Abstract <p>The maximum indicators of the functionality of a multiuser communication system are studied under a change in the capacities in the network’s edges. Based on the transmission routes of the maximum flows of the same type, the minimal cuts of the network are determined. The influence of changes in the capacity of the cut’s edges on the maximum allowable internodal flows under monopolistic control modes is studied. The maximum values of the internodal flows correspond to the corners of the set of allowable flows satisfying the constraints of the model. A convex combination of vectors corresponding to the corners is used to estimate the relative changes in network characteristics during deformation of the set of feasible flows. Multicriteria guaranteed estimates of the maximum feasible deviations from the reference performance indicators of the network are formulated. Summary diagrams for networks with various structural features are provided.</p>