IOT IoT Protocols and Standards 1 — Questions and Answers
Question 1: What does MQTT stand for in IoT communications?
- Multi-Queue Transport Technology
- Message Queuing Telemetry Transport (Correct answer)
- Mobile Query Transfer Terminal
- Managed Queue Telemetry Tool
Correct answer: Message Queuing Telemetry Transport
MQTT (Message Queuing Telemetry Transport) is a lightweight publish-subscribe messaging protocol designed for constrained IoT devices.
Question 2: Which IoT protocol uses a RESTful architecture and is designed for constrained devices, often compared to a lightweight HTTP?
- AMQP
- CoAP (Correct answer)
- MQTT
- XMPP
Correct answer: CoAP
CoAP (Constrained Application Protocol) is a RESTful protocol designed for use with constrained IoT nodes and networks.
Question 3: In the MQTT protocol, what role does the 'broker' play?
- It generates IoT data
- It receives messages from publishers and routes them to subscribers (Correct answer)
- It encrypts all device communications
- It assigns device addresses
Correct answer: It receives messages from publishers and routes them to subscribers
The MQTT broker acts as a central hub that receives messages from publishers and distributes them to all subscribed clients.
Question 4: What does the IEEE 802.15.4 standard define?
- High-speed Wi-Fi communications
- Low-rate wireless personal area networks used as the basis for Zigbee and Thread (Correct answer)
- Cellular LTE communications
- Bluetooth Classic profiles
Correct answer: Low-rate wireless personal area networks used as the basis for Zigbee and Thread
IEEE 802.15.4 defines the physical and MAC layers for low-rate wireless personal area networks, forming the foundation for Zigbee, Thread, and 6LoWPAN.
Question 5: Which MQTT Quality of Service (QoS) level guarantees that a message is delivered exactly once?
- QoS 0
- QoS 1
- QoS 2 (Correct answer)
- QoS 3
Correct answer: QoS 2
MQTT QoS level 2 ensures exactly-once delivery using a four-step handshake, the most reliable but highest overhead option.
Question 6: What is the primary advantage of the AMQP protocol over MQTT in enterprise IoT deployments?
- Lower power consumption
- Richer message routing, queuing, and enterprise broker features (Correct answer)
- Longer range communications
- Smaller packet size
Correct answer: Richer message routing, queuing, and enterprise broker features
AMQP (Advanced Message Queuing Protocol) offers richer routing, message acknowledgment, and enterprise-grade broker features compared to MQTT.
IOT IoT Protocols and Standards 1
What does MQTT stand for in IoT communications?