In phase 1, the initial split, the topology-split software assigns the subsets to the domains in a way that minimizes the number of device replications. In GUID-4A4CEDD8-A58F-466C-8D87-2EED00B08894.html#GUID-4A4CEDD8-A58F-466C-8D87-2EED00B08894___TOPO_SPLIT_APDX_DATA_MODEL_23810, the initial device-to-domain assignments are represented by the relationships between TopoSplit_Node and TopoSplit_Domain.