There are 3 frames :

1. Management Frame
2. Control Frames
3. Data Frames

Management Frames :

1. Beacons – to announce its present. It carried the SSID
2. Probes
   • Request – come from client calling for AP
   • Response – answer by AP to the probe request
3. Association
   • Association request – asking from one host to another and try to associate e.g. to synchronous a watch
   • Association response – answer to the association request
   • Disassociation – to disconnect the associate politely, then the host can unallocated any process that have been done.
4. Authentication

• Authentication
  • Open – Only two frames exchange asking for access and allow the access
  • WEP – Client send auth frame ask for access, BSSID will send auth frame containing the challenge key, then client send back the encrypted WEP key
  • WPA/WPA2 – it’s quite complicated, i’ll discuss later.
• De-Authentication
  • Send from one station to others to terminate sessions, the station may still associated but there are no connection each other