This figure shows the ICM API interfaces.
The highest layer contains the Root interface, WDIRoot, which manages connections from client applications.
The second layer contains the Manager interface, WDIManager, that provides operations for session, transaction and signal management.
The third layer contains the DLRSession, CircuitHierarchySession, and EquipmentSession interfaces.
In the fourth layer, the EquipmentSession interface provides operations that yield object references to CrossConnectSubSession, InstallationSubSession, NetworkElementSubSession, SoftwareSubSession, and SpecificationSubSession interfaces.