Reliability and availability analysis for large networking system

More business applications such as voice, e-commerce, storage and trading are migrated from single purpose communication network to converged IP network, thus the reliability and availability of an IP based system becomes critical. A reliability modeling tool is needed to analyze the reliability and availability of the complex IP networking system. The modeling tool needs to capture complex redundancy behavior, including M-of-N redundancy, imperfect switchover, unplanned hardware and software failures as well as planned software upgrades. Meanwhile, the tool needs to be user friendly for the engineering community. In this paper, we developed a reliability and availability analysis tool for large IP based networking system. The tool uses steady state markov transition diagrams to model the availability of M-of-N redundant components, active-standby and load-sharing redundant schemes, switchover success probability, switchover time, and both unplanned and planned failures. A user-friendly Excel format is also developed to make the complicated model easy to use.