Initializing a Conference on UNIX using the Backbone Driver

atarget.gif (1372 bytes) This scenario describes how to initialize a conference on UNIX using the Backbone driver.

Conferencing enables people who are geographically separated to dialog and work together as if they were virtually in the same room. Audio, video or chat tools enable the conference members to dialog while whiteboard or any other application sharing capabilities enable them to share documents or even applications. Usually, one member has a leading role, he is named the host or the master member.

The conferencing functionality is available on both the Windows and UNIX platforms.


Backbone is a Dassault Systèmes component which enables the creation of information channels between various applications running on various machines.

Backbone must be implemented on each computer that will be used by eventual conference members and on a reference server.


Applications do not communicate directly but through local servers (CATSysDemon servers), which communicate among themselves via a Domain Manager (which is itself CATSysDemon server)

As Backbone Manager, you must define the Domain that will enable the  CATSysDemon servers to communicate with one another.


  1. Select a machine which will be the Domain Manager (Backbone Manager), e.g. node1.

  2. Create a file containing the list of machines that will be allowed to connect to the Domain, e.g. domain.lst containing the following lines:


  1. Launch the CATSysDemon command with the above list of machines as parameter:

CATSysDemon -dm domain.lst

  1. Export the Domain Manager host name:

export CATBBDomainManager=node1

  1. All members of a conference must select the same conference driver, i.e. all members must select Backbone. To select the conference driver:

  • In the menu bar, select Tools->Options.
  • Click  the General category in the left-hand tree.
  • Click the General tab.
  • In the Conferencing area, check the Backbone option.
  • Click OK to confirm.


On UNIX it is possible to modify the default communication ports. The communication technology used for conferencing is socket-based. Your administrator must define the communication ports that will be used. On UNIX, the default ports are 6666 and 6667.

If these default ports are not available, you can modify their values in the file /etc/services by replacing 6666 and 6667 by the available ports in the following lines:

catiav5bb 55555/tcp
catiav5run 55556/tcp

On UNIX it is possible to automatically launch the CATSysDemon server by adding the following line in the file  /etc/inetd.conf:

catiav5run stream tcp nowait nobody runCATSysDemon CATSysDemon

where runCATSysDemon is a shell which will launch CATSysDemon as a Domain Manager, for which you also have the following options:


CATSysDemon server options

The -opendm option can also be added to enable ANY other machine to be connected. 

Ex: CATSysDemon -opendm -dm domain.lst

You can use -dmhost <hostname> option  instead, if the CATBBDomainManager environment variable is not set.

 Ex: CATSysDemon -dmhost nodehost

The "-h" option gives you a list of the available options. For instance:

-DebugL<n>, with n=1,2,3,4,10 provides information to follow communications between CATSysDemon servers. (Use it only if you encounter difficulties.)

-timeout <time in seconds> enables to leave the server running more than the default 300s when no client application is connected.

Ex: CATSysDemon -DebugL4 -timeout 3000

The Meta-Domain, How domains are linked together

A Domain Lister must be launched to enable a machine from domain A to communicate with a machine from domain B.

The domain Lister aims at providing a list of the domain managers. This consists in creating a meta-domain where the Domain Lister is Domain Manager, and where the Domain Managers are clients.

  • On the lister machine (let's call it node1), the CATSysDemon server must be launched using the "-dl <filepath>" option, <filepath> being a file containing the list of every (other) machine belonging to the meta-domain 

  Ex: CATSysDemon -dl domains.lst

  • Before running the other servers in the meta-domain, the Domain Lister host name must be specified via the CATBBDomainLister variable:

Ex: export CATBBDomainLister=nodelist

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