[Docs] [txt|pdf] [Tracker] [Email] [Diff1] [Diff2] [Nits]

Versions: 00 01 02 03 04 05 06 07 08

XCON Working Group                                             M. Barnes
Internet-Draft                                                   Polycom
Intended status: Standards Track                              C. Boulton
Expires: January 17, 2013                                NS-Technologies
                                                               S. Loreto
                                                                Ericsson
                                                           July 16, 2012


       Chatrooms within a Centralized Conferencing (XCON) System
                   draft-boulton-xcon-session-chat-08

Abstract

   The document "A Framework for Centralized Conferencing" defines a
   centralized conference as both signaling and protocol agnostic.  The
   primary examples within this framework focus on audio and video as
   the media types for the session.  This document provides an overview
   of the mechanisms defined in the centralized conferencing framework
   that can be used to support multi-user chat.  In addition, the
   document describes additional functionality and requirements
   necessary to provide feature rich functionality.

Status of this Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on January 17, 2013.

Copyright Notice

   Copyright (c) 2012 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of



Barnes, et al.          Expires January 17, 2013                [Page 1]


Internet-Draft                  XCON Chat                      July 2012


   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.


Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Conventions and Terminology  . . . . . . . . . . . . . . . . .  3
   3.  Overview . . . . . . . . . . . . . . . . . . . . . . . . . . .  4
     3.1.  Basic Protocol Operations  . . . . . . . . . . . . . . . .  5
     3.2.  Chat Session and Conferencing Identifiers  . . . . . . . .  7
   4.  Advanced Operations  . . . . . . . . . . . . . . . . . . . . .  8
   5.  Additional Operations  . . . . . . . . . . . . . . . . . . . .  8
     5.1.  Nicknames  . . . . . . . . . . . . . . . . . . . . . . . .  9
     5.2.  Logging  . . . . . . . . . . . . . . . . . . . . . . . . . 10
     5.3.  History  . . . . . . . . . . . . . . . . . . . . . . . . . 11
     5.4.  Indicating Alternate Venue . . . . . . . . . . . . . . . . 11
     5.5.  File Transfer  . . . . . . . . . . . . . . . . . . . . . . 11
     5.6.  Real Time Collaboration  . . . . . . . . . . . . . . . . . 12
   6.  Security Considerations  . . . . . . . . . . . . . . . . . . . 12
   7.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 13
   8.  Acknowledgments  . . . . . . . . . . . . . . . . . . . . . . . 13
   9.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 13
     9.1.  Normative References . . . . . . . . . . . . . . . . . . . 13
     9.2.  Informative References . . . . . . . . . . . . . . . . . . 13
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 15





















Barnes, et al.          Expires January 17, 2013                [Page 2]


Internet-Draft                  XCON Chat                      July 2012


1.  Introduction

   A Centralized Conference as defined by the "A Framework for
   Centralized Conferencing" (XCON Framework) [RFC5239] is both
   signaling and protocol agnostic.  The primary examples within the
   framework focus on audio and video as the media types for the
   session.  This document provides an overview of the mechanisms and
   associated framework elements involved when text is the media for the
   conference.  This functionality is often referred to as a "multi-user
   chat" as it enables a participant to join a chatroom (e.g. hosted by
   the conference server) for the exchange of messages between multiple
   participants.  The message can be plain text or can contain different
   format for more advanced functionality.

   Several existing protocols support this multi-user chat
   functionality, such as Extensible Messaging and Presence Protocol
   (XMPP) [RFC6120], [RFC6121] and Internet Relay Chat (IRC) defined in
   [RFC1459] and its successors: [RFC2810],[RFC2811],[RFC2812],
   [RFC2813].  In addition, [I-D.ietf-simple-chat] provides multi-user
   chat functionality for a purely SIP signaling based solution option
   using Message Session Relay Protocol (MSRP) [RFC4975].

   The focus of this document is to describe the interface and provide
   guidelines for the the support of existing multi-user chat
   functionality on a conferencing system based on the XCON framework
   using the Conference Control Manipulation Protocol (CCMP) independent
   of the specific media type used by the chat client.

