarId

8.3.  Handling a CCMP Response

   A response to the CCMP request MUST contain a response code and may
   contain other elements depending upon the specific request and the
   value of the response code.



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   In case of a RESTful implementation, the CCMP response message MUST
   be enclosed in a HTTP response message.  CCMP-related error codes
   will be carried in the body of the response: no mapping is proposed
   in this document regarding the potential association between CCMP and
   HTTP error codes.  For the sake of adhering to the principle of
   separation of concerns, HTTP maintains its own semantics, while
   delegating to the CCMP response message (which is in the body of the
   HTTP response) the task of informing the CCMP client about error
   conditions.  This means that, in case of a CCMP error, the client
   receives a 200 OK in the HTTP response, but a CCMP-specific response
   code in the body of such response.

   All response codes are application-level, and MUST only be provided
   in successfully processed transport-level responses.  For example
   where HTTP is used, CCMP Response messages MUST be accompanied by a
   200 OK HTTP response.

   The set of CCMP Response codes currently contain the following
   tokens:

   success:  This code indicates that the request was successfully
      processed.
   modified:  This code indicates that the object was created, but may
      differ from the request.
   badRequest:  This code indicates that the request was badly formed in
      some fashion.
   unauthorized:  This code indicates that the user was not authorized
      for the specific operation on the conference object.
   forbidden:  This code indicates that the specific operation is not
      valid for the target conference object.
   objectNotFound:  This code indicates that the specific conference
      object was not found.
   operationNotAllowed:  This code indicates that the specific operation
      is not allowed for the target conference object (e.g.., when
      trying to make a "confRequest" operation with a request type equal
      to "delete" on a conference object representing a blueprint, etc.)
   deleteFailedParent:  This code indicates that the conferencing system
      cannot delete the specific conference object because it is a
      parent for another conference object.
   changeFailedProtected:  This code indicates that the target
      conference object cannot be changed (e.g., due to policies, roles,
      privileges, etc.).
   requestTimeout:  This code indicates that the request could not be
      processed within a reasonable time, with the time specific to a
      conferencing system implementation.






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   serverInternalError:  This code indicates that the conferencing
      system experienced some sort of internal error.
   notImplemented:  This code indicates that the specific operation is
      not implemented on that conferencing system.

   CCMP Response codes are defined to allow for extensibility.  A
   conference control client SHOULD treat unrecognized response codes as
   it handles a Response code of "notImplemented".

8.3.1.  blueprintsResponse

   A "blueprintsResponse" message containing a response code of
   "success" MUST include the XML namespaces that the server understands
   and the namespaces to be used in subsequent responses that it
   requires the client to understand.  Future work may add more global
   capabilities rather than conferencing system specific.  Within the
   conferencing system, the namespaces correlate with blueprints, as
   specified in the XCON framework.  The blueprints are comprised of
   conference information initialized to specific values and ranges.

   Upon receipt of a successful "blueprintsResponse" message, a
   conference control client may then initiate a "blueprintRequest" with
   a "retrieve" operation per Section 7.1 to get a specific conference
   blueprint.

   In the case of a response code of "requestTimeout", a conference
   control client MAY re-attempt the request within a period of time
   that would be specific to a conference control client or conference
   control server.

   The response codes of "modified", "deleteParentFailed" and
   "changeFailedProtected" are not applicable to a "blueprintsRequest"
   and should be treated as "serverInternalError", the handling of which
   is specific to the conference control client.

   A "blueprintsResponse" message containing any other response code is
   an error and the handling is specific to the conference control
   client.  Typically, an error for a "blueprintsRequest" indicates a
   configuration problem in the conference control server or in the
   client.

8.3.2.  confsResponse

   A "confsResponse" message containing a response code of "success"
   MUST include the list of XCON-URIs associated with reserved/active
   conferences at the server.

   Upon receipt of a successful "confsResponse" message, a conference



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   control client may then initiate a "confRequest" with a "retrieve"
   operation per Section 7.1 to get a specific conference object.

   In the case of a response code of "requestTimeout", a conference
   control client MAY re-attempt the request within a period of time
   that would be specific to a conference control client or conference
   control server.

   The response codes of "modified", "deleteParentFailed" and
   "changeFailedProtected" are not applicable to a "confsRequest" and
   should be treated as "serverInternalError", the handling of which is
   specific to the conference control client.

   A "confsResponse" message containing any other response code is an
   error and the handling is specific to the conference control client.
   Typically, an error for a "blueprintsRequest" indicates a
   configuration problem in the conference control server or in the
   client.

8.3.3.  Operation Responses

   The following sections detail the operation specific handling of the
   response codes, including details associated with specific types of
   responses in the cases where the response handling is not generic.

8.3.3.1.  Retrieve Operation Responses

   A confResponse for a "retrieve" operation containing a response code
   of "success" MUST contain the full XML document describing the
   conference object in its current state including all inherited
   values.  Elements may be marked by attributes, in particular, whether
   they are specific to this instance or have been inherited from the
   parent node.

   A blueprintResponse for a "retrieve" operation containing a response
   code of "success" MUST contain the full XML document describing the
   conference object associated with the requested blueprint

   Any other CCMP response message (e.g., userResponse, usersResponse,
   etc.) for a "retrieve" operation containing a response code of
   "success" MUST contain the XML document describing the specific
   target parameter (as indicated by the specific type of Request) from
   the conference object.

   If a response code of "objectNotFound" is received in a
   "blueprintResponse" message to a "blueprintRequest" to get the
   initial blueprint, it is RECOMMENDED that a conference control client
   attempt to retrieve another conference blueprint if more than one had



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   been received in the "blueprintsResponse" message.  If there was only
   one blueprint in the "blueprintsResponse" initially, then the client
   should send another "blueprintsRequest" message to determine if there
   may be new or additional blueprints for the specific conferencing
   system.  If this "blueprintsResponse" message contains no blueprints,
   the handling is specific to the conference control client.  This
   might indicate, for example, that something is going wrong at the
   server, since no more blueprints are now available at it.  In such
   case, the client MAY interpret the new answer as a
   'serverInternalError' and assume that no more service associated with
   blueprints (e.g. creation of a new conference starting from a server-
   side template) is available.

   If a response code of "requestTimeout" is received in the CCMP
   response, a conference control client MAY re-attempt the request
   within a period of time that would be specific to a conference
   control client or conference control server.

   Response codes such as "notImplemented" and "forbidden" indicate that
   a subsequent "retrieve" would not likely be sucessful.  Handling of
   these and other response codes is specific to the conference control
   client.  For example, in the case of some clients a
   "blueprintsRequest" operation might be performed again or another
   conference control server may be accessed.

   The response codes of "modified", "deleteParentFailed" and
   "changeFailedProtected" are not applicable to the "retrieve"
   operation and SHOULD be treated as "serverInternalError", the
   handling of which is specific to the conference control client.

