Network Discovery is designed on the Windows Management Instrumentation (WMI) model. Although DDRs are stored in the SMS site database, Network Discovery uses WMI (formerly called WBEM) to allow users to access the data. The architecture is scalable and has an option that you can use to control Network Discovery on slow networks. For more information about the WMI model, see Chapter 10, “Customizing Hardware Inventory.” The following sections explain the architecture: