Knowing user experience resulting from the performance of network services is an extremely important target for service providers and researchers. Effects of even slight disturbances in network performance were not so damaging for user satisfaction level ever before than they are in todays changing network conditions in heterogeneous network environment, involving fixed, wireless and mobile networks. Quality of Service (QoS) is the ability of network to provide a service with an assured service level and Quality of Experience (QoE) is how a user perceives the usability of a service when in use. Monitoring the QoS can be an important indicator for the level of user satisfaction if the monitored parameters are strongly correlated to that user satisfaction. This paper presents a comprehensive analysis on the changing user behaviour at different service performance levels through both objective and subjective measurements. At first, it discusses the correlation of subjective grading of the service by users with service performance parameters and observes certain thresholds on the performance parameters where user experience changes. This analysis is based on the results of web surfing experiments on a testbed. Secondly, it discusses the correlation of traffic characteristics of user sessions with session throughputs in order to observe the dependence of these characteristics on network performance metrics. This discussion is based on traffic launched by real users on an ADSL network. Finally, the objectively measured traffic characteristics like user session volumes are compared to subjective responses of the users to see to what extent the session volumes reflect the user satisfaction level.
Detta pappret diskuterar hur användarens reaktion på tjänstekvalitet visar sig end-till-end samt i förändring av nätverksstatistik. Quality of Experience (QoE), Quality of Service (QoS), Mean Opinion Score (MOS)