Re: [lwip-users] Efficient sending small data packets

[Pomeroy, Marty]

-----Original Message-----
It worked but I noticed a relatively big latency (about 200ms or more)
between arrival of buf_n and buf_n+1.
Where does it come from? How lwip stack schedule an actual transmission
upon receipt of tcp_output?



If your receiving PC is running Windows, 200ms is a "smoking gun" for
Nagle's Algorithm.  Google that up.

On windows fix this by opening the Registry, go to
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\In
terfaces
Find the correct interface under there by IP Address
Add these DWORD values
    "TcpAckFrequency"  DWORD 1
    "TCPNoDelay" DWORD 1
Then restart the PC.

HTH!

Marty