Low-cost realization of hierarchical bandwidth sharing service in a residential switch

Abstract

This thesis focuses on design of hierarchical bandwidth sharing service model in low-cost residential switch. Main design considerations are (1) providing differentiated services to each subscriber, (2) small buffer size, and (3) low implementation and computational complexity. The first consideration makes us adopt hierarchical bandwidth sharing model as a service model, and the second and third stimulate us to develop simple and efficient buffer management scheme. For realization of hierarchical bandwidth sharing service model under constraint of low implementation and computational complexity, we suggest H-DRR (Hierarchical Deficit Round Robin) which has computational complexity of O(1), and require only simple integer subtraction, addition, and comparison operation. As simple and efficient buffer management scheme, we suggest early weighted longest queue drop scheme (E-WLQD). That scheme extends traditional longest queue drop scheme to improve average buffer sojourn time and to adapt it in our weighted fair share requirement. We presents theoretical evaluation of H-DRR via fairness index called B-WFI. We prove that H-DRR achieves hierarchical bandwidth sharing by simulation. Another simulation shows that our suggested buffer management scheme support greatest fairness and not poorest average delay compared to traditional schemes.