   The functionality described in this document is not intended to
   replace any of the existing chat protocols, nor is it specifying a
   new chat protocol.  The motivation for this document is to allow
   clients that use the conferencing framework model for other media
   types (e.g. voice/video) to utilize the same conference control
   mechanisms and conferencing system to establish, update and delete a
   chatroom associated with a conference instance, independent of the
   chat protocol.  This approach also allows the conferencing system to
   provide a natural interworking point for various chat protocols - the
   details of the interworking are outside the scope of this document.


2.  Conventions and Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC2119].

   This document reuses the terminology defined in the Centralized
   Conferencing Framework [RFC5239] and related protocol document



Barnes, et al.          Expires January 17, 2013                [Page 3]


Internet-Draft                  XCON Chat                      July 2012


   [RFC6503].

   Additional terminology used in this document:
   Chat Client:  a Conferencing Client as defined in [RFC5239] that
      participates in a "chatroom".
   Chatroom:  A virtual space that users figuratively enter in order to
      participate in real-time, text-based conferencing with other
      users.
   Multi-user chat:  The functionality that allows multiple users to
      exchange messages in the context of a room or channel, similar to
      Internet Relay Chat (IRC).
   Private message:  A message sent from one participant directly to
      another participant - i.e., not to the chatroom itself to all
      participants.


3.  Overview

   Figure 1 provides a general illustration of chat clients having a
   direct, 1:1 connection to the conferencing system.  Participants can
   use the chat clients to join a room associated with a conference
   instance and send messages.  The conferencing system receives the
   messages sent from a client participating in a conference instance
   and then distributes them to the other clients associated with the
   conference instance, that are also present in the chatroom.


                              +--------+
                              |  Chat  |
                              | Client |
                              +--------+
                                  |
                                  |
                                  |
                                  v
      +--------+            +------------+            +--------+
      | Chat   |            |Conferencing|            |  Chat  |
      | Client |----------->|  System    |<-----------| Client |
      +--------+            +------------+            +--------+
                                  ^
                                  |
                                  |
                                  |
                              +--------+
                              | Chat   |
                              | Client |
                              +--------+




Barnes, et al.          Expires January 17, 2013                [Page 4]


Internet-Draft                  XCON Chat                      July 2012


                        Figure 1: Client Connection

   The approach in this document is to have no impact on the existing
   chat protocols, while taking full advantage of the functionality
   provided by the centralized conferencing framework.

   A basic solution for MSRP based IM chat sessions is documented in
   [I-D.ietf-simple-chat].  It uses the concept of an "MSRP switch" as
   the centralized component, whose role is very similar to the
   Conferencing Server in this document.  The solution in
   [I-D.ietf-simple-chat] doesn't explicitly take advantage of the
   centralized conferencing framework model, as it primarily intends to
   make use of the basic SIP conferencing framework to provide the basic
   chat functionality.  The MSRP based IM chat solution is compatible
   with the solution components described in this document, with no
   impact on that basic solution proposal.  One of the advantages of
   applying the two solutions in concert would be to take advantage of
   the centralized conferencing framework model for advanced features,
   such as sidebars and private conferences, and manipulation of the
   conference data.

   XMPP assumes a decentralized client-server architecture similar to
   the one shown in Figure 1, wherein a client utilizing XMPP accesses a
   server and servers can also communicate with each other over TCP
   connections, similar to the email network.  The XMPP server can
   provide as additional functionality the multi-user conferencing
   services [XEP-0045].  The XMPP multi-user conferencing service is
   also compatible with the solution components described in this
   document with no impact on the basic solution proposal.  Indeed, the
   centralized conferencing framework model is perfectly able to manage
   the XMPP strong room control model, including the ability to kick and
   ban users, to name room moderators and administrators, to require
   membership or passwords in order to join the room.  However it is
   worth noting that the centralized conferencing framework does not
   encompass the communication between servers, as XMPP does.  Thus, for
   the solution proposal in this document, the XMPP client SHOULD only
   have a direct connection with the server hosting the chatroom
   instance, and federations between servers SHOULD NOT be allowed.

