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.     

Migration cost optimization for service provider legacy network migration to software-defined IPv6 network

This paper studies a problem for seamless migration of legacy networks of Internet service providers to a software-defined networking (SDN)-based architecture along with the transition to the full adoption of the Internet protocol version 6 (IPv6) connectivity. Migration of currently running legacy IPv4 networks into such new approaches requires either upgrades or replacement of existing networking devices and technologies that are actively operating. The joint migration to SDN and IPv6 network is considered to be vital in terms of migration cost optimization, skilled human resource management, and other critical factors. In this work, we first present the approaches of SDN and IPv6 migration in service providers' networks. Then, we present the common concerns of IPv6 and SDN migration with joint transition strategies so that the cost associated with joint migration is minimized to lower than that of the individual migration. For the incremental adoption of software-defined IPv6 (SoDIP6) network with optimum migration cost, a greedy algorithm is proposed based on optimal path and the customer priority. Simulation and empirical analysis show that a unified transition planning to SoDIP6 network results in lower migration cost.     

基于OpenFlow的软件定义网络路由技术研究

文中主要探索了基于OpenFlow的软件定义网络（SDN）路由技术,旨在优化和提高网络管理效率。通过深入解读SDN的核心构架、OpenFlow协议的关键组成,并将其与传统路由进行对比,发现SDN提供了一个更加灵活和集中的网络管理机制。在路由决策、性能优化和故障恢复上,基于OpenFlow的SDN明显优于传统方法。由此可见,基于OpenFlow的软件定义网络路由技术不仅可以大大提高网络的运行效率,还能简化网络管理流程,为未来的网络技术发展指明方向。     

层次化跨区域SDN验证示范系统的设计与建设

软件定义网络（SDN）架构给网络带来了卓越的灵活性和可管理性。为了给新型SDN技术与应用提供大规模可行性验证试验床与试点部署平台,提出了依托于CERNET的层次化跨区域SDN 异地验证示范网络试验系统的总体架构,建设了9个城市、13个节点的SDN验证示范核心网与包含3个数据中心的接入网,并对基于SDN的vCPE智能专线业务、IPv4/IPv6过渡技术、流量监控调度应用和数据中心应用进行验证与示范。     

基于软件定义网络的多区域网络虚拟化模型

提出了一种新的基于软件定义网络的多区域网络虚拟化模型。该模型引入了网络区域的逻辑概念,在同一个区域中使用某种网络虚拟化技术,在区域与区域的边界通过控制平面的统一控制实现不同虚拟网络标识符的转换,完成跨区域交互。该模型可以同时兼容多种网络虚拟化技术,实现高效率、可扩展、大规模的网络虚拟化。     

服务定制网络

针对当前互联网中存在的2个亟待解决的问题：OTT（over the top）流量占用大量网络带宽以及信息高度冗余,提出了一种具有差异化服务能力的未来网络体系架构——服务定制网络（SCN, service customized networking）。SCN基于软件定义网络设计,继承了其数据控制分离以及网络可编程的主要特点,并针对当前互联网中的问题,增加了网络虚拟化能力以及内容智能调度能力。通过构建具有不同等级服务能力的虚拟网络,SCN可以避免OTT业务大量占用带宽。同时,通过信息资源智能有序调度,SCN可以消减信息冗余。在小规模真实网络平台上进行的实验结果表明,SCN确实具备为不同用户提供差异化服务能力以及有效减少信息冗余的能力。     

Virtual network embedding in software-defined hybrid networks

Network virtualization provides a powerful way of sharing substrate networks. Efficient allocation of network resources for multiple virtual networks (VNs) has always been a challenging task. In particular, with the demands of the customized VN requests are increasing, many problems arise as network conditions change dynamically. Especially, when the resources conflicting appear during the lifetime of VNs, it needs service provider (SP) to provide a fast and effective solution. Recently, software defined network (SDN) has emerged as a new networking paradigm, SDN’s centralized control and customizable routing features present new opportunities for convenient and flexible embedding VNs in the network. However, due to the limitations of the SDN, in the short term, replacing all legacy devices in current operational networks by SDN-enabled switches is impractical. Thus, in our study, we focus on the scenario of VN embedding (VNE) in software-defined hybrid networks. In this work, first of all, we propose partially deploying SDN nodes, and then, we use the characteristics of SDN to allocate resources for VN requests, and redirect the path for requests conflict in hybrid SDN network. We formulate the problems and provide simple algorithms to solve them. Simulation results show that our scheme is high responsiveness and acceptance ratio.     

