Service Deployment Model Based on Virtual Network Function Resizing

Network function virtualization enables to deploy network services more flexibly with virtual network functions (VNFs). A service provider needs to allocate the required VNFs to hosts, with satisfying different requirements on service delay. It is challenging for service providers to deploy services as efficiently as possible. The previous work has addressed this challenge by studying that multiple services share a VNF instance whose computing capacity is fixed; different VNF instances do not share their computing resources. More efficiency is expected with sharing resources among different VNF instances. This paper proposes a service deployment model for network function virtualization to minimize the deployment cost with capacity sharing and priority queuing. 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.