软件定义网络中资源高效的多播传输研究

发布时间：2018-05-04 16:54

本文选题：软件定义网络 + 网络层多播　；参考：《中国科学技术大学》2017年博士论文

【摘要】：因特网在经历了几十年的辉煌之后遇到了发展瓶颈。随着大量协议及应用的加入,网络设备的功能越来越复杂,软件越来越庞大,再加上软硬件高度耦合且封闭的设备架构,网络创新变得步履维艰。软件定义网络是为促进网络创新而提出的一种新型网络架构,它采用控制面与数据面分离、控制面全局集中控制的网络体系结构,极大地简化了网络控制的实施、网络设备的开发以及网络应用的编写,使得新的应用及协议可以独立于设备厂商而实现快速部署,并且许多困扰着传统网络的问题在软件定义网络中都有可行的解决方案。因此,软件定义网络已被认为是最有希望的未来网络架构。多播是一种高效的点到多点传输方式。接收路径差异性问题是多播传输特有的问题,系指同一棵多播树上的接收路径可能支持不同的数据速率。目前,无论是在传统网络中还是在软件定义网络中,解决接收路径差异性问题都需要为一个多播组建立多棵树。这不仅增加了计算复杂度,也极大地增加了多播会话需要在网络中保留的状态,这对于流表空间非常宝贵的交换机来说是不能容忍的。本论文研究接收路径差异性问题在软件定义网络中资源(计算、带宽、流表空间)高效的解决方案。针对有损数据传输和无损数据传输两种情形,分别提出了基于单棵多播树的高效解决方案,可在满足带宽分配公平性、提高多播会话传输速率的同时,最小化多播会话需要的流表项及计算复杂度。论文的主要贡献和创新点如下:1.针对允许有损传输的分层编码视频应用,借鉴多速率多播思想设计与实现了面向软件定义网络的完整解决方案,在为接收者提供差异化服务的同时几乎不增加交换机流表空间的使用。2.针对因多播组动态变化带来的多播树更新问题,研究了网络带宽在多个多播应用之间实时的、增量式的公平分配问题,给出了问题的数学描述以及求解该问题的高效的启发式算法,在带宽分配公平性、更新代价和计算时间复杂度三个方面均取得较好的性能。3.针对典型局域网环境中的无损多播传输,通过仅为多播树上的瓶颈链路建立局部辅助路径解决了接收路径差异问题,并且没有显著增加交换机流表空间的使用。本论文面向实际网络应用,所提方案在满足带宽公平分配的同时,最小化计算开销和交换机流表空间的使用,因而是具有实际应用价值的解决方案。
[Abstract]:After decades of glory, the Internet has encountered a bottleneck of development. With the addition of a large number of protocols and applications, the functions of network devices are becoming more and more complex, the software is becoming more and more huge, and the hardware and software are highly coupled and closed device architecture, network innovation has become difficult. The software defined network is a new network architecture proposed to promote network innovation. It adopts the network architecture which separates the control surface from the data surface, and controls the whole world centralized control of the control surface, which greatly simplifies the implementation of the network control. With the development of network devices and the programming of network applications, new applications and protocols can be rapidly deployed independently of device manufacturers, and many of the problems puzzling traditional networks have feasible solutions in software defined networks. Therefore, the software definition network has been regarded as the most promising future network architecture. Multicast is an efficient point-to-multipoint transmission. The problem of receiving path difference is a special problem of multicast transmission, which means that the receiving path of the same multicast tree may support different data rates. At present, whether in traditional networks or in software-defined networks, it is necessary to build multiple trees for a multicast group to solve the problem of receiving path differences. This not only increases the computational complexity, but also greatly increases the state that multicast sessions need to remain in the network, which is intolerable for switches that are very valuable to stream tablespace. In this paper, we study the efficient solution to the problem of reception path difference in software-defined networks with resources (computation, bandwidth, stream table space). For two cases of lossy data transmission and lossless data transmission, an efficient solution based on single multicast tree is proposed, which can satisfy the fairness of bandwidth allocation and improve the transmission rate of multicast session. Minimize stream table items and computational complexity required for multicast sessions. The main contributions and innovations of this paper are as follows: 1. For layered video applications that allow lossy transmission, a complete solution for software-defined networks is designed and implemented based on the idea of multi-rate multicast. While providing differentiated services to recipients, there is little increase in the use of switch flow table space. 2. 2. Aiming at the problem of multicast tree updating caused by the dynamic change of multicast group, the problem of real-time and incremental fair allocation of network bandwidth among multicast applications is studied. The mathematical description of the problem and the efficient heuristic algorithm for solving the problem are given. The algorithm achieves good performance in three aspects: fairness of bandwidth allocation, update cost and computational time complexity. For lossless multicast transmission in a typical LAN environment, the problem of receiving path difference is solved by establishing only local auxiliary paths for bottleneck links in multicast trees, and the use of switch flow table space is not significantly increased. This paper aims at practical network applications. The proposed scheme not only satisfies the fair allocation of bandwidth, but also minimizes the computational overhead and the use of switch flow table space, so it is a solution with practical application value.
【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TP393.02

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