SRv6-based Time-Sensitive Networks (TSN) with low-overhead rerouting

Time-Sensitive Networks (TSN) aims at providing a solid underpinning for the support of application connectivity demands across a wide spectrum of use cases and operational environments, such as industrial automation and automotive networks. However, handling network updates in TSN entails additional challenges, stemming from the need to perform both flow rerouting and TSN schedule reconfiguration. To address this issue, we propose a software-defined network (SDN)-based approach for low-overhead TSN network updates, exploiting segment routing over IPv6 (SRv6) for path control. To this end, we introduce the concept of TSN subgraphs in order to quickly reschedule the flows traversing the problematic area and propose a TSN-aware routing heuristic to minimize the convergence time. We further describe the control plane implementation and its integration into Mininet, which empowers us to conduct a wide range of performance tests. Our evaluation results indicate that our approach yields faster recovery and reduces significantly the number of required reconfigurations upon failures, at the expense of a small SRv6 encoding/decoding overhead.     

An SDN approach to route massive data flows of sensor networks

With the advent of the Internet of Things (IoT), more and more devices can establish a connection with local area networks and use routing protocols to forward all information to the sink. But these devices may not have enough resources to execute a complex routing protocol or to memorize all information about the network. With proactive routing protocols, each node calculates the best path, and it needs enough resources to memorize the network topology. With reactive routing protocols, each node has to broadcast the message to learn the right path that the packets must follow. In all cases, in large networks such as IoT, this is not an appropriate mechanism. This paper presents a new software‐defined network (SDN)–based network architecture to optimize the resource consumption of each IoT object while securing the exchange of messages between the embedded devices. In this architecture, the controller is in charge of all decisions, and objects only exchange messages and forward packets among themselves. In the case of large networks, the network is organized into clusters. Our proposed network architectures are tested with 1000 things grouped in five clusters and managed by one SDN controller. The tests using OpenDayLight and IoT embedded applications have been implemented on several scenarios providing the ability and the scalability from dynamic reorganization of the end‐devices. This approach explores the network performance issues using a virtualized SDN‐clustered environment which contributes to a new model for future network architectures.     

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.     

融媒体应急广播系统设计及实践

贵州自然灾害频发,为了能在灾害发生前提供预警,灾害发生后提供应急广播、应急指挥、救灾、发布应急公共信息等,我台利用新媒体互联网技术的发展成果,结合广播媒体传播快捷、覆盖面广的优势,建设了融媒体应急广播系统,本文将介绍这一系统的设计及实施。     

Time-sensitive software-defined networking (Ts-SDN) control architecture for flexi-grid optical networks with data center application

Data center interconnected by flexi-grid optical networks is a promising scenario to meet the high burstiness and high bandwidth requirement of data center application, because flexi-grid optical networks can allocate spectral resources for applications in a dynamic, tunable and efficient control manner. Meanwhile, as centralized control architecture, the software-defined networking (SDN) enabled by OpenFlow protocol can provide maximum flexibility for the networks and make a unified control over various resources for the joint optimization of data center and network resources. Time factor is firstly introduced into SDN-based control architecture for flexi-grid optical networks supporting data center application. A traffic model considering time factor is proposed, and a requirement parameter, i.e., bandwidth-period product is adopted for the service requirement measurement. Then, time-sensitive software-defined networking (Ts-SDN)-based control architecture is designed with OpenFlow protocol extension. A novel deadline-driven PCE algorithm is proposed for the deadline-driven service under Ts-SDN-based control architecture, which can complete data center selection, path computation and bandwidth resource allocation. Finally, simulation results shows that our proposed Ts-SDN control architecture and deadline-driven PCE algorithm can improve the application and network performance to a large extent in blocking probability.     

