Fair and efficient bandwidth allocation of inelastic traffic in SDNs

软件定义网络(SDN)是一种新的网络模式，在资源配置效率、实时可配置性和网络管理等方面都有革命性的改进。SDN将网络重新定义为三个逻辑层：应用层、控制层和基础设施层(也称为数据转发)。基础设施层高速转发数据，而控制层集中实施网络智能，并使用OpenFlow等标准化协议与基础设施层(下层)通信，提供对网络资源的访问，并通过开放编程接口调用对应用层(上层)的控制功能。SDN通过可编程控制将控制平面与分组转发平面解耦，从而实现对网络的更多控制

Software Defined Networking (SDN) is a new networking paradigm with several revolutionary aspects including profound improvements in resource allocation efficiency, real-time configurability, and network management. SDN redefines the network into three logical layers: application, control, and infrastructure (a.k.a. data forwarding). The infrastructure layer forwards data at high speeds while the control layer centrally implements network intelligence and communicates with the infrastructure layer (the lower layer) using a standardized protocol like OpenFlow, provides access to network resources, and invokes control capabilities to the application layer (the upper layer) through open programming interface. By decoupling the control plane from the packet forwarding plane through programmable control, SDN places more control of network