The AtmUni subkey stores configuration data for the Asynchronous Transfer Mode ( ATM ) user-to-network interface ( UNI ) Call Manager. The ATM UNI Call Manager is a Windows 2000 component that creates switched and permanent virtual circuits for ATM signaling and communication.

The AtmUni\Parameters subkey stores entries that apply to all ATM network adapters. Entries that configure a particular adapter are stored in the subkey named by the globally unique identifier (GUID) of the adapter in the AtmUni\Parameters\Adapters subkey.

The AtmUni subkey and its subkeys appear in the registry only after you install an ATM network adapter. The system detects the adapter and installs the Windows ATM Services and their registry elements.

By default, the AtmUni subkey contains only the standard entries associated with a Windows service. However, Windows ATM Services adds entries to these subkeys when you use Network and Dial-up Connections to change the default properties of an ATM connection, the ATM Call Manager, or an ATM network adapter. You can also add the entries to configure your ATM adapters.