This document discusses MQTT (Message Queuing Telemetry Transport), a publish-subscribe based messaging protocol that is well-suited for machine-to-machine and Internet of Things communication. The presentation introduces MQTT, describing its key features such as publish/subscribe messaging, quality of service levels, retained messages, and last will and testaments. Real-world use cases of MQTT in applications like Facebook Messenger, smart homes, and pipeline monitoring are presented to demonstrate how MQTT enables low-latency and low-bandwidth communication between constrained devices.

1. Dominik Obermaier - Push! MQTT for the Internet of Things - IoTLive 2014
Push!
MQTT for the Internet of Things
1

2. Dominik Obermaier - Push! MQTT for the Internet of Things - IoTLive 2014 2
About me
Hi, I’m Dominik Obermaier.
• CTO of dc-square
• HiveMQ architect
• helped standardizing MQTT at OASIS
• Speaker and author about MQTT, M2M
and IoT
@dobermai

3. Dominik Obermaier - Push! MQTT for the Internet of Things - IoTLive 2014 3
1
MQTT?

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• Messaging Protocol
• Simple
• On top of TCP
• Publish / Subscribe Architecture
• Binary protocol
• Minimal Overhead
• Designed for unreliable networks
• Data agnostic
MQTT - Overview

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• Push instead of Poll
• Bandwidth is at a premium
• Enterprise applications should
interact with mobile applications
• Reliable delivery of messages over
unreliable networks
• Constrained devices
• Low latency
MQTT - Use cases

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MQTT - Features
• Topic Wildcards
• 3 Quality of Service Levels
• Retained Messages
• Last Will and Testament
• Persistent Sessions
• Heartbeats

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MQTT - Pub/Sub

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Protocol
• Username / Password
• Payload Encryption
Transport
• TLS
• Client certificate authentication
Broker
• Publish / Subscribe Permissions
• Integration to other systems (databases, APIs, ....)
MQTT - Security

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QoS 0
At most once delivery
The message is delivered once or never.
QoS 1
At least once delivery
The message is delivered once or more.
QoS 2
Exactly once delivery
The message is delivered exactly once.
Quality of Service Levels

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Last Will and Testament
• Clients can specify a LWT
• Broker publishes the LWT message
on behalf of the client on “death”
• Useful for reporting problems
• Real push on device “death”
• Mostly used for reporting the
connection status of a device

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Retained Messages
• Last known good value
• Last message is stored for a topic
• Publishing clients decide if the
message should be retained
• Clients automatically receive the
retained message after subscribing

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2
Brokers & Clients

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MQTT Brokers - Mosquitto
• Open Source
• Ideal for running in constrained
environments
• Supports Bridging

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MQTT Brokers - HiveMQ
• High Performance MQTT broker
• Native Websockets Support
• Plugin System
• Clustering
• Bridging

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MQTT Brokers - Others
+ Many others
see https://github.com/mqtt/mqtt.github.io/wiki/brokers

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MQTT Clients - Paho
• Open Source
• “Reference Implementation”
• Available in many languages: Java,
Javascript, Lua, C, C++, Go, Python
•The JS library uses websockets

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MQTT Clients - Others
https://github.com/mqtt/mqtt.github.io/wiki/libraries

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3
Real World Use
cases

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Facebook Messenger
Use case:
• more than 850M Facebook Messenger Users
• Chat application
• Improved Battery
• Lower latency
• Less bandwidth
https://www.facebook.com/notes/facebook-engineering/building-facebook-messenger/10150259350998920

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Smart Home
Use case:
• MQTT as central message “bus”
• Easy to integrate with other technologies
• Remote monitoring
• Many open source Smart Home Frameworks
support MQTT
• Remote control

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Pipeline Monitoring
Use case:
• 30.000 devices
• 17.000 km pipeline
• Remote monitoring
• Remote control
• Uses satellite links
• Bandwidth is very expensive

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MQTT - Gaining traction
22
Google Trends - 2014/04/09

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Thanks!