A Hybrid Modelling Approach for Analyzing Service Availability with Shared Path Protection in IP Networks

For a realistic dependability evaluation, network dynamics need to be considered when modelling. Compared to models based purely on connectivity, this yields more meaningful results but also an increase of the computational complexity to analysis. In this paper, we present a modelling method for quantitative evaluation of availability attributes for end-to-end transport services protected by shared backup paths in IP networks. The network´s operational dynamics, including path planning and traffic handling, are taken into account. A hybrid modelling approach with simulation and model analysis is pursued to avoid an excessive computational effort. A case study is provided, showing the applicability of the hybrid approach.