1. Under typical circumstances, the AP will talk to the SZ controller via an SSH tunnel. When a client joins a WISPr WLAN, AAA authentication/accounting traffic is sent to the SZ controller, which forwards it to the AAA.
2. In the case of WISPr survivability: If the APs' communications to the SZ are lost, the AP will instead send AAA authentication and accounting traffic directly to AAA, so that users can continue to be authenticated to the WISPr WLAN.
3. When AP <> SZ communications are restored (i.e. when the AP can re-establish an SSH tunnel to the SZ controller), the AP will go back to sending authentication/accounting traffic to SZ.