【作者】 谢亮；

【导师】 赵志峰；

【作者基本信息】 浙江大学 ， 信息与通信工程， 2015， 硕士

【摘要】 Software Defined Network(SDN),是一种创新的网络架构,通过将网络设备的控制面与数据面解耦,实现了对网络中数据流的灵活调度和网络行为的开放式编程控制,是未来网络的发展趋势。但在普及过程中,仍然有大量技术问题需要解决,比较重要的有控制面的扩展和数据面数据转发能力的提升。论文首先介绍了SDN当前的发展状况和提升SDN系统性能的相关研究,从SDN控制器和OpenFlow交换机两方面总结了各类SDN性能优化方案的设计思路和优缺点。论文其次提出了一种OpenFlow交换机流表自适配控制机制,主要包括控制器资源与交换机流表资源的动态平衡以及流表项停滞超时的优化处理,该机制实现了流表资源的高效利用,在提高了数据转发成功率的同时,降低了控制信道吞吐量。论文探讨了多级流表技术的实用化问题,如流表的分割方法、各流表间的容量分配及排序问题等,给出了具体的解决方案和设计原则,并在此基础上提出了一种灵活的OpenFlow可变多级流表架构设计,可以显著提高多流表架构下数据转发能力。论文的最后展望了SDN的发展前景,总结了论文中的相关工作并给出了本课题未来的研究方向。更多还原

【Abstract】 Software Defined Network (SDN), regarded as a newly designed network architecture, is capable of realizing flexibly scheduling the network traffic and openly programming the network behaviors through decoupling the control plane and the data plate of the network devices. However, a large quantity of the problems are remained to be solved, especially for the expansion of the control plane and the promotion of the data forwarding capability on the data plane.The thesis first introduces the state-of-the-art research on SDN including the background and the promotion of the system performance. The various performance optimization schemes of the controllers and the OpenFlow switches is then elaborated, with their advantages and disadvantages well organized in the thesis.The main part of the thesis lays on the design of an adaptive scheme for data forwarding in SDN. The design is carried out in two parts, namely the resource trade-off scheme between the controller resource and the switch flow table resource and the idle timeout reset optimization of the flow tables. The design achieves higher availability and the matching ratio of the flow table resource as well as alleviates the congestion of the control channels.Moreover, the thesis also analyzes the application of the multi-stage flow table technology, such as the partition method of the flow table and the capacity assignment and the sorting between each flow table, based on which the thesis then proposes specific solutions and design principles, as well as an OpenFlow-based architecture of variable multi-stage flow tables. The result indicates our method shows remarkable improvement of the data forwarding success of the multi-stage flow tables.Finally, the thesis views the prospect of the soft-defined networks. In addition, the relative research in the thesis is well summarized and the future directions are also discussed.更多还原