This paper proposes a new QoS framework, called the On-Demand QoS Path framework (ODP). ODP provides end-to-end QoS guarantees to individual flows with minimal overhead, while keeping the scalability characteristic of Diff-Serv. ODP exercises per-flow admission control and end-to-end bandwidth reservation at the edge of the network and only differentiates traffic classes in the core of the network. In addition, to adapt to dynamically changing traffic load, ODP monitors the bandwidth utilization of the network and performs dynamic bandwidth reconfiguration in the network core. Through extensive simulations, the performance of ODP is investigated and compared with that of IntServ and DiffServ frameworks. The simulation results clearly show that ODP provides end-to-end QoS guarantees to individual flows, which DiffServ can not provide, with much less overhead than Int-Serv.