A Research on Internet QoS Information Sharing Environment

我们研究了一种新的共享和使用应用级和网络级服务质量(Qos)信息的机制，用于Internet流量管理和控制。我们得到了以下结果：(1)我们证实了基于时间的服务质量和基于期望的服务质量与镜像服务器上的实际文档下载时间有合理的相关性。我们使用TimeIt在几周内每五分钟测量一次Qos样本，并希望得到一组Web镜像服务器。通过在每种情况下对一天中的每个时间段和一周中的每一天的QOS样本进行平均来获得QOS值。评估一天的同一时间段和一周的同一天的Qos值之间的相关性。结果表明，基于时间的Qos值比基于Echope的Qos值具有更强的相关性。我们比较了几种服务器选择算法，发现使用Qos统计量(过去几周的平均Qos值)和实时Qos PRO…可以提高服务器选择的性能更多的冰。具体地，基于一天和一周中的给定时间段的服务质量统计来选择一组候选服务器。然后，基于实时的服务质量测量，使用Eching从预先选择的候选服务器中选择目标服务器。(2)提出了一种新的VoIP网络服务质量管理体系结构。语音质量，特别是MOS(平均意见分数)，通过使用客观的语音质量评估工具对周期性生成的携带人工语音信号的测试呼叫进行连续和自动的监控。基于边到边测量的接纳控制用于在各种业务条件下将两个方向语音流的丢包率维持在预定值以下。给出了满足目标阻塞率和丢包率的网络设计方法。仿真用于评估基于边到边测量的接纳控制网络的阻塞率和丢包率等网络性能。结果表明，接纳控制在不同的网络条件下都能很好地控制丢包率。较少

We study a new mechanism to share and use information on application-level and network-level Quality of Service (QoS) for traffic management and control in the Internet We have obtained the following results.(1) We confirm that timeit-based QoS as well as echoping-based QoS have a reasonable correlation with actual document download time from mirror servers. We measure QoS samples every five minutes during several weeks using timeit and echoping for a set of Web mirror servers. QoS value is obtained by averaging QoS samples for each time section of the day and each day of the week in each case of timeit and echoping. Correlation in QoS values of the same time section of the day and the same day of the week is evaluated. It is shown that timeit-based QoS values have stronger correlation than echoping-based ones. We compared several server algorithms and found that performance of sever selection can be improved using QoS statistics (average of past weeks QoS values) and real time QoS pro … More bing. Specifically, a set of candidate servers are selected based on QoS statistics for a given time section of the day and day of the week. A target server is, then, selected among the pre-selected candidate servers based on real time QoS measurement using echoping.(2) We propose a new QoS management architecture for VoIP networks. Voice quality, specifically MOS (Mean Opinion Score), is continuously and automatically monitored by using objective voice quality evaluation tool for periodically generated test calls carrying artificial voice signals. Edge-to-edge measurement based admission control is used to maintain packet loss ratse for both directional voice flows below a pre-determined value under various traffic conditions. Network design method is given to meet target blocking probability and packet loss rate. Simulation is used to evaluate network performance such as blocking probabilities and packet loss rates for the network with edge-to-edge measurement based admission control. It is shown that admission control works well to control packet loss rate under various network conditions. Less