[lwip-users] LwIP RAW - Simultaneous (full-duplex) communication

[Nenad Pekez]

Hi guys,

if there is a LwIP TCP server that has 2 connected clients (therefore 2 
PCBs: lets say PCB A and PCB B) and tcp_write() + tcp_output() functions 
are performed on PCB A, but at the same time server is processing 
received packets on PCB B, is any conflict going to happen? Is this a 
valid sequence of events?

What I have tried so far is this:

[iperf server:address@hidden Windows 7] <------------------ [iperf 
client:address@hidden 2.0.2]

[iperf client:address@hidden Windows 7]-------------------->[iperf 
server:address@hidden 2.0.2]

in other words, there is an iperf client on Zynq board and it gets 
connected to iperf server running at PC - data is being sent from Zynq 
to PC and everything is working fine. As soon as PC iperf client gets 
connected to iperf server (while other connection is still alive) both 
connections crash and error -11 is returned from tcp_write ("not 
connected").

All in all, I guess that this kind of communication is possible, but 
there is some stuff that should be extra handled? Are there any examples 
or references on how full-duplex communication could be achieved with 
LwIP RAW?

Best regards,
Nenad

lwipopts.h
Description: Text document