802.11be Beacon frame , Association Request and Association Response - Malformed Packet

[chan “poi” B]

Hello Everyone:

 
I am using the file /ns-3-dev/examples/wireless/wifi-eth-network.cc to generate a pcap file for studying the specifics of the 802.11 protocol. However, when I use Wireshark to read the pcap file, the wireshark shows 'Malformed Packet' errors for Beacon frames, Association Requests, and Association Responses.(Picture 1)

In the first screenshot, Wireshark fails to recognize the byte after the 'Ext Tag: HE Capabilities' field and generates an error.

but after I copy the simulation file to /ns-allinone-3.40/ns-3.40/scratch/wifi-eht-network.cc and run it using version 3.40 of ns-3, Wireshark no longer display 'Malformed Packet' errors when reading the generated pcap file.(Picture 2)

Below is the code I added to the file wifi-eth-network.cc

phy.EnablePcap("eht-wifi-network", staDevices, true);

Simulator::Stop(Seconds(simulationTime + 1));

Simulator::Run();

I'm sorry, English is not my native language, so my English expression might not be good.

Best regards

poi

[Tommaso Pecorella]

Hi,

it might be a bug (and a nasty one, I'd say). We'll have to investigate.

Can you please open an issue on our tracker?

[chan “poi” B]

Thanks for your response, I have opened an issue.

poi

[Tom Henderson]

Have you checked whether your version (or any version) of Wireshark
claims to support 802.11be yet? 802.11be is still a draft standard.

- Tom

[chan “poi” B]

Thanks for your response

My Wireshark version is Version 4.2.0 (v4.2.0-0-g54eedfc63953) on Windows 10(figure 1)

I used the same version of Wireshark to open the two .pcap files: one generated from ns-3-dev, and the other from ns-3.40 . As a result,  Beacon frame , Association Request and Association Response  frame from ns-3-dev show 'Malformed Packet' errors, whereas those from ns-3.40 do not.

By analyzing the error, it appears that Wireshark stops reading after encountering the 'IEEE 802.11 Wireless Management-Ext Tag: HE Capabilities' field. However, there are subsequent fields—'Ext Tag: HE Operation,' 'Ext Tag: EHT Capabilities (802.11be D3.0),' and 'Ext Tag: EHT Operation (802.11be D3.0)'—after it.

I also tested using the example files for 802.11ax，After adding pcap file output to the 'examples/wireless/wifi-he-network.cc' file, when I opened the ns-3-dev resulting pcap file with Wireshark, the three types of frames still showed 'Malformed Packet' errors  (figure 2)  . However, the pcap file output of 802.11be from ns-3.40 does not show 'Malformed Packet' errors (figure 3).

poi