Stm32h7 Lwip - Slow Communication Problem

[Ey.1]

Hello, I'm using ST32H743ZI2 nucleo board as TCP client. When I setup the ethernet configuration/initialization, I considered the https://community.st.com/s/article/How-to-create-project-for-STM32H7-with-Ethernet-and-LwIP-stack-working article.

Additionally, I'm using Lwip Raw Api, I do not use Rtos.

My program is working, I can connect the server, I can communicate with the server, there is no problem. But communication speed is very slow. When I transmit data, which lengths about 30 bytes, from server to client, which is my nucleo board, in 1 ms period, it can not catch the data at time. When the period about 50ms there is no problem. And also I'm in trouble in transmitting packet from my board. It is also slow. By the way, pinging to board, replied <1ms.

I checked some questions in the forum, I tried something but I could not handle the solution.

Thanks a lot.

[Ozone]

Have you tried a clean network, with only the host and the nucleo board connected ?

Otherwise, your firmware needs to sort through all sorts of packages milling around in an office network.

[Ey.1]

Yes, I'm not connected the office network etc. Connection is only between the nucleo and my computer.

[Ey.1]

Additional info: I'm not sending queued way. I'm just transmitting data what i want to transmit:

		err_ret = tcp_write(m_tcpPcbClient, p_data, len, TCP_WRITE_FLAG_COPY); // Queues up data to be sent.
		if(err_ret == ERR_OK)
		{
			if(tcp_output(m_tcpPcbClient) != ERR_OK)			// Force to sent.
				return 1;
			else
				return ERR_OK;
                 }

Length of data is constant, it is 30 bytes. But it can not force the sent in a true way, sometimes sends 500 bytes, sometimes 50 bytes. Sometimes err_ret returns as out of memory error. Like I said, my period 1ms. But If I do it 50 ms, it is transmitting perfectly.

In receiving part I'm taking the data with callback function, but like i said, it can not take data what I send from host. As an example, when I transmit 50 packet from host with 1ms perdiod, it takes only 2 or 3 packet.

[Ozone]

I am not familiar with the H7 nucleo and the respective LwIP port.

I suppose profiling would help.

[Ey.1]

When nagle is disabled, most of problem is solved. But still sometimes sends 2-3 packet at once. This means that the host misses packets while parsing.