What must be configured on a downstream device to facilitate communication with IoT Hub via an IoT Edge Gateway?

To facilitate communication with IoT Hub via an IoT Edge Gateway, it is essential to configure the parent device on the downstream device. The parent device serves as a bridge between the downstream device and the IoT Edge Gateway, allowing the downstream device to communicate effectively within the IoT architecture.

This configuration is crucial because it establishes the hierarchy necessary for the downstream device to relay data and commands through the IoT Edge Gateway to the IoT Hub. The parent-child device relationship ensures that the data flow is managed appropriately and that the downstream device can leverage the connectivity provided by the Edge Gateway.

In the context of the other choices, while authentication, device health monitoring, and network type are all important aspects of IoT solution design, they are not specifically required to establish the direct communication link through an Edge Gateway. Parent device configuration is the fundamental step in enabling the hierarchy that allows the downstream device to communicate with the IoT Hub effectively.