Re: [lwip-users] ACK delay

[yueyue papa]

I attached my test data.

No.1 ~ 13.  xxx.8.130 --->  192.168.8.94(echo server)

                 1500 bytes send/received about 3.5s (connect, send, receive, disconnect)

No 14~ 27 the same.  3.5s

No  28~ 40  set TCP_NODLAY

                  3.0s about 500ms faster (connect, send, receive, disconnect)

No 41 ~ 56   the same as previous

                   3.0s

In normal case:  there will be 1.5K data send, and received. I tried to make response the faster as possible. 

Is there a suggest solution?

Whether the TCP DELAY is my performance killer?

Thanks for help

On Mon, Dec 28, 2009 at 4:57 PM, yueyue papa <address@hidden> wrote:

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

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