3.1.  Basic Protocol Operations

   The multi-user chat protocol operations, such as create, join and
   delete can be performed using both non-signaling specific mechanisms
   or protocol specific mechanisms, if defined.  Non-signaling specific
   mechanisms are defined in the Centralized Conferencing Framework
   [RFC5239] and related Conference Control Manipulation Protocol (CCMP)
   document [RFC6503].  This document provides the details for the non-
   signaling specific mechanisms using CCMP with detailed examples



Barnes, et al.          Expires January 17, 2013                [Page 5]


Internet-Draft                  XCON Chat                      July 2012


   provided in [RFC6504].  Protocol specific mechanisms are defined in
   other documents such as for SIP in the SIPPING Conference Framework
   [RFC4353] and for XMPP in Multi-User Chat [XEP-0045].

   The privilege to create a chatroom associated with a conference
   instance can be restricted to certain users or can be reserved to an
   administrator of the conference.  The room creation can be performed
   using non-signaling mechanism or protocol specific mechanism if
   defined.  In the case of CCMP, a confRequest message with a "create"
   operation is sent by the chat client.

   A participant can query the conferencing system to discover the list
   of the chat rooms associated with a hosted conference instance.  In
   the case of CCMP, a blueprintsRequest message for the chatrooms
   supported by a conferencing system or a confsRequest message for the
   active chatrooms can be sent by the chat client.

   In order to participate in the discussions held in a multi-user chat
   room, a participant MUST first enter the room.  A chat client wishing
   to enter a chatroom associated with a conference instance MAY use a
   non-signaling or protocol specific mechanism if defined.  In the case
   of CCMP, a participant MUST join a conference instance using the
   mechanisms which are described in [RFC6503] - e.g., userRequest
   message with a "create" operation to be added to a conference
   instance.

   The request to send a message is specific to the chat protocol (e.g.,
   MSRP SEND).  Upon receipt of a request to send a message, the
   conferencing system replicates and forwards the message to all other
   chat clients that are participants of the chat room.  Depending upon
   policy, a conferencing system MAY ignore or reject messages, in which
   case they are not distributed to the other chat room participants.

   A participant MAY send a "private message" to a selected participant
   or a group of participant.  This privilege SHOULD be allowed for all
   participants unless local policy dictates otherwise.

   A chat client wishing to exit a chat room uses a non-signaling
   mechanism or protocol specific mechanism, if defined.  If the chat
   client is the last to exit, the conferencing system can be
   responsible for deleting the room or the originator/owner/moderator
   The privilege to delete a chatroom associated with a conference
   instance can be restricted to certain users or can be reserved to an
   administrator of the conference.  The room deletion can be performed
   using non-signaling mechanism or protocol specific mechanism if
   defined.  In the case of CCMP, the client MUST send a CCMP
   confRequest message with an operation of "delete".




Barnes, et al.          Expires January 17, 2013                [Page 6]


Internet-Draft                  XCON Chat                      July 2012


3.2.  Chat Session and Conferencing Identifiers

   As highlighted in the overview section, a chat client connecting to a
   conferencing system has a 1:1 relationship with the chat signaling
   entity, each having a unique protocol specific chat session
   identifier (chat-ID).  When referring to chat-IDs the document is
   making reference to the locally (at conferencing system) generated
   chat-ID used for session signaling identification.  An important
   concept in this proposal is the creation and management of Group Chat
   sessions.  It is important that each chat session created, as
   identified by a unique chat-ID, is explicitly tied to an associated
   conference.  The Centralized Conferencing Framework [RFC5239]
   introduces the concept of a conference user identifier which is
   defined in [RFC6501].  When a user joins a conference instance
   through the signaling protocol, the user is allocated an appropriate
   conference user identifier either through authentication or system
   allocation.  The conference user identifier is represented by the
   'entity' attribute of a <user> element in the <users> element in the
   conference information.  The association of the chat-IDs is
   accomplished by including each of the chat-IDs in the conference
   information in the 'entity' attribute of an <endpoint> element in the
   <user> element.  The conference information as a whole is uniquely
   identified within the conferencing system by an XCON-URI, thus
   providing the relevant association between a chat session and a
   centralized conference.  Figure 2 shows the logical repesentation of
   the chat-IDs with the conf-userIDs, with each row in the table
   representing a single entry.



