Robust Multipath Multicast Routing Algorithms for Videos in Software-Defined Networks

IP multicast dictates high-end routers and incurs high administrative overhead, which prevent them from being deployed in many video streaming scenarios. In this paper, we study the problem of computing the multipath multicast routes for streaming videos in Software-Defined Networks (SDNs), which adopt less expensive switches and reduce administrative overhead for lower CAPEX/OPEX. The objectives of the considered problem are robustness, load balance, SDN compatibility, and adaptiveness. We formulate this routing problem into a mathematical optimization problem, and propose two algorithms to address this problem. We implement the proposed algorithms on a popular OpenFlow controller to demonstrate its practicality, and we conduct extensive experiments to evaluate the proposed algorithms. The experiment results clearly show the merits of our algorithms over the IP multicast, e.g., we observe: (i) frame loss rate reduction between 19% and 95%, (ii) video quality improvement between 4 dB and 15 dB, (iii) sink throughput increase between 25% and 66%, and (iv) maximal link utilization reduction between 15% and 50%. We also show the tradeoff between optimality and run time of the two proposed algorithms: one of them is more suitable for smaller and more static networks, and the other one is more suitable for larger and more dynamic networks.