Network Service Quality Measurement Technology Research

With the rapid development of multimedia technology and high-speed networktechnology, various new network applications which demand high network performanceare emerging. However traditional computer network only provides best effort service,when network operators and internet service providers launch new business or services,they are facing with the risk of quality of service (QoS) without guarantee. It’s difficultto assess the existing network’s support ability of specific new business. It’s difficult topredict the QoS for the new business plan. When network problems occur and result inquality decreasing of service, network operators often improve network performancewhich based on their intuitive feelings and experiences by extending bandwidth,upgrading equipments etc. Therefore, to guarantee the quality of service, it is of greatsignificance to study QoS measurement technology for obtaining network performanceindicators and assess it. This thesis studies the QoS architecture and QoS measurementtechnique and its performance evaluation in IP network. The main work and its resultsare as follows:(1)Study the network service quality indicators and measurement methods. Basedon network delay, packet loss rate, bandwidth and other basic network performance, thisthesis propose a new index system which can represent the network QoS performanceand studied its measurement methods.(2)Propose QoS performance evaluation algorithm. Because of the fuzzycharacteristic of the network QoS parameters, this thesis pick out some primaryindicators from the key performances indicators like network latency, networkbandwidth, packet loss rate etc, and refine out the corresponding secondary indicators.Combined with knowledge of the analytic hierarchy process, fuzzy theory and otherrelevant knowledge, this thesis propose a network QoS performance evaluation modeland achieve an effective assessment of the network QoS.(3) This thesis quantifies three main indicators of service availability in particularnetwork of application QoS and provided an evaluation model in network serviceavailability. The model introduces the concept of evaluation decision tree and reference to the definition of entropy of discrete sources, in order to improve operationalefficiency, this paper uses Maclaurin formula to simplify the complexity of thearithmetic and calculate the gain of sample information. On the basis information gain,calculate the weight of each node in the evaluation of decision trees, and calculatevalue of network service availability further more.(4) The design and implementation of measurement system. This thesis completesthe relevant part of the realization and performance test of the prototype system. And inthe education network environment of CERNET takes actual test of the system aimed atmain QoS parameters.