Research on mapping algorithm of virtual network oriented to SDN

In order to solve the problem of virtual network mapping,a mapping method based on ant colony hybrid genetic algorithm was put forward under SDN environment,which established a linear programming model for virtual network mapping,and divided the mapping process into node mapping and link mapping.Firstly,the fusion algorithm was adopted,in which virtual nodes were mapped to physical nodes.Then the shortest path algorithm was used to map the virtual link to a physical link.On this basis,the acceptance ratio of virtual network requests can be improved.Simulation experiment results show that acceptance rate of virtual network requests can be increased by 10% efficiently using the ant colony hybrid genetic algorithm,compared with existing mapping algorithms D-ViNE,RW-BFS and R-ViNE.Further more,proposed method can greatly improve the average utilization rate of nodes and links and the ratio of the mapping income to cost.     

A consistent QoS routing strategy for video streaming services in SDN networks

The software‐defined networking (SDN) paradigm proposes to decouple the control plane (decision‐making process) and the data plane (packet forwarding) to overcome the limitations of traditional network infrastructures, which are known to be difficult to manage, especially at scale. Although there are previous works focusing on the problem of quality of service (QoS) routing in SDN networks, only few solutions have taken into consideration the network consistency, which reflects the adequacy between the decisions made and the decisions that should be taken. Therefore, we propose a network architecture that guarantees the consistency of the decisions to be taken in an SDN network. A consistent QoS routing strategy is then introduced in a way that avoids any quality degradation of prioritized traffic while optimizing resources usage. Thus, we proposed a traffic dispersion heuristic in order to achieve this goal. We compared our approach with several existing framework in terms of best‐effort flows average throughput, average video bitrate, and video quality of experience (QoE). The emulation results, which are performed using the Mininet environment, clearly demonstrate the effectiveness of the proposed approach that outperforms existing frameworks.     

SDN Based Next Generation Mobile Network With Service Slicing and Trials

Software-Defined Network （SDN） empowers the evolution of Internet with the OpenFlow, Network Virtualization and Service Slicing strategies. With the fast increasing requirements of Mobile Internet services, the Internet and Mobile Networks go to the convergence. Mobile Networks can also get benefits from the SDN evolution to fulfill the 5th Generation （5G） capacity booming. The article implements SDN into Frameless Network Architecture （FNA） for 5G Mobile Network evolution with proposed Mobile-oriented OpenFlow Protocol （MOFP）. The Control Plane/User Plane （CP/UP） separation and adaptation strategy is proposed to support the User-Centric scenario in FNA. The traditional Base Station is separated with Central Processing Entity （CPE） and Antenna Element （AE） to perform the OpenFlow and Network Virtualization. The AEs are released as new resources for serving users. The mobile-oriented Service Slicing with different Quality of Service （QoS） classification is proposed and Resource Pooling based Virtualized Radio Resource Management （VRRM） is optimized for the Service Slicing strategy with resource-limited feature in Mobile Networks. The capacity gains are provided to show the merits of SDN based FNA. And the MiniNet based Trial Network with Service Slicing is implemented with experimental results.     

Programmable virtual network instantiation in IaaS cloud based on SDN

A possible approach to cope with the diversity of future networks is to set up multiple isolated virtual networks on top of a single shared physical substrate, and each virtual network is customized to some specific purposes. However, in the current realization of virtualized infrastructure, the OpenStack infrastructure as a service (IaaS) cloud, whose isolation and programmability are limited in terms of scalability and performance. To overcome these limitations, we propose a solution based on software defined networking (SDN) which is composed of a centralized server and distributed agents. The server has complete view of the whole network substrate, and is responsible for the installation and management of virtual network through the distributed agents. Each agent has the local view of the substrate node. They can manage the local resources, dispatch and filter the inner- programmable virtual network (PVN) traffic based on MAC isolation which is more scalable than virtual local area network (VLAN) and more efficient than GRE. Our prototype implementation shows that this architecture is feasible and provides a better compromise between flexibility and performance than the solo centralized and distributed solutions.     

