中文摘要：

为应对网络故障，提升网络的可靠性，针对SDN环境设计了节点的可靠度指标，提出了基于节点可靠度的虚拟SDN映射算法。在初始可靠映射阶段，该算法根据节点可靠度指标进行vSDN映射，部署控制器时兼顾了控制器与交换机的时延，同时考虑控制网络的重要性，为控制网络构建相应的备份资源；在故障恢复阶段，针对物理SDN单节点或单链路故障，算法使用迁移方法应对控制节点失效的情况，使用重映射方法应对其他故障。仿真结果表明，算法在请求接受率、故障恢复率、有效承载率和平均控制时延等指标上取得了较好的结果。

英文摘要：

In order to deal with network fault and increase the reliability of network, this paper designed degree of node reliability indicator in SDN environment and proposed a virtual SDN embedding algorithm based on degree of node reliability. Du-ring the initial reliable embedding stage, the algorithm embedded vSDN by degree of node reliability and deployed the controller considering the delay between controller and switches. Besides, it built backups for the control network in view of its importance. During the fault recovery stage, to solve the problem of single node or single link failure, the algorithm used the backup resources to deal with the invalidation of control nodes and used reembedding means to deal with other kinds of invalidation. Simulation experiments achieve better results of these performance parameters, including the acceptance ratio, the fault reco-very ratio, the valid loading ratio and the average controller-to-switch delay.