Matching Response and Request PDUs
The order in which the WinSNMP application receives SNMP responses may not match the order in which the application submits SNMP operation requests. To match the response with the request, the application must use the request identifier field (the request_id) of the response.
The request_id field is a unique numeric value that identifies the PDU. Applications can assign request identifiers by calling the SnmpCreatePdu function or the SnmpSetPduData function. Call the SnmpGetPduData function to retrieve a PDU's request_id.