[lwip-users] ACK delay

[yueyue papa]

Hi all,

I have a question on lwip ACK delay.

Echo sever is used

     lwIP    <-------------------------> PC WINDOWS
               --------------Send------>
                  <- - -windos ACK
               <------Echo back------
                  - -lwIP -tcp ACK -  - - >

I send  2047 data, (mtu is 1024).

driver send  1024  firsst
                  1024 send

In wireshark, I could see the ACK delay.

if small data, 123 byte,  lwip ACK send about 7xx ms
if  1024 data,  lwIP ACK is about 1s 

so 2048 data will be get after 2s. 

>>How could I change the default ACK delay?

I tried to let lwIP ACK remote as quick as possible.

Thanks