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。     

软件定义网络在云计算领域的实施部署

云计算与软件定义网络(SDN)是紧耦合的新兴技术领域,一套成熟的SDN解决方案才能实现云中复杂的企业网络架构。文章对软件定义网络的发展历程进行系统梳理,分析NFV和未来SDN的技术架构,结合国内外软件定义网络技术的应用发展现状和最新研究成果,以及国内软件定义网络技术在云计算领域的最佳实践,全面论述软件定义网络的技术体系、应用现状和未来发展趋势。     

SDN应用场景分析与探讨

SDN(软件定义网络)技术将网络的控制平面与数据转发平面分离,支持更灵活的网络控制和业务带宽按需调度的能力,为不断涌现的网络新应用和未来网络技术提供了一种新的解决方案。文章从SDN的概念和总体架构出发,介绍SDN技术特点,在此基础上对SDN在数据中心网络、数据中心互联、政企网络、电信运营商网络、互联网公司业务部署等场景的应用进行探讨。     

基于SDN架构的电信承载网和BNG设备演进思路

提出了一种新的承载网络架构,其最主要的特点是控制和承载分离.还根据当前软件定义网络（SDN）技术发展的水平、现有宽带网络网关（BNG）设备的实现以及电信承载网络自身的特点,提出了电信承载网和BNG设备向SDN架构演进的阶段性发展步骤,并对其中的一些细节进行了详细探讨.SDN网络的逐步部署必将加速互联网技术革新的步伐,为未来电信网络注入更多活力.     

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。     

SDN技术挑战及发展趋势

SDN技术是一种全局性、颠覆性的网络变革技术,它利用控制和转发分离、软件定义的方法对网络能力重新定义,增强了网络的灵活性。文章对当前SDN技术和产业发展的最新进展进行梳理,从产业发展的视角阐述当前SDN发展中面临的技术问题和非技术问题,并对未来SDN发展做出展望。     

SDN商业进程加速 成“去电信化”重要突破口

从传统设备制造商到IT服务商和芯片制造商,均致力于提供一个更好的平台,有利于产业共同提升SDN软硬件的交互能力。2014年,软件定义网络(SDN)技术从概念步入商用讨论阶段,几乎成为专业领域的热门议题。包括谷歌在内的不少最早推动SDN概念的互联网公司,已经开始在其数据中心使用SDN技术以提高网络的利用率。SDN逐渐成为业界公认的下一代网络发展方向。     

软件定义网络的模型研究综述

软件定义网络(SDN)是当前互联网最热门的研究课题之一。本文从控制平面抽象模型和转发资源模型进行分析,为SDN的理论研究奠定基础,推动SDN技术的优化和完善,并促进SDN技术的大规模应用。     

SDN交换机及其星载交换的实现方案初探

随着互联网技术和应用的不断发展,网络中的新技术、新业务层出不穷,网络的复杂度越来越高。传统的卫星网络已难以满足高吞吐量、灵活多变的业务需求。针对传统卫星网络中的问题,业界提出在卫星网络引入SDN技术,实现软件定义卫星网络SDSN。对现有SDN交换机的实现方式进行归纳总结,针对卫星网络特殊环境分析卫星结点中SDN星载交换设备的系统功能,并提出一种基于OpenFlow协议的SDN星载交换机实现方案。     

专题:软件定义光网络

<正>专题导读软件定义网络(SDN)是近年来网络通信领域最重要的创新之一。作为一种新型的网络构架,SDN通过将网络设备面与数据面分离开,从而实现网络流量的灵活控制,为核心网络及应用的创新提供良好的平台。SDN不仅对互联网、数据中心互联产生重要的影响,也将会对光网络产生深远的影响,但将SDN应用到光网络中时,需要考虑到光网络的特殊性,包括物理传输损伤、网     

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。     

An experimental feasibility study on applying SDN technology to disaster-resilient wide area networks

The Internet may get catastrophic impacts when unexpected disasters such as earthquakes, tsunami, etc. happen. Therefore, it is necessary to equip resilient technologies for the Internet backbones in order to face challenges (e.g., link, device failures, rerouting traffic, etc.) in the disasters. The emerging software-defined networking (SDN) technology, which logically centralizes network function on a controller and remotely manages distributed SDN devices, shows a lot of potential. This paper presents an experimental feasibility study on applying SDN to wide area backbones for the disaster-resilient purpose. To show the efficiency of SDN technology in responding fast to the network situation changes, we conduct three evaluations on real SDN devices and large-scale SDN-based wide area networks (WANs) assuming disaster scenarios. In the first evaluation, we explore the proactive recovery mechanism using the fast failover on SDN devices. In the second one, we investigate the communication latency between controllers and SDN devices, which is one of the most important factors in the reactive recovery in the software-defined backbone. In the last one, we experiment the fast end-to-end reactive recovery behavior of a TCP flow in a disaster scenario. The evaluation results clearly indicate that the SDN-based WAN is technically feasible and effective for fast recovery from disasters.     

