Enhanced weighted round robin schedules for accurate bandwidth distribution in packet networks

Weighted Round Robin (WRR) schedules constitute a popular solution for differentiating the bandwidth guarantees of heterogeneous IP flows, mostly because of their minimal implementation cost. However, the WRR formulations that are currently available are not sufficient to satisfy all the requirements of emerging Quality-of-Service frameworks. Flexible bandwidth management at the network nodes requires the deployment of hierarchical scheduling structures, where bandwidth can be allocated not only to individual flows, but also to aggregations of those flows. With existing WRR schedules, the superimposition of a hierarchical structure compromises the simplicity of the basic scheduler.