The use of high-speed multimedia technologies such as MPEG-based interactive Videoconferencing and IPTV for delivering Television content over the Internet is becoming increasingly common. With commercial vendors and content providers envisioning products and services for delivering audiovisual content equipped with greater user-control and higher resolutions, there has arisen a significant demand to identify and quantify various bottlenecks in the Internet to better support such ventures. In this paper, we attempt to develop an analytical model that reflects the effects of various device factors and network factors that affect the performance of high speed interactive audiovisual streams, i.e. the ultimate end-user perception of audiovisual quality. To develop our model, we use a set of experimental results obtained in both a LAN as well as on an Internet testbed.