Probius: Automated Approach for VNF and Service Chain Analysis in Software-Defined NFV

As the complexity of modern networks increases, virtualization techniques, such as software-defined networking (SDN) and network function virtualization (NFV), get highlighted to achieve various network management and operating requirements. However, those virtualization techniques (specifically, NFV) have a critical issue that the performance of virtualized network functions (VNFs) is easily affected by diverse environmental factors (e.g., various workloads, resource contentions among VNFs), so resulting in unexpected performance degradations - performance uncertainty. Unfortunately, existing approaches mostly provide limited information about a single VNF or the underlying infrastructure (e.g., Xen, KVM), which is deficient in reasoning why the performance uncertainties occur. For such reasons, we first deeply investigate the behaviors of multiple VNFs along service chains in NFV environments, and define a set of critical performance features for each layer in the NFV hierarchical stack. Based on our investigations and findings, we introduce an automated analysis system, Probius, providing the comprehensive view of VNFs and their service chains on the basis of NFV architectural characteristics. Probius collects most possible NFV performance related features efficiently, analyzes the behaviors of NFV, and finally detects abnormal behaviors of NFV - possible reasons of performance uncertainties. To show the effectiveness of Probius, we have deployed 7 open-source VNFs and found 5 interesting performance issues caused by environmental factors.