Study About Global Anycast Model Under IPv6 Environment

With the rapid development of computer network technology, Internet has already become the greatest-scalable network in the world. After astonished growths for 20 year in the 20th century, IPv4 had already gradually approached its limit. IPv6 solution brings new opportunity and challenge to the 21st century in information technology and new service. In Internet, in order to provide better service for replication or mirroring server, Mendez and Milliken proposed Anycast concept in RFC1546. As Unicast and Multicast, Anycast is a kind of IP communication service. Based on the command, anycast address standard has been formulated in IPv6, which anycast is supported, it brings a broader space for further research and application in the Anycsat technology.At present, the anycast researcher mainly concentrates on following several aspects: the routing protocol, stateless service, group management, LAN communications, address space, security, QoS, scalability etc. The protocols and standards for anycast are under the discussion, but have not reached a consensus. The Anycast technology mainly has two research directions at present. One is on the application layer research; The other is on network layer research.Base on pervious research, the thesis presents routing algorithm and protocol, server selection, the scalability of anycast, and group management. In order to find "the most appropriate" server, a new kind of compound measurement description method is proposed in view of the different type service to modify anycast routing algorithm. Considered the factors of link bandwidth, link delay, route hop and server load, the algorithm can balance network load and enhance the network performance to some extent. To solve the problem of anycast scale, the reasonable address structure is setup properly and anycast gateway is deployed at the network boundary. GIA (Global IP Anycast) is well supported by the method proposed. And then, a IPv6 global anycast model is proposed. The model combines the advantages of network layer and application layer, It' s easy-achieving, flexible, extensible and secure, which provides references and...