 are stored in RDBMS tables or flat files and users notified. Finally, Alert Observers, analogous to Event Observers, will be notified of the alert. OSS for Telecom Networks The server component of event management is the Event Manager, which includes the event and alert servers. These, in turn, are interfaces to the event browsers and alert viewers. Traps are received and processed by the Event Manager. The client components are the Event Browser and Alert Viewer. These are either Java applets that run in any Java-enabled web browser or ordinary HTML-based clients that are accessible from a web browser. 12.8.1 Extending Events Users can add properties to events for their convenience or for the specific needs of a particular carrier. The trade-off is that a greater number of user properties may reduce performance, as the time taken to execute database queries increases with the number of properties to be searched. Adding user properties to an event object does not extend the event object. If it is necessary to add a large number of proper- ties, then it is better to extend the event object. Based on the device types and the need for additional properties, the decision as to whether or not to extend the events is taken. If the networked environment includes specific devices which need more properties to represent an event object, then it is better to extend event objects. A custom class must be written to extend the Event class. Extended Events will have all the properties inherited from the Event object and the additional properties spec- ified by the user. The extended Event object is stored in the database and becomes part of the working functionality of the fault management system. 12.8.2 Filtering and Processing Events To identify the failure object corresponding to an event, the traps and input events should be parsed and the necessary details given. A trap parser makes notifications readable to the user. An event parser refines the message conveyed by the events. Although both the trap and event parsers see