A Graph-Theoretic QoS-Aware Vulnerability Assessment for Network Topologies

How to assess the topology vulnerability of a network has attracted more and more attentions recently. Due to the rapid growing number of real- time internet applications developed since the last decade, the discovery of topology weakness related to its quality of service (QoS) is of more interest. In this paper, we provide a novel QoS-aware measurement for assessing the vulnerability of general network topologies. Specifically, we evaluate the vulnerability by detecting the minimum number of link failures that decrease the satisfactory level of the QoS-Optimal source- destination path to a given value, which means a topology with a smaller amount of such link failures is more vulnerable. We formulate this process as a graph optimization problem called QoSCE and provide several exact and heuristic algorithms for various QoS constraint amounts. To our best knowledge, this is the first graph-theoretical framework to evaluate QoS-aware topology vulnerability. Through extensive simulations, the performance of the proposed algorithms are validated in terms of assessment accuracy and time complexity.