Exam AZ-220 topic 1 question 12 discussion

Actual exam question from Microsoft's AZ-220

Question #: 12
Topic #: 1

You have an Azure IoT solution that includes an Azure IoT hub and 100 Azure IoT Edge devices.
You plan to deploy the IoT Edge devices to external networks. The firewalls of the external networks only allow traffic on port 80 and port 443.
You need to ensure that the devices can connect to the IoT hub. The solution must minimize costs.
What should you do?

A. Configure the upstream protocol of the devices to use MQTT over TCP.
B. Configure the upstream protocol of the devices to use MQTT over WebSocket.
C. Connect the external networks to the IoT solution by using ExpressRoute.
D. Integrate cellular communication hardware onto the devices and avoid the use of the external networks.

Show Suggested Answer

Suggested Answer: B 🗳️
MQTT over WebSockets uses port 443.
Note: Devices can communicate with IoT Hub in Azure using various protocols. Typically, the choice of protocol is driven by the specific requirements of the solution. The following table lists the outbound ports that must be open for a device to be able to use a specific protocol:

Incorrect Answers:
A: MQTT over TCP uses port 883.
C: ExpressRoute uses BGP, which uses TCP port 179.
D: HTTPS proxy also uses port 443, but it would be a more expensive solution.
Reference:
https://docs.microsoft.com/en-us/azure/iot-hub/iot-hub-devguide-protocols

by BoomJosh at March 24, 2021, 7:26 p.m.

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BoomJosh

Highly Voted 4 years, 2 months ago

Appeared for exam on 3/24/2021 and successfully cleared it, this question was there. Only difference was instead of MQTT, AMQP was in the option.

upvoted 5 times

jracabrera

4 years ago

Thanks. Makes sense. Because AMQP is for cloud/field gateways.

upvoted 4 times

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