Question

在练习练习的过程中，我遇到了以下练习，我无法绕过头脑。看看解决方案，我不知道他们如何得出第6轮传输中发送数据包32到63的结论。如何计算63？

发送第70段的传输轮次是什么时候？

解决方案：

During the 1st transmission round, packet 1 is sent; 
packet 2-3 are sent in the 2nd transmission round; 
packets 4-7 are sent in the 3rd transmission round; 
packets 8-15 are sent in the 4th transmission round;
packets 16 to 31 are sent in the 5th transmission round; 
packets 32 to 63 are sent in the 6th transmission round; 
packets 64 to 96 are sent in the 7th transmission round. 
Thus packet 70 is sent in the 7th transmission round.

Answer 1

通过提供练习链接，我们可以看到TCP传输在练习1中的第6轮传输中从慢启动变为拥塞避免（我们可以看到图形变化梯度，下一段是为什么）。

根据RFC 2001 Article .1 & .2（link），我们可以看到当我们进入TCP拥塞避免拥塞窗口大小（cwnd）时，每个传输回合的段大小应该只增加1。 / p>

再次查看练习（以及上面的注释），我们看到传输了以下段大小（注意包是否包含非常重要，因此第6轮传输包含32数据包，第7轮包含33个数据包）：

During the 1st transmission round, packet 1 is sent;      | Current Window Size of (1)
packet 2-3 are sent in the 2nd transmission round;        | Increase window by 1 segment (2)
packets 4-7 are sent in the 3rd transmission round;       | Increase window by 2 segments (4)
packets 8-15 are sent in the 4th transmission round;      | Increase window by 4 segments (8)
packets 16 to 31 are sent in the 5th transmission round;  | Increase window by 8 segments (16)
packets 32 to 63 are sent in the 6th transmission round;  | Increase window by 16 segments (32)
*** Here we switch to Congestion Avoidance
packets 64 to 96 are sent in the 7th transmission round.  | Increase windows by 1 segment (33)

由于数据包是包容性的，所以练习是正确的，通过说明数据包32，一直到包括数据包63（因此让我们想象数据包63的结尾基本上是数据包64的开头）传输第6轮。

计算机网络：在第70段发送的传输轮次中？

1 个答案: