The article presents the main directions of the qualitative and quantitative assessment of sustainability in the field of infocommunications, shows the differences in approaches to the definition of sustainability. A method is proposed that differs from the known well-grounded application of the provisions of the theory of random impulse flows. The generalized impulse flow describes the robustness of data transmission in the information direction. The estimation method allows one to take into account both the states of the elements of a composite channel, represented by impulse flows of failures and restorations, and transient processes and sub-processes of information exchange (transmission over a communication line, switching, storage in memory, destructive influences, etc.), represented by separate impulse streams. The variability of the composition of the impulse streams makes it possible to increase the accuracy and reliability of the assessment.