You have to build an IoT solution which gathers data from 1000 devices, with the expected total load of 100k messages per day.
The fleet of devices is quite diverse which means that there is a significant number of legacy devices (some of which can only communicate on traditional industrial protocols), high-power devices capable of running resource-intensive algorithms on their own (edge), and, also there will be high-end devices (smart sensors)
While designing your solution, the connectivity capabilities of the different device types should be considered.
Which of the following statements is not true?
Click on the arrows to vote for the correct answer
A. B. C. D.Correct Answer: C.
Option A is incorrect because smart sensors are generally capable of communicating on MQTT.
MQTT can be used on all smart devices which don't need to operate as hubs for connecting other devices.In environments where the MQTT native port (8883) is not allowed, MQTT over Websockets can be an alternative.
Option B is incorrect all the devices acting as gateways must use the AMQP protocol which is the means of communicating with the IoT Hub.
Option C is CORRECT because the legacy industrial devices speak only “traditional” industry protocols like Modbus.
They can only be connected via gateway, using their native protocol.
It is the gateway device which can connect directly to the IoT Hub.
Option D is incorrect because MQTT and AMQP support cloud-to-device communication.
They enable immediate push of messages from IoT Hub to the device.
(HTTPS also might be a viable option but MQTT/AMQP is recommended.)
References:
The correct answer to the question is D. Devices which must receive C2D messages should connect via MQTT.
Explanation:
The question is related to building an IoT solution that collects data from a fleet of diverse devices. To design the solution, it is important to consider the connectivity capabilities of different device types.
In IoT, there are several protocols available for device connectivity, including HTTP, AMQP, MQTT, and others. Among these, the three most commonly used protocols are HTTP, AMQP, and MQTT.
Now, let's evaluate each statement one by one:
A. Smart sensors can connect to IoT hub via MQTT: This statement is true. MQTT is a lightweight, publish-subscribe protocol that is well suited for IoT devices with limited resources. Smart sensors can use MQTT to send data to the IoT Hub.
B. Gateway devices can connect to IoT Hub via AMQP: This statement is true. AMQP (Advanced Message Queuing Protocol) is a binary protocol that provides reliable and secure messaging. Gateway devices, which act as intermediaries between the IoT devices and the cloud, can use AMQP to connect to the IoT Hub.
C. Legacy field devices can connect to IoT hub on AMQP: This statement is also true. AMQP is a widely adopted protocol that supports different message exchange patterns, including request-response, publish-subscribe, and queuing. Legacy field devices, which may use traditional industrial protocols, can connect to the IoT Hub using AMQP.
D. Devices which must receive C2D messages should connect via MQTT: This statement is not true. C2D (Cloud-to-Device) messages are messages sent from the cloud to the device. While MQTT can be used to send C2D messages, it is not a requirement that devices that receive C2D messages should connect via MQTT. In fact, AMQP is a better option for devices that require bi-directional communication with the cloud, as it provides reliable and secure messaging.
In conclusion, the statement that is not true is D. Devices which must receive C2D messages should connect via MQTT.