What is a "class 3 frame" ?????

I just noticed one of our backhaul links between two of our version 2.9 towers dropped momentarily. When I looked at the log, it said that it “lost connection to 00:0B:6B:35:2C:40, got disassoc: class 3 frame received (7)”… This is very similar to the same message I get when I try to Radius authenticate a standard wireless client, as explained here, but this time I am not even trying to Radius authenticate… Does anyone know what the h*** a “class 3 frame” is???

Unfortunately I don’t exactly remember where I got this list from, but 802.11 frames are classified into 3 classes - I suppose this is what the error message is referring to…

Class 1 frames

  • Control frames
    Request to send (RTS)
    Clear to send (CTS)
    Acknowledgement (ACK)
    Contention free end (CF-end)+ ACK
    CF-End
    Management frames
    Probe request/response
    Beacon
    Authentication

Class 2 frames

  • Management frames
    Association request/response
    Reassociation request/response
    Disassociation

Class 3 frames

  • Data frames
    Management frames
    Control frames (power save)