Quizzes- MQTT

In a Publish/Subscribe model how does the publisher know who is subscribing.

MQTT uses

MQTT-SN uses

Each client that connects to a broker must have a unique client id?

When connecting to an MQTT broker you always need a username and password?

An MQTT broker can use any port, but by default it uses port 1883?

MQTT transmits data to and from a broker in which format.

Messages sent to an MQTT broker are encrypted by default?

You can subscribe to multiple topics at once using wild cards?

You must always start your topic hierachy with a / e.g. /topic name?

The Last Will Message is used to:

To Receive a last will message.

The Last will message is sent from?

When you publish a message to a topic with the retained flag set what happens to the message?

To receive a retained message?

To delete a retained message from a broker you must?

When you connect to a broker with clean session flag set to true what Happens?

You connect to a broker with the clean session flag set to false and subscribe to the topic house/sensor1.
You then disconnect and after about 10 minutes you reconnect with the same client. Do you need to Subscribe to the topic house/sensor1 again?

You connect to a broker with the clean session flag set to false, and subscribe to the topic house/sensor1 with QOS 1.You then disconnect, and after about 10 minutes you reconnect with the same client. If another client publishes messages on house/sensor1 with QOS 1 while you are disconnected. What happens when you reconnect?

You connect to a broker with the clean session flag set to false, and subscribe to the topic house/sensor1 with QOS 0.You then disconnect, and after about 10 minutes you reconnect with the same client. If another client publishes messages on house/sensor1 with QOS 1 while you are disconnected. What happens when you reconnect?

You install the paho python MQTT client using the pip command?

Before you can publish a message you need to create a connection to a MQTT broker?

You can use the Python client without an MQTT broker?

You need to subscribe before you can publish?

The broker stores all MQTT messages just like Email?

The retain flag is set by a client when it subscribes to a topic

You can tell if the message you receive is a retained message?

When connecting the clean session flag is False by default?

You have connected to a broker and subscribed to a topic that you know should contain your sensor data which is being published every seconds but you don’t’ see any data. What is the most likely cause?

You can publish on several topics with a single publish