Robustness Analysis of Australia's Internet Using a Multilayer Network Model
For Australian Internet infrastructure planners, this work demonstrates the importance of a diverse network ecosystem for resilience, though it is an incremental application of existing multilayer network models to a specific case.
The study models Australia's Internet as a multilayer network of six major ISPs and an IXP layer, finding that network diversity provides redundancy against failures, even when shared risks are present.
Australia depends on an Internet built from multiple networks of long-haul links. We study the interactions of these independent provider networks to investigate how the peering between these networks provides redundancy for failures on a single network, as well as the potential vulnerabilities introduced by failures of Shared Risk Link Groups (SRLGs), whereby ostensibly independent links of different providers fail simultaneously due to joint physical dependencies such as shared conduits. We introduce a generalised multilayer network model in which each layer represents the network of an individual Internet Service Provider (ISP), along with an Internet Exchange Point (IXP) layer that facilitates interconnections between ISP networks. We construct an Australia-specific model, consisting of six major ISPs. A failure analysis is performed on this network, revealing that diversity provides redundancy, even in the presence of shared risks, indicating the importance of a diverse network ecosystem.