A Tool for Automated Generation of Availability Models for Service Function Chains

Modern virtualized network infrastructures relying on Service Function Chaining (SFC) face new challenges in terms of availability issues related to Service Level Agreements (SLAs). In fact commercial standards for telecommunication services establish the “five nines” (or high availability) requirement which imposes a maximum (expected) tolerated downtime amounting to about 5 minutes per year. To facilitate the design of SFC-like network systems matching such availability levels, we introduce a software tool able to support network managers to automatically generate availability models for SFC structures. Such a tool embraces the Model Driven Engineering (MDE) paradigm and relies on the Stochastic Reward Networks (SRN) formalism to model the probabilistic behavior of an SFC. As a reference SFC-like infrastructure, we choose a virtualized version of IP Multimedia Subsystem (vIMS) that we characterize from an availability viewpoint through the proposed tool.