Beyond Node Degree: Evaluating AS Topology Models

TL;DR

This paper critically evaluates existing AS topology models by comparing them with observed data, revealing their inability to accurately capture local interconnection complexities and the impact of measurement locations.

Contribution

It provides a comprehensive comparison of AS topology models against real data without relying on structural assumptions, highlighting their limitations in modeling core connectivity.

Findings

Existing models match degree-based properties but miss local interconnection details.

Additional measurement points significantly influence local structure metrics.

Degree properties are stable across different measurement locations.

Abstract

Many models have been proposed to generate Internet Autonomous System (AS) topologies, most of which make structural assumptions about the AS graph. In this paper we compare AS topology generation models with several observed AS topologies. In contrast to most previous works, we avoid making assumptions about which topological properties are important to characterize the AS topology. Our analysis shows that, although matching degree-based properties, the existing AS topology generation models fail to capture the complexity of the local interconnection structure between ASs. Furthermore, we use BGP data from multiple vantage points to show that additional measurement locations significantly affect local structure properties, such as clustering and node centrality. Degree-based properties, however, are not notably affected by additional measurements locations. These observations are particularly valid in the core. The shortcomings of AS topology generation models stems from an underestimation of the complexity of the connectivity in the core caused by inappropriate use of BGP data.