We have recently simulated many sensors with MIMIC MQTT Simulator
publishing arbitrary messages to a subscriber client connected to Azure IoT Hub as a proof of concept of large-scale testing of IoT application
deployment using this platform.
Gambit Communications is a leading provider of network simulation tools that enhance the productivity of enterprises, device vendors, management software developers and outsourcers while lowering their costs.
Our IoT Simulator products aid development / testing / deployment / training / demonstration of large-scale Internet of Things applications.