作为一种新型网络架构,软件定义网络(software defined network,简称SDN)将网络的数据层和控制层分离,通过集中化控制和提供开放控制接口,简化网络管理,支持网络服务的动态应用程序控制.流量工程通过对网络流量的分析、预测和管理,实现网络性能的优化.在SDN中开展流量工程,可以为网络测量和管理提供实时集中的网络视图,灵活、抽象的控制方式以及高效、可扩展的维护策略,具有突出的研究意义.对基于SDN的流量工程相关工作进行综述.分别从测量的方法、应用和部署角度出发,对SDN中流量测量的基本框架、基于测量的正确态检测以及测量资源的管理进行概述.分析传统网络流量调度方案的问题,介绍SDN中数据流量和控制流量调度的主要方法.从数据层和控制层两个方面概述SDN中故障恢复方法.最后,总结并展望未来工作.
Software defined network (SDN) is an emerging network paradigm that proposes to decouple the control and data forwarding plane. Leveraging the centralized control ability and open programming interfaces SDN provides, network management can be dramatically simplified, and network services can be dynamically controlled by applications. Traffic engineering (TE) is a category of mechanisms that promises to optimize network performance through analyzing, predicting and regulating data flow in network. The unique features of SDN provide TE with unified and real-time global network view, flexible control manner and better policy for scalable traffic management, exhibiting profound research significance. This paper surveys the state-of-art works on TE for SDN. In terms of the methods, application and deployment of measurement, works on traffic measurement architecture, network invariant detection and measurement resource management with SDN are reviewed. The problems in traditional network traffic management are analyzed, and SDN-based data traffic management methods for efficient load balance and control traffic management methods for centralized bottleneck relief are presented. Moreover, network failure resilience technologies in SDN are described. Finally, the technological approaches are summarized and future research issues are discussed.