Traffic Control Policies And Implementation In Carirer Ethernet

Carrier Ethernet is the main emphasis of the concept of carrier-grade enhancements, including quality of services(QoS), management of operation and maintenance(OAM) capabilities, scalability and reliability, which determines if carrier Ethernet can be used as the key technology to be deployed to provide high-quality services for customers.This thesis mainly addresses traffic control of quality of service, it mentions several QoS-related service models which are widely used currently, among which differentiated service model runs through the paper. Moreover, it gives a detailed analysis on several commonly used flow control strategies in terms of its advantages, disadvantages, application condition in the following chapters. The test results in practical application verifies that single rate two color token bucket algorithm as a simple and practical flow control strategy is an effective strategy which can also prevents the network switching nodes with bursty traffic shocks to affecting transmission efficiency. A novel algorithm derived from the existing algorithm is the innovation of this thesis. After a simulation experiments it is found that network transmission performance can be improved in bandwidth utilization and delay characteristics under certain situations by improving the algorithm.This thesis consists of six chapters. Chapter1describes the importance of the flow control strategies in carrier-grade Ethernet, the significance of this study and the current development at domestic and abroad etc.; chapter2writes about the basic flow strategy principles, including QoS service model, QoS and differentiated services in the overall model analysis, in addition to the ideas and performance targets of flow control strategies in practical applications. Chapter3introduces token bucket algorithm, which can be divided into single rate twocolor, singlerate threecolor and two rate three color. Meanwhile, three practical applications of the token bucket algorithm:CAR agreed to access rate, Generic Traffic Shaping, LR port speed limit is also analysed. Chapter4explains one algorithm in an application of token bucket algorithm. Take Marvell switch chip as an example, the paper has tested and analysed the impact on the flow rate specifically after starting single-rate two-color flow control. Chapter5is the new point of the article. By analyzing the lack of the conventional single-rate three-color token bucket algorithm, it proposed an improved single-speed three-color token bucket algorithm. Besides, after simulating with opnet network simulation software and analysing the results, it concludes that the new algorithm do have some improvements in bandwidth utilization and delay characteristics in a certain extent. The last chapter concludes the thesis and envisons the development in the future.