Per-Subscriber On-Demand QoS Assurance in Distributed Web Cache System

A large number of subscribers and massive amount of Web content have caused an increase in the access network load of network service providers. To address this problem, various systems, such as a Web cache system, have been developed to enhance WWW service. In this article, we propose a per-subscriber QoS-assurance web cache system that is based on an added QoS assurance function to a distributed Web cache system (DCCS). The proposed system executes QoS configurations selectively for the flows of premium subscribers who have contracted for QoS assurance services. The proposed system selects premium subscribers by cooperating with the AAA function of the access network. The number of QoS flow entries is suppressed by means of dynamic selection of target routers in the QoS configuration. Also, the system controls increases in system load by selecting targets of QoS configuration in accordance with content size. By this means, we can construct a QoS-assurance Web cache system applicable for large scale access networks with a large number of subscribers. In this article, we evaluated scalability of the proposed system from two points of view, the number of QoS flow entries registered on each router and the control load of the QoS configuration device. We determined that the proposed system has sufficient scalability for access networks with the capacity for one million subscribers including 10% premium subscribers