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Traditional Internet applications such as FTP and e-mail are increasingly sharing bandwidth with newer, more demanding applications such as Web browsing, IP telephony, video conferencing and online games. These new applications have Quality of Service (QoS) requirements, in terms of delay and throughput, that are different than QoS requirements of traditional applications. Unfortunately, current Active Queue Management (AQM) approaches offer monolithic best-effort service to all Internet applications regardless of the current QoS requirements. This paper proposes and evaluates a new AQM technique, called RED-Worcester, that employs source hints to provide service at network routers that is sensitive to the aggregate QoS requirements for all flows passing through the router. Applications indicate their delay and throughput sensitivity via a delay hint embedded in their outgoing packets. The RED-Worcester router uses the delay hint to dynamically adjust Adaptive RED parameters to yield better overall QoS, providing lower delay when most flows are delay-sensitive. Using a new QoS metric, our simulations demonstrate that RED-Worcester yields higher overall QoS than Adaptive RED when there are delay sensitive flows and operates equally well in other traffic scenarios. RED-Worcester fit the current best-effort Internet environment without requiring traffic monitoring.