Cost-Efficient Server Provisioning for Deadline-Constrained VNFs Chains: A Parallel VNF Processing Approach

The fifth generation (5G) utilizes Network Functions Virtualization (NFV) and Software Defined Network (SDN) to provide applications. Among them, there are deadline constrained applications. When the traffic generated by applications traverses Virtual Network Functions (VNFs) chains, it may not be possible to meet the deadlines when the traffic is processed sequentially; even if very fast servers are provisioned to host the VNFs. We propose a parallel VNF processing approach for the traffic. This is done through pools of candidate servers that host VNFs which process the traffic. Considering the routing policy provided by the SDN routing application, the server selection problem with the aim of deadline satisfaction and cost minimization is modeled as a non-linear binary optimization problem. An iterative search algorithm is proposed to solve this problem. Simulations show enhancement in deadline satisfaction as well as cost reduction.