An improved preemption policy for higher user satisfaction
Works on QoS-enabled IP networks have led to two distinct approaches: the integrated service (IntServ) and the differentiated service (DiffServ) architectures. To address the tradeoff between service guarantee and scalability, a resource manager (a.k.a. bandwidth broker: BB) can be employed to complement the IntServ/RSVP with the DiffServ in the pursuit of end-to-end QoS. One major component of the resource manager is a decision mechanism for resource allocation, which enables hosts to request per-flow, quantifiable resources along the end-to-end path and to obtain feedback regarding the acceptance. However, most of existing resource manager implementations are still adopting the decision mechanism that makes a decision on the immediate availability of resources, especially bandwidth. Considering the variations in the demand over the time, we can easily expect some level of inefficiency due to this in terms of resource utilization and management. Thus, we are investigating the methods to support the request scheduling and advance reservation for the dynamic resource management. We use a time slot manager to ensure that the committed resources never exceed a specified limit and to predict the unused (but reserved) bandwidth. Network simulations are conducted to evaluate the enhanced performance of the proposed mechanism (i.e., with respect to the acceptance rate, the resource utilization, and others).