On Characterizing Network Hierarchy

Our previous work in topology characterization and hierarchy [1] introduced a hierarchy metric to explore the hierarchical structure in various networks. This metric is non-intuitive and complicated. In this paper, we propose a simpler and more natural metric for measuring network hierarchy. This simpler metric uses slightly different criteria in selecting backbone links than the more complicated one. Nevertheless, the network classifications according to both metrics agree with each other. Furthermore, we have extended the hierarchy analysis to examine path characteristics and found that the hierarchical nature of degree-based networks better resembles the hierarchy of the Internet at the AS level than at the routerlevel