  In this paper we have proposed a dynamic buffer allocation algorithm for the
prefix, based on the popularity of the videos. More cache blocks are allocated
for most popular videos and a few cache blocks are allocated for less popular
videos. Buffer utilization is also maximized irrespective of the load on the
Video-on-Demand system. Overload can lead the server getting slowed down. By
storing the first few seconds of popular video clips, a multimedia local server
can shield the users from the delay, throughput, and loss properties of the
path between the local server and the central server. The key idea of
controlled multicast is used to allow clients to share a segment of a video
stream even when the requests arrive at different times. This dynamic buffer
allocation algorithm is simulated and its performance is evaluated based on the
buffer utilization by multimedia servers and average buffer allocation for the
most popular videos. Our simulation results shows efficient utilization of
network bandwidth and reduced hard disk utilization hence resulting in increase
in the number of requests being served.
