Abstract

This work addresses the study of Chilean Internet robustness in how an outage at the physical layer (Internet backbone) affects the upper layer (BGP network) that routes from/to Internet Service Providers. We propose a novel way to model the Internet physical and logical networks coupled as an interdependent system, and study the effect of the shape in which the physical network is built and the interconnection level on the robustness of the whole interdependent system. We study three cases of simulated Internet structures with width and length proportions ranging from 1:1 to 1:25, where each case has the same overall area. Here 1:25 corresponds to the proportions of Chile, while 1:1 represents a square space. For each case we studied five scenarios of interdependent connections in order to determine the relation between network robustness, and its shape and interconnections. Our main findings are: (1) the shape area where physical network is located affects the overall robustness making the interdependent networks more fragile as the shape becomes narrower, and (2) this effect can be diminished on interdependent systems increasing the number of inter-links.