Estimating user-perceived Web QoS by means of passive measurement

To enforce SLA management, SLA metrics and quality assessment method for network services or application services are required. In this paper two metrics for Web application service intrinsic performance, average round-trip time and delivery speed are defined taking both implementation mechanism of Web applications and user access behavior into account. In three cases, Web traffic traces for a specific Web site were recorded at client-side to calculate above two metrics; meanwhile the user-perceived service qualities of the Web site were evaluated subjectively. Linear regress analysis of the observation data shows that user-perceived quality of Web application service can be objectively estimated by a linear regression function that uses the two metrics as independent variables.