The physical fiber links between network elements are modeled using two types of topological link, depending on whether the Optical Transport Manager manages the network element on one or both ends of the link.

  • DropSideTopologicalLink---Models links where the Optical Transport Manager for PDH manages only one end of the link. DropSideTopologicalLinks do not include CTPs.

    Topological link objects and relationships shows the connection between devices and fiber links, which is modeled using a ConnectedTo relationship between a TopologicalLink and the appropriate PTP object in the network element at each end of the link.

    Figure 1. Topological link objects and relationships

    The root-cause and impact analysis calculations are slightly different in each of the classes representing topological links. These calculations take account of the fact that some alarms are not received when problems happen on drop-side connections.


    The TopologicalLink class can be used in the VMware Smart Assurance model to represent unidirectional or bidirectional connections, as appropriate. In the PDH model, these objects represent a bidirectional connection. For example, each TopologicalLink object represents a fiber pair.