An Approach to the Analysis of Possible Structural Damages in Multicommodity Network Systems

Within the formalism of the multicommodity flow model, changes in the functional characteristics of a multiuser network after a damage are studied. To analyze the original limiting capabilities of the system, the maximum flow is calculated for each pair of vertices independently of other pairs. All edges of the corresponding minimum cut are removed, and the maximum possible flows for all origin–destination pairs are found in the damaged network and compared with their initial values. The detriment is evaluated for various cuts (structural damages). The influence of structural damages on the attainable values of the flow for each pair of vertices is investigated. This makes it possible to rank the origin–destination pairs by their susceptibility to the influence of damages from a given class. Ranking is performed on the basis of a bi-criteria detriment evaluation model. This approach is used for analyzing the vulnerability of large territory distributed systems, including telecommunication systems, communication and control systems.