Adaptive marking threshold method for delay-sensitive TCP in data center network

Due to the highly dynamic traffic load, providing delay-sensitive services is a challenge in data centers. Many recent transport protocols, such as DCTCP, D2TCPD2TCP, and L2DCT, use Explicit Congestion Notification (ECN) to control the switch queue length for achieving low-latency transmission. However, the original ECN marking threshold fails to make real-time tradeoff between bottleneck link utilization and queueing delay, thereby increasing the flow completion time. In this paper, we propose Adaptive Marking Threshold (AMT), which proactively tunes the marking threshold to eliminate the unnecessary queueing delay, and maintains high link utilization at the same time. The experimental results of NS2 simulation and physical testbed show that AMT significantly reduces the flow completion time of typical applications across different network scenarios with negligible change in the data center switch.