Chapter 8 – 8. Congestion Management in TCP Storage Networks

NVMe/TCP I/O Operations

Figure 8-7shows NVMe/TCP Read I/O Operation. A host (initiator) initiates a read I/O operation over a TCP connection to the target, which is called a controller in NVMe terminology. The target sends data to the host in one or more packets based on the amount of data requested by the I/O Operation (I/O size), the MTU of the network, and the MSS of the TCP connection. Finally, the I/O operation completes when the target sends a Response. 图 8-7 显示了 NVMe/TCP 读 I/O 操作。主机（启动器）通过 TCP 连接向目标（NVMe 术语中称为控制器）发起读取 I/O 操作。目标机根据 I/O 操作要求的数据量（I/O 大小）、网络的 MTU 和 TCP 连接的 MSS，以一个或多个数据包的形式向主机发送数据。最后，当目标机发送 “响应 “时，I/O 操作完成。

Figure 8-7NVMe/TCP Read I/O Operation

Figure 8-8shows NVMe/TCP Write I/O Operation. A host (initiator) initiates a write I/O operation over a TCP connection to the target or controller. The target sends a Ready2Transfer (R2T). This is optional. The initiator sends data to the target in one or more packets based on the amount of data requested by the I/O Operation (I/O size), the MTU of the network, and the MSS of the TCP connection. Finally, the I/O operation completes when the target sends a Response. 图 8-8 显示 NVMe/TCP 写 I/O 操作。主机（启动程序）通过 TCP 连接向目标机或控制器发起写 I/O 操作。目标机发送 Ready2Transfer (R2T)。这是可选项。启动程序根据 I/O