Differentiated services architecture is receiving wide attention as a framework for providing different levels of service in the Internet. Current architecture allows customers to mark their packets and the network provider to check them for conformance to service contracts. This paper looks at the problem of achieving specific QoS goals of individual flows by flexibly managing resources available to an aggregated source. The paper shows that an aggregated source can maintain state of individual flows at the edge of the network and utilize this state effectively in adaptively marking packets of individual flows to meet their QoS goals. The paper also proposes a simple scheme for improving the service provided to a receiving-intensive application by transferring resources to the edge of the network on the sender's side. The paper studies the impact of these sender's side marking strategy and the receiver's willingness to pay for resources in achieving QoS goals of individual flows.
