Dependability Measures for Access Networks and Their Evaluation

One of the most important characteristics of any communication networks is dependability, and the dependability requirements are increasing with the expansion and intensification of usage of information and communication systems. This paper analyzes dependability measures for access networks and gives recommendations for their usage. The existing measures such as availability and the Failure Impact are discussed. To assess the dependability from the network operator’s point of view, it is proposed to use the effectiveness retention ratio. It allows evaluating the whole network taking into account various partial failures. Methods for calculating this measure are given and its relationships with other measures, in particular, with end-to-end and full-end network availability, are revealed.