In our scenario, we have a bunch of devices that communicate locally with a gateway. The gateway is responsible to aggregate events from the devices and send it to the cloud. It should also receive device configuration changes from the the cloud and transport it to the specific device.
Based on my reading I would think that this is actually a typical IoT Hub scenario. And we would very much like to use the device management, messaging and maybe even twins that IoT Hub provides.
However, the way the devices communicate is already implemented and shall not be changed. That means the devices themselves cannot create connections and provide IoT Hub credentials. This rules out using the azure-iot-protocol-gateway or similar.
We would rather need the gateway to act as a device that can act on behalf of other devices. The gateway would detect which devices are in his local network and subscribe to their topics (via MQTT or AMQP).
Is this even possible? Can devices send events or listen to Cloud-To-Device messages in place of other devices?
Your scenario is a perfect fit for Azure IoT Edge:
https://docs.microsoft.com/en-us/azure/iot-edge/
"Azure IoT Edge is an Internet of Things (IoT) service that builds on top of IoT Hub. This service is meant for customers who want to analyze data on devices, a.k.a. "at the edge", instead of in the cloud. By moving parts of your workload to the edge, your devices can spend less time sending messages to the cloud and react more quickly to changes in status."
And I would suggest that you use IoT Edge as an identity or protocol translation Gateway:
https://docs.microsoft.com/en-us/azure/iot-edge/iot-edge-as-gateway
"Gateways in IoT solutions provide device connectivity and edge analytics to IoT devices that otherwise wouldn't have those capabilities. Azure IoT Edge can be used to satisfy all needs for an IoT gateway regardless of whether they are related to connectivity, identity, or edge analytics. "
来源：https://stackoverflow.com/questions/54328608/act-for-other-devices-on-azure-iot-hub