VSPACE: VNF Simultaneous Placement, Admission Control and Embedding

In future wireless networks, network functions virtualization lays the foundations for establishing a new dynamic resource management framework to efficiently utilize network resources. In this paper, a network service can be viewed as a chain of virtual network functions (VNFs), called a service function chain (SFC), served via placement, admission control (AC), and embedding into network infrastructure, based on the resource management objectives and the state of network. To fully exploit such a potential and reach higher network performance, resource management stages should be jointly performed. To this end, two main challenges are: how to present a system model that formulates the desired resource allocation problem for different types of SFCs as well as different features, and how to tackle the computational complexity of the problem and solve it in a tractable manner. In this paper, we address these two issues and solve the joint problem of AC and SFC embedding. We introduce a comprehensive system model, and formulate the joint task as a mixed integer linear programming. This formulation encompasses splittable VNF and multi-path routing scenarios. We employ relaxation, reformulation, and successive convex approximation methods to solve the problem. Simulation results demonstrate that the proposed schemes outperform the earlier works.