Simultaneous-Use and checkrad with Cisco Router

Dear Sir, I want to know the setup for the simultaneous logins and checkrad script with Cisco Router SNMP enabled. The settings are configured but checkrad is not returning any results from cisco snmp. Also, how can I know whether radius will block MPP attempts? I am looking for configuration and any additional documents that can help me understand it more. Best Regards, M. Faisal Butt