The Topology Server discovers and maintains a comprehensive and accurate repository of the devices, physical connections, logical connections, and protection groups that are present in an optical network. The information is obtained by collecting bulk data and events from EMSs and other OSSs such as inventory managers, adapters, databases, and flat files.

Every Topology Server contains an object model definition for the technology domain that it is managing. VMware Smart Assurance object models are defined using the VMware Smart Assurance Common Information Model (ICIM). The VMware Smart Assurance ICIM Reference found at BASEDIR/doc/html/icim/index.html provides more information.

The data model defines a class hierarchy and the properties, relationships (associations), and observable events (exceptional conditions) for each class. The model captures the alarm-reporting mechanism of optical networks including root-cause alarms such as LOS (Loss of Signal) and LOF (Loss of Frame), and indication alarms such as AIS (Alarm Indication Signal) and RDI (Remote Defect Indication).