802.11 Management Frames - LogeshVel/802.11 GitHub Wiki
Action Frames
Reason Code
Stations may send Disassociation or Deauthentication frames in response to traffic when the sender has not properly joined the network. Part of the frame is a 16-bit Reason Code field.
Status Code
Status codes indicate the success or failure of an operation.
Management Frame Information Elements
Supported Rates
FH-Paramter (Frequency Hopping)
DS Parameter
Direct-sequence 802.11 networks have only one parameter: the channel number used by the network. High-rate, distribution ststem networks use the same channels and thus can use the same parameter set.
TIM
To save transmission capacity, the Bitmap Offset field can be used to transmit a portion of the virtual bitmap. The Bitmap Offset is related to the start of the virtual bitmap. By using the Bitmap Offset and the Length, 802.11 stations can infer which part of the virtual bitmap is included.
Types of Management Frames
Beacon
Beacon frames announce the existence of a network and are an important part of many network maintenance tasks. They are transmitted at regular intervals to allow mobile stations to find and identify a network, as well as match parameters for joining the network. In an infrastructure network, the access point is responsible for transmitting Beacon frames.
Probe Request
Probe Response
Disassociation and Deauthentication
Disassociation frames are used to end an association relationship, and Deauthentication frames are used to end an authentication relationship.
Association Request
Reassociation Request
Association Response and Reassociation Response
Authentication
To authenticate to the access point, mobile stations exchange Authentication frames.
Different authentication algorithms may co-exist. The Authentication Algorithm Number field is used for algorithm selection. The authentication process may involve a number of steps (depending on the algorithm), so there is a sequence number for each frame in the authentication exchange. The Status Code and Challenge Text are used in different ways by different algorithms.
