1. A method for enabling Hierarchical Architecture of device management gateways, the method comprising: differentiating whether an End Device or Child DM Gateway type of a device is associated with an immediate lower level of a Device Management (DM) Gateway, by adding a ComponentType leaf node in a Gateway Management Object (GwMO) Device Tree (DM TND), and supporting the Hierarchical Architecture, in which a DM Gateway uses different interfaces, depending on whether the DM Gateway is associated with an End Device or a child DM Gateway, respectively, wherein the ComponentType leaf node is added to each entry in a Gateway Inventory Record, and is aligned with a sibling node DeviceID, which contains a public identifier of the device, and the DM Gateway is able to make use of the ComponentType field associated with the device related to invoke/expose the correct interface.