Application Multicast Based On P2p Overlay Network

This paper focuses on the study of building application-layer multicast system over P2P overlay. How to build an efficient, scalable, and large-scale application-layer multicast system is the research hotspot in recent years. Since IP multicast-based approach is limited by hardware support, a new approach that based on application-layer multicast had been proposed. The basic idea of application-layer multicast is that its group member nodes will be organized into a logical overlay network and provided efficient and reliable service through application-layer multicast routing protocols to build and maintain the network for data transmission. This paper focus on how to use the Cayley theory in building P2P overlay network with small world feature and implement an efficient, scalable application-layer multicast model. The study includes Cayley theory based P2P overlay network topology, construct and management multicast tree, and its load balancing and so on.Since most of the existing application-layer multicast system study based on decentralized unstructured model, its members of the multicast tree and node management which via a way of message flooding, through achieving easy, greatly increased the network load. The structured approach based models are relatively complex and inefficient. This paper applies the Cayley graph theory of group theory methods to construct an efficient dynamic P2P overlay network model CPN, and define its DHT protocol. CPN meet the definition of small-world network, with a shorter route length, high clustering coefficient, robustness and support for explicit grouping features. Because it is symmetric structured, the overlay network routing algorithm, compared to classical P2P overlay network is more easily implemented.For building a high-performance application-level multicast system, the key part is how to construct a stable distribution tree and adapt to network dynamics. This article proposed application-layer multicast system CPN-Multicast based on the construction of CPN, utilize of the features of CPN grouping, address a model of multiple multicast source, multi-session, using each group to provide redundant services, has good fault tolerance. In this paper, adapt to the dynamic changes of the network, we also propose "quick switch" and load balancing adaptive algorithm, which makes the multicast system is easily used for large-scale multicast networks. Simulation results show that the multicast model compared to common application-layer multicast overlay network model has better performance.