A per-flow based node architecture for integrated services packet networks

As the Internet transforms from the traditional best-effort service network into QoS-capable multi-service network, it is essential to have new archit ectural design and appropriate traffic control algorithms in place. This pa per presents a network node architecture and several traffic management mec hanisms that are capable of achieving QoS provisioning for the guaranteed s ervice (GS), the controlled-load (CL) service, and the best-effort (BE) ser vice for future integrated services networks. A key feature of our architec ture is that it resolves the out-of-sequence problem associated with the tr aditional design. We also propose two novel packet discarding mechanisms ca lled selective pushout (SP) and selective pushout plus (SP+). Simulation re sults show that, once admitted into the network, our architecture and traff ic management algorithms provide, under all conditions, hard performance gu arantees to CS flows and consistent (or soft) performance guarantees to CL flows, respectively; minimal negative impact to in-profile GS, CL and BE tr affic should there be any out-of-profile behavior from some CL flows.