Hi all!!! Im working on simple file transfering from embedded board with LWIP to server via TCP. Embedde board is custom STM32 with SIM7500 GSM modem, PPP is working fine(tested with sending UDP packets with way higher speed than TCP).
I'm using sockets. Right now I have huge lag when trying to receive acknolage packet from server.
Logic of transfer:
1) connect to server using TCP
2) send file size
3) receive acknolage from server (wait for packet from server)
4) start while loop
4.1) send some amount of data
4.2) wait for acknolage (same as 3)
Right now Im getting ~25kbytes/s.
Tryied to set TCP_NODELAY and TCK_QUICKACK(only on server because as far as I know lwip doesn't support this feature).
Source code of server, embedded part and lwipports.h are in attachments. Also attaching timings: time where blue line high is send, orange is for recv.
P.S. Sorry for my english.
embedded.c
timings.jpg