基于资源需求预测的动态服务功能链迁移方法

针对网络功能虚拟化环境下服务功能链资源需求变化引起的底层网络过载问题,提出一种基于资源需求预测的动态服务功能链迁移方法.首先,综合考虑迁移开销和迁移后底层网络的资源占用情况,建立底层网络开销模型.其次,利用经验模态分解将资源需求序列分解成本征模函数分量与残差分量,再通过径向基函数神经网络实现对各分量的预测,神经网络的训练过程采用粒子群算法进行参数优化.最后,对下一时隙即将过载的物理节点或链路,选择对过载资源占用最多的虚拟网络功能或虚拟链路进行迁出,并基于流量优化的原则,通过对全局拓扑的感知选择能最小化底层网络开销的物理节点迁入.仿真实验表明,所提的资源需求预测模型在提高预测精度的同时能缩短预测时间,所提的服务功能链迁移方法在降低底层网络开销、减少端到端时延和提高服务功能链可靠性等方面有较好性能.     

5G-C-RAN中最大化效用服务功能链部署算法

为解决5G无线虚拟化网络中的服务功能链的部署问题,保障多样化业务带来的网络差异化性能需求,并提高基础设施运营商和无线虚拟运营商的联合收益,提出一种基于最大化效用的服务功能链部署策略。该策略在考虑5G-C-RAN的架构特性下,联合考虑虚拟运营商的最大容忍端到端时延、最小服务速率需求和基础设施运营商的计算资源及链路资源限制,同时考虑不同服务功能链部署方案对网络性能的影响,采用商业化模型,以最大化基础设施运营商及虚拟运营商联合收益建立效用模型。最后,通过遗传算法和Matlab函数Linprog进行迭代求解。仿真结果表明,该方案可保证虚拟运营商的网络性能的同时提高基础设施运营商和虚拟运营商的联合总收益。     

基于VNF组合的服务功能链设计及映射算法

为优化网络功能虚拟化中服务功能链的设计和映射过程,提高物理资源利用率,提出一种基于虚拟网络功能(VNF)组合的服务功能链设计及映射算法A-VNFC.使用整数线性规划(ILP)模型,在小规模物理网络中求出目标函数总带宽消耗(TBC)的最优解,寻找可组合的VNF,并利用VNF决策树检查所有组合策略,通过迭代和优化降低TBC.仿真结果表明,A-VNFC算法可在不同场景下有效降低带宽消耗,其TBC数值接近ILP模型获得的最小带宽消耗值.     

网络功能虚拟化资源配置及优化研究综述

网络功能虚拟化(network functions virtualization,NFV)利用虚拟化技术将网络功能从专用硬件中分离形成虚拟网络功能,然后把虚拟网络功能映射到通用服务器、交换机或者存储器中,能有效地降低网络投资成本和运营成本,并提高网络服务部署的灵活性。网络功能虚拟化资源配置是实施NFV需要解决的一个关键问题。为深入剖析网络功能虚拟化资源配置,介绍了NFV的体系结构,重点阐述了资源配置的三个阶段及资源配置的优化,最后对高效资源配置面临的挑战和有价值的研究方向进行了思考,为NFV的研究提供参考。     

基于Q-learning的虚拟网络功能调度方法

针对现有调度方法多数未考虑虚拟网络功能在实例化过程中的虚拟机选择问题,提出一种新的虚拟网络调度方法。建立基于马尔科夫决策过程的虚拟网络功能调度模型,以最小化所有服务功能链的服务延迟时间。通过设计基于Q-learning的动态调度算法,优化虚拟网络功能的调度顺序和虚拟机选择问题,实现最短网络功能虚拟化调度时间。仿真结果表明,与传统的随机虚拟机选择策略相比,该方法能够有效降低虚拟网络功能调度时间,特别是在大规模网络中调度时间可降低约40%。     

基于协议无感知转发的服务功能链

IETF提出的服务功能链（Service Function Chain,SFC）解决了服务功能在部署过程中网络拓扑与硬件设备紧密耦合、灵活性差等问题,其中,NSH协议用于支持服务功能链的实现.然而,标准的OpenFlow协议对NSH协议支持不足、实现过程复杂且实现后造成兼容性等问题.本文基于软件定义网络（Software Defined Network,SDN）和网络功能虚拟化（Network Function Virtualization,NFV）技术,根据IETF规定的相关标准,提出一种基于协议无感知转发（Protocol Oblivious Forwarding,POF）的服务功能链,利用POF在数据平面深度可编程的能力实现NSH协议.文中基于FloodLight控制器和POF交换机实现了该服务功能链,实验结果表明,基于协议无感知转发的服务功能链可以高效地实现服务功能的部署.     

