hwDeviceTrapOrdinalNumber 1.3.6.1.4.1.2011.6.164.1.1.2.1

Site device event trap serial number (SN) is the unique ID of the device event trap. It is used to resend and synchronize event traps. Its value range is 0 to 4294967296. When the value exceeds the maximum value, the system automatically clears the value and numbers the alarm from 0 to 4294967296. If the network management system (NMS) recieve the alarm number is not consequential, in such case that it notifies the SNMP agent the event trap number required. So the monitor send the 50 event trap messages in maximum, after consequencial number required by NMS again. Specially, if NMS set the value to 0, the agent would clear the alarm queue automatically.