SDN Based Traffic Aware Placement of NFV Middleboxes
Network function virtualization (NFV) enables flexible deployment of middleboxes as virtual machines running on general hardware. Since different middleboxes may change the volume of processed traffic in different ways, improper deployment of NFV middleboxes will result in hot spots and congestion. In this paper, we study the traffic changing effects of middleboxes, and propose software defined networking based middlebox placement solutions to achieve optimal load balancing. We formulate the traffic aware middlebox placement (TAMP) problem as a graph optimization problem with the objective to minimize the maximum link load ratio. First, we solve the TAMP problem when the flow paths are predetermined, such as the case in a tree. For a single flow, we propose the least first greatest last (LFGL) rule and prove its optimality; for multiple flows, we first show the NP hardness of the problem, and then propose an efficient heuristic. Next, for the general TAMP problem without predetermined flow paths, we prove that it is NP hard even for a single flow, and propose the LFGL based MinMax routing algorithm by integrating LFGL with MinMax routing. We use a joint emulation and simulation approach to evaluate the proposed solutions, and present extensive experimental and simulation results to demonstrate the effectiveness of our design.
IEEE Transactions on Network and Service Management