网络功能虚拟化现实吗

在此文中,我们将讨论一下网络功能虚拟的历史和起源,还要讨论网络从以硬件为中心的方法演变到软件驱动模式的前景。最后还要看看未来的市场影响,并讨论在几乎所有网络功能都可被虚拟化时,网络功能虚拟化如何可以帮助企业实现其目标。     

基于软件定义的安全功能服务链部署方法

为减少传统安全设备实现安全功能灵活性差、部署成本高等弊端,深入研究软件定义网络(SDN)、网络功能虚拟化(N F V)和基于软件定义的安全服务部署技术,建立安全服务链部署模型,提出一种启发式算法.从节点的安全功能需求、物理资源需求,以及节点之间的网络资源需求和传输时延等方面综合评估部署安全功能服务链的资源需求,优先部署资源需求较大的安全功能服务链,避免资源能力成为瓶颈.实验结果表明,该算法可有效提升部署成功率.     

面向组播的动态虚拟网络功能放置算法

组播在支持日益增长的多媒体应用方面具有广阔的应用前景，面向组播的虚拟网络功能放置是网络功能虚拟化中不可避免的研究趋势.然而，对于该问题的大多数研究都聚焦于静态网络环境，难以应对网络中的各种资源随着时间动态变化，组播服务功能链（Service Function Chaining,SFC）请求动态到达的真实场景.本文提出一种基于组播SFC请求预测的足球联赛竞争算法，以Informer模型为基础，预测即将到达的组播SFC请求.基于足球联赛竞争的组播虚拟网络功能放置算法，设计多维个体编码策略，一次性求解所有活动组播组的SFC映射方案，提前部署预测的请求.针对预测结果与真实结果不一致的情况，提出一种由正向搜索与反向搜索组成的快速修复策略以完成对请求的快速响应.仿真结果表明，对比其它两种预测模型，Informer在组播SFC请求预测上取得了更低的均方误差与平均绝对误差.此外，与七种经典的启发式算法和深度强化学习算法相比，提出的算法在端到端时延和计算资源消耗方面达到更优性能的同时，取得了更低的组播SFC请求响应时间.     

一种基于动态规划的vEPC服务功能链部署方法

5G移动通信网虚拟化场景下,如何高效部署核心网服务功能链是实现虚拟化演进分组核心网业务高效部署的关键问题。针对现有部署方法难以满足移动通信低时延业务需求的问题,本文提出了一种基于动态规划的服务功能链部署方法。该方法通过解决相互依赖的每个虚拟网络功能部署这一子问题,然后递归的解决整个服务功能链的部署问题,找到网络服务时延开销最小的部署方案。仿真实验表明,该方法在网络服务的处理时间、请求接受率、收益和算法执行时间等方面具有良好的性能。     

SPIDER: An availability-aware framework for the service function chain placement in distributed scenarios

The network function virtualization (NFV) paradigm replaces hardware-dependent network functions by virtual network functions (VNFs) that can be deployed in commodity hardware, including legacy servers. Consequently, the use of NFV is expected to reduce operating and capital expenses, as well as improve service deployment operation and management flexibility. For many use cases, the VNFs must be visited and invoked following a specific order of execution in order to compose a complete network service, named service function chain (SFC). Nonetheless, despite the benefits from NFV and SFC virtualization technologies, their introduction must not harm network performance and service availability. On the one hand, redundancy is seen by network service planners as a mechanism well established to combat availability issues. At same time, there is a goal to optimize resource utilization in order to reduce operational expenditure. In this article, we share our experience in the design use of a framework, named SPIDER, focused on SFC placement that considers the network infrastructure condition and the required SFC availability to define the placement strategy. The SPIDER monitors the status of infrastructure nodes and links and defines which servers the VNFs should be placed on and the number of redundant replicas needed. We present a proof-of-concept of SPIDER using Kubernetes to launch the VNFs as containers. We also use Kubernetes to forward the traffic between the VNFs, composing the service chain. We perform experiments to evaluate the runtime of SPIDER and the SFC delay under different network conditions.     

