Managing client perceived pageview response time for multiple classes of service is essential in today's highly competitive, e-commerce environment. We present Connection and Performance Model Driven Optimization (CP-MDO), a novel approach for providing optimal QoS as defined by a cost objective based on client perceived pageview response time and pageview drop rate. Our approach combines two vital models: (1) a latency model for connection establishment that captures the interactions between web browsers and web servers across network protocol layers and (2) a server performance model based on queueing theory that models performance across all tiers of a server complex. An algorithm capable of enforcing the optimal admission control based on the inter-arrival time between pageview admissions is given. Our approach has been implemented and evaluated in an experimental setting, demonstrating how CP-MDO achieves the minimal cost while providing minimal pageview response times under minimal drop rates across multiple classes of service.

VoIP applications require the ability to identify speakers in real time. This paper presents compressed speaker recognition (CSR), an innovative approach to perform speaker recognition directly from the compressed voice packets. CSR performs online speaker recognition from live packet streams of compressed voice packets by performing fast clustering over a defined subset of the features available in each compressed voice packet. Our experimental results show that CSR is highly scalable and accurate across a broad range of speakers

As businesses continue to grow their World Wide Web presence, it is becoming increasingly vital for them to have quantitative measures of the mean client perceived response times of their web services. We present Certes (CliEnt Response Time Estimated by the Server), an online server-based mechanism that allows web servers to estimate mean client perceived response time, as if measured at the client. Certes is based on a model of TCP that quantifies the effect that connection drops have on mean client perceived response time by using three simple server-side measurements: connection drop rate, connection accept rate and connection completion rate. The mechanism does not require modifications to HTTP servers or web pages, does not rely on probing or third party sampling, and does not require client-side modifications or scripting. Certes can be used to estimate response times for any web content, not just HTML. We have implemented Certes and compared its response time estimates with those obtained with detailed client instrumentation. Our results demonstrate that Certes provides accurate server-based estimates of mean client response times in HTTP 1.0/1.1 environments, even with rapidly changing workloads. Certes runs online in constant time with very low overhead. It can be used at websites and server farms to verify compliance with service level objectives.

As businesses continue to grow their World Wide Web presence, it is becoming increasingly vital for them to have quantitative measures of the client perceived response times of their web services. We present Certes (CliEnt Response Time Estimated by the Server), an online server-based mechanism for web servers to measure client perceived response time, as if measured at the client. Certes is based on a model of TCP that quantifies the effect that connection drops have on perceived client response time, by using three simple server-side measurements: connection drop rate, connection accept rate and connection completion rate. The mechanism does not require modifications to http servers or web pages, does not rely on probing or third party sampling, and does not require client-side modifications or scripting. Certes can be used to measure response times for any web content, not just HTML. We have implemented Certes and compared its response time measurements with those obtained with detailed client instrumentation. Our results demonstrate that Certes provides accurate server-based measurements of client response times in HTTP 1.0/1.1 [14] environments, even with rapidly changing workloads. Certes runs online in constant time with very low overhead. It can be used at web sites and server farms to verify compliance with service level objectives.