I worked on the problem and it is now solved. The problem: Only the tcp_sent() callback called the next tcp_write() after the previous write was finished. Tcp_sent() is probably only triggered by an ACK from the other side. So, my code waited for the ACK, effectively.
Now, I use tcp_write(), called from a function that runs every few milliseconds. When there is no data left to write, tcp_output() is called. Some pseudo-code: === Regularly called function === Check If data is available Yes? --> call tcp_write Yes, but less than TCP_MSS? --> call tcp_write and then tcp_output No? --> do nothing Best regards, Adrian -----Ursprüngliche Nachricht----- Von: lwip-users [mailto:lwip-users-bounces+adrian.figueroa=tu-dresden...@nongnu.org] Im Auftrag von Sergio R. Caprile Gesendet: Friday, June 30, 2017 3:24 PM An: lwip-users@nongnu.org Betreff: Re: [lwip-users] Raw TCP Client - wait for ACK after each packet causes slowdown Without a _small_ and clear example (I won't browse your entire code) and a proper capture file I can't help you further. Perhaps someone else jumps in. _______________________________________________ lwip-users mailing list lwip-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/lwip-users _______________________________________________ lwip-users mailing list lwip-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/lwip-users