互联网AS级拓扑的局部聚团现象研究

Research on Local Clustering of the Internet AS Level Topology

互联网AS级的拓扑是互联网的核心协议BGP4赖以运行的基础,它对于路由的分析和研究具有重要的指导作用。但是,对于拓扑本身的研究却不如对于协议的研究来得全面和深入。聚团性是复杂网络的一个重要特性,它源于小世界网络模型,通常都用聚集系数来衡量。但聚集系数是一个宏观的度量参数,无法度量某些局部的微观聚团现象。本文将从不同的角度量化验证互连网AS级拓扑的强局部聚团现象。同时,通过量化分析指出PFP模型——目前被认为最准确的互联网AS拓扑模型——无法模拟互联网AS级拓扑的局部聚团现象。

The Internet AS level topology, upon which BGP4 runs, plays a vital role in the analysis and study of the global routing behavior. However, the study of the topology itself is not as comprehensive and extensive as the protocol. Clustering, originating from the small-world concept, is often measured by the clustering coefficient--a macroscopic topological metric. Nevertheless, macroscopic metric cannot determine the microscopic behavior. In this paper, the inherent microscopic local clustering behavior of the Internet AS level topology is studied from several perspectives. The presence of strong local clustering in the AS graph is quantitatively verified along with the demonstration of the weakness for PFP model-which is regarded as the most accurate Internet AS level topology generator to date-to capture it.