关键词: 软件定义网络（SDN）, OpenFlow, 多业务分级管理, 带宽保障

Abstract: With the rapid development of the technologies of the cloud computing and big data, there are more and more applications in data center. In order to realize the users’ good experience and the service providers’ good revenue, it becomes more important that we do researches on efficiently guaranteeing the application-bandwidth. Based on the advantage of SDN which separates controlling from forwarding, the paper presents the application-towards bandwidth guaranteed method. This method firstly makes coarse granularity classification of the various applications, then presents the ATBG（Application-towards Bandwidth Guarantee） algorithm, and efficiently realizes the application-bandwidth guarantee in multiple priority levels for various applications through a centralized control. The paper verifies this method through doing experiments using the floodlight+mininet simulation environment.

Key words: Software Defined Network（SDN）, OpenFlow, classified management for applications, Guaranteed bandwidth