   +-------------------------------------------------+
   |           XCON-URI: 711331@example.com          |
   +-----------------------+-------------------------+
   |      Chat-ID=8asjdhk  |  xcon-userid: 839ULjj   |
   |      Chat-ID=38iuhds  |  xcon-userid: 0283hHu   |
   |      Chat-ID=djiowid  |  xcon-userid: ncH37Hs   |
   |      Chat-ID=389hewu  |  xcon-userid: pakdjjH   |
   +-----------------------+-------------------------+



                       Figure 2: Session Association

   A more complex session association is necessary due to potential for
   a user to have multiple group chats in a single conference instance,
   such as multi-lingual conference support.  In an example with SIP and
   MSRP, the conference representation in Figure 2 allows for such
   functionality when separate SIP dialogs represent MSRP sessions.



Barnes, et al.          Expires January 17, 2013                [Page 7]


Internet-Draft                  XCON Chat                      July 2012


   This process becomes complex in the case that multiple SDP MSRP media
   sessions (m=) are defined in a single payload.  This internal
   representation needs expanding to enable a conferencing system to
   explicitly associate a media session (m=).  This involves including
   the media label, as defined in [RFC4574], to maintain the internal
   conference association.  An example is illustrated in Figure 3.



   +----------------------------------------------------------------+
   |                XCON-URI: 711331@example.com                    |
   +----------------------------------------------------------------+
   |      Chat-ID=8asjdhk  |  xcon-userid: 839ULjj   | Label=iede3  |
   |      Chat-ID=38iuhds  |  xcon-userid: 0283hHu   | Label=8heus  |
   |      Chat-ID=838unaH  |  xcon-userid: 0283hHu   | Label=3cnu7  |
   |      Chat-ID=djiowid  |  xcon-userid: ncH37Hs   | Label=jd38J  |
   |      Chat-ID=389hewu  |  xcon-userid: pakdjjH   | Label=U83hd  |
   |      Chat-ID=Ko03jdk  |  xcon-userid: pakdj7H   | Label=ehy3h  |
   +----------------------------------------------------------------+



           Figure 3: Advanced Session Association + Media Label

   In Figure 3, conference user identifiers '0283hHu' and 'pakdj7H'
   appear twice.  The combination of multiple conference user
   identifiers and a unique chat-ID enables the conference system to
   clearly identify a specific Group Chat instance.  Even in the
   simplest conferencing system, where users are allowed to enter
   anonymously, the internal representation described in this section
   should be observed.  In this case, the conferencing system would
   still internally create a conference user identifier for participant
   reference purposes.


4.  Advanced Operations

   Advanced chat features, such as sidebars and private messages can
   also be supported within the context of the centralized conferencing
   framework using CCMP.  Additional protocol details for these advanced
   features are provided in [RFC6504].


5.  Additional Operations

   This section discusses additional operations or features required to
   provide chat room functionality.  Most of the operations are not
   explicitly defined in the centralized conferencing framework.  While



Barnes, et al.          Expires January 17, 2013                [Page 8]


Internet-Draft                  XCON Chat                      July 2012


   most of the features and operations are achievable using the XCON
   data model [RFC6501] and data maintained by a conferencing system per
   the XCON framework, some advanced features require extensions to the
   XCON data model and may be optimized with more discrete CCMP
   messages.

5.1.  Nicknames

   Nicknames allow a user to define a text string that uniquely
   identifies the user within a particular chatroom without necessarily
   reflecting any protocol specific identity (e.g., SIP URI, Conference
   User Identifier, etc.).  It is also important to note that the
   functionality to provide nicknames is not limited to users involved
   in chatrooms, thus it should be a general feature of the conferencing
   system.

   Within a conferencing system, all nicknames MUST map to a conference
   user identifier.  The nicknames are unique only to the specific
   conferencing system.  To ensure uniqueness of nicknames, any new
   'nickname' created MUST be compared with nicknames already in use or
   reserved following the rules defined in Preparation and Comparison of
   Nicknames [I-D.saintandre-precis-nickname].

