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1. J. Antila, Scheduling and quality differentiation in Differentiated Services, Master's thesis, Helsinki University of Technology, 2003 (bib)

   Abstract: During the last decade the Internet has developed into a public multi service network that should be able to support heterogeneous applications and customers with diverse requirements. For this reason, quality of service (QoS) provisioning in the Internet has gained increasing attention. General service architectures have been proposed in the literature for providing QoS. At the moment, the Differentiated Services (DiffServ) architecture seems to be the most promising solution due to its scalability. In DiffServ, common resources are allocated among service classes. The mechanism that is primarily responsible for the allocation is packet scheduling. The DiffServ architecture sets certain limits to the services that can be offered to customers. However, a lot of freedom is still left for the operators. For example, the operators can choose what kind of differentiation models they will use and how these models will be implemented. This thesis studies issues related to quality differentiation and scheduling in Differentiated Services networks. The first part of the thesis provides a literature survey about QoS guarantees, architectures and mechanisms, with the focus on scheduling disciplines. In the second part of the thesis possible service approaches and differentiation models for an operator are examined and schedulers for implementing these models are proposed based on a qualitative analysis. Some of the proposed differentiation models and schedulers are evaluated with simulations. The simulations study both at aggregate and session/flow level what kind of service the schedulers provide and how well they are able to support the differentiation model that they are designed for. In addition, the simulations give insight into the effect of traffic mapping on the differentiation.