Network Alarms
Network Events, Alarms, and Alerts
It's not at all difficult to name and describe an event category or event-based transaction that can trigger an alert, alarm, or otherwise cause a network management system to bring something to the attention of a network manager; the difficulty is in limiting the description of such categories and transactions. Depending on the specific needs and architectures of the network and its users, the type of event or event-based transaction that might lead to the notification of a network manager could be pretty much anything. There are, however, some common event categories and event-based transactions that will trigger alarms or other notifications in the network management system and require attention form network managers. Several of these event and transaction types will be identified and described in the following pages, with their relevance discussed.
One broad category of events that commonly triggers alarms are RMON (Remote Network Monitoring) alarms which are typically created when an automatic function built into the information system measures a variable outside of set parameters (Cisco 2007). For example, the RMON could be configured to monitor the level of central processing unit utilization and to create a record of the levels of utilization through continual polling, and if the utilization drops below or rises above a certain...
This type of alarm is utilized to ensure that optimal levels of central processing unit utilization, as defined by the network administrators and applied to the system's parameters, remains in place during system operations.
This specific type of event category can actually cause an unnecessary drain on network bandwidth, thus limiting other capabilities, and so better alternatives that represent a slightly different type of event can be built into the network architecture to serve the same purpose. Using specified time intervals and a measurement of rates in the rise and fall of central processing unit utilization, an RMON can be implemented to trigger an alarm in a measure that is both more proactive -- a level of utilization potentially above or below the set threshold limits can be detected before it actually occurs -- and more efficient, using less bandwidth and fewer network resources to accomplish the same task (Cisco 2011). The alarms triggered by either method fall under the basic category of performance monitoring, which is one of the essential functions of a network management system and, when needed performance adjustments cannot be automated, the network manager.
Interestingly, certain transaction-based events that can trigger network manager-alerting alarms are themselves alarms. That is, there are…
