Service Deployment on Shared Virtual Network Functions with Flow Partition

Network operators can operate services in a flexible way with virtual network functions thanks to the network function virtualization technology. Flow partition allows aggregated traffic to be split into multiple parts, which increases the flexibility. This paper proposes a service deployment model with flow partition to minimize the total deployment cost with meeting service time delay requirements. A virtual network function of a service is allowed to have several instances, each of which hosts a part of flows and can be shared among different services, to reduce the initial and proportional cost. We provide the mathematical formulation for the proposed model. A heuristic algorithm is introduced to solve the original problem in practical time by decomposing it into several steps; each step handles a convex problem. The numerical results reveal that the proposed model saves the total deployment cost compared to the conventional one. It improves the maximum admissible traffic scale by 23% in average in our examined cases.