8.3.3.2.  Create Operation Responses

   The only valid responses containing a "create" operation are a
   "confResponse", a "blueprintResponse" and the "userResponse".  The
   "blueprintRequest" containing a "create" operation has to be
   considered a special operation, used by a conference server
   administrator wishing to remotely add a new blueprint to the
   conference server.  The operation requires that the new blueprint is
   associated with an XCON-URI.  Such URI is provided by the
   administrator in the request, but has to be considered as a
   suggestion.  The conference server MAY change such identifier and
   create a new one.  The new identifier MUST be returned to the client
   as part of the "blueprintResponse" message.  If the CCMP response
   contains a response code of "success", a "confResponse" message MUST
   contain the XCON-URI for the conference object and a "userResponse"
   message MUST contain the XCON-USERID.

   If the confResponse to a "create" operation contains a response code



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   of "modified", along with the XCON-URI for the conference object, the
   response MUST also contain the entire XML document associated with
   that conference object for a "confRequest".  For example, in the case
   where the conference object contained a calendar element, the
   conference server may only offer a subset of the dates requested,
   thus the updated dates are included in the returned XML document.

   In the case of a response code of "requestTimeout", a conference
   control client MAY re-attempt the request within a period of time
   that would be specific to a conference control client or conference
   control server.

   Response codes such as "unauthorized", "forbidden" and
   "operationNotAllowed" indicate the client does not have the
   appropriate permissions, there is an error in the permissions, or
   there is a system error in the client or conference control server,
   thus re-attempting the request would likely not succeed.

   The response codes of "deleteParentFailed" and
   "changeFailedProtected" are not applicable to the "create" operation
   and SHOULD be treated as "serverInternalError", the handling of which
   is specific to the conference control client.

   Any other response code indicates an error in the client or
   conference control server (e.g., "forbidden", "badRequest") and the
   handling is specific to the conference control client.

8.3.3.3.  Change Operation Responses

   If the CCMP response to the "change" operation contains a response
   code of "success", the response SHOULD also contain the XCON-URI for
   the conference object that was changed.

   The "blueprintRequest" containing a "change" operation has to be
   considered a special operation, used by a conference server
   administrator wishing to remotely an existing blueprint in the
   conference server.

   If the CCMP response to the "change" operation contains a response
   code of "modified", the response MUST contain the XCON-URI for the
   conference object and the appropriate XML document (either the full
   XML document for a confResponse or specific paramaters for the other
   CCMP request types) associated with that conference object.  For
   example, a conferencing system may not have the resources to support
   specific capabilities that were changed, such as <codecs> in the
   <available-media>, thus the <codecs> supported are included in the
   returned XML document.




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   If the CCMP response code of "requestTimeout" is received, a
   conference control client MAY re-attempt the request within a period
   of time that would be specific to a conference control client or
   conference control server.

   Response codes such as "unauthorized", "forbidden",
   "operationNotAllowed" and "changeFailedProtected" indicate the client
   does not have the appropriate permissions, the conference is locked,
   there is an error in the permissions, or there is a system error in
   the client or conference control server, thus re-attempting the
   request would likely not succeed.

   The response code of "deleteParentFailed" is not applicable to the
   "change" operation and SHOULD be treated as "serverInternalError",
   the handling of which is specific to the conference control client.

   Any other response code indicates an error in the client or
   conference control server (e.g., "forbidden", "badRequest") and the
   handling is specific to the conference control client.

   [Note by spromano: In case of "change" with a userRequest, the server
   first has to change the user's information stored; then, it has to
   update all conference objects which include that user.  The
   association between the user and the conferences in which she/he is
   participating is guaranteed through the "entity" attribute of the
   <user> element.  IMO, after doing all that, the server just answers
   with a userResponse message; then, if it is also using notifications,
   it might raise events towards the interested subscribers, to notify
   them about the changes in the updated conference objects.  Is this
   right??]

8.3.3.4.  Delete Operation Responses

   If the CCMP response to the "delete" operation contains a response
   code of "success", the response MUST contain the XCON-URI for the
   conference object that was deleted for a "confResponse" or whose data
   element(s) were deleted for the other response types.

   The "blueprintRequest" containing a "delete" operation has to be
   considered a special operation, used by a conference server
   administrator wishing to remotely remove a blueprint from the
   conference server.

   The response code of "deleteParentFailed" indicates that the
   conference object could not be deleted because it is the Parent of
   another conference object that is in use.  In this case, the response
   also includes the XCON-URI for the conference object and is only
   applicable to a "confResponse".  If this response code is received



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   for any other type of CCMP response, it should be treated as
   "serverInternalError", the handling of which is specific to the
   conference control client.

   If a response code of "requestTimeout" is received, a conference
   control client MAY re-attempt the request within a period of time
   that would be specific to a conference control client or conference
   control server.

   Response codes such as "unauthorized", "forbidden" and
   "operationNotAllowed" indicate the client does not have the
   appropriate permissions, the conference is locked, the object that
   the client is trying to delete is actually a blueprint, there is an
   error in the permissions, or there is a system error in the client or
   conference control server, thus re-attempting the request would
   likely not succeed.

   The response code of "changeFailedProtected" is not applicable to the
   "delete" operation and SHOULD be treated as "serverInternalError",
   the handling of which is specific to the conference control client.

   Any other response code indicates an error in the client or
   conference control server (e.g., "forbidden", "badRequest") and the
   handling is specific to the conference control client.

   [Note by spromano (same comment as for "change"): In case of "delete"
   with a userRequest, the server first has to delete the user's
   information stored; then, it has to update all conference objects
   which include that user.  The association between the user and the
   conferences in which she/he is participating is guaranteed through
   the "entity" attribute of the <user> element.  IMO, after doing all
   that, the server just answers with a userResponse message; then, if
   it is also using notifications, it might raise events towards the
   interested subscribers, to notify them about the changes in the
   updated conference objects.  Is this right??]


9.  Managing sidebars

   Sidebars can be either "by reference" or "by value".  The management
   of sidebars differs in the two cases, as discussed below

9.1.  Sidebars by value

   Sidebars by value represent an inner part of the conference object
   associated with the root conference from which they stem.  One or
   more sidebars by value are then created by using the "confRequest"
   message with an operation of "change".  The conference description



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   provided in the request MUST contain the desired sidebars
   information, in the form of a sequence of one or more <entry>
   elements under the <sidebars-by-val> element.  Information about a
   sidebar by value can be accessed directly through a "sidebarRequest"
   message containing the identifier of the required sidebar (i.e. its
   "entity" attribute value).

9.2.  Sidebars by reference

   Sidebars by reference represent semi-independent conference objects,
   i.e. objects that exist on their own, but which are strictly coupled
   to the conference object from which they stem.  A sidebar by
   reference is then created by using the "confRequest" message with an
   operation of "create".

