There has been some questions and discussion related to cross-vendor and cross-distro communication support in ROS 2.

• https://answers.ros.org/question/341372/can-nodes-from-different-ros-2-distributions-communicate-compatibly/
• https://discourse.ros.org/t/ros-cross-distribution-communication/27335

And the answer is NO for both cases. currently ROS 2 does not support any cross-distro or cross-vendor communication officially. (which is my understanding, if i am mistaken, let me know) some of these cases are implemented in test code, but that does not mean that we support these compatibility.

No matter this is being current limitation or specification, it would be probably nice to describe clearly that is not supported in ROS 2 documentation officially? So that we can avoid potential unexpected problems and questions in the future.

Adding documentation would not be good enough to guarantee to avoid these cases, maybe we can add warning if the communication takes place with different distro or vendor implementation at runtime.

This topic was from today's MW WG meeting. (CC: @wjwwood @alsora @asorbini @ros2/middleware_working_group )

Related but out of scope from this issue:

• Service Interoperability with different RMW implementation