Service modelling has become an increasingly important area in today's telecommunications and information systems practice. We have adapted a Network Design course in order to teach service modelling to a mixed class of both the telecommunication engineering and information systems backgrounds. An integrated approach engaging mathematics teaching with strategies such as problem-solving, visualization, and the use of examples and simulations, has been developed. From assessment on student learning outcomes, it is indicated that the proposed course delivery approach succeeded in bringing out comparable and satisfactory performance from students of different educational backgrounds.