Studies on provision of Quality of Service for multi-class traffic on the Internet

(1)多类业务的流量监管和优先级控制研究假设网络具有多类业务的优先级控制，我们首先提出了在入口路由器的监管，标记和调度机制，并通过分析方法和计算机模拟来评估这些性能。通过一些数值结果，我们调查了网络中的每种业务类型的可实现的服务质量（QoS）。然后，我们提出了一些网络中的QoS推断机制，并解释了其有效性。(2)多类业务的路由机制研究我们首先研究了一种路由机制，它能有效地为每个实时业务分配带宽，提高TCP等尽力而为业务的吞吐量。在该机制中，我们为这两类流量引入了“虚拟剩余带宽”的概念。以“虚拟剩余带宽”作为路由度量，通过计算机仿真对路由性能进行了评估，并在实验床网络上进行了验证。我们进一步研究重新路由机制的性能，重新分配已建立的流量接受新到达的和高优先级的流量。

(1) Study on traffic policing and priority control for multi-class trafficSupposing the network with priority control for multi-class traffic, we first propose mechanisms for policing, marking and scheduling at ingress routers and evaluate these performance by both analytical approach and computer simulation. Through some numerical results, we investigated achievable Quality of Service(QoS) of each traffic type in the network. We then propose mechanisms for inferring QoS in some network and explained its effectiveness.(2) Study on the routing mechanism for multi-class trafficWe first investigate the routing mechanism which effectively allocates bandwidth to each real-time traffic and improves throughput of best-effort traffic such as TCP. In the mechanism, we introduced the concept of "virtual residual bandwidth" for both classes of traffic. By using "virtual residual bandwidth" as routing metric, we evaluated routing performance by computer simulation and made clear it on the test-bed network. We further investigate performance of re-routing mechanism which re-allocates established traffic for accepting newly arrival and high-priority traffic.