Abstract
Videoconferencing has progressed from being an expensive system to become commodity items.It is one of popular multimedia communication services and is becoming a research focus.A new videoconferencing system is designed and implemented in this research.The proposed system works in a distributed environment and supports two-way communicationwith variable service rate according to each conferee's network bandwidth.It disseminates data by multicasting that really saves the Internet bandwidth.We also synchronize a variable-rate video stream and a audio stream by new synchronization methods.The proposed system is suitable for the heterogeneous network such as Internet.