centives and discounts, quick closure of troubles reported all help to improve customer satisfac- tion. A well-defined assurance process can be a key differentiator in increasing a service provider's competitiveness. The network operations are monitored and maintained by administrators work- ing from the network operations center (NOC; see Figure 20.8). To control and maintain the network activity there can be multiple NOCs for a single service pro- vider. The device status data, alarms generated, performance records, and critical element failure information are all collected by the network management system at the NOC. The records collected by the NMS are used to generate reports that will be used for network planning and service management. The fault information from NMS can be aggregated to provide service level fault data. So a trouble condition in an offered service can be mapped to the associated network and further drilled down to the specific element that caused the issue. The NOC professionals have to continuously monitor the critical performance and fault information required to ensure smooth network operation. The management solution in NOC deals with: Collection: The data from the network elements has to be collected. All fault, configuration, accounting, performance, and security related data are col- lected using management solution. Proprietary protocols and standard proto- cols like SNMP, CMIP, and T1 can be used for collecting the data. There can also be multiple networks involved in offering a service, in which case data from all participating networks needs to be collected by NOC. Consolidation: The data from different element managers need to be consoli- dated and fed to the network manager. CORBA IDL or XML based inter- faces are used to make this communication possible where data needs to be Fundamentals of EMS, NMS and OSS/BSS Service Operation Network Third party NMS management reports planning modules Distribution Analysis Network management system Consolidation Element managers Collectio