The key performance bottleneck for a video-on-demand (VOD) server is bandwidth, which controls the number of clients the server can simultaneously support. Previous work has shown that a strategy called stream tapping can make efficient use of bandwidth when clients are not allowed to interact (through VCR-like controls) with the video they are viewing. Here we present an interactive version of stream tapping and analyze its performance through the use of discrete event simulation. In particular, we show that stream tapping can use as little as 10% of the bandwidth required by dedicating a unique stream of data to each client request. Keywords: Interactive video on demand, bandwidth efficiency, stream tapping 1 Introduction Video-on-demand(VOD) is a service that allows clients to communicate with a VOD server to select and then view the video of their choice at the time of their choice. A few companies, such as IBM [17] and the DIVA Systems Corporation [8], are successfully running ..
