This is the slides ProcessOne IoT Studio session #1. At the core of the discussion is an introduction to Internet of Things protocols. Here are the topics / questions that I have been addressing: - What are the main classes of protocols for the Internet of Things ? - What are the strengths of XMPP for the Internet of things ? - What are the main XMPP Extensions for building the Internet of Things ? - How can I leverage XMPP to build a real device / appliance ? As such, the session ends with a hands-on demonstration of a Soundcloud connected Jukebox built with: - Raspberry Pi 2 - Connected to ejabberd - Client is developed in Go using Go XMPP library Gox Video of the session is available on Youtube: https://www.youtube.com/watch?v=YtommTbCxCc

1. IoT Studio #1
16th February 2016
Mickaël Rémond, @mickael

2. Questions
Connected Things
• What are the main classes of protocols for the Internet of Things ?
• What are the strengths of XMPP for the Internet of things ?
• What are the main XMPP Extensions for building the Internet of Things ?
• How can I leverage XMPP to build a real device / appliance ?
=> Tutorial / Demo

3. What are the Main Classes of Protocols for the Internet of
Things ?
• There are numerous protocols for the Internet of Things.
• They act at different levels and fill different needs.
• We can split IoT protocols into two classes:
• Infrastructure protocols
• Messaging protocols

4. IoT Infrastructure Protocols
• Infrastructure protocols focus on low level communications.
• Long range / Low power:
• Sigfox (Proprietary)
• LoRA
• LTE-M
• Wi-Fi HaLow
• Weightless, On-Ramp, …
• Short range communication:
• ZigBee
• NFC
• Bluetooth
• Wifi
• ...

5. IoT Messaging Protocols
• Messaging protocols are higher level and can be transported on various lower level
protocols.
• Most typical uses cases are:
• Sensors / metrics reporting (upstream)
• Control: Control device parameters and behaviours (downstream)
• Examples:
• MQTT for example over TCP/IP or MQTT-SN variant over UDP
• XMPP
• STOMP
• Statsd
• Riemann protocol
• ...

6. IoT Messaging Protocols
• An IoT Messaging platform typical speak several protocols.
• The underlying semantic is the same: Broadcast, control, reporting, …
• The platform act as a bridge.
• Over time, we are seeing a shift from lower level messaging protocols to higher
level protocols, as things are spreading and get more and more powerful.
• For example:
• Raspberry Pi Zero is demonstrating how a whole Linux computer is now going
down the stack to power smaller and smaller devices.

7. What are the Strengths of XMPP for the Internet of things ?
• XMPP is very good as a hub / platform for things. It can support both sensor reading /
reporting and access.
• However, its main strengths are very unique in the IoT protocol landscape. XMPP
natively and easily supports:
• Identity: Ability to manage things identity thanks to Jabber ID (global / universal
identity).
• Federation: Things from different manufacturer, plugged on different platform can
interoperate.
• Delegation: Ability to trust user ID on the network and this thus simplify provisioning /
delegation of rights to interact with devices.

8. What are the main XMPP Extensions for Building the
Internet of Things ?
• XMPP core contains features that play well with IoT:
• SASL Authentication
• Federation
• Encryption
• Synchronous (iq) and asynchronous messaging support (message / presence)
• Offline message store / delayed delivery
• ...
• Additionally, many general purpose extensions are very relevant to the IoT topic:
• XEP-0060: Pubsub
• XEP-0178: Best Practices for Use of SASL EXTERNAL with Certificates
• XEP-0050: Ad-Hoc Commands
• XEP-0004 and others: Data forms
• XEP-0115: Entity capabilities
• XEP-0184: Message delivery receipts
• XEP-0280: Message carbons
• ...

9. What are the main XMPP Extensions for Building the
Internet of Things ?
• An XMPP IoT Initiative is working on extending the protocol for the purpose of the Internet of Things.
• Some XMPP Extensions have been designed with the Internet of Things in mind, with the purpose of
supporting sensors or controllers:
• XEP-0322: Efficient XML Interchange (EXI) Format
• XEP-0323: Internet of Things - Sensor Data
• XEP-0324: Internet of Things - Provisioning
• XEP-0325: Internet of Things - Control
• XEP-0326: Internet of Things - Concentrators
• XEP-0347: Internet of Things - Discovery
• ejabberd also brings some important features to the table by supporting important feature to handle a
large number of devices:
• Clustering
• Massive scalability

10. How can I leverage XMPP to Build a real device /
appliance ?
• I have prepared a demo showing how to plug various things together.
• I will demonstrate building a Jukebox to play songs from SoundCloud by simply sending
control instruction to a Raspberry Pi 2 base device.
• I will use the following technologies:
• XMPP protocol.
• ejabberd as messaging platform.
• Go programming language with my Go XMPP Library (Gox) to write the Jukebox
software.
• Raspberry Pi 2 hardware running with our own custom minimal Linux image, with a
speaker connected to the analog sound output.

11. Architecture diagram
ejabberd serverJukebox

12. Client Control Operation
• Client can be a simple chat bot:
• It will play a URL when receiving it in chat message:
<message type="chat" to="test@localhost" id="aac9a">
<body>https://soundcloud.com/radiohead/spectre</body>
</message>
• It will stop the stream when receive the command “stop” in chat message:
<message type="chat" to="test@localhost" id="aacaa">
<body>stop</body>
</message>

13. Implementing IoT XMPP Control
• Our XMPP Jukebox is also able to play using IOT control operations as defined in XEP-0325:
<iq type='set'
to='test@localhost/jukebox'
id='2'>
<set xmlns='urn:xmpp:iot:control' xml:lang='en'>
<string name='action' value='play'/>
<string name='url' value='https://soundcloud.com/radiohead/spectre'/>
</set>
</iq>

14. Jukebox broadcasts User Tune
<message from="test@localhost" type="headline" to="admin@localhost/MacBook-Pro-
de-Mickael">
<event xmlns="http://jabber.org/protocol/pubsub#event">
<items node="http://jabber.org/protocol/tune">
<item id="5AFB0605CB069">
<tune xmlns="http://jabber.org/protocol/tune">
<artist>Radiohead</artist>
<title>Spectre</title>
</tune>
</item>
</items>
</event>
<addresses xmlns="http://jabber.org/protocol/address">
<address type="replyto" jid="test@localhost/jukebox"/>
</addresses>
</message>

15. Go XMPP Jukebox client
Main
function

16. Go XMPP Jukebox client
XMPP
Client
Connect

17. Go XMPP Jukebox client
Message
Processing

18. Go XMPP Jukebox client
IoT
Control
IQ
Processing

19. Go XMPP Jukebox client
Sending
PEP
User Tune

20. Go XMPP Jukebox client
Playing
Song
with
mpg123
player

21. Demo

22. See you at next