OpenThread released by Google is an open-source implementation of the Thread networking protocol. Google Nest has released OpenThread to make the technology used in Nest products broadly available to developers to accelerate the development of products for the connected home.

The Thread specification defines an IPv6-based reliable, secure and low-power wireless device-to-device communication protocol for home applications. OpenThread implements all Thread networking layers including IPv6, 6LoWPAN, IEEE 802.15.4 with MAC security, Mesh Link Establishment, and Mesh Routing.

This Codelab will walk you through simulating a Thread network on emulated devices.

What you'll learn

What you'll need

Git

Git is required to complete this Codelab. Download and install it before continuing.

Download Git

Once installed, follow the instructions for your specific OS to download and build OpenThread.

XCode for Mac OS X

XCode is required to install and build OpenThread on Mac OS X.

Download XCode

After XCode is installed, install the XCode Command Line Tools:

$ xcode-select --install

Build on Linux / Mac OS X

These installation instructions have been tested on Ubuntu Server 14.04 LTS and Mac OS X Sierra 10.12.6.

Install OpenThread. The bootstrap commands make sure the toolchain is installed and the environment is properly configured:

$ mkdir -p ~/src
$ cd ~/src
$ git clone --recursive https://github.com/openthread/openthread.git
$ cd openthread
$ ./script/bootstrap
$ ./bootstrap

Install wpantund:

$ cd ~/src
$ git clone --recursive https://github.com/openthread/wpantund.git
$ cd wpantund
$ ./script/bootstrap
$ ./bootstrap.sh
$ ./configure
$ make
$ sudo make install

Sometimes there are issues with dbus when it comes to wpantund. Force a restart of dbus to be safe:

$ sudo service dbus restart

Using Windows

If you prefer Windows, we recommend trying the Docker version of this Codelab.

OpenThread Simulation on Docker

Once your installation is complete, build the example OpenThread application. For this Codelab we are using the emulated POSIX example.

$ cd ~/src/openthread
$ make -f examples/Makefile-posix

The example application you'll use for this Codelab demonstrates a minimal OpenThread application that exposes the OpenThread configuration and management interfaces via a basic command-line interface (CLI).

This exercise takes you through the minimal steps required to ping one emulated Thread device from another emulated Thread device.

The figure below describes a basic Thread network topology. For this exercise, we'll emulate the two nodes within the green circle: a Thread Leader and Thread Router with a single connection between them.

Ping a node

1. Start Node 1

Navigate to the openthread directory and spawn the CLI process for an emulated Thread device using the ot-cli-ftd binary.

$ cd ~/src/openthread
$ ./output/x86_64-unknown-linux-gnu/bin/ot-cli-ftd 1

This binary implements an OpenThread device emulated on top of POSIX. The IEEE 802.15.4 radio driver is implemented on top of UDP (IEEE 802.15.4 frames are passed within UDP payloads).

The argument of 1 is a file descriptor that represents the least-significant bits of the "factory-assigned" IEEE EUI-64 for the emulated device. This value is also used when binding to a UDP port for IEEE 802.15.4 radio emulation (port = 9000 + file descriptor). Each instance of an emulated Thread device in this Codelab will use a different file descriptor.

Note: Only use file descriptors of 1 or greater as noted in this Codelab when spawning the process for an emulated device. A file descriptor of 0 is reserved for other use.

If you don't see the > prompt after running this command, press enter.

Create a new Operational Dataset and commit it as the active one. The Operational Dataset is the configuration for the Thread network you are creating.

> dataset init new
Done
> dataset
Active Timestamp: 1
Channel: 20
Channel Mask: 07fff800
Ext PAN ID: d6263b6d857647da
Mesh Local Prefix: fd61:2344:9a52:ede0/64
Master Key: e4344ca17d1dca2a33f064992f31f786
Network Name: OpenThread-c169
PAN ID: 0xc169
PSKc: ebb4f2f8a68026fc55bcf3d7be3e6fe4
Security Policy: 0, onrcb
Done
> dataset commit active
Done

Bring up the IPv6 interface:

> ifconfig up
Done

Start Thread protocol operation:

> thread start
Done

Wait a few seconds and verify that the device has become the Thread Leader. The Leader is the device responsible for managing router ID assignment.

