ROS2 Network Communication (does it even work reliably?)

asked 2022-07-07 12:19:29 -0500

rodrigo55 gravatar image

Hi,

I've been working on setting up 3 computers to see each other with ROS2. I keep reading that it is super easy, and in theory it is, but there are problems that make it impossible to work with it, unless I'm not seeing the solution.

First, I can say that I've managed to get 2 computers to see each other. Super easy, just set them in the same wifi and BAM you can see the topics being published from a computer in another. However, the communication drops randomly, and I have to reset the ros2 daemon in order for it to work again. Also, publishing and subscribing to topics accross computers seems to work, but I tried sending a navigation goal (action server call), and the goal was never accepted. This seems incredibly unreliable for such a simple task.

Second, it seems like the WiFi rate (I can see this running nmcli dev wifi is crucial for discovery between computers. I have two computers that have a rate of 540 Mbit/s and they have no problem seeing each other (mentioned above), but I have two others (with a WiFi dongle) that only have a rate of 16 Mbit/s, and there is no way to make them see anything from another computer. Does that make sense?

Third, it seems like there is no way to communicate unless they are in the same WiFi network. I say this because I have the opportunity to switch this slow 16 Mbit/s dongle for an ethernet cable, but there is no way to discover other computers with the ethernet cable.

Lastly, I have to say that all the pings between computers work, they are in the same WiFi network and most importantly (unless I'm going crazy) I have been able to communicate a 16 Mbit/s with a 540 Mbit/s, but now I just can't get them to see each other.

I know it's a long post but maybe someone will be able to give me a good tip.

Cheers!

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Comments

1

There is no single, simple answer to this. See the various discussions on Discourse for instance. Unconfigured DDS considered harmful to Networks would be one of those, but there are more.

gvdhoorn gravatar image gvdhoorn  ( 2022-07-07 12:30:19 -0500 )edit