面向密集部署的超高吞吐率Wi-Fi融合应用技术

为了降低网络密集部署对超高吞吐率( VHT) Wi-Fi性能的影响,提出了VHT Wi-Fi基于软件定义网络( SDN)的网络架构、无线网络侧虚拟化和增强型认证与快速切换技术,以提高系统的共存性、抗干扰性和安全性。实验结果表明,VHT Wi-Fi与SDN、网络功能虚拟化、伽罗瓦/计数模式协议结合,吞吐率性能获得约10%的提升,在保证安全性同时平均切换时延降低至40 ms,可保障VHT Wi-Fi在密集部署网络中发挥重要作用。     

Research on distributed mobile management of satellite network based on software define network

Distributed mobility management (DMM) was an effective method to solve the mobile address handover.Therefore,it was considered to be a technology that can be applied to satellite network mobility management.A distributed mobile management scheme which based on software definition network (SDN) was proposed to solve the traffic redirection problem in satellite network.Different from the traditional DMM application scenario which was network-based or terminal-based,the SDN-DMM scheme implements location management and address handover in SDN controllers.Therefore,SDN-based satellite network distributed mobile management scheme can realize packet forwarding path optimization compared with traditional scheme,and it shows significant advantages in managementcost and traffic management.     

面向SDN的数据中心网络更新研究综述

近年来,由于软件定义网络(SDN)的控制平面与数据平面分离、集中式控制的特点,被广泛应用于数据中心网络(DCN).分四个部分对DCN更新的相关研究进行了综述.首先,介绍了DCN和SDN的基本概念及研究现状;随后,详细说明了传统DCN在更新方面遇到的缺陷;其次,重点讨论了基于SDN的数据中心网络(SD-DCN)更新场景的研究现状与存在的不足,同时指出了一些方案存在的缺点;最后,对基于SDN的数据中心网络未来研究方向进行了展望,以期为SD-DCN的研究与应用提供一定的参考.     

SD-WAN在中国移动国际网络中的应用

软件定义广域网(SD-WAN)是将SDN技术应用到广域网场景中所形成的一种服务,用于降低互联成本,提升业务部署灵活性.本文简要分析了SD-WAN技术优势,重点介绍了SD-WAN在中国移动国际网络中的应用解决方案,并从多角度给出了国际网络拓展SD-WAN建设的后续发展建议.     

一种面向Portal认证的IPv6可信地址分配机制

随着网络规模的增长,对网络进行精细化管控变得尤为重要。在下一代互联网中将用户可信身份嵌入 IPv6 地址后缀形成可信地址,能够进一步提高网络行为的可追溯性。目前已有研究基于 Portal 认证配合DHCPv6将用户的身份信息嵌入用户终端的IPv6地址中,但是为了分配可信地址而改动的DHCPv6过程造成了机制对用户终端不透明,无法大规模部署。提出了一种面向Portal认证的IPv6可信地址分配机制,通过服务器信令交互配合软件定义网络（SDN）技术实现IPv6可信地址的间接分配,而且与地址分配方式无关。最后,实现了一个原型系统并在江苏南京电信现网机房评估了其可行性和性能,结果表明此机制在对终端透明的情况下仅带来很少的额外开销。     

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。     

基于server SAN超融合架构的电子政务异地灾备中心研究

超融合架构作为软件定义数据中心较为先进的技术方案,在扩展性、可靠性、兼容性等方面具有独特的优势。基于服务器分布式存储和超融合架构两种技术的结合,研究电子政务异地灾备中心的建设模式、存储资源系统、网络系统业务流程,可作为电子政务异地灾备中心建设的重要参考。     

SDN/NFV技术演进趋势分析

作为未来网络领域的关键技术,SDN/NFV在工业互联网、5G切片、云化电信网络等应用场景先后成熟。2019年,SDN/NFV技术正式进入v2.0发展阶段。梳理了SDN/NFV技术的演进历程,归纳了其v2.0阶段的整体架构和关键技术,给出了我国产业界发展的建议。