   Editor's Note: should we have a means to indicate that the object we
   are creating is actually a sidebar?  This would go in the
   confRequest/create message.  Otherwise, we might add a
   sidebarRequest/create operation which basically does a conference
   creation, but, e.g., stores it in a different repository (/sidebars
   rather than /confs).

   Once the sidebar has been created, you can add it to a conference by
   issuing a "confRequest" message with a "change" operation on the
   conference object which the sidebar belongs to.  Information about a
   sidebar by reference can be accessed directly through a
   "sidebarRequest" message containing the identifier of the required
   sidebar (i.e. the value of its <uri> element).


10.  Protocol Parameters

   This section describes in detail the parameters that are used for the
   CCMP protocol.

10.1.  Operation Parameter

   The "operation" attribute is a mandatory token included in all CCMP
   request and response messages.  This document defines four possible
   values for this parameter: "retrieve", "create", "change" and
   "delete".

10.2.  ConfObjID Parameter

   The "confObjID" attribute is an optional URI included in the CCMP
   request and response messages.  This attribute is required in the
   case of an "operation" of "retrieve", "change", and "delete" in the
   CCMP request and response messages.  The attribute is optional for an



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   "operation" of "create" in the "confRequest" message.  The "create"
   cases for which this parameter is REQUIRED are described in
   Section 7.2.  This attribute is the XCON-URI which is the target for
   the specific operation.  [Editor's Note: it might be good to re-
   iterate the normative text here.]

   This attribute is not included in the "userRequest" message for an
   operation of "create".  In this case, the conference control client
   is requesting the creation of a new conference user, as detailed in
   Section 10.3.

   In the cases where the "conference-info" parameter Section 10.6 is
   also included in the requests and responses, the "confObjID" MUST
   match the XCON-URI in the "entity" attribute.

10.3.  ConfUserID Parameter

   The "confUserID" attribute is optional URI included in the CCMP
   request and response messages.  This is the XCON-USERID for the
   conference control client initiating the request.  The attribute is
   required in the CCMP request and response messages with the exception
   of the "userRequest" message.  The "confUserID" parameter is used to
   determine if the conference control client has the authority to
   perform the operation.  Note that the details for authorization and
   related policy are specified in a separate document [TBD].

   This attribute is optional only for an "userRequest" message with a
   "create" operation.  In this case, the request MUST include
   information about the user in the "user" element.  At a minimum, the
   request MUST include the "user" element with an "entity" attribute.
   For this case, the conference control server MUST create a new
   conference user and return the associated confUserID in the response,
   if the allocation of a new XCON-USERID is succesful.

   In the case where there is a confUserID in the request that has
   already been allocated, this request may be the creation of a
   confUserID for the conference control client to take on an additional
   role.

   This attribute is required in the "userResponse" message in the case
   of an "operation" of "create" and for all other responses.

10.4.  ResponseCode Parameter

   The "responseCode" attribute is a mandatory parameter in all CCMP
   response messages.  The values for each of the "responseCode" values
   are detailed in Section 8.3 with the associated processing described
   in Section 8.3.3.



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10.5.  Blueprints Parameter

   The "blueprints" attribute is an optional parameter in the CCMP
   blueprintsResponse message.  In the case of a "blueprintsRequest"
   message, the "blueprintsResponse" message with a "responseCode" of
   "success" SHOULD include the "blueprints" supported by the conference
   control server.  The "blueprints" attribute is comprised of a list of
   blueprints supported by the specific conference server and includes a
   conference system specific "blueprintName" and a "confObjID" in the
   form of an XCON-URI for each of the blueprints.

10.6.  Conference-info Parameter

   The "conference-info" element is optional in the CCMP confRequest and
   confResponse messages.

   The "conference-info" element contains the data for the conference
   object that is the target for the "confRequest" operations for
   "create", "change" and "delete" operations.  It is returned in a
   "confResponse" if the "confResponse" contains a responseCode of
   "modified" or if the original CCMP request for the "create" operation
   did not contain a "conference-info" element.  The latter case occurs
   when a conference control client sends a "confRequest" containing any
   of the following: - a "confObjID" associated with a specific
   blueprint - a "confObjID associated with a specific active conference
   or conference reservation that was included in a "confsResponse"
   message - no "confObjID" (or "conference-info") element, in which
   case the request is to create a conference object based on a default
   provided by a conferencing system.

   The "conference-info" element is also returned in a "userResponse"
   message, in the case of a "change" operation.  In such case, in fact,
   the request contains the <user> element to be added to the conference
   indicated in the <confObjID> parameter; the associated answer SHOULD
   carry the updated conference object in its body.

   The details on the information that may be included in the
   "conference-info" element MUST follow the rules as specified in the
   XCON Data Model document [I-D.ietf-xcon-common-data-model].  The
   conference control client and conference control server MUST follow
   those rules in generating the "conference-info" in any of the CCMP
   request and response messages.

   Note that the "conference-info" element is not explicitly shown in
   the XML schema (Section 12) due to XML schema constraints.






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10.7.  User Parameter

   The "user" element contains the data for the conference user that is
   the target for the CCMP request operations.  It is REQUIRED for all
   "userRequest" messages.

   The details on the information that may be included in the "user"
   element MUST follow the rules as specified in the XCON Data Model
   document [I-D.ietf-xcon-common-data-model].  The conference control
   client and conference control server MUST follow those rules in
   generating the "user" in any of the CCMP request and response
   messages.

   Note that the "user" element is not explicitly shown in the XML
   schema Section 12 due to XML schema constraints.

10.8.  Users Parameter

   The "users" element contains the data for the conference users that
   are the target for the CCMP request operations.  It is REQUIRED for
   all "usersRequest" messages.

   The details on the information that may be included in the "users"
   element MUST follow the rules as specified in the XCON Data Model
   document [I-D.ietf-xcon-common-data-model].  The conference control
   client and conference control server MUST follow those rules in
   generating the "users" in any of the CCMP request and response
   messages.

   Note that the "users" element is not explicitly shown in the XML
   schema Section 12 due to XML schema constraints.

10.9.  Sidebar Parameters

   The "sidebar" parameter contains the data for the sidebar that is the
   target for the CCMP request operations.  It is REQUIRED for all
   "sidebarRequest" messages.  There are two elements associated with a
   sidebar: "sidebar-by-val" and "sidebar-by-ref".  The elements relate
   to whether the data for the sidebar is in the same conference object
   for which it serves as a sidebar or whether a new conference object
   is created for the sidebar.

   The details on the information that may be included in the "sidebar-
   by-val" or "sidebar-by-ref" element MUST follow the rules as
   specified in the XCON Data Model document
   [I-D.ietf-xcon-common-data-model].  The conference control client and
   conference control server MUST follow those rules in generating the
   "sidebar-by-val" or "sidebar-by-ref" element in any of the CCMP



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   request and response messages.


