Network outage impact measures for telecommunications

Standard measures do not adequately reflect the importance of the very large and significant outages that can now occur in the modern telecommunications networks. The impact measure developed originally at Bellcore that is the basis for the new T1A1 measure of network performance is described. We assumed a useful impact measure must: (a) appropriately order a set of outages by the severity of the outages, and (b) allow for meaningful comparisons of network performance on a yearly or quarterly basis. Comparisons of the new impact measure to some standard measures of reliability illustrate that the new measure provides a significant improvement in the ability to assess the severity of individual outages, and the performance of the network over a given time period. Also provided are examples consistent with network performance which illustrate that the new impact measure is more consistent with the actual assessment of the network performance than other proposed measures of reliability.