SDN特征剖析及典型应用介绍

通过与基于策略的网络管控、软交换等技术的对比,梳理了SDN技术源流,阐述了SDN体系结构及其包含的网络可编程、网络虚拟化等技术思想,剖析了其创新特征和对网络发展的意义;分析了SDN目前还缺乏清晰的商业模式、集中控制器存在状态收集和可伸缩性等问题,指出违背复杂系统管控规律所带来的局限性;介绍了SDN典型应用场景,说明SDN的适用范围主要是在局部自治网络中跨IP网、光网络、无线网络等层面进行一体化管控。     

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/NFV——机遇和挑战

SDN/NFV是电信业受云计算、虚拟化技术的深化发展趋势影响,在产业内进行网络IT化的尝试。本文分析了SDN/NFV对于电信领域的商业模式、技术趋势的影响,以及对于运营商、不同层面供应商的影响,并对其带来的机遇和挑战进行了分析和研究。     

基于SDN的量子密码通信网络设计与研究

软件定义网络(SDN)采用OpenFlow技术分离网络设备的数据平面和控制平面,实现灵活控制网络资源的目的。基于此,设计了量子密码通信网络模型,实现灵活控制密码通信网络整体量子密匙资源,确保了信息的安全传输。此外,提出了综合到端可用密匙和跳数的路由算法,提高了QKD生成密匙的有效利用率。由测试结果可知,通过基于SDN的量子密码通信网络及路由算法,可提高量子密匙资源利用率,提高网络性能。     

A virtualized resource management scheme for heterogeneous cellular networks

Because of random deployment patterns of femtocells, interference scenarios in a heterogeneous cellular network can be very complicated because of its changing network topology. Especially when each eNodeB occupies a fixed bandwidth, interference management becomes much more difficult. The benefit of dynamic management for local resource optimation is limited. Recently, resource virtualization has been proposed as a dynamic resource management scheme to optimize network performance. In fact, resource virtualization is viewed as a more flexible model, in which mobile network service providers can control physical resources in a global scope. This paper presents a joint resource virtualization and allocation scheme for its applications in heterogeneous macro‐femto‐cellular networks. The proposed scheme involves two major processes. First, it virtualizes physical resources as logical resources. Second, it carries out logical resource allocation optimization globally and aggregates logical and physical resources for resource allocation. The proposed scheme takes into account spectrum reuse and frequency domain interference jointly in order to achieve a high spectral efficiency and provide rate‐on‐demand services to all users. Simulation results demonstrate the effectiveness of the proposed scheme. Copyright © 2016 John Wiley & Sons, Ltd.     

SDN在IDC网络的应用方案研究

首先介绍了SDN的起源、概念及其对网络的影响。然后,详细阐述了IDC网络的使用需求,提出了基于SDN技术的解决方案,并通过对关键功能实现效果的对比,揭示了SDN技术在IDC场景下的优越性。最后,简述了SDN未来发展所面临的主要挑战。     

Research on software-defined network and the security defense technology

Software-defined network (SDN) separated the traditional control plane from the data plane,formed a centralized controller,opened up the network programming interface,simplified network management,promoted network innovation and optimized network operation.However,SDN's “three-layer two-interface” architecture increased the network attack surface,resulting in many new security issues.The development,characteristics and working principle of SDN were first introduced,and the existing security problems from the application layer,the northbound interface,the control plane,the southbound interface,the data plane were summarized respectively.Secondly,the latest research progress and existing solutions were discussed.Finally,SDN current and future security challenges were summarized,and the future SDN security development direction was looked forward to.     

基于节点可靠性感知和共享路径保护的虚拟网映射算法研究

网络虚拟化技术为目前的网络架构提供了一种有效的扩展手段。近年来,底层网络基础设施失效事件频发,因此如何提高虚拟网络的可靠性成为目前该领域一个研究热点。对在保证虚拟网络可靠性的同时如何最小化底层网络映射开销问题进行研究,设计了一个新的启发式算法对其进行求解。实验表明,相比其他算法,所提算法网络带宽资源开销更低。     

IP网SDN+NFV云化能力探索

SDN/NFV逐渐成为新一代网络发展的核心技术,也为未来运营商网络重构变革提供有力的技术支撑。SDN/NFV在运营商IP网络的引入促进运营网向新的业务模式演进,能够实现更高效的部署、更便利的维护、更快速的灵活满足业务变更需求和动态的资源调整。为了抢占市场先机并提高用户粘性,运营商将会持续进行探索与尝试,构建新一代面向未来云化城域网络。     

