A significant challenge arising from today's increasing Internet traffic is the ability to flexibly incorporate intelligent control in high performance commercial network devices. This paper tackles this challenge by introducing the Active Flow Manipulation (AFM) mechanism to enhance traffic control intelligence of network devices through programmability. With AFM, customer network services can exercise active network control by identifying distinctive flows and applying specified actions to alter network behavior in real-time. These services are dynamically loaded through Openet by the CPU-based control unit of a network node and are closely coupled with its silicon-based forwarding engines, without negatively impacting forwarding performance. AFM is exposed as a key enabling technology of the