There are not many QoS settings made in the ROS2 RMW code; the Connext libs will look for a source of user QoS settings using the normal search order (detailed here) - meaning you can provide your own QoS settings to the Connext libs under ROS2, using a variety of methods. Here's what I did:
To disable multicast in ROS2, create a file named "NDDS_DISCOVERY_PEERS" in a directory from which your ROS2 application(s) will be launched (directory where the ros2 command is entered and run). Place in this file a list of the initial peers for discovery (make sure to exclude multicast and shmem) format as detailed here.
My file had: localhost,192.168.1.44
For other QoS settings, place in the same directory as above a "USER_QOS_PROFILES.xml" file containing the QoS settings you'd like to use in ROS2. These settings will affect the ROS2 applications launched from that directory.
this is the answer i received from a RTI colleague.
Originally posted by aks with karma: 667 on 2018-09-07
This answer was ACCEPTED on the original site
Post score: 3
Comment by machinekoder on 2019-08-26:
That's a good answer. I just would like to add that this answer is Connext DDS specific. Changing this setting for eProsima fastrtps works different by creating a
DEFAULT_FASTRTPS_PROFILES.xml with an