Cost minimization in placing service chains for virtualized network functions

Network function virtualization (NFV) places network functions onto the virtual machines (VMs) of physical machines (PMs) located in data centers. In practice, a data flow may pass through multiple network functions, which collectively form a service chain across multiple VMs residing on the same or different PMs. Given a set of service chains, network operators have two options for placing them: (a) minimizing the number of VMs and PMs so as to reduce the server rental cost or (b) placing VMs running network functions belonging to the same service chain on the same or nearby PMs so as to reduce the network delay. In determining the optimal service chain placement, operators face the problem of minimizing the server cost while still satisfying the end‐to‐end delay constraint. The present study proposes an optimization model to solve this problem using a nonlinear programming (NLP) approach. The proposed model is used to explore various operational problems in the service chain placement field. The results suggest that the optimal cost ratio for PMs with high, hybrid, and low capacity, respectively, is equal to 4:2:1. Meanwhile, the maximum operating utilization rate should be limited to 55% in order to minimize the rental cost. Regarding quality of service (QoS) relaxation, the server cost reduces by 20%, 30%, and 32% as the end‐to‐end delay constraint is relaxed from 40 to 60, 80, and 100 ms, respectively. For the server location, the cost decreases by 25% when the high‐capacity PMs are decentralized rather than centralized. Finally, the cost reduces by 40% as the repetition rate in the service chain increases from 0 to 2. A heuristic algorithm, designated as common sub chain placement first (CPF), is proposed to solve the service chain placement problem for large‐scale problems (eg, 256 PMs). It is shown that the proposed algorithm reduces the solution time by up to 86% compared with the NLP optimization model, with an accuracy reduction of just 8%.     

基于SDN的跨数据中心承载技术

互联网产业的发展和云计算的兴起催生了跨数据中心互联的需求,而软件定义网络技术为解决数据中心互联的网络瓶颈提供了重要途径.首先介绍了几种常用的数据中心互联技术,分析了SDN的技术优势,然后提出了一种基于SDN的运营商数据中心互联承载技术方案,并阐述其实现思路.该方案可实现DC间的网络虚拟化,能够提供用户业务定制、网络自动开通、任意虚拟机间的策略隔离、流量调度、用户就近访问、DC间的容灾备份等业务功能.     

SDN网络发展的探讨

随着IT技术的发展,网络也在不断变化.在IT依靠虚拟化将计算资源和存储资源从服务器上抽象出来,使之调度灵活性得以改变、资源的价值得以更充分的调配时,网络在技术的演进中,配合着IT虚拟化,也将其抽象为硬件资源池和软件管控部分,使网络资源得以最佳运用.通过对IT发展导致网络演进的分析研究,深层次地对SDN网络发展进行了阐述,并对广电运营商的适用环境提出了参考性建议.     

基于SDN的战术通信网络架构研究

战术通信网络具有高动态、弱连接、低带宽和多链路备份等特性,软件定义网络（software defined network,SDN）技术通过传统网络控制设备软硬件解耦,将核心控制功能软件化,通过集中控制策略获取全局视图,从而实现资源的灵活调度与信道资源的高效利用,推动战术通信网络朝着更加智能化的弹性适变网络发展。首先介绍了SDN的发展现状及优势,分析了传统架构战术通信网络的若干问题,并对SDN技术在外军战术通信领域的应用情况进行了分析,提出了SDN在军事通信领域应用的可行性思路,对应用场景进行了构想,最后对SDN在军事通信领域的应用可行性进行了总结。     

Reliable transmission mechanism with differentiated protection in virtualized fiber-wireless access network

In view of the different reliability requirements of network service,a reliable transmission mechanism with differentiated protection was proposed in virtualized fiber-wireless access network.The quality of protection required by users and the fees that can be paid were used as a prerequisite.The backup protection resources were flexibly allocated by quantifying the multi-level protection quality with the probability of recovery.Then,for reducing traffic congestion and the unprotected services,the level service differentiation algorithm was used to choose protection link which was satisfied with the level of protection quality.The results show the proposed mechanism has more advantages in terms of long-term benefit-to-cost ratio and underlying network resource overhead,and provides users with a more flexible virtual network transmission while satisfying users’ reliability requirements.     

基于SDN/NFV的未来网络实验平台

依据SDN/NFV集中管控、动态、灵活、高效、可编排等特点,提出了基于SDN/NFV技术的未来网络实验平台的构建方案.该平台主要采用OpenStack和OpenDaylight的开源架构,同时研发设计SDN跨域虚拟网络通信、虚拟网元管理以及网络服务编排三大关键技术,实现了底层异构资源的实时动态管理与开放共享.同时,根据实验用户对网络资源的需求,灵活按需编排各种网络资源与SFC服务,为用户提供端到端的网络实验验证服务.