Latency-aware VNF Protection for Network Function Virtualization in Elastic Optical Networks

In network function virtualization (NFV), the customer may request a set of virtual network functions (VNFs) that the customer traffic will go through. To accommodate such requests, the service providers have to embed the requested VNFs onto the substrate network (SN) to form an actual traffic forwarding path called service function path (SFP). In the elastic optical network (EON), how to protect the running network services against VNF failures becomes an attractive research focus. Most existing work concentrates on the protection or restoration of the physical node or fiber link failures in the SN. Few research attention has been paid to the failure of the virtual machines running a VNF. In this paper, we study how to protect VNFs when a VNF failure occurs in an EON. We define a new VNF failure protection cover (VFPC) problem and mathematically formulate VFPC. We propose a protection cover list based VNF protection (PCL-VP) algorithm against any single VNF failure while satisfying the latency requirement. Extensive simulations and analysis show the effectiveness of the proposed algorithm.