A Research on Internet QoS Information Sharing Environment

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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