Publisher Summary This chapter provides a review on managed overlays. Physical networks are managed by their operators to assure that network services perform as expected. Although overlays are self-organizing, experience with deployed overlays indicates that additional management mechanisms are needed in some cases. This chapter compares the traditional network management functions with the requirements for managing large-scale overlays and outlines a general approach for integrating an external management agent with an overlay. In addition, we review current trends in addressing the impact of P2P traffic on ISP networks.