Design of a load-balancing middlebox based on SDN for data centers

Modern cloud-based applications are becoming more communication-intensive, posing a challenge for data centers to supply sufficient bandwidth. Current data centers are not optimized for such cloud-based software services. In practice, due to the variability of traffic load, data centers may suffer from lower throughput, as well as higher latency, dramatically reducing quality of service (QoS). This paper addresses this challenging problem by introducing a programmable middlebox that can distribute traffic more evenly. The middlebox is based on a Clos network design and uses Software Defined Networking (SDN) to enhance bandwidth utilization while guaranteeing QoS. The SDN controller of the middlebox collects information from switches and servers to learn the traffic distribution and server loads and to perform load balancing accordingly. When implemented in a data center, the middlebox can greatly improve bandwidth utilization and reduce latency up to 50%. Since the middlebox does not rely on any specific feature of the data center, it can readily be deployed in current data centers.