This is a client for dynamic DNS services, aimed at ESP (ESP32, etc) devices. Your node can use such a service to make its IP address known as a public DNS name, so you can find it, and use it from applications.
RTPS / DDS component for ESP-IDF: ROS 2-interoperable pub/sub, services (RMI), and actions (AMI) over an embeddedRTPS engine with espp transport and task abstractions