网络功能虚拟化技术综述

无论是企业网还是数据中心,为实现相关应用功能、提升网络性能和加强网络安全等部署了大量的网络功能设备,但这些网络功能设备大多基于硬件,存在功能固化、扩展能力差、统一管理困难等问题。为解决上述问题,学术界和工业界不约而同将目光投向了网络功能虚拟化NFV技术。通过解耦网络功能和物理设备,使网络功能不受物理设备的约束,便于网络设备服务的升级更新,同时,NFV为新的体系结构、系统和应用的产生提供了可能。首先介绍了NFV技术,并与云计算和SDN进行对比,然后从VNF的系统结构、数据平面、控制平面、部署方式、实现语言和应用6个维度详细阐述了当前的研究成果,最后总结并展望了NFV未来的研究发展方向。     

基于资源感知的多域服务功能链编排成本优化

网络功能虚拟化技术的兴起使得实例化为服务功能链(SFC)的网络服务能够共享基底网络,缓解了传统网络体系结构僵化的问题.然而,网络中大量服务请求给多域SFC编排带来了新的挑战.首先由于域内网络资源信息及内部策略的保密性,使得多域SFC的编排更为复杂.其次多域SFC编排要确定最佳候选编排域集,先前的研究较少考虑域间负载的均衡性,对服务接受率造成了消极影响.此外跨网络域编排服务请求对服务的成本和响应时间提出了更严格的要求.为解决上述挑战,在本文中,我们首先针对多域网络隐私性需求,提出了域级图的构造方法;然后基于域间负载均衡提出了域权重的计算方法进行SFC编排域的选择;最后,针对多域网络成本和响应时间需求,提出编排算法.实验结果表明,提出的算法有效地权衡了平均服务成本和接受率,并且在服务平均响应时间方面也得到了优化.     

CloudSimSDN-NFV: Modeling and simulation of network function virtualization and service function chaining in edge computing environments

Software-defined networking (SDN) has evolved and brought an innovative paradigm shift in computer networks by utilizing a programmable software controller with open protocols. Network functions, previously served on dedicated hardware, have shifted to network function virtualization (NFV) that enabled functions to be virtualized and provisioned dynamically upon generic hardware. In addition to NFV, edge computing utilizes the edge resources close to end-users, which can reduce the end-to-end service delay and the network traffic volume. Although these innovative technologies gained significant attention from both academia and industry, there are limited tools and simulation frameworks for the effectiveness evaluation in a repeatable and controllable manner. Furthermore, large-scale experimental infrastructures are expensive to setup and difficult to maintain. Even if they are created, they are not available or accessible for the majority of researchers throughout the world. In this paper, we propose a framework for simulating NFV functionalities in both edge and cloud computing environments. In addition to the basic network functionalities supported by SDN in CloudSimSDN, we added new NFV features, such as virtualized network functions allocation, migration, and autoscaling with the support of corresponding network functionalities, such as flow load balancing, rerouting, and service function chaining (SFC) maintenance. We evaluated our simulation framework with autoscaling and placement policies for SFC in the integrated edge and cloud computing environments. The results demonstrate its effectiveness in measuring and evaluating the end-to-end delay, response time, resource utilization, network traffic, and power consumption with different algorithms in each scenario.     

Wetland landscape design based on 5 G network and FPGA system

5 G-demand service is the key feature of the network, the network function virtualization (NFV) to provide services through the virtualization of existing 5 G network infrastructure. NFV created on a shared physical network a variety of virtual network, but one of the main challenges of the future 5 G network is a virtual network function (VNF), less manual intervention. And automatically end network service (NS) orchestration modeling. Wetlands has been more and more important. It is the only nature conservation area. Search in the storm of sand entering from the road. Wetlands, it is northwest ecological shelter and is the first circle of protection band, under the influence of the powerful Force factor, resources and structures are quietly changed in the last ten years, and it has threatened the healthy development. Use the 5 G network and FPGA system resources and sensing technology, it gave a field environment monitoring. Through this research, the area of the wetlands had declined more than half. In addition, there is a tendency that the environment is degraded. Analyzed the reason for the wetland dynamics. This is the base for the recovery and protection of wetlands. Construction of savings and friendly Wetland Park in the environment of the resource will be able to promote the sustainable development of the fact park.     