> state
leader
Done

View the IPv6 addresses assigned to Node 1's Thread interface (your output will be different):

> ipaddr
fd61:2344:9a52:ede0:0:ff:fe00:fc00
fd61:2344:9a52:ede0:0:ff:fe00:5000
fd61:2344:9a52:ede0:d041:c5ba:a7bc:5ce6
fe80:0:0:0:94da:92ea:1353:4f3b
Done

Note the specific IPv6 address types:

Mesh-local address types are classified further:

Identify the EID in your console output make a note of it for later use. In the sample output above, the EID is:

fd61:2344:9a52:ede0:d041:c5ba:a7bc:5ce6

2. Start Node 2

Open a new terminal and navigate to the openthread directory and spawn the CLI process. This is your second emulated Thread device:

$ cd ~/src/openthread
$ ./output/x86_64-unknown-linux-gnu/bin/ot-cli-ftd 2

If you don't see the > prompt after running this command, press enter.

Configure the Thread Master Key and PAN ID, using the same values as Node 1's Operational Dataset:

> dataset masterkey e4344ca17d1dca2a33f064992f31f786
Done
> dataset panid 0xc169
Done
> dataset commit active
Done

Bring up the IPv6 interface:

> ifconfig up
Done

Start Thread protocol operation:

> thread start
Done

The device will initialize itself as a Child. A Thread Child is equivalent to an End Device, which is a Thread device that transmits and receives unicast traffic only with a Parent device.

> state
child
Done

Within 2 minutes you should see the state switch from child to router. A Thread Router is capable of routing traffic between Thread devices. It is also referred to as a Parent.

> state
router
Done

Verify the network

An easy way to verify the mesh network is to look at the router table.

1. Check connectivity

On Node 2, get the RLOC16. The RLOC16 is the last 16 bits of the device's RLOC IPv6 address.

> rloc16
5800
Done

On Node 1, check the router table for Node 2's RLOC16. Make sure Node 2 has switched to the router state first.

> router table
| ID | RLOC16 | Next Hop | Path Cost | LQI In | LQI Out | Age | Extended MAC     |
+----+--------+----------+-----------+--------+---------+-----+------------------+
| 20 | 0x5000 |       63 |         0 |      0 |       0 |   0 | 96da92ea13534f3b |
| 22 | 0x5800 |       63 |         0 |      3 |       3 |  23 | 5a4eb647eb6bc66c |

Node 1's RLOC of 0xa800 is found in the table, confirming that it is connected to the mesh.

2. Ping Node 1 from Node 2

Verify connectivity between the two emulated Thread devices. In Node 2, ping the EID assigned to Node 1:

> ping fd61:2344:9a52:ede0:d041:c5ba:a7bc:5ce6
> 16 bytes from fd61:2344:9a52:ede0:d041:c5ba:a7bc:5ce6: icmp_seq=1 hlim=64 time=12ms

Press enter to return to the > CLI prompt.

Test the network

Now that you can successfully ping between two emulated Thread devices, test the mesh network by taking one node offline.

Return to Node 1 and stop Thread:

> thread stop
Done

Switch to Node 2 and check the state. Within two minutes, Node 2 detects that the leader (Node 1) is offline, and you should see Node 2 transition to be the leader of the network:

> state
router
Done
...
> state
leader
Done

Once confirmed, stop Thread and factory reset Node 2 before exiting. A factory reset is done to ensure that the Thread network credentials we used in this exercise are not carried over to the next exercise.

> thread stop
Done
> factoryreset
>
> exit

Also factory reset and exit Node 1:

> factoryreset
>
> exit

See the OpenThread CLI Reference to explore all available CLI commands.

In the previous exercise, you set up a Thread network with two simulated devices and verified connectivity. However, this only allows unauthenticated IPv6 link-local traffic to pass between devices. To route global IPv6 traffic between them (and the Internet via a Thread border router), nodes must be authenticated.

