1.1 SDN defined
ONRC definition:
SDN is a new network architecture for centralized control logic, the key attributes comprising: a data plane and a control plane ; controlling OpenFlow unified open interface between a plane and data plane .
ONF definition:
SDN is a dynamic support, the new flexible management of network architecture, the architecture is ideal for high bandwidth and dynamic networks.
1.2 SDN features
Main features:
1. Open Programmable Network:
SDN to establish a new network abstract model, to provide users with a complete set of common API, allowing users to configure the network programming on the controller, control and management, to accelerate network service deployment process
2. Control plane and data plane separation:
Isolated decoupled here refers to the control plane and data plane. Control is no longer interdependence between the plane and the data plane, both of which can be done independently of the evolution of architecture, similar to the Wintel mode of the computer industry, the two sides just have to follow a unified open interface to communicate. Network architecture is the foundation for more programmability.
3. Centralized management of logic:
Mainly it refers to the centralized management of distributed network status. In the SDN architecture, the controller will assume the task of collecting and managing all network status information. Centralized control logic provides the architectural foundation for the software-defined network programming network functions, but also provides the possibility of automated network management.
1.3 SDN network architecture
SDN network architecture include:
1. SDN network applications: to achieve a corresponding network application function.
2. Northbound Interface: provides a common programming interface for the open SDN applications.
3. SDN Controller: also known as network operating system. The controller does not enter the interface to provide different levels of programmability through the north to the upper network applications, but also through the South unified configuration, management and control of SDN to the data plane interface.
4. southbound interface: SDN open interface controller and a data plane controller. Southern SDN controller is programmed to control the data plane interface, forwarding data plane network behavior and the like.
5. SDN Data plane: the device and data plane implemented in hardware based on software implementation.