11.  Examples

   Examples on the use of HTTP as the CCP based on a RESTful
   implementation are provided in Section 11.1.  The body of the HTTP
   methods contains the CCMP operations and data.  Examples of the CCMP
   operations and related data are provided in section Section 11.2

11.1.  HTTP methods for realizing a RESTful CCMP

   This section provides a series of examples using the HTTP methods for
   realization of the CCMP.  The examples provide a sequence of
   operations that a typical user might invoke in activating a
   conference, adding users to a conference, retrieving conference data
   and then deleting an active conference.  Note, the examples do not
   include any details beyond the basic operation.  For example, the
   "Host" that would be the result of discovery of the conference server
   per Section 8.1 would be included in the HTTP messages.

   Alice retrieves info about active/scheduled CCMP 'conferences':




    CCMP client "Alice"                               ConfS
         |                                              |
         | GET /confs                                   |
         |--------------------------------------------->|
         |                                              |--+ Prepare
         |                                              |  | formatted
         |                             200 OK (w/ body) |<-+ conf info
         |<---------------------------------------------|    (list of
         |                                              |     conf objs)



               Figure 3: Getting a List of Active Coferences












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   Alice is now able to retrieve info about a specific conference:




   CCMP client "Alice"                               ConfS
   |                                              |
   | GET /confs/confid-34fg67h                    |
   |--------------------------------------------->|
   |                                              |--+ Prepare
   |                                              |  | formatted
   |                             200 OK (w/ body) |<-+ XML info
   |<---------------------------------------------|
   |                                              |



                  Figure 4: Getting a Specific Coference

   Alice decides to add a new user to this conference:




    CCMP client "Alice"                               ConfS
     |                                              |
     | PUT /confs/confid-34fg67h/users/pippo876     |
     | (w/ body=new user info)                      |
     |--------------------------------------------->|
     |                                              |--+ Add new user
     |                                              |  | to data model
     |                             200 OK (w/ body) |<-+ and update
     |<---------------------------------------------|   user in system
     |                                              |
     |                                              | (event triggered
     |                                              |  e.g. RFC4575)
     |                                              |---------------->
     |                                              |



            Figure 5: Adding a New User to an Active Conference









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   Subsequent GETs on both the conference object as a whole and the
   users portion reflect the addition of the New User:





    CCMP client "Alice"                               ConfS
          |                                              |
          | GET /confs/confid-34fg67h/users/pippo876     |
          |--------------------------------------------->|
          |                                              |--+ Prepare
          |                                              |  | formatted
          |                             200 OK (w/ body) |<-+ XML info
          |<---------------------------------------------|
          |                                              |
          | GET /users/pippo876                          |
          |--------------------------------------------->|
          |                                              |--+ Prepare
          |                                              |  | formatted
          |                             200 OK (w/ body) |<-+ XML info
          |<---------------------------------------------|
          |                                              |



       Figure 6: Getting a Specific Conference Object after Changes

   Alice updates some info related to the same user:





    CCMP client "Alice"                               ConfS
         |                                              |
         | POST /confs/confid-34fg67h/users/pippo876    |
         | (w/ body=updated user info)                  |
         |--------------------------------------------->|
         |                                              |--+ Update user
         |                                              |  | in data
         |                             200 OK (w/ body) |<-+ and in
         |<---------------------------------------------|    system
         |                                              |
         |                                              |Event trigger
         |                                              |e.g. RFC4575
         |                                              |------------->
         |                                              |



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                  Figure 7: Updating a User's Information

   Alice destroys the running conference: when trying to access it, the
   server returns an error:





    CCMP client "Alice"                               ConfS
         |                                              |
         | DELETE /confs/confid-34fg67h                 |
         |--------------------------------------------->|
         |                                              |--+ Prepare
         |                                              |  | formatted
         |                             200 OK (w/ body) |<-+ XML info
         |<---------------------------------------------|
         |                                              |
         | GET /confs/confid-34fg67h                    |
         |--------------------------------------------->|
         |                                              |--+ ConfS can't
         |                                              |  | find the
         |                             200 OK (w/body:  |<-+ conference
         |<---------------------------------------------|
         |                 responseCode=objectNotFound  |
         |                                              |



                  Figure 8: Deleting an Active Coference

11.2.  CCMP Detailed Message Body Examples

   The examples below contain simply the <body> of the requests and
   responses.  In the case that HTTP serves as the transport, the HTTP
   methods as identified in Table 1 (and per the examples in
   Section 11.1) would include the CCMP requests and Responses as the
   body of the HTTP methods.

11.2.1.  Creating a New Conference

   The first example creates a new conference.









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          <confRequest xmlns="urn:ietf-params:xml:ns:xcon:ccmp">
          <operation>create</operation>
          <confUserID> userA-confxyz987 </confUserID>

          <conference-info
            xmlns="urn:ietf:params:xml:ns:conference-info"
            version="1">
            <conference-description>
             <parent>http://example.com/conf200</parent>
             <subject>Agenda: This month's goals</subject>
             <conf-uris>
               <entry>
                 <uri>sips:conf223@example.com</uri>
                 <purpose>participation</purpose>
               </entry>
             </conf-uris>
             <service-uris>
               <entry>
                <uri>http://sharep/salesgroup/</uri>
                <purpose>web-page</purpose>
               </entry>
               <entry>
                <uri>http://example.com/conf233</uri>
                <purpose>control</purpose>
               </entry>
              </service-uris>
             </conference-description>
          </conference-info>

        </confRequest>



                     Figure 9: Create Request Example

   The response to this request is shown below; it returns the object
   identifier as a URL and the final conference description, which may
   modify the description offered by the user.













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    <confResponse xmlns="urn:ietf-params:xml:ns:xcon:ccmp"
      <operation>create</operation>
      <responseCode> modified </responseCode>
      <confObjID> xcon:confxyz987@example.com </confObjID>
      <confUserID> userA-confxyz987 </confUserID>

      <conference-info
        xmlns="urn:ietf:params:xml:ns:conference-info"
        version="1">
        <entity> xcon:confxyz987@example.com </entity>
        <conference-description>
         <parent>http://example.com/conf200</parent>
         <subject>Agenda: This month's goals</subject>
         <conf-uris>
           <entry>
             <uri>sips:conf223@example.com</uri>
             <purpose>participation</purpose>
           </entry>
         </conf-uris>
         <service-uris>
           <entry>
            <uri>http://sharep/salesgroup/</uri>
            <purpose>web-page</purpose>
           </entry>
           <entry>
            <uri>http://example.com/conf233</uri>
            <purpose>control</purpose>
           </entry>
          </service-uris>

      <!-- Addt'l modified conference description including users alice,
           bob and userA... -->

          <allowed-users-list>
           <target uri="sip:alice@example.com" method="dial-out"/>
           <target uri="sip:bob@example.com" method="dial-out"/>
           <target uri="sip:userA@example.com" method="dial-in"/>
          </allowed-users-list>

         </conference-description>
      </conference-info>

      </confResponse>



                    Figure 10: Create Response Example




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11.2.2.  Creating a New Conference User

   The request below creates a new conference user, independent of a
   specific conference object.



