Research On NACK-oriented & Tree-based NTRMP Protocol

The rapid development of Internet provides a good environment and opportunities for applications of multicast. But also more requests of the safety and performance of multicast are proposed. At present, there have been many reliable multicast protocols, but mostly for different applications'demands. In normal applications, the small delay of recovery, high use ratio of bandwidth and good scalability are the demands of multicast applications. With the increasements of the network and communication of many-to-many, it puts new demands and challenges for reliable multicast.At first, the concept, features, architecture and applications of multicast are introduced in this paper, at the same time, the paper analyses the problems of multicast applications. Then, introduces briefly data authentication of reliable multicast, and the principles and safety of several reliable multicast protocols are analysed and compared detailedly. After that, this paper proposes a NACK-oriented and tree-based reliable multicast protocol which is called NTRMP. The protocol which uses NACK confirmation method, in the network as long as there is a NACK, can effectively solve the feedback information explosion problem. At last, the error recovery will be limited to the local network by the regional grouping and hierarchical tree structure. This protocol has better performance in recovery delay and use ratio of bandwidth by analysis and comparison.