802.11 管理帧

Management Frames

Generic management frame Format

Management frames (type=00)a

Management frames

Subtype value Subtype name
0 Association request
1 Association response
10 Reassociation request
11 Reassociation response
100 Probe request
101 Probe response
1000 Beacon
1001 Announcement traffic indication message (ATIM)
1010 Disassociation
1011 Authentication
1100 Deauthentication
1101 Action (for spectrum management with 802.11h, also for QoS)

FrameFormat（每一种帧的FrameBody中Field/IE的构成）

field在前，IE在后，顺序固定

FrameBody （不区分帧类型，这里描述了field/IE的全集） 

(1) fixed field (fixed length and appear in a known order)

• Authentication Algorithm Number
• Authentication Transaction Sequence Number
• Beacon interval
• Capability Information
• Current AP Address
• Listen interval
• Association ID
• Timestamp
• Reason Code
• Status Code

(2) information elements (variable-length fields)

Element ID Name

---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
0 Service Set Identity (SSID)
1 Supported Rates
2 FH Parameter Set
3 DS Parameter Set
4 CF Parameter Set
5 Traffic Indication Map (TIM)
6 IBSS Parameter Set
7 (802.11d) Country
8 (802.11d) Hopping Pattern Parameters
9 (802.11d) Hopping Pattern Table
10 (802.11d) Request
11-15 Reserved; unused
16 Challenge text
17-31 Reserved(a) (formerly for challenge text extension, before 802.11 shared key authentication was discontinued)
32 (802.11h) Power Constraint
33 (802.11h) Power Capability
34 (802.11h) Transmit Power Control (TPC) Request
35 (802.11h) TPC Report
36 (802.11h) Supported Channels
37 (802.11h) Channel Switch Announcement
38 (802.11h) Measurement Request
39 (802.11h) Measurement Report
40 (802.11h) Quiet
41 (802.11h) IBSS DFS
42 (802.11g) ERP information
43-49 Reserved
48 (802.11i) Robust Security Network
50 (802.11g) Extended Supported Rates
32-255 Reserved; unused
221(b) Wi-Fi Protected Access

---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
(a) 802.11 shared key authentication is no longer recommended, so it is unlikely that these fields will ever be used.
(b) This is used by WPA, and is not an official part of 802.11. However, it is widely implemented, so I include it in the table.