       <userRequest xmlns="urn:ietf-params:xml:ns:xcon:ccmp">
          <operation>create</operation>

          <user entity="sip:bob@example.com">
               <role>observer</role>
          </user>

       </userRequest>



                      Figure 11: Create User Example

   The response to this request is shown below; it returns the
   conference user identifier.


      <userResponse xmlns="urn:ietf-params:xml:ns:xcon:ccmp">
        <operation>create</operation>
        <responseCode> success </responseCode>
        <confUserID>userC-confxyz987</confUserID>
      </userResponse>




                    Figure 12: Create Response Example

11.2.3.  Adding a User to a Conference

   The request below adds a user to the conference identified by the
   XCON-URI.  Note that the user in "confUserID" element is the user
   requesting that the user "sip:claire@example.com" be added to the
   conference.  The user may or may not be "claire" (i.e., a user, such
   as the moderator, can add another user to the conference.

   Editor's note: Do we need to consider users adding users OBO of other
   users or in that case do we just change the conference object as a
   whole?





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      <userRequest xmlns="urn:ietf-params:xml:ns:xcon:ccmp">
          <operation>change</operation>
          <confObjID> xcon:confxyz987@example.com </confObjID>
          <confUserID> userC-confxyz987 </confUserID>

          <user entity="sip:claire@example.com">
            <role>participant</role>
            <type>dial-out</type>
          </user>

       </userRequest>


                        Figure 13: Add User Example

   The response to this request is shown below.


      <userResponse xmlns="urn:ietf-params:xml:ns:xcon:ccmp">
        <operation>change</operation>
        <responseCode> success </responseCode>
        <confObjID> xcon:confxyz987@example.com </confObjID>
        <confUserID> userC-confxyz987 </confUserID>

                           <user entity="sip:claire@example.com">
                   <role>participant</role>
                   <type><dial-out/></type>
              </user>
            </users>
          </conference-info>

      </userResponse>




                   Figure 14: Add User Response Example


12.  XML Schema

   This section provides the XML schema definition of the "application/
   ccmp+xml" format.

   Editor's Note: the schema currently matches the prototype - it needs
   updating to include changes/additions to request names (e.g.,
   optionsRequest -> blueprintsRequest, addition of blueprintRequest and
   confsRequest.



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   <?xml version="1.0" encoding="utf-8"?>
      <xs:schema
          targetNamespace="urn:ietf:params:xml:ns:xcon:ccmp"
          xmlns="urn:ietf:params:xml:ns:xcon:ccmp"
          xmlns:tns="urn:ietf:params:xml:ns:xcon:ccmp"
          xmlns:dm="urn:ietf:params:xml:ns:xcon-conference-info"
          xmlns:xs="http://www.w3.org/2001/XMLSchema">

          <!-- Import data model schema (as per the latest draft) -->
          <xs:import
              namespace="urn:ietf:params:xml:ns:xcon-conference-info"
              schemaLocation="DataModel-11.xsd"/>

          <xs:element name="ccmpRequest"
                      type="ccmp-request-type" />
          <xs:element name="ccmpResponse"
                      type="ccmp-response-type" />

           <!-- CCMP request definition -->

   <xs:complexType name="ccmp-request-type">
            <xs:sequence>
                   <xs:element name="ccmpRequest"
           type="ccmp-request-message-type" />
       </xs:sequence>
             <xs:attribute name="xconURI" type="xs:string"
                                   use="optional" />
   </xs:complexType>

           <!-- CCMP response definition -->

   <xs:complexType name="ccmp-response-type">
            <xs:sequence>
                   <xs:element name="ccmpResponse"
           type="ccmp-response-message-type" />
            </xs:sequence>
            <xs:attribute name="xconURI" type="xs:string"
                                   use="optional" />
            </xs:complexType>

           <!-- Definition of ccmp-request-message-type as an
                        abstract complex type -->

      <xs:complexType abstract="true"
          name="ccmp-request-message-type">
        <xs:sequence>
         <xs:element name="confObjID" type="xs:string"
                                       minOccurs="0" maxOccurs="1" />



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         <xs:element name="confUserID" type="xs:string"
                                       minOccurs="0" maxOccurs="1" />
        </xs:sequence>
       </xs:complexType>

           <!-- blueprintsRequest -->

      <xs:complexType
               name="ccmp-blueprints-request-message-type">
       <xs:complexContent>
         <xs:extension base="tns:ccmp-request-message-type"/>
       </xs:complexContent>
      </xs:complexType>

                   <!-- confsRequest -->

      <xs:complexType name="ccmp-confs-request-message-type">
        <xs:complexContent>
         <xs:extension base="tns:ccmp-request-message-type"/>
        </xs:complexContent>
      </xs:complexType>

      <!-- confRequest -->

      <xs:complexType name="ccmp-conf-request-message-type">
        <xs:complexContent>
         <xs:extension base="tns:ccmp-request-message-type">
          <xs:sequence>
            <xs:element ref="confRequest" />
          </xs:sequence>
         </xs:extension>
        </xs:complexContent>
      </xs:complexType>

     <!-- usersRequest -->

      <xs:complexType name="ccmp-users-request-message-type">
        <xs:complexContent>
         <xs:extension base="tns:ccmp-request-message-type">
          <xs:sequence>
           <xs:element ref="usersRequest" />
          </xs:sequence>
         </xs:extension>
        </xs:complexContent>
      </xs:complexType>

    <!-- userRequest -->




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      <xs:complexType name="ccmp-user-request-message-type">
        <xs:complexContent>
         <xs:extension base="tns:ccmp-request-message-type">
          <xs:sequence>
           <xs:element ref="userRequest" />
          </xs:sequence>
         </xs:extension>
        </xs:complexContent>
       </xs:complexType>

      <!-- [TODO: sidebarRequest -->

    <!--  Definition of ccmp-response-message-type -->

       <xs:complexType abstract="true"
                   name="ccmp-response-message-type">
         <xs:sequence>
          <xs:element name="confObjID" type="xs:string"
                                   minOccurs="0" maxOccurs="1" />
          <xs:element name="confUserID" type="xs:string"
                                   minOccurs="0" maxOccurs="1" />
          <xs:element ref="response-code" minOccurs="1"
                                   maxOccurs="1" />
                   </xs:sequence>
        </xs:complexType>

     <!-- blueprintsResponse -->

       <xs:complexType name="ccmp-blueprints-response-message-type">
         <xs:complexContent>
          <xs:extension base="tns:ccmp-response-message-type">
           <xs:sequence>
                   <xs:element ref="blueprintsResponse" />
           </xs:sequence>
          </xs:extension>
         </xs:complexContent>
        </xs:complexType>

