Interesting interesting. A while back I had put together my own web server on top of Espressif’s AT command set for ESP8266. The whole thing was working as a UI for a sealed embedded system with no display or keyboard.
The web pages that I would feed were crafted to re-request periodically, like every 10-15 seconds. (I can’t remember the details) The page would refresh nicely for about a minute or 90 seconds to many minutes(again details), but eventually the page would write and then immediately blink to a server reset the connection screen. After much frobbing and tweaking, I fired up Wireshark and I could see that all normal transactions would finish with an ACK, but the same request a little while later would finish with an [RST, ACK] being sent from the ESP8266 module. Eventually my customer complained that this wasn’t good enough and needed to be fixed. I spent a whole lot of time and effort sending messages back and forth with Espressif, grabbing their latest code, building it all from source, testing, and adjusting to their undocumented API, but I definitely ran into the saving face culture when trying to report an issue. Eventually I had a system that would be stable if I reduced the re-request delay to about 9 seconds, because at 10 seconds the connection would get closed and never reopen again without a reboot (anyway, their code has issues and I traded one set of bugs with no path forward for another with some pretty terrible hacks as a work around). So, Espressif’s stack is based on FreeRTOS, LwIP, and a whole bunch of magic. I’ve seen this same issue in their stack. I can’t say that it’s an LwIP problem, but it wouldn’t surprise me as well. Hope this helps, Andrei > On 2021-September-15, at 07:37, Info <i...@winformatik.ch> wrote: > > Hi > > I'm using lwIP (2.1.3-RC1) with the httpd web server from the apps directory > in my embedded application. After loading a web content from the web server a > periodic communication starts from the web browser that opened the website. > This all works, but after a view minutes the periodic communication gets > broken (the web server/lwIP stack itself does not crash). After a reload of > the web site the periodic communication is established again for a view > minutes. > > In the attached Wireshark capture file I can see many frames (from the web > browser) with the set ACK RST flags. For me it not clear why the web browser > sends this frames and if it is the reason for the broken periodic > communication ? Any help and maybe some explanation would be very welcome. > > I also activated the debugging output and the internal lwIP asserts, but this > did not help me to track down the problem. The web server does not support > encryption. > > The lwIP uses FreeRTOS with the sys_arch files found in the contrib package. > > IPs used in the Wireshark capture : The web server uses 192.168.3.131 and the > client (web browser) 192.168.10.103 . > > Thank you very much for any help > Roland > <HTTPD_WebServer_2_1_3.pcapng>_______________________________________________ > 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