   There may be multiple nicknames associated with a single conference
   user identifier (e.g., a user that has different nicknames for
   different chat rooms and/or voice/video conferences).  In order to
   support nicknames, a 'nickname' attribute is defined in the XCON data
   model within the <user> element.  A 'nickname' can be assigned to the
   conference user when an XCON-USERID is assigned to the user.  The
   conferencing client MAY include a preferred nickname in the CCMP
   userRequest with a "create" operation.

   The conferencing system allocates a conference user identifier and a
   nickname using system specific mechanisms, which can also include
   authentication.  The conferencing system MUST associate the assigned
   nickname with the specific conference user identifier that has been
   allocated by updating the conference information.  Another option
   would be to define a new CCMP message to just manipulate the
   'nickname' element, but that is not necessary.

   As described Section 3.2, the XCON-userid identifier is used in
   conjunction with a chat-ID to internally represent a participant in a
   conference instance.  This association is created when a conferencing
   client requests to create or join a specific chatroom.  The nickname
   allocated for the specific conferencing user identifier MUST also be
   associated with the chat session ID.  Figure 4 provides an example of
   the association between the chat session identifier, the conference
   user identifier and conference nickname for a specific Group Chat



Barnes, et al.          Expires January 17, 2013                [Page 9]


Internet-Draft                  XCON Chat                      July 2012


   represented by the conference identifier.



   +-----------------------------------------------------------------+
   |                XCON-URI: 711331@example.com                     |
   +-------------------+---------------------------------------------+
   |  Chat-ID=8asjdhk  |  xcon-userid: 839ULjj  | nickname=Alice     |
   |  Chat-ID=38iuhds  |  xcon-userid: 0283hHu  | nickname=Bob       |
   |  Chat-ID=838unaH  |  xcon-userid: 0283hHu  | nickname=CliffyBob |
   |  Chat-ID=djiowid  |  xcon-userid: ncH37Hs  | nickname=Dude      |
   |  Chat-ID=389hewu  |  xcon-userid: pakdjjH  | nickname=Elliott   |
   |  Chat-ID=Ko03jdk  |  xcon-userid: pakdj7H  | nickname=Fluffy    |
   +-----------------------------------------------------------------+



             Figure 4: Nickname Associations for a Group Chat

   Depending upon the conferencing system, the conference system either
   allocates the preferred nickname for that user or allocates a
   different nickname.  The nickname MUST be included in the CCMP
   userResponse message.

   In the future, if a more generic nickname mechanism is available,
   rather than provide nicknames that are specific to the conferencing
   system, a conferencing system may interface with a nickname registry,
   for example, in order to allocate a new nickname for a specific
   conferencing client.  This change in how a conferencing system
   allocates nicknames should not impact the CCMP protocol interface to
   support nicknames.

5.2.  Logging

   A common chat feature involves logging the history of a chat room.
   This provides a record of a chat room that can be used when a user
   first joins a chat room as discussed in Section 5.3.  It can also be
   used to provide a complete capture of a specific chat room session.
   When a participant enters a room in which the discussions are logged,
   the conferencing system MUST warn the participant that the
   discussions are logged.

   The centralized conferencing framework does not fully describe the
   role of recording or logging of active conferences.  However, this
   functionality can be realized with the manipulation of the
   appropriate elements in the data model using the general conference
   control protocol operations.  One approach for implementing this
   function would be to have it be based on specific manipulation of the



Barnes, et al.          Expires January 17, 2013               [Page 10]


Internet-Draft                  XCON Chat                      July 2012


   conference by a user with the appropriate permissions (i.e.,
   confRequest messaage with an "update" operation to start and stop
   recording).  Another mechanism for implementing this function would
   be to have a specific user as part of the conference to perform this
   function, and having the media proxied to a logging device.  In the
   case of systems that support the Media Control archictecture
   [RFC5567] and SIP Control Framework [RFC6230] along with the specific
   Mixer control package [RFC6505], the addition of a user to proxy the
   media for recording is described in section 6.2.3 in
   [I-D.ietf-mediactrl-call-flows]

5.3.  History

   A common chat feature allows users to view the past history of chat
   rooms.  This operation is common when a user first joins a chat room
   that is underway.  A user is often offered the option to review a
   specific number of past messages.