     <!-- confsResponse -->

       <xs:complexType name="ccmp-confs-response-message-type">
        <xs:complexContent>
         <xs:extension base="tns:ccmp-response-message-type">
          <xs:sequence>
           <xs:element ref="confsResponse" />
          </xs:sequence>
         </xs:extension>
        </xs:complexContent>



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       </xs:complexType>

      <!-- confResponse -->

       <xs:complexType name="ccmp-conf-response-message-type">
        <xs:complexContent>
         <xs:extension base="tns:ccmp-response-message-type">
          <xs:sequence>
           <xs:element ref="confResponse" />
          </xs:sequence>
         </xs:extension>
        </xs:complexContent>
       </xs:complexType>

       <!-- usersResponse -->

        <xs:complexType name="ccmp-users-response-message-type">
         <xs:complexContent>
          <xs:extension base="tns:ccmp-response-message-type">
           <xs:sequence>
            <xs:element ref="usersResponse" />
           </xs:sequence>
          </xs:extension>
         </xs:complexContent>
        </xs:complexType>

      <!-- userResponse -->

      <xs:complexType name="ccmp-user-response-message-type">
       <xs:complexContent>
         <xs:extension base="tns:ccmp-response-message-type">
          <xs:sequence>
           <xs:element ref="userResponse" />
          </xs:sequence>
         </xs:extension>
        </xs:complexContent>
           </xs:complexType>

      <!-- [TODO: sidebarResponse -->


      <!-- response-code -->

       <xs:element name="response-code" type="response-codeType" />

       <xs:simpleType name="response-codeType">
         <xs:restriction base="xs:token">
               <xs:enumeration value="success"/>



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               <xs:enumeration value="pending"/>
               <xs:enumeration value="modified"/>
               <xs:enumeration value="badRequest"/>
               <xs:enumeration value="unauthorized"/>
               <xs:enumeration value="forbidden"/>
               <xs:enumeration value="objectNotFound"/>
               <xs:enumeration value="operationNotAllowed"/>
               <xs:enumeration value="deleteFailedParent"/>
               <xs:enumeration value="modifyFailedProtected"/>
               <xs:enumeration value="requestTimeout"/>
               <xs:enumeration value="serverInternalError"/>
               <xs:enumeration value="notImplemented"/>
             </xs:restriction>
           </xs:simpleType>

     <!-- blueprintsResponse -->

      <xs:element name="blueprintsResponse"
                  type="blueprintsResponseType" />

           <xs:complexType name="blueprintsResponseType">
             <xs:sequence>
                <xs:element ref="namespace"
                                 minOccurs="1"
                                 maxOccurs="unbounded" />
             </xs:sequence>
           </xs:complexType>

           <xs:element name="namespace">
                   <xs:simpleType>
                           <xs:restriction base="xs:string" />
                   </xs:simpleType>
           </xs:element>


          <!-- confsResponse -->

          <xs:element name="confsResponse"
                      type="confsResponseType" />

           <xs:complexType name="confsResponseType">
             <xs:sequence>
                <xs:element ref="namespace"
                            minOccurs="1"
                            maxOccurs="unbounded" />
             </xs:sequence>
           </xs:complexType>




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           <!-- confRequest -->

           <xs:element name="confRequest"
                       type="confRequestType" />

             <xs:complexType name="confRequestType">
             <xs:sequence>
                <xs:element name="operation"
                            type="operationType"
                            minOccurs="1"
                            maxOccurs="1" />
                <xs:element name="confInfo"
                            type="dm:conference-info"
                            minOccurs="0"/>
             </xs:sequence>
           </xs:complexType>

          <!-- confResponse -->

           <xs:element name="confResponse" type="confResponseType" />

             <xs:complexType name="confResponseType">
             <xs:sequence>
               <xs:element name="operation"
                           type="operationType"
                           minOccurs="1"
                           maxOccurs="1" />
               <xs:element name="confInfo"
                           type="dm:conference-info"
                           minOccurs="0"/>
             </xs:sequence>
           </xs:complexType>

           <!-- userRequest -->

           <xs:element name="userRequest" type="userRequestType" />

             <xs:complexType name="userRequestType">
             <xs:sequence>
                <xs:element name="operation"
                            type="operationType"
                            minOccurs="1"
                            maxOccurs="1" />
                <xs:element name="userInfo"
                            type="dm:user"
                            minOccurs="0"/>
             </xs:sequence>
           </xs:complexType>



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          <!-- userResponse -->

           <xs:element name="userResponse"
                       type="userResponseType" />

             <xs:complexType name="userResponseType">
             <xs:sequence>
               <xs:element name="operation"
                           type="operationType"
                           minOccurs="1"
                           axOccurs="1" />
               <xs:element name="userInfo"
                           type="dm:conference-info"
                           minOccurs="0"/>
             </xs:sequence>
           </xs:complexType>

      <!-- usersRequest -->

           <xs:element name="usersRequest"
                       type="usersRequestType" />

            <xs:complexType name="usersRequestType">
             <xs:sequence>
                <xs:element name="operation"
                            type="operationType"
                            minOccurs="1"
                            maxOccurs="1" />
                <xs:element name="usersInfo"
                            type="dm:users"
                            minOccurs="0"/>
             </xs:sequence>
           </xs:complexType>

          <!-- confResponse -->

           <xs:element name="usersResponse"
                       type="usersResponseType" />

             <xs:complexType name="usersResponseType">
             <xs:sequence>
               <xs:element name="operation"
                           type="operationType"
                           minOccurs="1"
                           maxOccurs="1" />
               <xs:element name="usersInfo"
                           type="dm:users"
                           minOccurs="0"/>



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             </xs:sequence>
           </xs:complexType>

            <!-- operationType -->

           <xs:simpleType name="operationType">
             <xs:restriction base="xs:token">
               <xs:enumeration value="retrieve"/>
               <xs:enumeration value="create"/>
               <xs:enumeration value="change"/>
               <xs:enumeration value="delete"/>
             </xs:restriction>
           </xs:simpleType>
     </xs:schema>


                                 Figure 15


13.  Managing notifications

   This section is still "Under Construction" and currently contains
   some views on handling notifications.

   One proposal is to stick with SIP notification.  Another alternative,
   which is commonly done in other web-based systems, is a "call back",
   i.e., the CCMP client provides the conference server with an HTTP URL
   which is invoked when a change occurs.  This is apparently how most
   credit card shopping cards work, having implemented one.  This works
   well for our scenario since a CCMP "client" is likely to be a web
   server that provides the graphical HTML user interface and uses CCMP
   as the backend to talk to the conference server.  In that particular
   case, there doesn't seem to be a problem of having both models.  PC-
   based clients behind NATs would provide a SIP event URI, web servers
   would probably find the HTTP model much easier to program with.