In order to authenticate, one device must act as a Commissioner. The Commissioner is the currently elected authentication server for new Thread devices, and the authorizer for providing the network credentials required for the devices to join the network.

In this exercise, we will use the same two-node topology as before. For authentication, the Thread Leader will act as the Commissioner, the Thread Router as a Joiner.

1. Create a network

If continuing from the previous exercise, you should already have two terminal windows open. If not, make sure two are open and ready to use. One will serve as Node 1, the other as Node 2.

In Node 1, spawn the CLI process:

$ cd ~/src/openthread
$ ./output/x86_64-unknown-linux-gnu/bin/ot-cli-ftd 1

If you don't see the > prompt after running this command, hit enter.

Create a new Operational Dataset, commit it as the active one, and start Thread:

> dataset init new
Done
> dataset
Active Timestamp: 1
Channel: 12
Channel Mask: 07fff800
Ext PAN ID: e68d05794bf13052
Mesh Local Prefix: fd7d:ddf7:877b:8756/64
Master Key: a77fe1d03b0e8028a4e13213de38080e
Network Name: OpenThread-8f37
PAN ID: 0x8f37
PSKc: f9debbc1532487984b17f92cd55b21fc
Security Policy: 0, onrcb
Done
> dataset commit active
Done
> ifconfig up
Done
> thread start
Done

Wait a few seconds and verify that the device has become a Thread Leader:

> state
leader
Done

2. Start the Commissioner role

While still on Node 1, start the Commissioner role:

> commissioner start
Done

Allow any Joiner (by using the * wildcard) with the J01NME Joiner Credential to commission onto the network. A Joiner is a device that is added by a human administrator to a commissioned Thread Network.

> commissioner joiner add * J01NME
Done

3. Start the Joiner role

In a second terminal window, spawn a new CLI process. This is Node 2.

$ cd ~/src/openthread
$ ./output/x86_64-unknown-linux-gnu/bin/ot-cli-ftd 2

On Node 2, enable the Joiner role using the J01NME Joiner Credential.

> ifconfig up
Done
> joiner start J01NME
Done

... wait a few seconds for confirmation ...

Join success

As a Joiner, the device (Node 2) has successfully authenticated itself with the Commissioner (Node 1) and received the Thread Network credentials.

Now that Node 2 is authenticated, start Thread:

> thread start
Done

4. Validate network authentication

Check the state on Node 2, to validate that it has now joined the network. Within two minutes, Node 2 transitions from child to router:

> state
child
Done
...
> state
router
Done

5. Reset configuration

To prepare for the next exercise, reset the configuration. On each Node, stop Thread, do a factory reset, and exit the emulated Thread device:

> thread stop
Done
> factoryreset
>
> exit

You may have to press enter a few times to bring the > prompt back after a factoryreset command.

For this exercise, we are going to simulate one CLI instance (a single embedded SoC Thread device) and one Network Co-Processor (NCP) instance.

wpantund is a user-space network interface driver/daemon that provides a native IPv6 network interface to a low-power wireless NCP. It can be used to simplify supporting Thread connectivity on Unix-like operating systems, and is designed to marshall all access to the NCP, ensuring that it always remains in a consistent and well-defined state.

wpanctl is a CLI provided by wpantund to manage and configure the NCP. Using this, we'll connect the NCP to the network created by the Thread device.

Use wpantund

This exercise will use three terminal windows, corresponding to the following:

  1. CLI instance of simulated Thread device (Node 1)
  2. wpantund process
  3. wpanctl CLI instance

If continuing from the previous exercise you should already have two terminal windows open. Open a third to ensure you have three terminal windows available for this exercise.

1. Start Node 1

In the first terminal window, spawn the CLI process for your emulated Thread device:

$ cd ~/src/openthread
$ ./output/x86_64-unknown-linux-gnu/bin/ot-cli-ftd 1

If you don't see the > prompt after running this command, hit enter.

