delayed ack與nagle's算法

delayed ack和nagles算法都能減少tcp傳輸過程中的小資料包的問題

tcpip卷二25章中提到tcp為每個連接配接建立7個定時器：

1.connection established

2.restransmission

3.delayed ack（https://en.wikipedia.org/wiki/TCP_delayed_acknowledgment）

4.persist

5.keepalive

6.fin_wait_2

7.time_wait

下面是wikipedia對nagle’s算法描述的url，

https://en.wikipedia.org/wiki/Nagle%27s_algorithm

最主要的應該就是這段代碼：

if there is new data to send
  if the window size >= MSS and available data is >= MSS
    send complete MSS segment now
  else
    if there is unconfirmed data still in the pipe
      enqueue data in the buffer until an acknowledge is received
    else
      send data immediately
    end if
  end if
end if      

MSS（maximum segment size）