Design of Multimedia Caching System based on Windows Media Service

• Main Authors: Yu-Pin Chen, 陳育斌
• Other Authors: Jenq-Muh Hsu
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/76321191525289756112

碩士 === 國立中正大學 === 通訊工程研究所 === 93 === Streaming media over the Internet brings a huge amount of network traffic which makes the Internet suffering from network congestion. The characteristics of multimedia objects such as huge size, requirement of high bandwidth and the effect of interaction imply that web proxy is not appropriate for caching multimedia streaming object. With the segmentation of multimedia object, we can easily cache the prefix of multimedia object to absorb startup latency or calculate a cache value for each segment for making replace decision accurately. In general, there are two segmentation methods：fix-sized segmentation(FSS) and variable-sized segmentation(VSS). In FSS, when the cache space is not enough to store a new arrival media segments, the replacement policy will select a victim which has the least cache value and evict the last segment of victim for a new segment. However, these causes too many replacement times while evict a big chunk of data. We proposed a caching replacement policy that can be applied to the FSS-based multimedia proxy. The Narrowest Access Gap first replacement policy(NAG) evicts appropriate segments according to the history access records to reduce the overhead caused by FSS. Finally, simulations are performed to evaluate Least-Recently-Used, VSS and NAG replacement policy performance. Simulation results indicate that our policy can achieve higher Byte-hit ratio than others.