关于tcp的滑动窗口流控协议

gta

写了两个socket程序，一个server，一个client，运行起来后用tcpdump抓了下包，发现如下情况：

14:23:24.059508 IP localhost.localdomain.38513 > localhost.localdomain.ruptime: S 224203101:224203101(0) win 32792 <mss 16396,sackOK,timestamp 23578726 0,nop,wscale 4>
14:23:24.180622 IP localhost.localdomain.ruptime > localhost.localdomain.38513: S 230999157:230999157(0) ack 224203102 win 32768 <mss 16396,sackOK,timestamp 23578727 23578726,nop,wscale 4>
14:23:24.180650 IP localhost.localdomain.38513 > localhost.localdomain.ruptime: . ack 1 win 2050 <nop,nop,timestamp 23578727 23578727>


14:23:30.516600 IP localhost.localdomain.ruptime > localhost.localdomain.38513: . 1:16385(16384) ack 1 win 2048 <nop,nop,timestamp 23585186 23578727>
14:23:30.517151 IP localhost.localdomain.38513 > localhost.localdomain.ruptime: . ack 16385 win 3086 <nop,nop,timestamp 23585187 23585186>
14:23:30.557110 IP localhost.localdomain.ruptime > localhost.localdomain.38513: P 16385:32769(16384) ack 1 win 2048 <nop,nop,timestamp 23585227 23578727>

红色的win 2050已经表明客户端的窗口只有2050了，为什么在紧接着的蓝色那行，server还向client发16384个字节呢，这已经超出client的接收窗口大小了啊。非常不解，请大家指点，谢谢

qtdszws

wscale 4,窗口被缩放，因此实际的窗口大小是2050<<4

Godbach

前两个包的WIN比较大啊

gta

谢谢q兄，一句话就把我的疑问解释清楚了