A cost-efficient, load-balanced and fragmentation-aware approach for deployment of VNF service chains in Elastic Optical Networks

Abstract

By emerging Network Function Virtualization (NFV), service providers use VNFs (Virtual Network Functions) and VNF service chain (VNF-SC) as an agile, scalable, and cost-efficient way for providing new network services. As traditional backbone networks fail to deal with the high volume and burstiness of traffic patterns generated by today popular services, using Elastic Optical Networks (EONs) for interconnecting data centers (inter-DC EONs) gets more attention. EONs are an ideal backbone for supporting NFV technology and transporting VNF-SC heterogeneous traffics. In this paper, we propose a solution named CELFA for the problem of VNF-SC deployment to minimize resource costs, balance resource utilization, and avoid spectrum fragmentation in EONs. At first, to find an optimal solution for saving computing and optical resources, we formulate the VNF placement problem as an Integer Quadratic Program (IQP). Then, we propose an efficient load-balanced and fragmentation-aware algorithm for the problem of Routing and Spectrum Assignment (RSA). The performance of the proposed strategy is evaluated based on resource balancing and blocking probability metrics. The simulation results verify that the proposed algorithm outperforms existing algorithms in terms of all important metrics.