Analyzing failure frequency and severity in communication networks

Methods for analyzing failures in communication networks are described and a new method is proposed. Failure frequency and severity are important as criteria to evaluate the impacts of failures on users and network operation. The time trend of failure frequency is analyzed by using the cumulative number failures, and the failure severity is described by the product of outage time and the number of users affected by a failure. The relationship of failure frequency and severity is estimated by the generalized Pareto probability distribution. Examples of analyzing failures by using the outage data collected in an actual communication network are presented. The proposed method facilitates the operation and management of carrier-grade communication networks provided to millions of end users. Our proposed method can be flexibly applied to various types of network structures and has been used successfully in our work.