Bad performance of ROS2 via Wifi
I have a simple setup with a laptop on a mobile robot (Foxy) from which I only want to stream data from a laserscanner to a stationary computer that has a wifi dongle. If I only open the scanner on the laptop, I get around 30Hz but If I also subscribe on the workstation, this frequency drops to 20Hz (on the laptop!) and I only get 2-3 Hz on the workstation (always a small burst of messages every 5 seconds).
Streaming a laser scanner really shouldn't be an issue and a slow or unreliable connection to a new subscriber shouldn't decrease the local performance. Reliability is on Best_effort, Durability Volatile.
I'm using the default DDS, are there any settings I have to change?
Possibly related: ROS2 Default Behavior (Wifi).
I've seen suggestions to use Cyclone DDS, but also reports that newer versions of FastRTPS should fix this.
If you have time I would appreciate it if you reported your experience in our Foxy RMW survey.
I have this same problem and just tried Cyclone DDS, but it shows the same results. What bothers me most is that the local rate on the computer on the mobile robot also decreases. This makes monitoring using rviz kind of risky, because it lowers the rate at which control happens on the mobile robot...
I would suggest to post a comment on the Discourse thread (in addition to the survey @kscottz linked), as that is currently the central place for these types of reports to get noticed.