What is a Thread Border Router & Why Do You Need One?
Thread is the backbone communication protocol of modern smart homes built on Matter. At the center of this technology is core device type called a Thread Border Router. But what exactly is a Thread Border Router? Why is it essential for using Thread devices? And what role does it play in your smart home?
Thread Border Router at a Glance
- Connects a Thread mesh to other networks and the internet
- Required to use Thread devices over Matter
- Provides local, low-latency communication
- Built-in security, redundancy and resilience
- Solidifies and extends your Thread mesh network
- Included in Homey Pro and Homey Pro mini
What Is a Thread Border Router?
A Thread Border Router (TBR) is a device that links a Thread mesh network to other IP-based networks, such as Wi-Fi or Ethernet. It provides a two-way IP connection between Thread and these external networks, allowing Thread devices to access cloud services, interact with non-Thread devices, and work over Matter.
Image source: CSA
In simple terms, a TBR translates communication between Thread devices and the wider internet, enabling them to work with other protocols and ecosystems. Without one, Thread devices would be isolated and unusable with Matter.
Functions of a Thread Border Router
Besides connecting Thread devices to Wi-Fi, Ethernet, and the wider internet, a Thread Border Router also takes on several important roles within the mesh. It not only enables Matter devices to function properly but also ensures the Thread network stays secure, reliable, and discoverable to other devices in your smart home.
- IP Routing and Discovery: Provides IPv6 connectivity between Thread and external networks like Wi-Fi or Ethernet, while also allowing these devices to discover and interact with Thread devices.
- Secure Commissioning: Helps onboard new devices securely and supports credential sharing across multiple Border Routers.
- Thread Over Infrastructure: Connects separate Thread partitions over Wi-Fi or Ethernet, keeping the network stable and unified.
- Redundancy: Ensures reliability by allowing multiple Border Routers to exist and take over if one goes offline.
- Traffic Management: Filters and limits multicast traffic to protect low-power Thread devices from being overloaded.
- Advanced Features: Some implementations add extras such as DHCP for IPv4, NAT functions, or VPN endpoint hosting.
In summary, a Thread Border Router acts as both the gateway and the guardian of your Thread network. It keeps devices connected to the wider smart home while ensuring communication remains fast, secure, and reliable.
The Difference Between a Thread Border Router and a Thread Router
A Thread Router, also known as a Thread Mesh Extender, is a device within the Thread network that forwards data, manages connected devices, and helps maintain the health of the mesh. Routers operate exclusively within the Thread network and do not communicate with other networks. One Thread Router is also automatically elected as the leader, responsible for assigning roles and managing routing tables.
A Thread Border Router sits at the edge of the network. Instead of just relaying traffic within the mesh, it connects the Thread mesh to external networks like Wi-Fi or Ethernet. This allows Thread devices to reach the internet, communicate with non-Thread devices, and become part of Matter fabrics. In short, Thread Routers maintain the network, while the TBR links it to the rest of your smart home. TBRs are also Thread Routers.
Looking to learn more about Thread topology?
Read about other Thread Device Types and Network Roles.
Why Do You Need a Thread Border Router?
A Thread Border Router is necessary for any Thread device to communicate outside its own mesh. Matter over Thread specifically requires a Border Router for device setup, discovery, and secure messaging. Without one, a Thread network would operate as a closed system with no connection to other devices or services.
This means that a Thread smart lock, thermostat, or motion sensor could not work with Wi-Fi products, cloud services, or Matter devices from other brands unless a Border Router is in place. By including certified Border Router functionality, Homey Pro and Homey Pro mini ensure that you can add Thread devices to your setup without needing any extra hardware.
How Many Thread Border Routers Do You Need?
Only one Border Router is technically needed to connect a Thread mesh to your home’s IP network. A single device provides the necessary routing to move Thread traffic in and out of the mesh. If that Border Router becomes unavailable, the Thread mesh will continue to work locally, but external communication will stop until another Border Router takes over.
For most homes, a single Border Router is enough to handle this link to external networks. However, having more than one can add redundancy. If one device fails or goes temporarily offline, another Border Router will take over, maintaining a seamless connection. For instance, running Homey Pro and Homey Pro mini together can provide an extra layer of reliability in your smart home.
Thread Border Routers and Their Role in Matter
Thread provides an underlying network protocol for Matter devices, while Matter defines the application layer that allows devices from different brands to work together. For Matter over Thread devices to function, a Thread Border Router must be present. It provides the IP routing that enables these devices to join a Matter fabric and communicate securely with controllers, apps, and other devices.
For the user, this means a Border Router is the silent enabler that makes Matter devices work as expected. Without it, adding a Matter over Thread smart plug or contact sensor would not be possible in a smart home. With it, the device can be added to Homey and controlled alongside other devices like Zigbee or Z-Wave.
Homey Pro as a Thread Border Router
Both Homey Pro and Homey Pro mini function as full-featured Thread Border Routers. They translate Thread traffic and enable Matter over Thread devices to work correctly in your smart home. Your Homey Pro becomes the bridge between your Thread devices and other connected devices in your home.
For users, this means simplicity. Since both are TBRs, adding a Thread device to Homey is simple and straightforward. At the same time, Homey Pro supports Zigbee, Z-Wave, Wi-Fi, Bluetooth, Infrared, and 433MHz devices, providing you with a single smart home hub for all smart home technologies.
