802.11 MAC Sublayer format

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General 802.11 MPDU Format

The technical term for an 802.11 frame is an 802.11 MAC Protocol Data Unit (MPDU)

MAC Header – Contains frame control information, duration information, addressing, and sequence control information. Furthermore, QoS data frames contain specific QoS control information.

Frame Body –  Can be variable in size and also contains information that is different depending on the frame type and frame subtype.

Frame Check Sequence (FCS) –  Comprises 32-bit cyclic-redundancy check (CRC) that is used to validate the integrity of received frames.



Frame Control Field

The first two bytes of the MAC header consists of 11 subfields within the Frame Control field. These subfields include Protocol Version, Type, Subtype, To DS, From DS, More Fragments, Retry, Power Management, More Data, Protected Frame, and Order.


Frame control field Wireshark


To DS From DS reference table

 

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