奇怪的网络问题，抓包结果分析疑问中。。。

写的网络收发程序。
很奇怪，常会出现长时间的busy。20次中有一次。。:'(
服务端在linux环境。客户端XP。
两边都设定了NODELAY参数了的。
流程是。 客户端连接上，发送一点数据，接受返回的数据，断开连接。
抓包后结果很诡异。:mad :mad

速度正常的抓包结果：
[code]
21:51:14.652845 IP (tos 0x0, ttl 120, id 37748, offset 0, flags DF, proto 6, length: 48) 60.12.15.67.38192 > 202.75.108.213.4900: S |tcp sum ok|266584611:2266584611(0) win 16384 <mss 1380,nop,nop,sackOK>
21:51:14.652859 IP (tos 0x0, ttl  64, id 0, offset 0, flags DF, proto 6, length: 48) 202.75.108.213.4900 > 60.12.15.67.38192: S tcp sum ok 3221936989:3221936989(0) ack 2266584612 win 5840 <mss 1460,nop,nop,sackOK>
21:51:14.659878 IP (tos 0x0, ttl 120, id 37749, offset 0, flags DF, proto 6, length: 40) 60.12.15.67.38192 > 202.75.108.213.4900: . tcp sum ok 1:1(0) ack 1 win 16560
21:51:14.666343 IP (tos 0x0, ttl 120, id 37750, offset 0, flags DF, proto 6, length: 183) 60.12.15.67.38192 > 202.75.108.213.4900: P 1:144(143) ack 1 win 16560
21:51:14.666371 IP (tos 0x0, ttl  64, id 13319, offset 0, flags DF, proto 6, length: 40) 202.75.108.213.4900 > 60.12.15.67.38192: . tcp sum ok 1:1(0) ack 144 win 5840
21:51:14.667728 IP (tos 0x0, ttl  64, id 13321, offset 0, flags DF, proto 6, length: 1420) 202.75.108.213.4900 > 60.12.15.67.38192: . 1:1381(1380) ack 144 win 5840
21:51:14.667759 IP (tos 0x0, ttl  64, id 13323, offset 0, flags DF, proto 6, length: 1420) 202.75.108.213.4900 > 60.12.15.67.38192: . 1381:2761(1380) ack 144 win 5840
21:51:14.667904 IP (tos 0x0, ttl  64, id 13325, offset 0, flags DF, proto 6, length: 111) 202.75.108.213.4900 > 60.12.15.67.38192: FP 2761:2832(71) ack 144 win 5840
21:51:14.680198 IP (tos 0x0, ttl 120, id 37754, offset 0, flags DF, proto 6, length: 40) 60.12.15.67.38192 > 202.75.108.213.4900: . tcp sum ok 144:144(0) ack 2761 win 16560
21:51:14.680390 IP (tos 0x0, ttl 120, id 37755, offset 0, flags DF, proto 6, length: 40) 60.12.15.67.38192 > 202.75.108.213.4900: . tcp sum ok 144:144(0) ack 2833 win 16489
21:51:14.685191 IP (tos 0x0, ttl 120, id 37763, offset 0, flags DF, proto 6, length: 40) 60.12.15.67.38192 > 202.75.108.213.4900: F tcp sum ok 144:144(0) ack 2833 win 16489
21:51:14.685217 IP (tos 0x0, ttl  64, id 0, offset 0, flags DF, proto 6, length: 40) 202.75.108.213.4900 > 60.12.15.67.38192: . |tcp sum ok|833:2833(0) ack 145 win 5840
[/code]

慢的结果
[code]
21:51:14.774967 IP (tos 0x0, ttl 120, id 37825, offset 0, flags DF, proto 6, length: 48) 60.12.15.67.7743 > 202.75.108.213.4900: S |tcp sum ok|20724250:220724250(0) win 16384 <mss 1380,nop,nop,sackOK>
21:51:14.775000 IP (tos 0x0, ttl  64, id 0, offset 0, flags DF, proto 6, length: 48) 202.75.108.213.4900 > 60.12.15.67.7743: S tcp sum ok 3217730836:3217730836(0) ack 220724251 win 5840 <mss 1460,nop,nop,sackOK>
21:51:14.783530 IP (tos 0x0, ttl 120, id 37826, offset 0, flags DF, proto 6, length: 40) 60.12.15.67.7743 > 202.75.108.213.4900: . tcp sum ok 1:1(0) ack 1 win 16560
21:51:17.717161 IP (tos 0x0, ttl 120, id 37840, offset 0, flags DF, proto 6, length: 183) 60.12.15.67.7743 > 202.75.108.213.4900: P 1:144(143) ack 1 win 16560
21:51:17.717198 IP (tos 0x0, ttl  64, id 17089, offset 0, flags DF, proto 6, length: 40) 202.75.108.213.4900 > 60.12.15.67.7743: . tcp sum ok 1:1(0) ack 144 win 5840
21:51:17.718493 IP (tos 0x0, ttl  64, id 17091, offset 0, flags DF, proto 6, length: 1420) 202.75.108.213.4900 > 60.12.15.67.7743: . 1:1381(1380) ack 144 win 5840
21:51:17.718523 IP (tos 0x0, ttl  64, id 17093, offset 0, flags DF, proto 6, length: 1420) 202.75.108.213.4900 > 60.12.15.67.7743: . 1381:2761(1380) ack 144 win 5840
21:51:17.718673 IP (tos 0x0, ttl  64, id 17095, offset 0, flags DF, proto 6, length: 111) 202.75.108.213.4900 > 60.12.15.67.7743: FP 2761:2832(71) ack 144 win 5840
21:51:17.734781 IP (tos 0x0, ttl 120, id 37844, offset 0, flags DF, proto 6, length: 40) 60.12.15.67.7743 > 202.75.108.213.4900: . tcp sum ok 144:144(0) ack 2761 win 16560
21:51:17.735000 IP (tos 0x0, ttl 120, id 37845, offset 0, flags DF, proto 6, length: 40) 60.12.15.67.7743 > 202.75.108.213.4900: . tcp sum ok 144:144(0) ack 2833 win 16489
21:51:17.739447 IP (tos 0x0, ttl 120, id 37854, offset 0, flags DF, proto 6, length: 40) 60.12.15.67.7743 > 202.75.108.213.4900: F tcp sum ok 144:144(0) ack 2833 win 16489
21:51:17.739475 IP (tos 0x0, ttl  64, id 0, offset 0, flags DF, proto 6, length: 40) 202.75.108.213.4900 > 60.12.15.67.7743: . |tcp sum ok|833:2833(0) ack 145 win 5840
[/code]
慢的结果在第三个包与第四个包间将近3秒的延迟2:funk: :funk:

第三个包还是客户端握手的最后一个包啊。发生啥事情啦:'( :'(

附件是好看点的两次抓包过程，文本版的。：）

无人解答啊