Design and implementation of SIP User-Agent based on applet

Multimedia conference system based on SIP is a real-time interactive communication service with multimedia applications, e.g., audio, video, whiteboard, and all users in the system should have the SIP clients which can create or receive SIP messages and send or display audio or video data for multimedia conference system. In this paper, the design and implementation of SIP User-Agent as applet for multimedia conference system is introduced which can run in Web browser. All modules of SIP UA are introduced separately, including user interface, call control module, media processing module and JAIN SIP stack. The test results prove that the system can correctly carry out multimedia communication.