Create a new Operational Dataset, commit it as the active one, and start Thread:

> dataset init new
Done
> dataset
Active Timestamp: 1
Channel: 13
Channel Mask: 07fff800
Ext PAN ID: 97d584bcd493b824
Mesh Local Prefix: fd55:cf34:dea5:7994/64
Master Key: ba6e886c7af50598df1115fa07658a83
Network Name: OpenThread-34e4
PAN ID: 0x34e4
PSKc: 38d6fd32c866927a4dfcc06d79ae1192
Security Policy: 0, onrcb
Done
> dataset commit active
Done
> ifconfig up
Done
> thread start
Done

View the IPv6 addresses assigned to Node 1's Thread interface:

> ipaddr
fd55:cf34:dea5:7994:0:ff:fe00:fc00
fd55:cf34:dea5:7994:0:ff:fe00:d000
fd55:cf34:dea5:7994:460:872c:e807:c4ab
fe80:0:0:0:9cd8:aab6:482f:4cdc
Done
>

As explained in the Simulate a Thread network step, one address is link-local (fe80) and three are mesh-local (fd). The EID is the mesh-local address that does not contain ff:fe00 in the address. In this sample output, the EID is fd55:cf34:dea5:7994:460:872c:e807:c4ab.

Identify the specific EID from your ipaddr output, which will be used to communicate with the node.

2. Start wpantund

In the second terminal window, navigate to the openthread directory, and start wpantund with an interface of utun6:

$ cd ~/src/openthread
$ sudo /usr/local/sbin/wpantund -o Config:NCP:SocketPath \
    "system:output/x86_64-unknown-linux-gnu/bin/ot-ncp-ftd 2" \
    -o Daemon:SyslogMask " -info" \
    -o Config:TUN:InterfaceName utun6

When successful, wpantund generates output similar to the following:

wpantund[66]: Starting wpantund 0.08.00d (May 24 2019 23:14:00) . . .
wpantund[66]:         SOURCE_VERSION = 0.07.01-124-g038e8b0
wpantund[66]:         BUILD_VERSION = 0.07.01-153-g6752c40
wpantund[66]: Configuration file "/etc/wpantund.conf" read.
wpantund[66]: Ready. Using DBUS bus ":1.0"
wpantund[66]: Running as root without dropping privileges!
wpantund[67]: About to exec "output/x86_64-unknown-linux-gnu/bin/ot-ncp-ftd 2"
wpantund[66]: [-NCP-]: NCP was reset (STATUS_RESET_POWER_ON, 112)
wpantund[66]: State change: "uninitialized" -> "offline"
wpantund[66]: NCP is running "OPENTHREAD/20180926-00638-g4aca0256; POSIX; May 24 2019 23:17:23"
wpantund[66]: Driver is running "0.08.00d (0.07.01-124-g038e8b0/0.07.01-153-g6752c40; May 24 2019 23:14:00)"
wpantund[66]: Network is not joinable
wpantund[66]: Resetting interface(s). . .
wpantund[66]: Finished initializing NCP

3. Use wpanctl to join the network

The network interface is currently down because we haven't told wpantund to connect to anything yet. This is where wpanctl comes in.

In a third terminal window, start wpanctl for the interface utun6:

$ sudo /usr/local/bin/wpanctl -I utun6
wpanctl:utun6>

Check the status of the interface you just created:

wpanctl:utun6> status
utun6 => [
        "NCP:State" => "offline"
        "Daemon:Enabled" => true
        "NCP:Version" => "OPENTHREAD/20180926-00638-g4aca0256; POSIX; May 24 2019 23:17:23"
        "Daemon:Version" => "0.08.00d (0.07.01-124-g038e8b0/0.07.01-153-g6752c40; May 24 2019 23:14:00)"
        "Config:NCP:DriverName" => "spinel"
        "NCP:HardwareAddress" => [18B4300000000002]
]

Use the scan command to see the network you created earlier on Node 1:

wpanctl:utun6> scan
   | Joinable | NetworkName        | PAN ID | Ch | XPanID           | HWAddr           | RSSI
---+----------+--------------------+--------+----+------------------+------------------+------
 1 |       NO | "OpenThread-34e4"  | 0x34E4 | 13 | 97D584BCD493B824 | 9ED8AAB6482F4CDC |  -20

Note the row index of 1 (the first column in the table). You'll need this to join the network.

