1 Undefined the reason, disconnect because unknow reason
2 client associated but not authorized
  EX: The STA connect to the AP by WPA-EAP, for a while, the server ask disconnect and re-authentication.
3 deauthenticated, STA is leaving IBSS or ESS, send from the STA
  EX: Click the "reconnect" or "disconnect" in the STA UI
4 AP send to STA
  EX: age timeout
5 AP is busy, can't handle the STA
  EX: load blance
6 Class 2 frames: association request/response, reassociation request/response, disassociation
7 Class 3 frames: data frames, management frames, control frames
8 Disassociated, STA is leaving the BSS, send from the STA
9 The station is not authenticated, but the station requesting association, the AP will disconnect the STA