Study Of Multicast Congestion Control Solutions Based On Active Network

In recent years there are more and more new applications. Especially applications involving the reliable transfer of large volumes of data from a source to multiple destinations across wide-area networks are expected to become increasingly important in the near future. A few examples are point-to-multipoint ftp, newsdistributions. Multicast technology promises to enhance the capabilities of wide-area networks for supporting these applications. Multicast transport mechanisms have been a topic of intense research and development efforts over the past couple of years. Both the Internet Engineering and Internet Research Task Forces (IETF and IRTF) have been heavily involved in coordinating multicast transport protocol research, development and standardization.However, congestion control for multicast protocols has emerged as one of the biggest challenges in the large-scale deployment of multicast applications in the Internet. It also is a hard problem and an active research area. The IETF has pointed out that effective congestion control mechanisms must be proposed before standardizing multicast protocols.In this paper, first the background and the cause of multicast congestion are introduced, and the necessity of implementing multicast congestion control is analyzed. We also discuss the research work related to multicast congestion control and existing problems in current multicast congestion control. Then we focuses on the technology of Active Network. The computation capability of the Active Node in Active Network makes it different from generic"passive"network. Finally we discribe the congestion control solutions which is based on Active Network.When the Active node detects congestion it changes the send-rate and takes the congestion control hop-by-hop.The simulation results show that the solutions improves the effects of multicast congestion control. And it also has good TCP-friendliness.