Internet Autonomous System Level Topology Optimization Of The Model

In the past few years, there has been increasing interest in studying complex network as relevant to many areas of science. Complex network is different from former network. It is dynamic, growing, and great-hearted. In the part aspect, complex network is disorder. But in the whole aspect, complex network has small-world, high-clustered and scale-free character. Since BA model was put forward, there has been a great concern on complex network. The Internet has experienced a tremendous growth in its size and complexity since its commercialization. Until now, either network researchers or people who research on topology theory have agree on a unified metrics set to characterize a topology graph. Therefore, it is still an open question for researchers.Many topology generators have been created to model network,especially Internet, to implement simulations. As the base of Internet development and exploitation on higher levels, the Internet topology modeling starts from the random model to the hierarchical model. Then it developed to a more realistic one, the scale-free network model.Based on the results of former researchers, we have done the research as follows:1.We analyze current main topology models such as Waxman and so on. Thinking about average degree and clustering coefficient and characteristic path length, we compare the advantage and disadvantage between current topology models.2.We have studied AS level topology of Internet and the form of power-law. PLOD is a network topology generating algorithm for power-laws. But PLOD cannot guarantee the connectivity of the topology.Futhermore, PLOD has the"credit overstock"problem.Based on PLOD, PLOD+ adds the connectivity check and gives link preference to nodes which have more out-degrees. PLOD+ ensures the connectivity and mitigates the"credit overstock"problem. The experiment indicates feasibility and efficiency of PLOD+.3.Recent work has shown that the Internet topology has two properties: (1)The Internet is a hierarchical network; (2)The Internet topology in AS-level follows power-law degree distribution. By integrating the power-law degree distribution and the hierarchical structure, we present a hierarchical network topology generating algorithm for power-law HIPL. HIPL is verified by simulation. With the parameters identified from real Internet data, HIPL captures the hierarchical structure and power-law degree distribution well. The experiments concern with the topological properties such as clustering coefficient, diameter, average degree and so on.