QoS assertion in distributed systems based on content delivery network

Web caching has been recognized as an effective scheme to alleviate the service bottleneck and reduce the network traffic, thereby minimizing the user access latency on the Internet. Increased number of subscribers and massive amount of Web content have caused an augment in the access network load of network service providers (NSP). To address this problem, Web cache system has been developed to enhance World Wide Web (WWW) service. The QoS assertion Web cache system that is based on an QoS assertion function to a distributed Web cache system (DWCS). The system runs multiple cooperative cache servers to increase the cache hit rate with an equivalently large cache. The system executes QoS configurations selectively for the flows of premium subscribers who have contracted for QoS assertion services. The system controls increase in system load by selecting targets of QoS configuration in accompanied with content size. QoS assertion Web cache system is applicable for large scale access network with a large number of subscribers. Evaluation of scalability from the number of QoS flow entries registered on each router and the control load of the QoS system. QoS assurance Web cache system has sufficient scalability for access networks.