  As robotics systems become more distributed, the communications between
different robot modules play a key role for the reliability of the overall
robot control. In this paper, we present a study of the Linux communication
stack meant for real-time robotic applications. We evaluate the real-time
performance of UDP based communications in Linux on multi-core embedded devices
as test platforms. We prove that, under an appropriate configuration, the Linux
kernel greatly enhances the determinism of communications using the UDP
protocol. Furthermore, we demonstrate that concurrent traffic disrupts the
bounded latencies and propose a solution by separating the real-time
application and the corresponding interrupt in a CPU.