   Conferencing systems that maintain the history associated with
   specific chat rooms through logging, as described in Section 5.2,
   should provide a mechanism, using the conference identifier, to
   access the specific information requested by a user based on a
   specific timestamp.  The user request for the information and the
   rendering of the information is specific to the user's session based
   messaging protocol and may not be supported by all the messaging
   protocols.

5.4.  Indicating Alternate Venue

   Another chat room feature provides the details of an alternate chat
   room venue for previously active chat rooms that have been closed,
   with a related topic.  While not detailed in the centralized
   conferencing framework, this functionality can be accomplished by
   creating the new chat room as a child or sibling of the previous chat
   room and providing the Active chat conference object identifier to
   any valid users that attempt to join a previous chat room.  The
   information about the new chat room can also be provided at the end
   of a chat room that is being de-activated at the end of the session.

5.5.  File Transfer

   The ability to send files to a selected participant or group of
   participants is another common functionality, supported by messaging
   protocols.  This functionality also enables the exchange of
   information (e.g. name, size, and date) about the file to be
   transferred and usually provides a mechanism to show an image
   thumbnail for files such as photos.  This capability could be
   reflected in the conference data (in the conference instance) and



Barnes, et al.          Expires January 17, 2013               [Page 11]


Internet-Draft                  XCON Chat                      July 2012


   requires at least an extension to the "available-media" element.  The
   thumbnail rendering of the image is outside the scope of the data
   model and is specific to the client application.  Additional
   functionality to support this capability requires further study.

5.6.  Real Time Collaboration

   The messaging protocols can be used, and are being used, in
   applications quite different from a simple exchange of text messages
   between two participants in the context of a chatroom.  Real-time
   collaboration tools (e.g.  Whiteboarding, screen-share, co-browse or
   document-share) are some of these applications.

   The Conferencing Systems are usually bound to Real-time collaboration
   tools to increase the productivity of distributed teams.  In terms of
   correlating this functionality with CCMP, the mechanisms for
   manipulating the conference are the same in terms of updating the
   data associated with the conference with the additional attributes to
   reflect the multiple sources of media for the chatroom.  This
   capability could be reflected in the conference data (in the
   conference instance) with an extension to the "available-media"
   element.  Some current systems using SIP embed the attributes in the
   media stream.  Overall, supporting this functionality requires
   further study, in particular with regards to the RTCWeb initiative as
   described in documents such as
   [I-D.ietf-rtcweb-use-cases-and-requirements]


6.  Security Considerations

   As discussed in the Centralized Conferencing Framework, there are a
   wide variety of potential attacks related to conferencing, due to the
   natural involvement of multiple endpoints and the many, often user-
   invoked, capabilities provided by the conferencing system.  Examples
   of attacks associated with chatrooms includes the following: an
   endpoint attempting to receive the messages for conferences in which
   it is not authorized to participate, an endpoint attempting to
   disconnect other users, and theft of service, by an endpoint, in
   attempting to create conferences it is not allowed to create.

   Since this document describes the use of existing protocols (i.e.,
   MSRP/SIP, CCMP, XMPP, etc.), it depends on the security solutions for
   those protocols and the associated authorization mechanisms.  This
   solution is based on the Centralized Conferencing framework and makes
   use of the policy associated with the conference object to ensure
   that only authorized entities are able to manipulate the data to
   access the capabilities.  This solution also makes use of the privacy
   and security of the identity of a user in the conference, as



Barnes, et al.          Expires January 17, 2013               [Page 12]


Internet-Draft                  XCON Chat                      July 2012


   discussed in the Centralized Conferencing Framework.


7.  IANA Considerations

   This document requires no IANA registrations.


8.  Acknowledgments

   The authors appreciate the input and comments from Miguel Garcia-
   Martin and Dave Morgan.


9.  References

9.1.  Normative References

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

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

   [RFC6501]  Novo, O., Camarillo, G., Morgan, D., and J. Urpalainen,
              "Conference Information Data Model for Centralized
              Conferencing (XCON)", RFC 6501, March 2012.

   [RFC6503]  Barnes, M., Boulton, C., Romano, S., and H. Schulzrinne,
              "Centralized Conferencing Manipulation Protocol",
              RFC 6503, March 2012.