   Another option being considered is BOSH
   (http://xmpp.org/extensions/xep-0124.html), which is basically an
   extension to XMPP designed with the following aim: "...a transport
   protocol that emulates a bidirectional stream between two entities
   (such as a client and a server) by efficiently using multiple
   synchronous HTTP request/response pairs without requiring the use of
   polling or asynchronous chunking."

   A final consideration (under discussion only) is basic XMPP.






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14.  Role based access control

   Editors' Note: this section is also under construction.  This topic
   is planned to be described in a separate document that will be
   reference here.  XACML is the current proposed direction for which
   the authors would like feedback.


15.  IANA Considerations

   This document registers a new XML namespace, a new XML schema, and
   the MIME type for the schema.  This document also registers the
   "XCON" Application Service tag and the "CCMP" Application Protocol
   tag.  This document also defines registries for the CCMP operation
   types and response codes.

15.1.  URN Sub-Namespace Registration

   This section registers a new XML namespace,
   ""urn:ietf:params:xml:ns:xcon:ccmp"".

      URI: "urn:ietf:params:xml:ns:xcon:ccmp"
      Registrant Contact: IETF, XCON working group, (xcon@ietf.org),
      Mary Barnes (mary.barnes@nortel.com).
      XML:


         BEGIN
           <?xml version="1.0"?>
           <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
             "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
           <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
             <head>
               <title>CCMP Messages</title>
             </head>
             <body>
               <h1>Namespace for CCMP Messages</h1>
               <h2>urn:ietf:params:xml:ns:xcon:ccmp</h2>
   [[NOTE TO IANA/RFC-EDITOR: Please update RFC URL and replace XXXX
       with the RFC number for this specification.]]
               <p>See <a href="[[RFC URL]]">RFCXXXX</a>.</p>
             </body>
           </html>
         END







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15.2.  XML Schema Registration

   This section registers an XML schema as per the guidelines in
   [RFC3688].

   URI:  urn:ietf:params:xml:schema:xcon:ccmp
   Registrant Contact:  IETF, XCON working group, (xcon@ietf.org), Mary
      Barnes (mary.barnes@nortel.com).
   Schema:  The XML for this schema can be found as the entirety of
      Section 12 of this document.

15.3.  MIME Media Type Registration for 'application/ccmp+xml'

   This section registers the "application/ccmp+xml" MIME type.

   To:  ietf-types@iana.org
   Subject:  Registration of MIME media type application/ccmp+xml
   MIME media type name:  application
   MIME subtype name:  ccmp+xml
   Required parameters:  (none)
   Optional parameters:  charset
      Indicates the character encoding of enclosed XML.  Default is
      UTF-8.
   Encoding considerations:  Uses XML, which can employ 8-bit
      characters, depending on the character encoding used.  See RFC
      3023 [RFC3023], section 3.2.
   Security considerations:  This content type is designed to carry
      protocol data related conference control.  Some of the data could
      be considered private and thus should be protected.
   Interoperability considerations:  This content type provides a basis
      for a protocol
   Published specification:  RFC XXXX [[NOTE TO IANA/RFC-EDITOR: Please
      replace XXXX with the RFC number for this specification.]]
   Applications which use this media type:  Centralized Conferencing
      control clients and servers.
   Additional Information:  Magic Number(s): (none)
      File extension(s): .xml
      Macintosh File Type Code(s): (none)
   Person & email address to contact for further information:  Mary
      Barnes <mary.barnes@nortel.com>
   Intended usage:  LIMITED USE
   Author/Change controller:  The IETF
   Other information:  This media type is a specialization of
      application/xml [RFC3023], and many of the considerations
      described there also apply to application/ccmp+xml.






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15.4.  DNS Registrations

   Section 15.4.1 defines an Application Service tag of "XCON", which is
   used to identify the centralized conferencing (XCON) server for a
   particular domain.  The Application Protocol tag "CCMP", defined in
   Section 15.4.2, is used to identify an XCON server that understands
   the CCMP protocol.

15.4.1.  Registration  of a Location Server Application Service Tag

   This section registers a new S-NAPTR/U-NAPTR Application Service tag
   for XCON, as mandated by [RFC3958].

   Application Service Tag: XCON

   Intended usage: Identifies a server that supports centralized
   conferencing.

   Defining publication: RFCXXXX

   Contact information: The authors of this document

   Author/Change controller: The IESG

15.4.2.  Registration of a Location Server Application Protocol Tag for
         HELD

   This section registers a new S-NAPTR/U-NAPTR Application Protocol tag
   for the CCMP protocol, as mandated by [RFC3958].

   Application Service Tag: CCMP

   Intended Usage: Identifies the Centralized Conferencing (XCON)
   Manipulation Protocol.

   Applicable Service Tag(s): XCON

   Terminal NAPTR Record Type(s): U

   Defining Publication: RFCXXXX

   Contact Information: The authors of this document

   Author/Change Controller: The IESG







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15.5.  CCMP Protocol Registry

   This document requests that the IANA create a new registry for the
   CCMP protocol including an initial registry for operation types and
   response codes.

15.5.1.  CCMP Message Types

   The CCMP messages are described in Section 8 and defined in the XML
   schema in Section 12.  The following summarizes the requested
   registry:

   Related Registry:   CCMP Message Types Registry
   Defining RFC:  RFC XXXX [NOTE TO IANA/RFC-EDITOR: Please replace XXXX
      with the RFC number for this specification.]
   Registration/Assignment Procedures:  New CCMP message types are
      allocated on a specification required basis.
   Registrant Contact:  IETF, XCON working group, (xcon@ietf.org), Mary
      Barnes (mary.barnes@nortel.com).

   This section pre-registers the following initial CCMP message types:

   blueprintsRequest:  Used by a conference control client to query a
      conferencing system for its capabilities, in terms of available
      conference blueprints.
   blueprintsResponse:  The optionsResponse returns a list of Blueprints
      supported by the specific conference server.
   confsRequest:  Used by a conference control client to query a
      conferencing system for its scheduled/active conferences.
   confsResponse:  The confsResponse returns the list of the currently
      activated/scheduled conferences at the server.
   confRequest:  The confRequest is used to create a conference object
      and/or to request an operation on the conference object as a
      whole.
   confResponse:  The confResponse indicates the result of the operation
      on the conference object as a whole.
   userRequest:  The userRequest is used to request an operation on the
      "user" element in the conference object.
   userResponse:  The userResponse indicates the result of the requested
      operation on the "user" element in the conference object.
   usersRequest  This usersRequest is used to manipulate the "users"
      element in the conference object, including parameters such as the
      allowed-users-list, join-handling, etc.
   usersResponse:  This usersResponse indicates the result of the
      request to manipulate the "users" element in the conference
      object.





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   sidebarRequest:  This sidebarRequest is used to retrieve the
      information related to a sidebar or to create, change or delete a
      specific sidebar.
   sidebarResponse:  This sidebarResponse indicates the result of the
      sidebarRequest.

