My FPGA is continuously sending UDP packets on network using 10/100/1000 Mbps Ethernet. I am using Wireshark to capture the packets directly to a .pcap file & then extract & display UDP data in Matlab GUI. FPGA kit is connected to a 1 Gbps switch and then to PC.
Initially i tried using Matlab's built in UDP object instead of .pcap files but using that i was facing packet drop issue at high BW (>1 Mbps) and was only able to achieve drop free reception for very low BW around 110 kbps. That was not acceptable for my case. A link to the problem is given below:
Incorrect UDP data reception in Matlab
Based on these problems i moved towards using Wireshark. I use wireshark to create multiple .pcap files (1 Mb) of UDP data and then start extracting UDP data from these files in Matlab. A link also guided towards this approach i.e. writing packets directly to file(High speed UDP receiver in MATLAB ).
The problem is that i am getting some packets dropped at random intervals. The problem is very frequent when operating at High Ethernet BW - 220 Mbps. So i reduced my BW to around <50 Mbps still i get some packet drops. I tried using some of the tips provided by Wireshark (http://wiki.wireshark.org/Performance) for optimizing performance but still the issue persists.
This seems to be issue with memory as far as i have understood.
Some details about the design:
UDP Data Size = 64 Bytes
Ethernet Frame Size = 110 Bytes
PCAP File Size = 1 Mb
Wireshark Buffer Size = 1 Gb
Please guide me towards a possible solution.
Regards,
Sameed
tcpdump -n -s 0 -i INTERFACE -w file.pcap. Also see this. – Slava Bacherikov