Robustness Analysis of Australia's Internet Using a Multilayer Network Model

2026-06-17

AI Summary

This study evaluates the robustness of the Australian Internet under single-point failures and Shared Risk Link Group (SRLG) disruptions. By constructing a multilayer network model encompassing six major Internet Service Providers (ISPs) and their interconnection points at Internet Exchange Points (IXPs), it applies a general multilayer modeling framework to national Internet infrastructure for the first time, explicitly capturing the interplay between ISP and IXP layers. Integrating SRLG analysis, failure simulations, and redundancy assessments, the research reveals that despite underlying physical co-location risks, a diverse ISP ecosystem substantially enhances system redundancy, underscoring the critical role of network diversity in bolstering national Internet resilience.

Abstract

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.

Problem

• Internet robustness
• multilayer network
• Shared Risk Link Groups
• network redundancy
• ISP interconnection

Innovation

• multilayer network model
• Shared Risk Link Groups
• Internet Exchange Point
• network robustness
• ISP interconnection