SDN:未来互联网的挑战与机会

SDN:Challenges and Opportunities for Future Internet

当前,互联网经典架构的许多方面都是非常固化的——即所谓的互联网的僵化,这已经成IPv6部署的主要障碍并且导致IP多播服务使用的困难。然而,现在存在许多让我们扩展互联网理由,例如,改进域内和域间路由以实现网络的高可用性,为用户提供端到端连接,以及允许新应用程序的网络资源的动态Qo S管理,如数据中心、云计算和网络虚拟化。为了满足这些需求,未来互联网的下一代架构引入软件定义网络(SDN)的概念。这种新兴范例的核心是控制平面与网络中的转发元件的分离和集中,而不是现有网络的分布式控制平面。这种解耦允许在比传统网络设备(例如,交换机/路由器)更强大的计算机平台上部署控制平面软件组件(例如,Open Flow控制器),同时保护这种设备的供应商的数据和知识产权。为了解决实现未来互联网多重挑战的问题,还有现有互联网的僵化问题,对这种新兴模式的理解是非常必要的。为了满足这些要求,对现有的技术和最近的和最先进的SDN项目进行调查,随后对这一领域的一些案列进行讨论。

Currently many aspects of the classical architecture of the Internet are etched in stone - a so called ossification of the Interact-which has led to major obstacles in IPv6 deployment and difficulty in using IP multicast services. Yet, there exist many reasons to extend the Internet, e.g., for improving intra-domain and inter-domain routing for high availability of the network, providing end-to-end connectivity for users, and allowing dynamic QoS management of network resources for new applications, such as data center, cloud computing, and net- work virtualization. To address these requirements, the next-generation architecture for the Future Internet has introduced the concept of Software-Defined Networking （SDN）, At the core of this emerging paradigm is the separation and centralization of the control plane from the forwarding elements in the network as opposed to the distributed control plane of existing networks. This decoupling allows deploy- ment of control plane software components （e.g., OpenFlow controller） on computer platforms that are much more powerful than traditional network equipment （e.g., switches/routers） while protecting the data and intellectual property of the vendors of such equipment. A critical understanding of this emerging paradigm is necessary to address the multiple challenges in realizing the Future Internet and to resolve the ossification problem of the existing Interact. To address these requirements, surveys existing technologies and the wide range of recent and state--of-the-art projects on SDN followed by an in-depth discussion of the major challenges in this area.