软件定义网络中基于密码标识的报文转发验证机制

针对软件定义网络(SDN)中缺乏安全高效的数据来源验证机制问题,该文提出基于密码标识的报文转发验证机制。首先,建立基于密码标识的报文转发验证模型,将密码标识作为IP报文进出网络的通行证。其次,设计SDN批量匿名认证协议,将SDN控制器的验证功能下放给SDN交换机,由SDN交换机进行用户身份验证和密码标识验证,快速过滤伪造、篡改等非法报文,提高SDN控制器统一认证与管理效率,同时可为用户提供条件隐私保护。提出基于密码标识的任意节点报文抽样验证方案,任何攻击者无法通过推断采样来绕过报文检测,确保报文的真实性的同时降低其处理延迟。最后,进行安全性分析和性能评估。结果表明该机制能快速检测报文伪造和篡改及抵抗ID分析攻击,但同时引入了大约9.6%的转发延迟和低于10%的通信开销。     

DSL: Dynamic and Self‐Learning Schedule Method of Multiple Controllers in SDN

For the reliability of controllers in a software defined network (SDN), a dynamic and self‐learning schedule method (DSL) is proposed. This method is original and easy to deploy, and optimizes the combination of multiple controllers. First, we summarize multiple controllers’ combinations and schedule problems in an SDN and analyze its reliability. Then, we introduce the architecture of the schedule method and evaluate multi‐controller reliability, the DSL method, and its optimized solution. By continually and statistically learning the information about controller reliability, this method treats it as a metric to schedule controllers. Finally, we compare and test the method using a given testing scenario based on an SDN network simulator. The experiment results show that the DSL method can significantly improve the total reliability of an SDN compared with a random schedule, and the proposed optimization algorithm has higher efficiency than an exhaustive search.     

全要素SDN指纹攻击及其模糊混淆防御机制研究

软件定义网络（Software-Defined Networking，SDN）的"三层两接口"架构使攻击者可以通过分析数据包往返时延分布规律推测网络类型、控制器类型及关键流规则等指纹信息.目前SDN指纹攻击及其防御研究基本处于空白状态，为此，本文系统构建了全要素SDN指纹攻击链，并在双重时间维度分别设计了概率加扰和控制器混淆调度防御机制，通过渐变概率加扰与最优混淆调度协同提升SDN指纹信息隐藏度.实验结果表明该机制能够在有效隐藏SDN指纹信息的同时减少对网络性能的影响.     

Software defined vehicular networks: A comprehensive review

The recent breakthroughs in the automobile industries and telecommunication technologies along with the exceptional multimodal mobility services brought focus on intelligent transportation system (ITS), of which vehicular ad hoc networks (VANETs) gain much more attention. The distinctive features of software‐defined networking (SDN) leverages the vehicular networks by its state of the centralized art having a comprehensive view of the network. Its potential to bring the flexibility, programmability and other extensive advancements to vehicular networks has set the stage for a novel networking paradigm termed as software‐defined vehicular networks (SDVNs). Many researchers have demonstrated the SDN‐based VANETs with the various configuration of the SDN components in VANET architecture. However, a compilation of the work on the SDN‐based VANET system as a whole, incorporating its architecture, use‐cases, and opportunities, is still inadequate. We start with the summary of the recent studies that exist on the SDVNs, followed by the comprehensive explanation of its components. Next, we present the taxonomy of SDVN based on the architecture modes, protocols, access technologies, and opportunities with trending technologies. Finally, we highlight the challenges, open research issues, and future research directions.     

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。     

Scalability of software defined network

With the development of software-defined networking (SDN),its scalability has become one of the most important issues of SDN.The features of SDN was studied which lead to its scalability problem when SDN was applied to large-scale network.The three main causes leading to scalability problem were discussed:control plane and data plane separation,logical centralized control and fine-grained flow control.Meanwhile,the studies which focus on the scalability of SDN from three aspects:scalability of performance,scalability of geographic and scalability of control was presented.Further,the studies on the performance evaluation of the scalability of SDN were introduced.Finally,the future work was discussed.     

软件定义网络中可靠性优化控制器的位置研究(英)

By decoupling control plane and data plane,Software-Defined Networking(SDN) approach simplifies network management and speeds up network innovations.These benefits have led not only to prototypes,but also real SDN deployments.For wide-area SDN deployments,multiple controllers are often required,and the placement of these controllers becomes a particularly important task in the SDN context.This paper studies the problem of placing controllers in SDNs,so as to maximize the reliability of SDN control networks.We present a novel metric,called expected percentage of control path loss,to characterize the reliability of SDN control networks.We formulate the reliability-aware control placement problem,prove its NP-hardness,and examine several placement algorithms that can solve this problem.Through extensive simulations using real topologies,we show how the number of controllers and their placement influence the reliability of SDN control networks.Besides,we also found that,through strategic controller placement,the reliability of SDN control networks can be significantly improved without introducing unacceptable switch-to-controller latencies.