Absolute Differentiated Service Control Mechanisms

Internet has been developing at the surprising speed since 1960s. From then on, more and more users have launched various kinds of application through Internet, which serves as the data transmission platform. So far, the content on the Internet has already developed from originally simple data to the multimedia information. Furthermore, the demands have become greater and greater for transmiting distributed multimedia applications on Internet (such as video conference, IP telephone, game on line, distance learning, tele-medicine, etc. ), besides such traditional data application as WWW, E-mail, FTP etc...Therefore, it is more important for researches on scalable QoS controlling mechanism to offer delay guaranteed service than to promote IP multimedia real-time application and even to the whole Internet.Nowadays,DiffServ has become an important QoS provision model for its scalability in data forwarding plane. However, providing delay guaranteed services in DiffServ network necessitates scalable QoS control mechanisms. This thesis mainly focuses on how to provide delay guaranteed services in static priority DiffServ networks. What's more, many mechanisms in control plane, including traffic shaping in end-system, scalable admission control algorithms to support heterogeneous applications, effective resource provision and adaptive resource management etc., are discussed in detail in order to improve the scalability and resource utilization,. Finally, this thesis puts forward relevant algorithm and mechanisms, and has realized a prototype system QNET2.0.The main creativities of this dissertation are explained as follows:(1) Proposing an end-system fair shaping mechanism. End-system traffiic shaping is an effective method to assuare the traffic characteristic of real-time applications according to its flow description. In order to improve accuracy, this thesis proposes a fair shaping method, which integrates depart time event driven shaping method into SCSF schedule mechanism so as to make the output traffic strictly conform to Token Ring traffic model(σ,ρ). This method has been realized in windows 2000 NDIS intermediate driver, and the experimental results prove its effectiveness.(2) Improving the utilization based admission control mechanism in order to provide delay guaranteed service to heterogeneous applications. Around the scalable admission control mechanisms in static priority Differv networks, which can be used to provide delay guaranteed services to heterogeneous applications within a service class. This thesis has expanded the connection-population-insensitive delay computing method, and deduced the relations between the minmum burst ratio, maximum burst ratio of all real-time applications, and the pre-provision link bandwidth. Therefore, utilization based admission control method can be used efficiently.