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

摘要： 随着云计算、大数据技术的蓬勃发展，部署于数据中心的网络业务随之也越来越多，为了确保用户的良好体验以及服务提供商的经济收益，对业务带宽的高效保障逐渐成为研究的热点。基于SDN将控制和转发相分离的技术优势，提出一面向业务的带宽保障方法，该方法首先将多种业务进行了粗粒度分类，以此为基础提出了ATBG（Application-towards Bandwidth Guarantee）算法，并通过集中式的调度控制，实现了多业务不同优先级的带宽高效保障。利用floodlight+mininet模拟环境验证了文中所提方法的有效性。

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