Add the network key you specified on Node 1 to the interface:

wpanctl:utun6> set Network:Key --data ba6e886c7af50598df1115fa07658a83

Join the network using the join command and the row index from the earlier scan:

wpanctl:utun6> join 1
Joining "OpenThread-34e4" 97D584BCD493B824 as node type "end-device"
Successfully Joined!

A quick status check now yields more information:

wpanctl:utun6> status
utun6 => [
        "NCP:State" => "associated"
        "Daemon:Enabled" => true
        "NCP:Version" => "OPENTHREAD/20180926-00638-g4aca0256; POSIX; May 24 2019 23:17:23"
        "Daemon:Version" => "0.08.00d (0.07.01-124-g038e8b0/0.07.01-153-g6752c40; May 24 2019 23:14:00)"
        "Config:NCP:DriverName" => "spinel"
        "NCP:HardwareAddress" => [18B4300000000002]
        "NCP:Channel" => 13
        "Network:NodeType" => "end-device"
        "Network:Name" => "OpenThread-34e4"
        "Network:XPANID" => 0x97D584BCD493B824
        "Network:PANID" => 0x34E4
        "IPv6:LinkLocalAddress" => "fe80::544f:440:b6e:9339"
        "IPv6:MeshLocalAddress" => "fd55:cf34:dea5:7994:8bd3:3d1d:da77:abe3"
        "IPv6:MeshLocalPrefix" => "fd55:cf34:dea5:7994::/64"
        "com.nestlabs.internal:Network:AllowingJoin" => false
]

Quit wpanctl and ping Node 1, using its EID with the ping6 command. If the wpantund interface is successfully joined to and communicating with the Thread network, the ping succeeds.

wpanctl:utun6> quit

$ ping6 fd55:cf34:dea5:7994:460:872c:e807:c4ab
PING fd55:cf34:dea5:7994:460:872c:e807:c4ab (fd55:cf34:dea5:7994:460:872c:e807:c4ab): 56 data bytes
64 bytes from fd55:cf34:dea5:7994:460:872c:e807:c4ab: icmp_seq=0 ttl=64 time=4.568 ms
64 bytes from fd55:cf34:dea5:7994:460:872c:e807:c4ab: icmp_seq=1 ttl=64 time=6.396 ms
64 bytes from fd55:cf34:dea5:7994:460:872c:e807:c4ab: icmp_seq=2 ttl=64 time=7.594 ms
64 bytes from fd55:cf34:dea5:7994:460:872c:e807:c4ab: icmp_seq=3 ttl=64 time=5.461 ms
--- fd55:cf34:dea5:7994:460:872c:e807:c4ab ping statistics ---
4 packets transmitted, 4 packets received, 0% packet loss
round-trip min/avg/max/stddev = 4.568/6.005/7.594/1.122 ms

You can also check the wpantund log in the second terminal window to confirm the scan by wpanctl, as well as the successful join:

wpantund[66]: Scan -> Name:OpenThread-34e4  , PanId:0x34E4, Ch:13, Joinable:NO , XPanId:0x97D584BCD493B824, HwAddr:0x9ED8AAB6482F4C24, RSSI:-20 , LQI:0  , ProtoId:3  , Version: 0, ShortAddr:0xFFFF
wpantund[66]: State change: "offline" -> "associating"
wpantund[66]: State change: "associating" -> "associated"
wpantund[66]: Node type change: "unknown" -> "end-device"
wpantund[66]: Adding address "fe80::4a52:6216:6eb7:98fc/64" to NCP

You've successfully simulated your first Thread network using OpenThread. Awesome!

In this Codelab you learned how to:

If you want to learn more, explore these references: