                      Raider3D live: Raider3D conferencing

  Okyz Documentation Group

   Copyright (c) 2003 by OKYZ

   $Id: r3dconf-en.sgml,v 1.7 2004/02/17 08:38:30 dockes Exp $ (C) 2002 OKYZ

   This document describes Raider3D conferencing general concepts and usage.

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   Table of Contents

   1. Introduction

   2. Using Raider3D live

   3. Notes

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                                1. Introduction

1.1. Raider3D conferencing

   The Raider3D live conferencing tool allows a group of people distributed
   anywhere on the Internet to share the same view of a Raider3D file. One
   member of the group is designated as the conference master, and all his
   moves are replicated on the other screens (slaves).

     * At any time, a member of the group can ask and become the conference
       master.

     * The conference tool has an integrated chat application which allows
       sharing text messages. Of course, it can also be used in conjunction
       with an audio conference call or another chat tool.

     * The display systems can be vastly different in terms of resolution and
       performance. The update rate will automatically adapt to the
       capabilities of each client.

     * Only visualization parameters data circulates during the conference.
       The data rate is very low (for example, a GSM phone link at 9600 bauds
       can be used quite comfortably).

     * Conferences are hosted by server machines, which can be the free Okyz
       conference server, or a private server located on a customer network.

     * The architecture is generally optimized to allow participation of
       clients located behind a firewall. The client can connect through an
       HTTP proxy.

     * Any free Raider3D viewer can be a full conference member (which
       includes becoming a conference master).

     * The capability to initiate (create) a conference requires the capture
       version of Raider3D and a specific conferencing license. Check the
       Okyz web site for more information about the conditions.

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1.2. How it works: a quick explanation

   Each of the clients participating in a Raider3D conference must have a
   copy of the same Raider3D (.r3d) file. As the conference software does not
   transmit any data, but only visualization parameters, this file must be
   sent to all attendees before the conference takes place (using E-mail, FTP
   transfers, web site access, etc ...).

   To start the conference, the conference creator will load the .r3d file,
   possibly enter a conference password, and connect to the conference server
   (the conference will be destroyed as soon as the creator disconnects).

   A hashed value derived from the file contents is transmitted as part of
   the connection data. This value must be the same for all members, which
   will ensure that everybody is working with the same file. The hash
   function is applied to the whole file, which means that even minor
   modifications to the file (like adding a view or annotation) will prevent
   joining the conference.

   The role of the password value is to allow for distinct conferences using
   the same .r3d file simultaneously on the same server. The different
   meetings can be distinguished by using different passwords.

   The triplet of (server, hash value, password) identify the conference you
   are connecting to. [1]

   Even if it is relatively unlikely that several conferences using the exact
   same file will take place at the same time, using a password will prevent,
   for example, accidental sharing of chat messages.

   Once the conference is started, the master conference client will send
   messages to the server each time its visualization parameters change. The
   server then sends the state changes to the other clients.

   Having a central server allows for clients located behind a firewall, and
   unable to accept incoming connections.

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1.3. Confidentiality and security issues

   No encryption is used on the conference channels, on which 2 kinds of data
   are transferred:

     * The visualization parameters.

     * Chat and pseudonym data.

   It is extremely unlikely that anything useful about the underlying object
   could be derived from the visualization parameters, which are mostly
   independent of the object. The only specific data are the measurement
   values, which are of little use without knowing what is being measured.

   The likeliness that the chat text could be intercepted is small. But, as
   the communication channel is not encrypted, no secret information should
   be exchanged if you are dealing with sensitive issues (the confidentiality
   level is analog to the one for unencrypted E-mail).

   A conference password should be used to protect against collision with
   another conference using the same file. Alternatively, you could modify
   the file before sharing it with the other conference members (for example:
   add an annotation).

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1.4. Firewalls and proxies

   Each Raider3D live client uses one TCP connection to the conference
   server.

