Design And Realization Of Quality Of Service System Base On Chips Of BCM XGS Series

With the rapid development of computer network, more and more video, voice and other services which is sensitive to jitter, delay, bandwidth, is transferred in the network. This puts forward higher service quality assurance requirements for network equipment.In order to provide different quality of service for the traffic, network equipment widely use QoS (Quality of Service) technology to ensure the quality of transmission and bandwidth and to improve network utilization. This thesis analyzes and studies design and realization of quality of service system base Chip of BCM XGS Series chip.The main work has done by the author of this thesis is as follows:First this thesis introduced three Internet service models (Best-Effort, Int-Serv and Diff-Serv), and give a brief introduction to the development of service model. This thesis also introduces the importance of QoS in the network transmission and important technologies of QoS include priority trust, priority mapping, queue scheduling, flow classification, flow strategy, congestion avoidance, queue shaping, and so on. The development status and direction of QoS are summarized.Secondly, it analyzes QoS hardware implementation base the XGS series of BCM chip. On this basis, provides a framework of design and realization of quality of service system base Chip of BCM XGS Series chip, including hardware and software design solutions and introduced Qos development of key technologies and implementation of the program conditions. And then introduces the detailed design and implementation QoS functions, including priority mapping, QoS policies, traffic policing, traffic shaping, congestion management, congestion avoidance, HQoS and son on. QoS system design ideas are based on the module, the first to create a corresponding function template, configure specific parameters, and then apply to the specific object.Finally, using dedicated network test equipment set up environment to verify the QoS system function test results and analysis. The results show that the system meets the goals and requirements of the design.The QoS system proposed in this thesis is based on the existing embedded platform in the actual environment, the function and code can be used in the real network environment. So the work of this paper has a great significance to the theoretical research and the actual deployment.