Quality-of-service scheduler for next generation network services

Flows have different characteristics depending on the type of application, and this leads to consideration of the QoS needed to guarantee that the application will work satisfactorily. However, the scheduling algorithms such as WFQ, DRR, or hierarchical scheduling algorithms are complex to guarantee QoS in per-flow level because of buffer management. Calendar queue is appropriate to service per-flow based scheduling because it is simple enough to implement and easy to manage buffers. However, the nature of the calendar queue - fixed slot size can degrade the network throughput. So we propose a QoS scheduler based on calendar queue with an algorithm to improve the network throughput. Also, we verify the performance of the proposed scheduler with ns2 simulator especially in terms of throughput.