基于OpenFlow的SDN可靠性综述

软定义网络(SDN)是一种新型的网络架构,其将控制平面和数据转发平面分离,并为网络管理提供了可编程的接口,简化了网络管理。随着基于OpenFlow的SDN技术在现实中的广泛应用,其所存在的问题也凸显出来,可靠性就是其中的一个重要方面。文中针对基于OpenFlow的SDN在可靠性方面存在的问题,分析总结了导致OpenFlow网络失效的因素,将网络失效划分为控制器、链路和节点失效,并归纳出相应的解决方案,探讨了未来基于OpenFlow的SDN在可靠性方面的研究方向与趋势。     

SDN网络及其在流媒体领域的应用探索

一项新的网络技术正在声名鹊起,那就是SDN,即软件定义网络。SDN把网络系统的控制平面与数据转发平面进行了分离,使网络建设更加快捷、成本更低、利用率更高、维护更方便。这一新网络建设模式的出现,将给网络技术架构、网络建设带来一场新的变革,也将为流媒体网络建设和视频服务带来非常大的影响;本文从技术架构、优点与挑战、在流媒体业务中的应用,以及OpenFlow协议等几个方面对SDN做了较为详细的介绍。     

软件定义网络核心原理与应用实践

本书分为核心原理和应用实践两大部分,对软件定义网络(SDN)技术进行了全面剖析和深入解读。第一部分首先阐述了SDN的设计思想与体系架构,详细分析了软件定义网络的控制转发分离和可编程两个突出属性,其次介绍了以OpenFlow为代表的SDN南向接口协议,以及北向和东西向接口协议,接下来根据SDN的层次化架构,依次介绍了SDN数据平面、控制平面以及SDN应用案例,最后梳理总结了SDN标准化进展以     

基于OpenFlow的SDN技术研究

作为一种新网络架构,SDN实现网络控制平面和数据平面分离,为未来互联网的发展提供一种新解决思路。文中简述OpenFlow与SDN技术的起源与发展,深入阐述SDN/OpenFlow技术的原理和技术标准,论述两大SDN标准制定组织ONF和OpenDayLight的发展现状,并给出SDN市场发展情况。     

基于Mininet的网络负载均衡仿真研究

软件定义网络(Software Defined Network, SDN)是一种新型的网络体系架构,其原理是采用OpenFlow对网络结构进行自定义的扩展与管理。为进一步研究SDN架构的特性并实现网络负载均衡,文章基于Mininet仿真工具对SDN的网络负载均衡进行深入研究,分析了OpenFlow协议技术及其原理,验证了SDN架构的功能和基本工作流程,构建了网络负载均衡仿真研究的实验环境,并在Mininet中进行了模拟实现,为进一步研究SDN架构提供了有效的技术支撑。     

对基于OpenFlow的SDN技术分析

基于OpenFlow的软件定义网络技术(SDN)技术可以为新的网络应用与未来互联网技术的发展提供支持。本文主要对基于OpenFlow的SDN技术的关键组件、系统架构、OpenFlow的运作模式、基于OpenFlow技术的应用进行了探究,并在此基础上论述了相关领域的研究重点与发展趋势。     

基于SDN的云计算网络

移动互联网和云计算的高速发展促使传统的互联网数据中心向云计算数据平台迁移。随着云平台负担的加重,当面对如用户私有云隔离、网络底层流量控制、访问控制、自动网络配置等诸多技术问题时,传统的云平台网络架构己经很难满足其需求。软件定义网络(SDN)作为一种新兴的网络技术,被认为是解决当前云计算问题的有效方法。文章在概要介绍云计算技术概念、架构以及关键技术的基础上,结合SDN技术的发展演进、网络架构和协议标准,重点介绍基于SDN的云计算网络,同时,还将结合一种特定的SDN云计算网络平台架构Meridian,讨论基于SDN的云计算技术发展趋势。     

基于SDN的网络虚拟化平台及其隔离性研究

随着云计算的高速发展,虚拟化正成为近年来在企业级环境下广泛应用的技术。除服务器及存储虚拟化外,在SDN和OpenFlow技术的推动下,网络虚拟化成为热点,基于SDN的网络虚拟化平台也应运而生。在分析基于SDN的网络虚拟化设计目标的基础上,对近年来业界推出的4种典型SDN网络虚拟化平台的系统架构和原理进行了对比,并对其安全和隔离性进行了分析总结。     

迎接SDN/OpenFlow网络测试的挑战

新出现的网络部署场景,例如超大规模数据中心内的虚拟化和云环境,都会使现有的网络技术和架构不堪重负。ONF执行总裁DanPitt描述了传统联网技术面临的3项关键挑战,即成本、敏捷性和设计。事实证明,联网的新方法,即所谓的软件定义联网(SDN)和相关的协议OpenFlow,能够应对这些挑战,并且解决更多的问题。然而,尽管SDN和OpenFlow具备巨大的潜力,但它们仍然会对包括网络测试在内的网络生态体系中的许多方面造成干扰。思博伦通信的《迎接SDN/OpenFlow网络测试的挑战》一文首先对SDN和OpenFlow进行了介绍,然后对其所带来的优势进行了阐述,最后对如何迎接SDN和OpenFlow网络测试的挑战给出了解决方案。     

