TCP Congestion Control(3)

最新推荐文章于 2025-09-11 22:47:27 发布

转载最新推荐文章于 2025-09-11 22:47:27 发布 · 83 阅读

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原文链接：http://www.cnblogs.com/geeklove01/p/9765828.html

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#网络

本文详细解析了TCP协议中的快速重传和快速恢复算法。当接收到第三个重复ACK时，将执行以下操作：更新ssthresh，执行快速重传并调整cwnd，临时增加cwnd以响应每个接收的重复ACK，以及在接收到有效ACK后重置cwnd。这些步骤共同构成了快速恢复过程。

Standard TCP

When fast retransmit is invoked because of receipt of a third duplicate ACK (or other signal, if conventional fast retransmit initiation is not used), the follow- ing actions are performed:

1. ssthresh is updated to no more than the value given in equation [1].
2. The fast retransmit algorithm is performed, and cwnd is set to (ssthresh + 3*SMSS).

3. cwnd is temporarily increased by SMSS for each duplicate ACK received.

4. When a good ACK is received, cwnd is reset back to ssthresh.

The actions in steps 2 and 3 constitute fast recovery.

Step 2 first adjusts cwnd, which usually causes it to be reduced to half of its former value, and then tempo- rarily inflates it to take into account the fact that the receipt of each duplicate ACK indicates that some packet has left the network (and thus should permit another to be inserted).

en: 778 cn: 544

Evolution of the Standard Algorithms

//todo

转载于:https://www.cnblogs.com/geeklove01/p/9765828.html