  The Data Distribution Service (DDS) is an Object Management Group (OMG)
standard for high-performance and real-time systems. DDS is a data-centric
middleware based on the publish-subscribe communication pattern and is used in
many mission-critical, or even safety-critical, systems such as air traffic
control and robot operating system (ROS2).
  This research aims at identifying how the usage of multicast affects the
performance of DDS communication for varying numbers of participants
(publishers and subscribers). The results show that DDS configured for
multicast communication can exhibit worse performance under a high load (a
greater number of participants) than DDS configured for unicast communication.
This counter-intuitive result reinforces the need for researchers and
practitioners to be clear about the details of how multicast communication
operates on the network.
