13. ROS2 Distributed Communication

1. Concept

Multi-machine communication, or distributed communication, refers to a communication strategy that enables data exchange between different hosts over a network.

ROS2 itself is a distributed communication framework that facilitates communication between different devices. The middleware underlying ROS2 is DDS. When running on the same network, distributed communication is achieved through the DDS domain ID mechanism (ROS_DOMAIN_ID). The general process is as follows: Before starting a node, you can set the domain ID value. Nodes with the same domain ID can freely discover and communicate with each other. Conversely, if the domain ID values ​​are different, this communication is impossible. By default, all nodes start with domain ID 0. In other words, as long as they are on the same network, distributed communication can be achieved between different nodes on different ROS2 devices without any configuration