If you want to reject certain messages when the load gets too heavy, you can use the Supervision Service. With this service you can select one of the following overload protection strategies:
Radius_AccessRequest - For rejecting requests of type AccessRequest
Radius_AccountingIntermediate - For rejecting AccountingIntermediate requests
Radius_AccountingStart - For rejecting AccountingStart requests
Radius_AccountingStop - For rejecting AccoutningStop requests
For each strategy, you can select if you want to reject 25, 50, or 100 % of the requests. See /wiki/spaces/MD/pages/3192638 for further information.