基于GPU加速的NFV系统的框架设计和性能优化

GPU可以显著提升一些网络功能的性能,但在GPU加速的网络功能虚拟化(Network Function Virtualization,NFV)系统中,由于网络功能需要以虚拟化方式独立开发和部署,其CPU-GPU处理流水线的CPU处理阶段会有较大的额外开销,使得网络功能GPU加速的效果不明显。为解决该问题,提出一个新的支持GPU加速的NFV系统框架。利用服务链中网络功能之间共享数据和流状态的特性,设计了共享式状态管理机制,以减少网络功能中重复性的协议栈处理和流状态管理开销,提升GPU加速的效果。对原型系统进行评估表明,相比于现有的系统框架,该框架能够显著地降低多种GPU加速的网络功能中CPU处理阶段的时间开销,并在常见的网络功能服务链上实现了高达2倍的吞吐量提升。     

Mobile Fog Computing by Using SDN/NFV on 5G Edge Nodes

Fog computing provides quality of service for cloud infrastructure. As the data computation intensifies, edge computing becomes difficult. Therefore, mobile fog computing is used for reducing traffic and the time for data computation in the network. In previous studies, software-defined networking (SDN) and network functions virtualization (NFV) were used separately in edge computing. Current industrial and academic research is tackling to integrate SDN and NFV in different environments to address the challenges in performance, reliability, and scalability. SDN/NFV is still in development. The traditional Internet of things (IoT) data analysis system is only based on a linear and time-variant system that needs an IoT data system with a high-precision model. This paper proposes a combined architecture of SDN and NFV on an edge node server for IoT devices to reduce the computational complexity in cloud-based fog computing. SDN provides a generalization structure of the forwarding plane, which is separated from the control plane. Meanwhile, NFV concentrates on virtualization by combining the forwarding model with virtual network functions (VNFs) as a single or chain of VNFs, which leads to interoperability and consistency. The orchestrator layer in the proposed software-defined NFV is responsible for handling real-time tasks by using an edge node server through the SDN controller via four actions: task creation, modification, operation, and completion. Our proposed architecture is simulated on the EstiNet simulator, and total time delay, reliability, and satisfaction are used as evaluation parameters. The simulation results are compared with the results of existing architectures, such as software-defined unified virtual monitoring function and ASTP, to analyze the performance of the proposed architecture. The analysis results indicate that our proposed architecture achieves better performance in terms of total time delay (1800 s for 200 IoT devices), reliability (90%), and satisfaction (90%).     

基于NFV的新的协作式DDoS防御技术

在采取网络功能虚拟化技术构建的协作式网络抵御分布式拒绝服务攻击的过程中,由于协作网络中的资源有限,协作网络中的参与者存在为了自身安全而采取自私行为的问题,进而减弱协作网络缓解 DDoS攻击能力。针对上述问题,提出了一种新的缓解DDoS攻击策略。该策略在协作网络中构建重复囚徒困境博弈模型,引入奖罚分明激励机制加强协作网络的合作性,并采取基于社会信誉值评估的动态资源分配机制。仿真实验表明,新的协作式DDoS攻击防御技术在分组丢失率、合作性和资源分配率方面优于现有方案,提高了DDoS攻击防御的有效性。     

一种保证NFV可靠性的最优备份拓扑生成方法

网络功能虚拟化（NFV）将服务功能链（SFC）映射到底层网络时,与传统的虚拟网络一样,会存在可靠性问题。本文针对NFV环境中的单链路故障,在考虑SFC拓扑设计和映射的基础上添加备份拓扑提高可靠性,再进一步简化备份拓扑,减少资源消耗。按照服务路径是否可分离,提出了两种最优备份拓扑的生成算法。仿真结果表明,最优备份拓扑在提高可靠性的基础上能够有效的减少备份带宽资源的消耗,提高资源利用率。