Criticality analysis of Internet infrastructure

The Internet has evolved into an indispensable component of our daily lives and protecting its critical infrastructure has thus become a crucial task. In this work, we present and compare different methods to assess the criticality of individual facilities of the Internet infrastructure at a national-level: graph-theoretical analysis, route-based analysis, traffic-based analysis, and consequence-based analysis. Our key observations are: (1) The geographical topology, which is derived from a national-level IP backbone network, has a power-law degree distribution and is a small-world network; (2) A few locations appear much more frequently among all paths in the IP backbone topology than others, and they also witness a high percentage of US Internet traffic. (3) Relative ranking of Internet facility locations from traffic-based analysis differs significantly from those derived from graph-theoretical analysis and route-based analysis, suggesting that a comprehensive, high-fidelity Internet model is necessary to assess critical Internet infrastructure facilities. (4) Consequence-based analysis, although computationally intense, cannot be replaced by other rankings, including traffic-based analysis. Conclusions drawn from this work extend our knowledge regarding the Internet and also shed lights on which critical Internet infrastructure facilities should be protected with limited resources.