An Enhanced Congestion Control Mechanism in InfiniBand Networks for High Performance Computing Systems

InfiniBand is quickly becoming the choice of interconnection networks for high performance computing (HPC) systems. It defines a system area network (SAN) environment where multiple processor nodes and I/O devices are interconnected using a switched point-to-point network. The unique characteristics of InfiniBand networks, such as no packet dropping, small buffer size and low latency, make the congestion control different from the traditional mechanisms for other high-speed networks and propose more challenges. This paper presents an improved explicit congestion notification (ECN) packet marking mechanism for InfiniBand. In addition, we propose an effective source response function-power increase and power decrease (PIPD), which adopts the rate control with a window, limit to reduce congestion of multiple-class traffic in InfiniBand networks. Simulation experiments have demonstrated that the proposed new resource response function is quite effective in InfiniBand networks and outperforms the existing ECN schemes