Adaptive and Flexible SDN-based Multicast for Efficient Data Center Networking

Data center networks (DCNs) rely heavily on the use of group communications for various tasks. For example, data center management utilities (e.g., software update/upgrade, log management, resource monitoring, scaling up or down of resources, access control etc.), collaborative applications (e.g., social media, project management tools, version control systems, etc.), multimedia applications and multi-player on-line games are few examples of tasks that require efficient group communications. Although multicast is useful for efficient group communications, IP multicast has seen very low deployment in the data center networks due to its shortcomings, such as inefficient switchmemory, inability to adapt to network load, and initial receiver latency due to the creation of multicast routing tree. Even with the advent of Software-defined Networking (SDN), which makes it easier to implement multicast in the SDN controller, this approach too faces many challenges. In this paper we propose a novel approach to using SDN-based multicast (SDMC) for flexible, network-load aware, and switchmemory efficient group communication, suitable particularly to data center networks. Our SDN-based multicast adaptively uses a combination of unicast and software-defined multicast by switching between the two at run-time while ensuring that the application remains agnostic to this adaptation and to find a better trade-off to retain the benefits of group communication while avoiding its disadvantages. We describe the design and implementation of SDN-enabled Multicast using SDN controllers and OpenFlow-enabled switches, and evaluate it along a number of metrics, such as initial receiver latency, network loadawareness, and switch-memory utilization efficiency.