Observing the evolution of internet as topology

Abstract

Characterizing the evolution of Internet topology is important to our understanding of the Internet architecture and its interplay with technical, economic and social forces. A major challenge in obtaining empirical data on topology evolution is to identify real topology changes from the observed topology changes, since the latter can be due to either topology changes or transient routing dynamics. In this paper, we formulate the topology liveness problem and propose a solution based on the analysis of BGP data. We find that the impact of transient routing dynamics on topology observation decreases exponentially over time, and that the real topology dynamics consist of a constant-rate birth process and a constant-rate death process. Our model enables us to infer real topology changes from observation data with a given confidence level. We demonstrate the usefulness of the model by applying it to three applications: providing more accurate views of the topology, evaluating theoretical evolution models, and empirically characterizing the trends of topology evolution. We find that customer networks and provider networks have distinct evolution trends, which can provide an important input to the design of future Internet routing architecture.

Cyclops

“…some neighbors in x's ground truth may be invisible in Public-View. However by accumulating the observation of x's neighbors over time, one can significantly reduce the differences [22]. At the same time, accumulating the observed x's connectivity over time can also introduce stale links that are no longer exist, hence contributing to the difference between inferred connectivity and ground truth.…”

“…The first two causes of the differences, namely invisible or stale AS links in the inferred topology, result from limitations of the measurement infrastructure and have been mitigated to a certain degree recently [21,22]. The third cause is the results of faults or malicious attacks, which can affect data delivery to AS-x or to other ASes.…”

“…As noted by [22], changes in the observed topology may not correspond to changes in the real topology, e.g. a link Figure 7: Activity graph.…”

“…This topology collection effort has enabled us to observe the Internet topology growth [22] as well as to qualify the completeness of the collected topology as compared to the actual AS connectivity [21]. More recently, when we shared the inferred AS connectivity information with network operators, some operators detected network misconfigurations by comparing their expected AS connectivity with our inferred connectivity, showing us the potential of applying our inferred topology connectivity to fault detection in the global routing system.…”

Research on a Scale-Free Network with Tunable Clustering Coefficient

“…Many illuminated as follows: networks were put forward after that, such as evolved BA model, which took account of reconnection; local-world A. Degree distribution P(k) evolving network model and all kinds of evolving models based on local-world [4][5][6][7] , which model the local world effect.…”