软件定义网络（Software Defined Networking, SDN）解耦控制平面和数据平面，具备网络可编程能力，不仅可以简化网络管理，而且可以灵活控制网络流量，促进网络进化与发展。作为一种非常有希望的新的联网范型，SDN受到学术界和产业界的关注。本项研究面对把SDN应用于Internet这样的超大规模网络时所产生的严峻挑战，研究面向Internet的SDN运行机制。主要内容如下：（1）适应Internet多域、多层、多粒度的实际，提出面向Internet的SDN功能结构模型；（2）基于功能结构模型，提出可行、高效的运行机制，包括：控制平面和数据平面基础运行机制，网元布控、动态迁移、应用和服务定制等性能优化机制；（3）实验验证和性能评价。预期的研究成果将形成比较完整的面向Internet的SDN运行机制，为SDN的发展提供理论和技术支持。

SDN (Software Defined Networking) decouples control plane and data plane, and provides network programmability. It can not only simplify network management but also support flexible control on network traffic, prompting network evolution and development. As a promising new networking paradigm, it has become the common focus of both academia and industry. Oriented to the significant challenges emerged when SDN is applied to the ultra-large-scale network, i.e., Internet, the Internet-oriented SDN operating mechanisms will be investigated in this proposal. The main researches are as follows: (1) the Internet-oriented SDN functional and structural model will be built to adapt to the multi-domain, multi-layer, and multi-granularity of the Internet; (2) based on the above model, the feasible and efficient SDN operating mechanisms will be investigated, including the basic operating mechanisms for control plane and data plane, and the performance-optimizing mechanisms for network element deployment and control, dynamic migration, application and service customization; (3) experiment validation and performance evaluation will be done. The expected outcomes from this proposal will form a suite of Internet-oriented SDN operating mechanisms, and provide theoretical and technical support for SDN development.