Weighted fairness guarantee for scalable DiffServ assured forwarding

This paper presents a new mechanism of weighted fair bandwidth sharing for differentiated services (DiffServ) assured forwarding (AF) services. The mechanism is named SCALE-WFS, i.e. Scalable Core with Aggregation Level labEling-Weighted Fair bandwidth-Sharing. It aims to achieve near-optimal max-min weighted fairness without per-flow management at core routers. Through extensive simulation and simple analysis, we show its advantages over the current solutions (CSFQ or TCM+RED3) for different flow weights, RTTs and protocols (TCP and UDP), especially under the scenarios of different bandwidth provisioning and multiple congested gateways. Apart from "per-flow" and completely "core-stateless", SCALE represents a third management level-the label-based flow "aggregation" level. It reduces the information redundancy in the "per-flow" and surpasses the performance of the "core-stateless". Thus we avoid the non-scalability of per-flow management in DiffServ networks while keeping its good quality of services. We show that the SCALE-WFS is effective, scalable and robust for weighted fairness guarantees.