"Connection refused: server unavailable" error while connecting Arduino MKRGSM with Azure IoT Hub

Question

I am registering my Arduino MKRGSM board with Azure Iot Hub by following this link:

https://create.arduino.cc/projecthub/Arduino_Genuino/securely-connecting-an-arduino-nb-1500-to-azure-iot-hub-af6470

Arduino MKRGSM 1400 device is successfully registered in the IoT Hub. but, when I am trying to connect the MKRGSM board to IoT Hub with the example provided in the arduino IDE,
Arduino IDE using File -> Examples -> Arduino Cloud Provider Examples -> AzureIoTHub-> Azure_IoT_Hub_GSM

In the serial monitor, I could see that, the board is getting connected to cellular network successfully, but whenever it is attempting to connect with MQTT, I am getting an error 3(Connection refused:Server unavailable) from the mqttClient.connect(broker, 8883). what would be the reason for this error?
But after few hours(around 10 hours) of registering the device in IoT Hub, i could able to communicate with the device without any error.

why it is taking time to connect with IoT Hub? can anyone suggest me to get through this. Thanks.

Answer 1

Hello all,

As a troubleshooting step in this scenario, we recommend using a new Azure IoTHub created and connect another real IoT Device example using the: IoT Plug and Play app quickly.https://play.google.com/store/apps/details?id=com.iot_pnp&hl=en_IN&gl=US

and connect to the IoT hub. Then send the telemetry messages. It can be monitored using IoT explorer Install and use Azure IoT explorer | Microsoft Learn

Please comment in the below section if you also face the same issue. Happy to help!