aces are: EMSMgr_I: The NMS uses this interface to request information about the EMS. Active alarms, top level equipments, subnetworks, and topological links information can be obtained using this interface. In addition to collect- ing information, operations such as add/delete can also be performed using this interface. EquipmentInventoryMgr_I: The NMS uses this interface to request infor- mation about equipment and equipment holders. In addition to collecting information, operations such as provision/unprovision can also be performed using this interface. PerformanceManagementMgr_I The NMS uses this interface to request current and historical performance data from EMS. File transfer is another mechanism to collect performance data. GuiCutThroughMgr_ The NMS uses this interface to launch an EMS GUI from the NMS GUI and hence access data from the EMS. ManagedElementMgr_I: The NMS uses this interface to request information about managed elements. Information about terminations points like PTP or CTP and the cross connections can also be obtained using this interface. MaintenanceOperationsMgr_I The NMS uses this interface to request infor- mation on the possible maintenance operations and to perform maintenance operations. MultiLayerSubnetworkMgr_I The NMS uses this interface to request infor- mation about connections, managed elements, and topological links in the Fundamentals of EMS, NMS and OSS/BSS subnetwork. In addition to collecting information, operations such as add/ delete on a subnetwork can also be performed using this interface. ProtectionMgr_I: The NMS can use this interface to request information about equipment protection and its relationships. SoftwareAndDataMgr_I: The NMS uses this interface to request backup of configuration data. TransmissionDescriptorMgr_I The NMS uses this interface to request infor- mation about transmission descriptors. In addition to collecting information, operations such as create/delete can also be performed using this interface. FlowDomainMgr_I: The NMS uses this interfa