Congestion control for RDMA with end-network collaboration in computing power network

To address the long control loop and hybrid traffic congestion issues caused by cross-domain interconnection scenarios of remote direct memory access (RDMA) technology, a congestion control method for computing power networks, named WRCC (WAN RDMA congestion control), was proposed. A fair rate computing strategy based on input rate was employed, enabling switches to accurately calculate the port fair rate of congested queues. Combined with dual control loops on the near-source switch and in-band network telemetry technology, it achieved end-network collaboration rate control and rapidly responded to congestion. Simulation experiments demonstrate that compared with existing commercial methods, WRCC reduces the average and tail flow completion time by 8%~47% and 10%~70%. Prototype system tests indicate that compared with NVIDIA CX7, WRCC reduces the tail latency by 7%~49% in short-distance scenarios. In long-distance scenarios of 640 kilometers, WRCC reduces the average and tail latency by 2%~7% and 45%~49%, while achieving the average throughput improvement of 26%~90%.