Zhou Wenpeng Provision and Route Optimization in Differentiated Services Networks

With the occurrence of new applications such as delay-sensitive real-time services, Quality of Service is becoming increasingly important in the Internet. DiffServ is motivated by the desire to improve the overall performance of IP networks. The performance and efficiency of the DiffServ architecture can be enhanced with per-class traffic engineering. This master's thesis examines the issues of provision in DiffServ networks and a per-class routing approach (PERD). Traffic of different classes can be distributed in accordance with network state and QoS requirements in provisioned networks. The first part introduces some of the theory and literature related to the topic. The DiffServ architecture and end-to–end QoS are presented. In addition, provision and link sharing are described and discussed. In the second part, we discuss the traffic engineering based on a per-class approach which we call PERD. With the help of the QRS simulator, we analyzed performance of networks under different routing algorithms. As results, we found that PERD can improve throughput and reduce end-to-end delay of the EF class service as well as lower priority classes. Under the same conditions, we find that the cost with PERD does not increase much compared to the widest bandwidth algorithm. Acknowledgements This master's thesis has been written in the Networking Laboratory of Helsinki University of Technology within the IRoNet project. My special thanks go to my supervisor, Professor Raimo Kantola, for his guidance and support during the writing of the thesis. I gratefully acknowledge the inspiring ideas and valuable suggestions given by my instructor Ph. I sincerely thank Vesa Kosonen and his wife, Kirsti, for their support when I was filled with immense grief. I would also like to thank the people within the team who have contributed to my thesis with their knowledge and support. I want to thank my colleagues at the lab for an innovative and harmonious atmosphere. Last, but most importantly, I would like to thank my friends and close relatives for their support and encouragement during my study in Finland, special thanks to my parents, my wife and my brothers, for their unconditional love, continuing support.