RADIUS & SNMP

Dear All, I want to monitor the RADIUS with SNMP. but i need to know exactly what is that OID means ( radiusAccServTotalNoRecords ) i searched and found that it means " The number of RADIUS Accounting-Request packets which were received and responded to but not recorded " but i can't understand how come that the radius respond to a packet but it is not recorded ?? i'm using mysql as accounting DB regards, Amr Ali