d view and a back end view. On the NMS GUI, the user should be able to view where a particular element is placed in the chassis. So when a fault occurs on a par- ticular network element it would be easier to isolate the correct element in the chassis and perform debugging or replacement operation using the chassis diagram created using the interfaces offered by chassis viewer application. 2. Map viewers: When the network elements are spread across various geo- graphical locations as in a distrusted network environment, it would be Management collection function components components components Figure 11.4 Flow of data from NE to user. Fundamentals of EMS, NMS and OSS/BSS Service Figure 11.5 Sample performance chart. easier to locate a faulty element when the elements are displayed over a geographical map of the local area, specific country or in some cases the world map. Tools like "MICA" and "Picolo" can be used for implementing the same. 3. Performance chart viewers: The formatted performance records can be rep- resented graphically using applications like "JFreeChart," "iReport," and "DataVision." These applications provide interfaces to represent performance data to the user in a graphical manner. The figure of the sample performance chart (see Figure 11.5), shows the count of service outages for a specific period of time against the specific service. 4. Fault browsers: Similar to performance data, fault data also needs to be pre- sented in a user friendly manner. The fault data generated at the network ele- ment is first parsed and formatted by the management function components that collect this data using data collection components. This formatted data has a set of fields and this data in GUI should be represented in such a way that the data can be filtered based on a specific field. A tabular representation is usually used with a fault data display in GUI. 5. User administration: The administration screen is a necessity to perform net- work related operations like adding a new node to monitor, deleting a 