1. Why Connext?

ROS 2 uses the Data Distribution Service (DDS) as its underlying communication middleware. ROS 2 shares many concepts with DDS, such as the following:

  • Both use a publish-subscribe communication model.

  • Nodes in ROS 2 are equivalent to DomainParticipants in DDS.

  • Messages in ROS 2 are equivalent to samples in DDS.

This means a Connext DDS application can interoperate with ROS 2 systems, bringing high performance and full access to DDS Quality of Service (QoS) settings and capabilities that are used in countless critical systems around the world.

For an in-depth review of ROS 2, visit https://docs.ros.org/en/kilted/Concepts.html.

Using Connext as your ROS 2 middleware (RMW) layer allows you to use features unique to Connext, including the RTI Security Plugins, Real-Time WAN Transport, Simple Participant Discovery 2.0, Admin Console, Routing Service, and more.

This document explains how ROS 2 and Connext work together, the relationship between different ROS 2 distributions and Connext versions, and the factors that influence compatibility:

  • Section 2 and Section 3 describe how to use ROS 2 with the Connext RMW.

  • Section 4 and Section 5 describe how to use Connext standalone with ROS 2, regardless of the RMW that your ROS 2 application uses.