An Empirical Study of RealVideo Performance Across the Internet

The tremendous increase in computer power and bandwidth connectivity has fueled the growth of streaming video over the Internet to the desktop. While there have been large scale empirical studies of Internet, Web and multimedia traffic, the performance of popular Internet streaming video technologies from the user perspective and the impact of streaming video on the Internet is still largely unkown. This paper presents analysis from a wide-scale empirical study of RealVideo traffic from several Internet servers to many geographically diverse users. We find typical video quality to be high, achieving an average of frame rate of 10 fps and very smooth playout, but very few videos achieve full-motion video playout rates. Overall video performance is most influenced by the bandwidth of the end-user connection to the Internet, but high-bandwidth Internet connections are pushing the video performance bottleneck closer to the server. RealVideo traffic appears responsive to network congestion since much of RealVideo traffic uses TCP, and RealVideo traffic that uses UDP appears to have data rates similar to that of TCP over the duration of a video clip