I'm using keil TCP IP stack on many devices but I've observed a strange thing: My device is server and the client open the socket. If the client doesn't transmit data after socket opening (SYN sequence), the socket is closed by the server (my device) after less than a second. The TCP socket "lease" time is fixed to 120" but a real event of TCP_EVT_CLOSE is generated by stack..... Can anyone explain this, please?
I've seen the correct sequences and the wrong ones with Ethereal and the match with your indications is complete. Thanks a lot. Unfortunately I haven't a debug serial line but now all seems work well. About 100ms ticks, this value makes quite slow the "send_data" state machine. I've tried to speed up the system (tick of RTL = 1ms, timer and tcp tick = 5ms) and all run well. Thanks again.
It is better not to reduce the tick interval too much. It makes no difference for the TCP stack because the timeout timers have a resolution of 1 second. Higher tick timer rate means more decrements of timeout timers per second. This effectively means heavier CPU load.