On the Placement of VNF Managers in Large-Scale and Distributed NFV Systems

The European Telecommunications Standards Institute management and orchestration framework is designed to enable automated management of the network services and their corresponding virtualized network functions (VNFs). In that context, the network function virtualization (NFV) orchestrator (NFVO) manages the lifecycle of the network services and coordinates with the VNF managers (VNFMs) which manage the VNFs lifecycle. In large-scale and distributed NFV deployments, these management functions face critical challenges such as delays, and variations in VNFs workload. Placing NFVO and VNFM in a large-scale distributed NFV deployment is therefore a very challenging problem due to the potential negative impact on performance and operational cost. However, to the best of our knowledge, the problem has not yet been addressed in the literature. This paper is a first step toward a solution to the overall problem. It focuses on the VNFM placement and aims at minimizing the operational cost without violating the performance requirements. We call this the VNFM placement problem (MPP). We provide an integer linear programming formulation and propose a tabu search algorithm to solve larger instances of the MPP. We evaluate our algorithm in a real-world large-scale scenario. The results show that it leads to significant reductions in the operational cost of large-scale distributed NFV deployments.