Throughput Maximization of NFV-Enabled Unicasting in Software-Defined Networks.

Data transfers in contemporary networks usually have associated enforcement policies to ensure data transfer security and system performance. These policies are represented by a service chain that consists of different network functions such as firewalls, Intrusion Detection Systems (IDSs), transcoders, etc. Network Function Virtualization (NFV) has emerged as a promising technology to meet the stringent requirement imposed on the service chain. In this paper, we study NFV-enabled unicasting in SDNs with and without end-to-end delay constraints. We aim to maximize network throughput by dealing with a sequence of NFV-enabled unicast requests without the knowledge of future request arrivals. We first formulate the problems as novel optimization problems in terms of both computing and bandwidth resource consumptions, and provide a generic optimization framework for it. We then develop an online algorithm with guaranteed performance for the problem without the delay requirement and a heuristic with the delay requirement. We finally evaluate the performance of the proposed algorithms through experimental simulations. The results of experimental simulations show that the proposed algorithms are promising.