Minimum Cost Hybrid Node Protection in NFV

In network function virtualization (NFV), the customer’s service requests are delivered by going through a set of deployed service functions (SFs). To accommodate customer’s requests, service providers have to install the required SFs onto a physical network (PN) and route the traffic through the installed SFs to form a traffic forwarding path called the service function path (SFP). Any failures of physical nodes or SF instances can significantly impact the service delivery. In the literature, existing work has focused on how to protect the PN from physical node failures. Few research attention has been paid to efficiently protecting the network while jointly taking physical and virtual node failures into consideration. In this work, we investigate a novel minimum cost hybrid node protection (MC-HOP) problem, which is proved to be an NP-hard problem. We propose an efficient algorithm called minimum cost pairwise node assistance (NOTION) to optimize the MC-HOP problem with latency requirements. Extensive simulations and analysis show that the proposed scheme significantly outperforms the algorithms that are directly extended from the existing work.