This volume forms the edited proceedings of the Sixth International Symposium on Communications Interworking, held in Perth, Western Australia, from 13-16 October, 2002. In total, 39 research papers were submitted for consideration, and after full refereeing by international referees, 27 papers from authors in 11 countries were accepted for publication. Invited keynote addresses were presented by Dr Hugh Bradlow, Chief Technology Offleer for Telstra Corporation, Australia, and Dr Sathya Rao, Director ofTelscom A.G., Switzerland. The symposium brought together 60 active international researchers and telecommunications engineers to discuss the important questions as to whether there is a convergence of all communications, including real-time communications, over the Internet Protocol (IP), and whether existing IP technology is capable of supporting this convergence, or whether it requires further development of that technology. The papers selected to appear in this volume make an important and timely contribution to this debate. Specific symposium paper sessions were held to present and discuss ernerging research on the topics of converged networking, real-time communications over IP, quality of service, routing and metrics, ernerging issues in mobile networks, differentiated services, and wireless networking.