1-3If the value of a sampled alarm variable overpasses the same threshold multiple times, only the first onecan cause an alarm event. That is, the rising alarm and falling alarm are alternate.Private alarm groupThe private alarm group calculates the values of alarm variables and compares the result with thedefined threshold, thereby realizing a more comprehensive alarming function.System handles the prialarm alarm table entry (as defined by the user) in the following ways:z Periodically samples the prialarm alarm variables defined in the prialarm formula.z Calculates the sampled values based on the prialarm formula.z Compares the result with the defined threshold and generates an appropriate event.If the count result overpasses the same threshold multiple times, only the first one can cause an alarmevent. That is, the rising alarm and falling alarm are alternate.History groupThe history group defines that the system periodically collects statistics on traffic information at aninterface and saves the statistics in the history record table (ethernetHistoryTable) for queryconvenience of the management device. The statistics data includes bandwidth utilization, number oferror packets, and total number of packets.A history group collects statistics on packets received on the interface during each period, which can beconfigured through the command line interface (CLI).Ethernet statistics groupThe statistics group defines that the system collects statistics on various traffic information on aninterface (at present, only Ethernet interfaces are supported) and saves the statistics in the Ethernetstatistics table (ethernetStatsTable) for query convenience of the management device. It providesstatistics about network collisions, CRC alignment errors, undersize/oversize packets, broadcasts,multicasts, bytes received, packets received, and so on.After the creation of a statistics entry on an interface, the statistics group starts to collect traffic statisticson the interface. The result of the statistics is a cumulative sum.Configuring the RMON Statistics FunctionRMON statistics function can be implemented by either the Ethernet statistics group or the history group,but the objects of the statistics are different, you can choose to configure a statistics group or a historygroup accordingly.
