ce level agreements (SLAs), the data collected by network management systems must be malleable SO that it can be formatted for different sets of corporate eyes. For the pur- poses of monitoring performance relative to service level agreements, customers require information that details the performance of the net- work relative to the requirements of their applications. For network operations personnel, reports must be generated that detail network per- formance to ensure that the network is meeting the requirements of the SLAs that exist between the service provider and the customer. Finally, for the needs of sales and marketing organizations, reports must be available which allow them to properly represent the company's capabil- ities to customers, and to allow them to anticipate requirements for net- work augmentation and growth. Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. Telephony Telephony For the longest time, the Telecommunications Management Network (TMN) has been considered the ideal model for network management. As the network profile has changed, however, with the steady migration to IP and a renewed focus on service rather than technology, the standard TMN philosophy has begun to appear somewhat tarnished. Originally designed by the ITU-T, TMN is built around the OSI Model and its attendant standards, which include the Common Management Information Protocol (CMIP) and the Guidelines for the Development of Managed Objects (GDMO). TMN employs a model, shown in Figure 3-69, made up of a network element layer, an element management layer, a network management layer, a service management layer, and a business management layer. Each has a specific set of responsibilities closely related to those of the layers that surround it. The network element layer defines each manageable element in the network on a device-by-device basis. Thus