Act for other devices on Azure IoT Hub

Question

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

Answer 1

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. "