Computer networks have revolutionized the way people and machines communicate. We are interested in all aspectes of computer networking, from wireless networks to high speed backbones, from medium access up to distributed applications. Our focus is on solving real-world problems: we often start our work by looking at a specific application and then investigate what is missing to provide optimal network support for this application. We enjoy working with, building, and evaluating real-world systems. At the same time we use theoretical analysis to determine the fundamental characteristics of our solutions and simulation to gain an insight how they work in a complex environment. The following sections give an overview of our current research activities.