TCP/IP 详解卷1 ch20 TCP Bulk Data Flow

滑动窗口协议解析

于 2010-11-12 16:06:00 发布 · 96 阅读

文章标签：

#网络

本文详细介绍了滑动窗口协议的工作原理及其特点。包括窗口关闭、打开及缩小的过程，发送方无需等待完整窗口的数据即可发送，并且接收方可以不等到窗口满就发送确认。此外，还解释了窗口大小变化的条件及限制。

1. 滑动窗口协议

1） The window closes as the left edge advances to the right. This happens when data is sent and acknowledged.

2） The window opens when the right edge moves to the right, allowing more data to be sent. This happens when the receiving process on the other end reads acknowledged data, freeing up space in its TCP receive buffer.

3） The window shrinks when the right edge moves to the left.

2. 总结滑动窗口

1） The sender does not have to transmit a full window's worth of data.

2） One segment from the receiver acknowledges data and slides the window to the right. This is because the window size is relative to the acknowledged sequence number.

3） The size of the window can decrease, but the right edge of the window must not move leftward.

4） The receiver does not have to wait for the window to fill before sending an ACK. We saw earlier that many implementations send an ACK for every two segments that are received.