   The simplest way to enable Raider3D conferencing for the local network
   users is to allow outgoing connections to the Okyz conference server
   (currently conference1.okyz.com). The server indifferently listens on
   ports 80, 443, 3000. Attendees of a conference need not all use the same
   port. Other ports could easily be opened on request.

   As conference1.okyz.com is a very secure Unix dedicated server and no
   sensitive data transits through it anyway (except possibly for chat text),
   this should not raise a security issue.

   In cases where it is not possible to allow direct outgoing connections,
   the conference client can use an HTTP proxy to connect to the conference
   server. This uses the HTTP proxy CONNECT method, normally used by SSL
   connections. Raider3D supports the BASIC and DIGEST authentification
   methods (see RFC 2617, RFC 2817). The proprietary NTLM method is not
   supported for the moment.

   As a last resort, if neither direct nor proxy connection to the Okyz
   server is compatible with the local security policy, it is also possible
   to run a conference server on an internal network host. Of course this
   supposes that all conference attendees can connect to this host, which may
   be plausible in some cases.

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                             2. Using Raider3D live

   The conference interface can be started from the File menu inside the
   Raider3D viewer. The Open conference panel entry will activate as soon as
   a file is loaded.

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2.1. The "connection" section

   Figure 1. The conference panel, connection tab

   This section of the conference panel holds the connection parameters:

   Host

           The conference host and port to be used should be entered here as
           host:port. This can be either the public Okyz conference server
           (conference1.okyz.com:443), or a private host. [1] [2]

   Use HTTP proxy

           You should check this box if you are behind a firewall which won't
           allow direct connections to internet hosts, but allows you to
           access the WEB through a proxy machine. If in doubt, you can
           probably retrieve the appropriate information by checking the
           relevant section in your web browser setup. When the box is
           checked, the text area will activate and let you enter the name or
           address of the proxy machine.

   Proxy port

           Port to be used for the connection to the proxy machine. If you
           are using a proxy, this parameter can probably also be found in
           your browser parameters. Else ask the system administrator.

   Conference password

           All the members of a conference should enter the same value here.
           It is used to better ensure that two meetings using the same file
           will not collide. A blank password is acceptable if you think that
           a collision is very unlikely because the file has not been shared
           with other people.

   pseudo

           The value entered here will be used to identify you in chat
           messages and user lists. Choose a short but characteristic value

   Create conference

           Check this box if you are the conference creator. Don't check it
           if you are joining a conference created by someone else.

   Connect/Disconnect

           Press the Connect button once the connection parameters have been
           entered. Upon connection, the button label will change to
           Disconnect. If you are connecting through a proxy host and it
           requires user authentication, a user/password dialog window will
           pop up on connection.

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2.2. The conference status section

   Figure 2. The conference panel, conference status tab

   This section of the conference panel holds the conference members
   interaction data.

   Text display area

           In addition to chat text sent by conference members, miscellaneous
           messages about the conference state are displayed there.

   Chat text entry area

           Type in there text that you want to broadcast to other conference
           members (the text is sent when you hit <CR>).

   Become Master

           This button allows you to request becoming the conference master
           (your moves will then be reflected to other conference members).
           Once you click the button, a window will pop up on the current
           master screen, requesting that he releases master status, which he
           can refuse to do.

   Current users

           The current list of conference member pseudonyms is displayed
           there. The master member is marked with a small m before his name.
           The conference creator is marked with a small c.

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                                    3. Notes

  Notes

   [1] Ports: a Raider3D teleconference server will usually listen on         
       different ports (80, 443, 3000 for conference1.okyz.com). In general,  
       the clients of a given conference need not connect on the same port.   
       The port value is not part of the rendez-vous data, and different      
       ports are only used to make it easier to deal with different firewall  
       policies.                                                              
   [2] If you are the conference creator, using a UNIX machine, and the host  
       value that you enter is localhost:port, the viewer will try to create  
       a local server that can be used to host the conference. You should     
       chose a high port value (like 3000) in this case, so that you don't    
       need to be root to listen to the port. The other clients will be able  
       to connect to yourRealHostname:yourport, if no firewall prevents it.   

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