What are the components of the RTC & their functionalities?

The URL of RTC component is of the form

http:///imtapp/app/home.uix where host is the address of the middle tier’s Web Cache.

The virtual path imtapp maps onto the OC4J component OC4J_imeeting, which must

be running.

To start the OC4J, use the opmnctl utility

$opmnctl startproc process-type=OC4J_imeeting

The server itself is another component that must be started separately:

$opmnctl startproc process-type=rtcpm

The server is implemented as an Apache module that acts as a listening process for all Real-Time Collaboration communication, mod_imeeting, and an independent process, the rtcpm, the Real-Time Collaboration Process Manager.

The mod_imeeting module, deployed as a shared object library, is installed within Apache by including the mod_imeeting.conf file in the oracle_apache.conf file, which is included in the httpd.conf file in the Apache configuration directory. It is dynamically linked and runs on demand, as does any other Apache module. The mod_imeeting module acts as a central point for receiving web requests, which it manages by handing off the socket to the rtcpm process.

The rtcpm process manages several other processes. First, there are three communication services: the Redirector, the Multiplexer, and the Connection Manager. The Redirector receives all connection requests, whether for Web Conference or for

Messenger, and routes Web Conference requests to the Multiplexer, and Messenger requests to the Connection Manager. All the Multiplexers and Connection Managers will have access to the same database schemas.

The Multiplexer acts as a communication hub between end users running the Web Conferencing client and three back-end server processes: the Web Conferencing server,the Document Conversion server and the Voice Conversion server.

The Connection Manager handles sessions between end users running the Messenger client and the Presence server. The Presence servers use the SIMPLE protocol (SIP for Instant

Messaging and Presence Leveraging Extensions SIP stands for Session Initiation Protocol). SIMPLE is layered on top of TCP and is becoming the standard for instant messaging applications and much more. The Oracle Presence server manages the publication of user’s availability and their membership of chat sessions and distributes messages via the connection manager.

A secondary process that may be required by the Presence server is the Voice Proxy server. If the Messenger client is being used for an audio conversation (which is possible, but only between two people) the Presence server sets up a direct connection between the two Messenger clients. If this is not possible, typically because of network protocol and security restrictions, the communication can be via a Voice Proxy server.

The limitations of VoIP is that make it impossible to have full-duplex voice communication between all participants in a web conference (though it is certainly possible for any one participant to broadcast to the others) can be overcome by using the PSTN to establish a parallel telephone conference. The audio traffic over the telephone conference will be integrated into the web conference by the Voice Conversion server.