SDN技术在预警指挥系统中的应用研究

以预警指挥系统网络技术发展为背景,分析了软件定义网络(SDN)的体系、原理、协议标准,对SDN网络体系架构、OpenFlow 可编程协议等相关关键技术的研究。结合预警指挥网络的特点和发展趋势,展开对SDN在预警指挥作战领域中的应用分析,评估SDN 在该领域的应用前景及指导意义。最后,搭建仿真验证环境,验证了SDN 技术在预警指挥系统中的应用技术路线和应用可行性。     

A virtualized infrastructure to offer network mapping functionality in SDN networks

The separation of control and forwarding planes in software‐defined networking (SDN) networks is a key issue of the SDN technology. This feature and the existence of the SDN controller allow the developing of dynamic, adaptable and manageable networks, networks that require adequate services, and applications. However, the separation of these planes prevents the use of existing powerful tools that were coded considering traditional networks. In this paper, we make use of the potential of network virtualization (NV) technologies to propose the use of a virtualized infrastructure that makes possible the incorporation of these existing services and/or applications to an SDN network, without the need for programming additional and complex software modules in the SDN controller. Thus, in this paper, NV is not employed to develop a network managed by SDN but to broaden and give support to the SDN control layer. As an example, we describe the incorporation of nmap (a versatile and powerful tool widely used by security experts for network exploration) into the SDN framework. It is only necessary to develop a simple control plane service that thanks to the proposed virtualized infrastructure allows the inclusion of this powerful management application. The result offers the complete functionality of the nmap utility to the network administrators, who control the SDN network through the out‐of‐band control plane. In addition, a northbound REST API has been defined to offer the main functionality of the tool (host discovery, port scanning, and operating system detection) to the application layer.     

SDN试验床网络虚拟化切片机制综述

未来网络体系架构和关键技术的研究需要灵活开放的测试验证环境,基于传统分布式的网络架构难以达到动态虚拟化、有效管控和新协议灵活部署的需求。随着软件定义网络（SDN）技术的出现和发展,上述问题找到了有效的解决途径,因此,基于SDN构建网络试验床成为了近年来该领域的主流研究方向之一。其中,基于SDN的网络虚拟化切片技术更是试验床中的核心支撑技术,可以根据不同试验的需求切分物理网络资源,从而提供并行、独立的网络环境。将重点研究基于SDN的试验床中使用的网络虚拟化切片机制,从“流量识别和切片网络标识”、“虚拟节点抽象”和“虚拟链路抽象”这3个关键技术出发,对当前基于SDN试验床中的典型网络虚拟化切片机制进行介绍与分析,并总结了该领域未来可行的研究方向。     

软件定义网络安全研究

软件定义网络（SDN）采用控制和转发的分离架构,使研究者可以通过软件实现任意的网络控制逻辑,而不需对网络设备本身进行修改,具备极强的灵活性,已经在路由决策、网络虚拟化、无线接入、云计算数据中心网络等领域得到研究和应用,成为一项热点技术。但SDN在蓬勃发展的同时,也引入了新的安全风险,带来新的安全问题。另一方面,SDN也给传统安全技术以冲击,带来创新的网络安全应用发展的机会。鉴于此,结合SDN网络架构的特点综述了SDN安全的研究现状,包括SDN安全风险分析和安全技术及应用,并思考了SDN对信息安全的意义。     

基于SDN技术的校园网虚拟网络业务流程实现方案

随着信息技术的快速发展,校园网在现代教育和科研中起着越来越重要的作用。SDN技术作为一种新型的网络架构和管理技术,可以对校园网进行优化和管理,提高网络的灵活性、可靠性和安全性。文中主要介绍了基于SDN技术的校园网虚拟网络业务流程的实现方案,具体包括SDN技术概述、校园网虚拟网络技术概述、SDN技术在校园网虚拟网络中的应用、校园网虚拟网络业务流程设计等。     

ONVisor: Towards a scalable and flexible SDN‐based network virtualization platform on ONOS

Network virtualization (NV) technologies have attracted a lot of attention as an essential solution for future networking infrastructure. The NV enables multiple tenants to share the same physical infrastructure and to create independent virtual networks (VNs) by decoupling the physical network in terms of topology, address, and control functions. One feasible way to realize full NV involves considering solutions based on the software‐defined networking (SDN) paradigm using its programmability. The SDN contributes many benefits to both network operations and management including programmability, agility, elasticity, and flexibility. There are several SDN‐based NV solutions; however, they suffered from a lack of scalability, high availability. Also, they have high latency between control and data plane because of proxy‐based architecture. In this thesis, we introduce a new NV platform, named Open Network Hypervisor (ONVisor). The design objectives include, among the features, (1) multitenancy, (2) scalability, (3) flexibility, (4) isolated VNs, and (5) VN federation. ONVisor was designed and implemented by extending Open Network Operating System, an open‐source SDN controller. The main features of ONVisor are (1) isolated control and data plane per VN, (2) support of distributed operations, (3) extensible translators, (4) on‐platform VN application development and execution, and (5) support of heterogenous SDN data‐plane implementations. Several experiments are conducted on various test scenarios in different test environments in terms of control and data plane performance compared to nonvirtualized SDN network. The results show that ONVisor can provide VNs a little bit lower control plane performance and similar data plane performance.     

