Hierarchical approach for low cost and fast QoS provisioning

In order to provide practical QoS services, we propose a new traffic engineering approach for low-cost and fast QoS provisioning. The new scheme utilizes network resources more evenly by exercising an enhanced QoS path computation algorithm that finds maximally disjoint multiple QoS paths. An efficient mechanism for managing computed paths and allocating calls is also discussed as a component of the system, and this path management allows fast QoS provisioning by avoiding unnecessary path recomputation. Moreover, the naive approaches to link state information acquisition in conventional QoS routing are replaced with a more effective approach dividing the link state update process into three hierarchical subprocesses. Via simulation experiments, based on an IP telephony application, we show that we can improve the performance and at the same time reduce the link overhead