Improving resource utilization by over admission

BBQ, budget-based management infrastructure, is designed to offer end-to-end QoS assurance for all-IP networks. Each edge router in a core network is pre-allocated with some short-path resources, which are the paths from edges to edges of the core network. Short-paths are then allocated to individual incoming service requests on a reservation basis when they are admitted to the network. However, some types of traffics such as telephony traffics may not be persistently active during their life time leaving part of reserved resources unused. To enhance resource utilization, we propose an over- admission method in which each edge router can grant more resources to the incoming requests than it actually acquired. We developed an analytical model that can be used for estimating the optimal level of over-admission without incurring too much overflow. Simulations show that our analytical model is accurate and this method can enhance resource utilization effectively. For regular telephony traffics, near 100% improvement can be reached when their active ratios are near 50%.