Pattern-Aware Reliable Virtual Network Function Chain Deployment

Network function virtualization enables network middlebox running as virtual network function (VNF) on general servers, and further be chained in a certain order to provide specific services. In order to meet reliability requirement, the VNFs need certain backups against both nodes (servers) and links failures. Previous backup strategies for VNF focuses on node failures based on an unreasonable assumption that VNFs do not share any server. In this paper, we focus on the reliable virtual network function chain (VNFC) deployment problem taking both node and link failure into consideration, with the objective to minimize loss of profit due to server energy consumption and requests rejection. We formulate reliable VNFC problem with an Integer Linear Programming model, and prove the NP-hardness. We propose an efficient pattern-aware reliable VNFC deployment strategy considering link insurance as well as node backups, which can save resources by finding patterns. Extensive simulation experiments show that, under availability constraint of each VNFC request, our strategies can reduce 18% energy consumption and increase 54.7% request accept ratio compared with greedy strategies.