I've implemented lwIP on following hardware:
CC1312R (ARM Cortex M4F) - TI Launchpad Board,
lwIP 2.1 in operation system mode (TI-RTOS),
My lwIP MQTT client (the one which comes with the stack) succesfully connects to the broker and can both publish and subscribe.
At this moment I'm testing only publishing (one publish per second) - the messages are published without problem for some time (one time it is about 50 publish packets, one time 300), then the communication stops.
I've recorded packets using Wireshark (with MQTT and TCP filters). IP 192.168.1.171 is lwIP, 22.214.171.124 is broker IP.
What I can observe is that lwIP somehow can't handle TCP retransmission packets properly.
I don't have any messages about too small memory or assertions before communication stops.
What can I do more to solve my problem? Did you see something like that?
I'm attaching .pcap file with described problem (at the end of file).