Dynamic switch migration with noncooperative game towards control plane scalability in SDN

As software‐defined networking (SDN) is a logically centralized technology, the control plane scalability in SDN is increasingly important with the network scale increasing. Load balancing and maximizing resource utilization are very critical to the control plane in SDN, while switch migration is an effective approach to achieve these two performance metrics. However, switch migration is NP‐hard problem because it belongs to the problem of combinatorial optimization. To avoid the NP‐hard problem, we propose a switch migration scheme by adopting noncooperative game to improve the control plane scalability in SDN. First, we design a novel load balancing monitoring scheme to detect the load imbalance between controllers and trigger migrating switches. Then, we use noncooperative game among controllers to decide switch migration to get the maximizing overall profits. Last, we prove that our proposed approach can get Pareto optimality. Extensive simulations prove that our method is able to achieve a more scalable control plane with load balancing and maximizing resource utilization.     

SDN技术和产业分析及运营商应对策略建议

软件定义网络（SDN）提出了一种全新的网络设计理念,强调控制与转发的分离以及网络的可编程,实现网络架构的开放。SDN正和云计算一道重塑互联网网络模型和产业结构。介绍了SDN的基本概念、本质及特征,分析了SDN核心技术体系及其产业发展现状,从运营商视角探讨了SDN对未来网络的影响,并给出了相应的应用建议。     

Pluggable SDN framework for managing heterogeneous SDN networks

Software‐defined networking (SDN) is a new network paradigm that is separating the data plane and the control plane of the network, making one or more centralized controllers to supervise the behaviour of the entire network. Different types of SDN controller software exist, and research dealing with the difficulties of consistently integrating these different controller types has mostly been declared future work. In this paper, the Domino framework is proposed, a pluggable SDN framework for managing heterogeneous SDN networks. In contrast to related work, the proposed framework allows research into SDN networks controlled by different types of SDN controllers attempting to standardize the northbound API of them. Domino implements a microservice plugin architecture where users can link different SDN networks to a processing algorithm. Such an algorithm allows for, eg, adapting the flows by building a pipeline using plugins that either invoke other SDN operations or generic data processing algorithms. The Domino framework is evaluated by implementing a proof‐of‐concept implementation, which is tested on the initial requirements. It achieves the modifiability and the interoperability with an average successful exchange ratio of 99.99%. The performance requirements are met for the frequently used commands with an average response time of 0.26 seconds, and the framework can handle at least 72 plugins simultaneously depending on the available amount of RAM. The proposed framework is evaluated by means of the implementation of a shortest path routing algorithm between heterogeneous SDN networks.     

Stateful firewall‐enabled software‐defined network with distributed controllers: A network performance study

SummarySoftware‐defined network (SDN) is constructed by decoupling the control and data plane from the forwarding devices. The control plane operations are managed by centralized or distributed controllers, and the data plane operation is managed by respective forwarding devices. SDN provides an easy and efficient management solutions for software‐programmed consolidated middlebox in virtual machines. Additionally, SDN with centralized controller faces complications like scalability, network bottle neck, and single point failure. In this study, a stateful inspection firewall acts as a middlebox in distributed SDN‐controlled network. The controller is programmed with a failure detection and recovery mechanism to provide reliability and redundancy and enhance the overall performance of the network. The objective of stateful firewall on SDN architecture is to secure the network by monitoring the current connections and maintain its state information until the connection is active. In this paper, the performance of firewall‐enabled SDN with centralized and distributed controllers are measured, compared, and analyzed. The experiments are done using POX controller, and the results are verified by Mininet network emulation tool. The results show that the stateful firewall‐enabled SDN with distributed controller network improves the security, reliability, availability, and overall performance of the network. In the proposed SDN, average network throughput is improved by 43%, average network delay is reduced by 4%, average channel utilization is increased by 40%, average network overhead is reduced by 26%, and average network response time is reduced by 23%.     

面向SDN网络虚拟化平台的控制器放置算法

随着网络技术发展,以网络虚拟化为手段解决TCP/IP网络体系结构僵化问题已成为未来网络领域发展的主流方向之一.SDN(software defined networking,软件定义网络)作为一种新兴的网络体系结构,为网络虚拟化提供了有效的解决方案.首先总结了当前具有代表性的SDN网络虚拟化平台,并对比了SDN与传统网络环境中部署虚拟网的区别,然后针对SDN网络虚拟化平台中的虚拟网络映射问题,提出一种时延敏感的虚拟化控制器放置算法,最后通过实验验证了该算法在提高网络资源的利用效率的同时,保证了控制器与底层交换机的通信时延在可接受范围之内.