In the Ethernet lossless Data Center Networks (DCNs) deployedwith Priority-based Flow Control (PFC), the head-of-line blocking problemis still difficult to prevent due to PFC triggering under burst trafficscenarios ev...In the Ethernet lossless Data Center Networks (DCNs) deployedwith Priority-based Flow Control (PFC), the head-of-line blocking problemis still difficult to prevent due to PFC triggering under burst trafficscenarios even with the existing congestion control solutions. To addressthe head-of-line blocking problem of PFC, we propose a new congestioncontrol mechanism. The key point of Congestion Control Using In-NetworkTelemetry for Lossless Datacenters (ICC) is to use In-Network Telemetry(INT) technology to obtain comprehensive congestion information, which isthen fed back to the sender to adjust the sending rate timely and accurately.It is possible to control congestion in time, converge to the target rate quickly,and maintain a near-zero queue length at the switch when using ICC. Weconducted Network Simulator-3 (NS-3) simulation experiments to test theICC’s performance. When compared to Congestion Control for Large-ScaleRDMA Deployments (DCQCN), TIMELY: RTT-based Congestion Controlfor the Datacenter (TIMELY), and Re-architecting Congestion Managementin Lossless Ethernet (PCN), ICC effectively reduces PFC pause messages andFlow Completion Time (FCT) by 47%, 56%, 34%, and 15.3×, 14.8×, and11.2×, respectively.展开更多
无损以太网对于数据中心网络有着很强的吸引力,如今为了实现无损这一目的,诞生了很多新的拥塞控制协议如Data Center TCP(DCTCP)、Quantized Congestion Notification(QCN)、Data Center Quantized Congestion Notification(DCQCN)等。...无损以太网对于数据中心网络有着很强的吸引力,如今为了实现无损这一目的,诞生了很多新的拥塞控制协议如Data Center TCP(DCTCP)、Quantized Congestion Notification(QCN)、Data Center Quantized Congestion Notification(DCQCN)等。对DCTCP、DCQCN等拥塞控制算法进行仿真实验,分析不同的拥塞控制在数据中心网络模型中应对大量突发流的情况,并分析其中存在的拥塞扩散、发送源阻塞、死锁等问题。针对这些问题进行改进,提出融合控制拥塞通知(Fusion Control Congestion Notification,FCCN),以改善拥塞扩散和死锁问题,减少了拥塞控制的吞吐量损失。多次仿真结果表明提出的FCCN方法在不丢包的情况下应对的突发流达到DCTCP的1.5倍,同时突发流对于整个网络吞吐量的下降减少了20%,延迟减少了25%。展开更多
无损压缩在遥感领域有极其重要的作用。该文提出一种基于感知器模型的遥感图像无损压缩编码方法,该方法利用感知器具有学习能力的特点,自适应地调整图像的预测系数,对遥感图像进行空间和谱间去相关,然后进行熵编码。实验表明,对于多波...无损压缩在遥感领域有极其重要的作用。该文提出一种基于感知器模型的遥感图像无损压缩编码方法,该方法利用感知器具有学习能力的特点,自适应地调整图像的预测系数,对遥感图像进行空间和谱间去相关,然后进行熵编码。实验表明,对于多波段的遥感图像,该方法的压缩效果明显优于无损JPEG(Joint of Picture Expert Group)最优预测模式。展开更多
基金supported by the National Natural Science Foundation of China (No.62102046,62072249,62072056)JinWang,YongjunRen,and Jinbin Hu receive the grant,and the URLs to the sponsors’websites are https://www.nsfc.gov.cn/.This work is also funded by the National Science Foundation of Hunan Province (No.2022JJ30618,2020JJ2029).
文摘In the Ethernet lossless Data Center Networks (DCNs) deployedwith Priority-based Flow Control (PFC), the head-of-line blocking problemis still difficult to prevent due to PFC triggering under burst trafficscenarios even with the existing congestion control solutions. To addressthe head-of-line blocking problem of PFC, we propose a new congestioncontrol mechanism. The key point of Congestion Control Using In-NetworkTelemetry for Lossless Datacenters (ICC) is to use In-Network Telemetry(INT) technology to obtain comprehensive congestion information, which isthen fed back to the sender to adjust the sending rate timely and accurately.It is possible to control congestion in time, converge to the target rate quickly,and maintain a near-zero queue length at the switch when using ICC. Weconducted Network Simulator-3 (NS-3) simulation experiments to test theICC’s performance. When compared to Congestion Control for Large-ScaleRDMA Deployments (DCQCN), TIMELY: RTT-based Congestion Controlfor the Datacenter (TIMELY), and Re-architecting Congestion Managementin Lossless Ethernet (PCN), ICC effectively reduces PFC pause messages andFlow Completion Time (FCT) by 47%, 56%, 34%, and 15.3×, 14.8×, and11.2×, respectively.
文摘无损以太网对于数据中心网络有着很强的吸引力,如今为了实现无损这一目的,诞生了很多新的拥塞控制协议如Data Center TCP(DCTCP)、Quantized Congestion Notification(QCN)、Data Center Quantized Congestion Notification(DCQCN)等。对DCTCP、DCQCN等拥塞控制算法进行仿真实验,分析不同的拥塞控制在数据中心网络模型中应对大量突发流的情况,并分析其中存在的拥塞扩散、发送源阻塞、死锁等问题。针对这些问题进行改进,提出融合控制拥塞通知(Fusion Control Congestion Notification,FCCN),以改善拥塞扩散和死锁问题,减少了拥塞控制的吞吐量损失。多次仿真结果表明提出的FCCN方法在不丢包的情况下应对的突发流达到DCTCP的1.5倍,同时突发流对于整个网络吞吐量的下降减少了20%,延迟减少了25%。
文摘无损压缩在遥感领域有极其重要的作用。该文提出一种基于感知器模型的遥感图像无损压缩编码方法,该方法利用感知器具有学习能力的特点,自适应地调整图像的预测系数,对遥感图像进行空间和谱间去相关,然后进行熵编码。实验表明,对于多波段的遥感图像,该方法的压缩效果明显优于无损JPEG(Joint of Picture Expert Group)最优预测模式。
