A Thread Border Router connects a Thread network to other IP-based networks, such as Wi-Fi or Ethernet. A Thread network requires a Border Router to connect to other networks. A Thread Border Router minimally supports the following functions:
OpenThread Border Router (OTBR) released by Google is an open-source implementation of the Thread Border Router.
Follow the CodeLab tutorial on openthread.io to set up your OpenThread Border Router on a Raspberry Pi 3 or Raspberry Pi 4 device. Ubuntu and debian hosts are also supported. The CodeLab uses Nordic Semiconductor's nRF52840 DK as the Border Router RCP device.