The implementation of real-time communication within the design of embedded systems becomes more and more the real system bottleneck. For this reason the evaluation of the communication characteristics is very essential in an early design stage. In this paper we present an evaluation method for real-time communication based on rapid prototyping. Key points are the ISO/OSI layer conform implementation, exchangeable hardware and software modules and the adaptation of a wide range of real-time protocols. These aspects are implemented and illustrated in our casestudy: Two interacting robots with five degrees of freedom, each.