Providing quality of service guarantees without per-flow state

Two approaches have been proposed to improve the quality of service provided by the Internet: integrated services and differentiated services. Integrated services requires per-flow state at each router On the other hand, differentiated services does not require per-flow state, but provides a lower level of quality of service. We present a protocol which provides quality of service similar to that provided by integrated services, but without maintaining per-flow state. To accomplish this, both the signaling protocol and the packet scheduling protocol must function without per-flow state. Our signaling protocol maintains only a constant amount of state at each router In addition, it is accurate, and it is resilient to process and link failures. Our scheduling protocol is a combination of the dynamic packet state technique and flow aggregation techniques. This approach combines the strengths of both techniques and eliminates their weaknesses. Furthermore, our approach is applicable across multiple domains.