15.5.2.  CCMP Response Codes

   The following summarizes the requested registry for CCMP Response
   codes:

   Related Registry:   CCMP Response Code Registry
   Defining RFC:  RFC XXXX [NOTE TO IANA/RFC-EDITOR: Please replace XXXX
      with the RFC number for this specification.]
   Registration/Assignment Procedures:  New response codes are allocated
      on a first-come/first-serve basis with specification required.
   Registrant Contact:  IETF, XCON working group, (xcon@ietf.org), Mary
      Barnes (mary.barnes@nortel.com).

   This section pre-registers the following thirteen initial response
   codes as described above in Section 8.3:

   success:  This code indicates that the request was successfully
      processed.
   modified:  This code indicates that the object was created, but may
      differ from the request.
   badRequest:  This code indicates that the request was badly formed in
      some fashion.
   unauthorized:  This code indicates that the user was not authorized
      for the specific operation on the conference object.
   forbidden:  This code indicates that the specific operation is not
      valid for the target conference object.
   objectNotFound:  This code indicates that the specific conference
      object was not found.
   operationNotAllowed:  This code indicates that the specific operation
      is not allowed for the target conference object (e.g.., due to
      policies, etc.)
   deleteFailedParent:  This code indicates that the conferencing system
      cannot delete the specific conference object because it is a
      parent for another conference object.
   changeFailedProtected:  This code indicates that the target
      conference object cannot be changed (e.g., due to policies, roles,
      privileges, etc.).
   requestTimeout:  This code indicates that the request could not be
      processed within a reasonable time, with the time specific to a
      conferencing system implementation.





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   serverInternalError:  This code indicates that the conferencing
      system experienced some sort of internal error.
   notImplemented:  This code indicates that the specific operation is
      not implemented on that conferencing system.


16.  Security Considerations

   Access to conference control functionality needs to be tightly
   controlled to keep attackers from disrupting conferences, adding
   themselves to conferences or engaging in theft of services.  In the
   case of a RESTful implementation of the CCMP, implementors need to
   deploy standard HTTP authentication and authorization mechanisms.
   Since conference information may contain secrets such as participant
   lists and dial-in codes, all conference control information SHOULD be
   carried over TLS (HTTPS).


17.  Acknowledgments

   The authors appreciate the feedback provided by Dave Morgan, Pierre
   Tane, Lorenzo Miniero and Tobia Castaldi


18.  Changes since last Version

   NOTE TO THE RFC-Editor: Please remove this section prior to
   publication as an RFC.

   The following summarizes the changes between the WG 00 and the 01:

   1.  Changed the basic approach from using SOAP to REST - the
       fundamentals are the same in terms of schema, basic operations.
       This impacted most sections, in particular introduction and
       motivation.
   2.  Added new request types - blueprintsRequest, blueprintRequest and
       confsRequest.  The first replaces the optionsRequest and the
       latter allows the client to get a list of all active conferences.
   3.  Merged all requests into the basic operations table.  Added
       summary of RESTful examples (referenced by the basic operations
       table.
   4.  Added examples showing RESTful approach - i.e., HTTP methods for
       message exchange.
   5.  Removed requestID from the schema (it should be handle by the
       transport - e.g., HTTP).  Updated schema (based on current
       prototype - it still needs another revision.





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   6.  Added placeholders for Notifications and Role Based Access
       Control.
   7.  Added some text for discovery using DNS (including IANA
       registrations)
   8.  Updated References: updated XCON FW RFC, SOAP/W3C moved to
       informational section.


19.  References

19.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC2616]  Fielding, R., Gettys, J., Mogul, J., Frystyk, H.,
              Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext
              Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999.

   [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
              January 2004.

   [RFC5239]  Barnes, M., Boulton, C., and O. Levin, "A Framework for
              Centralized Conferencing", RFC 5239, June 2008.

   [I-D.ietf-xcon-common-data-model]
              Novo, O., Camarillo, G., Morgan, D., Even, R., and J.
              Urpalainen, "Conference Information Data Model for
              Centralized Conferencing (XCON)",
              draft-ietf-xcon-common-data-model-12 (work in progress),
              October 2008.

19.2.  Informative References

   [REST]     Fielding, "Architectural Styles and the Design of Network-
              based Software Architectures", 2000.

   [RFC3023]  Murata, M., St. Laurent, S., and D. Kohn, "XML Media
              Types", RFC 3023, January 2001.

   [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.

   [RFC3880]  Lennox, J., Wu, X., and H. Schulzrinne, "Call Processing
              Language (CPL): A Language for User Control of Internet
              Telephony Services", RFC 3880, October 2004.



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   [RFC3958]  Daigle, L. and A. Newton, "Domain-Based Application
              Service Location Using SRV RRs and the Dynamic Delegation
              Discovery Service (DDDS)", RFC 3958, January 2005.

   [RFC3966]  Schulzrinne, H., "The tel URI for Telephone Numbers",
              RFC 3966, December 2004.

   [I-D.ietf-xcon-event-package]
              Camarillo, G., Srinivasan, S., Even, R., and J.
              Urpalainen, "Conference Event Package Data Format
              Extension for Centralized Conferencing  (XCON)",
              draft-ietf-xcon-event-package-01 (work in progress),
              September 2008.

   [I-D.royer-calsch-xcal]
              Royer, D., "iCalendar in XML Format (xCal-Basic)",
              draft-royer-calsch-xcal-03 (work in progress),
              October 2005.

   [W3C.REC-soap12-part1-20030624]
              Gudgin, M., Hadley, M., Mendelsohn, N., Moreau, J., and H.
              Nielsen, "SOAP Version 1.2 Part 1: Messaging Framework",
              World Wide Web Consortium FirstEdition REC-soap12-part1-
              20030624, June 2003,
              <http://www.w3.org/TR/2003/REC-soap12-part1-20030624>.

   [W3C.REC-soap12-part2-20030624]
              Moreau, J., Mendelsohn, N., Hadley, M., Nielsen, H., and
              M. Gudgin, "SOAP Version 1.2 Part 2: Adjuncts", World Wide
              Web Consortium FirstEdition REC-soap12-part2-20030624,
              June 2003,
              <http://www.w3.org/TR/2003/REC-soap12-part2-20030624>.


Authors' Addresses

   Mary Barnes
   Nortel
   2201 Lakeside Blvd
   Richardson, TX

   Email: mary.barnes@nortel.com









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   Chris Boulton
   Avaya
   Building 3
   Wern Fawr Lane
   St Mellons
   Cardiff, South Wales  CF3 5EA

   Email: cboulton@avaya.com


   Simon Pietro Romano
   University of Napoli
   Via Claudio 21
   Napoli  80125
   Italy

   Email: spromano@unina.it


   Henning Schulzrinne
   Columbia University
   Department of Computer Science
   450 Computer Science Building
   New York, NY  10027

   Email: hgs+xcon@cs.columbia.edu

























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Full Copyright Statement

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