A device may manage end-to-end traffic across a network based on adjusting Quality of Service (QoS) parameters. The device may receive performance requirements for packets corresponding to different applications and QoS levels within segments across the network, and measure performance values along the segments across the network. The device may also identify the application data flows and their associated network locations failing to meet performance values across network segments, and detect an application data flow failing to meet end-to-end (E2E) performance requirements. The device may determine network location(s) to adjust the QoS parameters of the detected application data flow, and adjust its QoS parameters at the determined network location(s) to bring the detected application data flow into compliance with its E2E performance requirements, while maintaining E2E performances compliance of other application data flows.