| ## Creating and Managing Hierarchical Cells You can use CDS to connect independent cells into a hierarchical cell configuration. In this configuration, one cell's CDS acts as a higher-level directory service to connect other independent cells. The cell whose CDS acts as the higher-level directory service is known as a parent cell while the cells connected through the parent's CDS are known as child cells. The cell at the top of the hierarchy must be registered in a global directory service, such as GDS or DNS, but the cells underneath it do not need to be in order to communicate with each other. The next topics describe how to create a cell hierarchy, how to add cells to an existing hierarchy, and the implications of changing a cell's primary name when it is part of a hierarchical cell configuration. Note: In order to create hierarchical cells or cell name aliases, you need to use CDS 4.0 directories. More: Creating a Cell Hierarchy ###