Evolution of the Codebook Technique for Automatic Fault Localization

In this letter we present an evolution of the classical Codebook Technique for automatic Fault Localization, which is a well-known problem in the context of Network Fault Management. In particular, we propose two heuristics which handle multiple simultaneous faults and probabilistic fault-symptom dependencies (also in presence of lost/spurious symptoms). We have evaluated their performance by applying them to the IMS control layer of a real national-wide Next Generation Network (NGN) deploying VoIP telephony services.