The Internet's unexploited path diversity

TL;DR

This paper models Internet connectivity at the Autonomous System level using directed graphs to quantify path diversity and reveals unexploited redundancy despite policy-imposed directionality.

Contribution

It introduces a directed graph approach to represent Internet paths and analyzes how policies affect connectivity and path diversity.

Findings

Significant path diversity remains after policy application.

Current BGP protocols do not exploit all available paths.

Directed graph analysis reveals unexploited redundancy in Internet routing.

Abstract

The connectivity of the Internet at the Autonomous System level is influenced by the network operator policies implemented. These in turn impose a direction to the announcement of address advertisements and, consequently, to the paths that can be used to reach back such destinations. We propose to use directed graphs to properly represent how destinations propagate through the Internet and the number of arc-disjoint paths to quantify this network's path diversity. Moreover, in order to understand the effects that policies have on the connectivity of the Internet, numerical analyses of the resulting directed graphs were conducted. Results demonstrate that, even after policies have been applied, there is still path diversity which the Border Gateway Protocol cannot currently exploit.