URL: <https://savannah.nongnu.org/bugs/?62302>
Summary: LWIP 2.0.2 / Xilinx Zynq: TCP hang data transmission after packets loss events Project: lwIP - A Lightweight TCP/IP stack Submitted by: nirshem Submitted on: Tue 12 Apr 2022 10:17:06 AM UTC Category: TCP Severity: 3 - Normal Item Group: Faulty Behaviour Status: None Privacy: Public Assigned to: None Open/Closed: Open Discussion Lock: Any Planned Release: None lwIP version: 2.0.2 _______________________________________________________ Details: Hi, An issue Iām working on for a while. My setup as follow: 1) Unit A: Embedded unit: Xilinx board (Zynq 7020) running FreeRTOS +LWIP 2.0.2 2) Unit B: PC client running WIN10 Connectivity between the units is fiber ā and I added sniffer in the middle for debugging of the issue. Unit A transmit in TCP (LWIP 2.0.2) data at around 1.7[Mbps] to unit B. The problem: after hour of system running the throughput is dropped to zero (except of TCP keep alive) and return back after around 6 seconds. After reviewing the Wireshark in the middle (connected via sniffer) I found a 3 dup acks event that cause fast retransmission reply, From that moment the Application traffic stopped for 6 seconds and only TCP keep alive was active. After checking the location of the packet loss I can tell for sure it was in the PC side (running Iperf UDP test client /server locally shows some packet loss due to the load on the PC). I attached two wiresharks files of two events. Now my question are: 1) Why there is a drop in the traffic from Unit A ? 2) Why Fast recovery is not working as it should after fast retransmission event ? 3) Is there a way to fix it by timers/windows size configuration ? 4) Is there a known issue about it ? ā I looked on the change log since 2.0.2 and haven't found something special. Any help here will be much appreciated. _______________________________________________________ File Attachments: ------------------------------------------------------- Date: Tue 12 Apr 2022 10:17:06 AM UTC Name: Event_1.pcapng Size: 123KiB By: nirshem <http://savannah.nongnu.org/bugs/download.php?file_id=53079> ------------------------------------------------------- Date: Tue 12 Apr 2022 10:17:06 AM UTC Name: Event_2.pcapng Size: 286KiB By: nirshem <http://savannah.nongnu.org/bugs/download.php?file_id=53080> _______________________________________________________ Reply to this item at: <https://savannah.nongnu.org/bugs/?62302> _______________________________________________ Message sent via Savannah https://savannah.nongnu.org/ _______________________________________________ lwip-users mailing list lwip-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/lwip-users