On efficient quality of service provisioning in the next generation internet
Chee Kheong Siew · 2007
In this thesis, we address the issue of efficiently providing a range of per-flow QoS guarantees in the Internet paradigm. After a review of the relevant work on QoS guarantees, we propose a Flow-state-dependent Dynamic Priority Scheduling (FDPS) algorithm that provides Service Curves assurance. In this scheduling scheme, admitted QoS-based flows are protected yet allowing best effort traffic to co-exist in a multiservice network environment. The proposed FDPS scheme performs packet monitoring, marking, scheduling and discarding. With its fine granularity in packet marking, individual packets are forwarded and scheduled in a controlled and orderly manner. By means of mathematical analysis, we show that the FDPS algorithm realizes the arrival and service curves required in Service Curves and thus allows the theory of Service Curves to be applicable in a real network for per flow QoS provisioning. We also present an example for the admission control policing associated with FDPS. Compared with existing scheduling algorithms for QoS provisioning, FDPS achieves a tight end-to-end delay for QoS flows in a multi-service packet switching network. The complexity of this algorithm is independent of the number of flow, facilitating high scalability and possible implementation. Experimental results based on NS-2 validate the theoretical analysis and demonstrate the superiority of the proposed scheme.