Service Deployment Model with Virtual Network Function Resizing

This paper proposes a service deployment model for network function virtualization to minimize the deployment cost with capacity sharing and priority queuing. A service provider needs to allocate the the required virtual network functions (VNFs) to hosts, with satisfying different requirements on service delay. In the previous work, it has been studied that multiple services share a VNF instance whose computing capacity is fixed; different VNF instances do not share their computing resources. In the proposed model, VNF instances on the same host share the computing capacity in the host by VNF resizing during runtime. In addition, the priority queuing system is applied to each host. We formulate the proposed model as an optimization problem to minimize the service deployment cost. We develop a solution strategy named FlexSize to solve it heuristically in practical time. We evaluate the proposed model with a baseline which does not share the computing capacity among VNF instances in the host. The numerical results show that the proposed model reduces the service deployment cost compared with the baseline.