Unit -II in IOT

In MQTT, what is the central entity responsible for message distribution?

• Broker

• Subscriber

• Publisher

• Client

MQTT is a lightweight messaging protocol designed for:

• Video streaming

• Email communication

• Internet of Things (IoT) devices

• Social media sharing

Which MQTT packet type is used by a client to unsubscribe from a specific topic?

• CONNECT

• SUBSCRIBE

• UNSUBSCRIBE

• PUBLISH

CoAP (Constrained Application Protocol) is designed for communication between:

• High-performance servers and clients

• Low-power, resource-constrained devices

• Satellites and ground stations

• Public Wi-Fi networks

CoAP operates on top of which transport layer protocol?

• TCP

• UDP

• HTTP

• SMTP

Which of the following is a CoAP request method used to retrieve information from a resource?

• GET

• POST

• PUT

• DELETE

Which CoAP message type is used by a client to request a resource from a server?

• Confirmable (CON)

• Non-confirmable (NON)

• Acknowledgment (ACK)

• Reset (RST)

Which security mechanism is often used with CoAP to ensure secure communication?

• SSL/TLS

• SSH

• Kerberos

• OAuth

XMPP stands for:

• Extensible Messaging and Proxy Protocol

• Extra Message and Presence Protocol

• Extensible Messaging and Presence Protocol

• Extended Messaging and Push Protocol

XMPP is primarily used for:

• Video streaming

• Real-time communication and instant messaging

• File sharing between servers

• Voice over IP (VoIP)