   [I-D.saintandre-precis-nickname]
              Saint-Andre, P., "Preparation and Comparison of
              Nicknames", draft-saintandre-precis-nickname-00 (work in
              progress), March 2012.

9.2.  Informative References

   [RFC6504]  Barnes, M., Miniero, L., Presta, R., and SP. Romano,
              "Centralized Conferencing Manipulation Protocol (CCMP)
              Call Flow Examples", RFC 6504, March 2012.

   [RFC1459]  Oikarinen, J. and D. Reed, "Internet Relay Chat Protocol",
              RFC 1459, May 1993.

   [RFC2810]  Kalt, C., "Internet Relay Chat: Architecture", RFC 2810,
              April 2000.



Barnes, et al.          Expires January 17, 2013               [Page 13]


Internet-Draft                  XCON Chat                      July 2012


   [RFC2811]  Kalt, C., "Internet Relay Chat: Channel Management",
              RFC 2811, April 2000.

   [RFC2812]  Kalt, C., "Internet Relay Chat: Client Protocol",
              RFC 2812, April 2000.

   [RFC2813]  Kalt, C., "Internet Relay Chat: Server Protocol",
              RFC 2813, April 2000.

   [RFC6120]  Saint-Andre, P., "Extensible Messaging and Presence
              Protocol (XMPP): Core", RFC 6120, March 2011.

   [RFC6121]  Saint-Andre, P., "Extensible Messaging and Presence
              Protocol (XMPP): Instant Messaging and Presence",
              RFC 6121, March 2011.

   [RFC4353]  Rosenberg, J., "A Framework for Conferencing with the
              Session Initiation Protocol (SIP)", RFC 4353,
              February 2006.

   [RFC4975]  Campbell, B., Mahy, R., and C. Jennings, "The Message
              Session Relay Protocol (MSRP)", RFC 4975, September 2007.

   [I-D.ietf-simple-chat]
              Niemi, A., Garcia, M., and G. Sandbakken, "Multi-party
              Chat Using the Message Session Relay Protocol (MSRP)",
              draft-ietf-simple-chat-15 (work in progress), July 2012.

   [RFC4574]  Levin, O. and G. Camarillo, "The Session Description
              Protocol (SDP) Label Attribute", RFC 4574, August 2006.

   [RFC5567]  Melanchuk, T., "An Architectural Framework for Media
              Server Control", RFC 5567, June 2009.

   [RFC6505]  McGlashan, S., Melanchuk, T., and C. Boulton, "A Mixer
              Control Package for the Media Control Channel Framework",
              RFC 6505, March 2012.

   [RFC6230]  Boulton, C., Melanchuk, T., and S. McGlashan, "Media
              Control Channel Framework", RFC 6230, May 2011.

   [I-D.ietf-mediactrl-call-flows]
              Amirante, A., Castaldi, T., Miniero, L., and S. Romano,
              "Media Control Channel Framework (CFW) Call Flow
              Examples", draft-ietf-mediactrl-call-flows-09 (work in
              progress), July 2012.

   [I-D.ietf-rtcweb-use-cases-and-requirements]



Barnes, et al.          Expires January 17, 2013               [Page 14]


Internet-Draft                  XCON Chat                      July 2012


              Holmberg, C., Hakansson, S., and G. Eriksson, "Web Real-
              Time Communication Use-cases and Requirements",
              draft-ietf-rtcweb-use-cases-and-requirements-09 (work in
              progress), June 2012.

   [XEP-0045]
              Saint-Andre, P., "Multi-User Chat", XSF XEP 0045,
              July 2007.


Authors' Addresses

   Mary Barnes
   Polycom

   Email: mary.ietf.barnes@gmail.com


   Chris Boulton
   NS-Technologies

   Email: chris@ns-technologies.com


   Salvatore Loreto
   Ericsson
   Hirsalantie 11
   Jorvas  02420, Finland

   Email: salvatore.loreto@ericsson.com





















Barnes, et al.          Expires January 17, 2013               [Page 15]


Html markup produced by rfcmarkup 1.129d, available from https://tools.ietf.org/tools/rfcmarkup/