| With the development of science and technology, computer network technology has made rapid development in the past few decades. Remote login services, voice services, Web and more online transmission service has been used in Internet. In traditional,the network mainly transmit data, and the network was the main provider of best-effort service. With the appear of more service,the traditional best-effort service model system can not meet the QoS requirement。So people raised a comprehensive service model. Integrated Services model provides an end to end QoS service model. Now network use both Int Serv and DiffServ model.QoS DiffServ model includes the main packet classification, congestion management, traffic policing, shaping. In this thesis,we focus on the princle of QoS applied on the three layer switch,and then test it use testcenter.In order to provide better service for the network, we must pay more attention to congestion management. Congestion Control scheduling are currently the hotspot of research.Queue scheduling algorithm based on the idea of the main time-stamped and polling scheduling algorithm. The DRR(Deficit Weighted Round Robin) algorithm has good fairness, low latency and complexity. We research the DRR algorithm and propose an improved algorithm.At last,we simulate it use NS2. |
