Hi David,
These are the definitions according to the documentation:
Controller
+ Overall Usage: The total number of clients and APs that have the low usage and throughput data in the
last 15 minutes.
+ Usage by WLANs: The total number of clients per WLAN and throughput data in the last 15 minutes. You
can view only three WLANs in a graph and the remaining WLANs are displayed in other graph.
Airwave
+Usage: The combined bandwidth through the device at time of polling.
What versions are you running on your Controllers/Airwave ?
I would suggest you kee it up to date. Updating AMP to 8.2.7 resolved some client data differences between WLC and AMP for us.
DSP