Many believe that it is impossible to resolve the challenges facing today’s Internet without rethinking the fundamental assumptions and design decisions underlying its current architecture. Therefore, a major research effort has been initiated on the topic of Clean Slate Design of the Internet’s architecture. In this paper we first give an overview of the challenges that a future Internet has to address and then discuss approaches for finding possible solutions, including Clean Slate Design. Next, we discuss how such solutions can be evaluated and how they can be retrofitted into the current Internet. Then, we briefly outline the upcoming research activities both in Europe and the U. S. Finally, we end with a perspective on how network and service operators may benefit from such an initiative. Categories and Subject Descriptors C.2.1 [Computer-Communication Networks]: Network Architecture and Design General Terms Design, Management, Performance, Reliability Keywords Clean-Sla...