增值服务(VAS)(例如,动态站点加速、媒体管理)在内容分发网络(CDN)中起着关键作用。网络功能虚拟化(NFV)实现了VAS的敏捷配置。在NFV设置中,VAS被提供为虚拟网络功能(VNF)的有序集合,形成部署在CDN基础设施中的VNF转发图(VNF-FG)。CDN VAS VNF-FG具有特定的特性:它们具有一个端点(对应于内容服务器),该端点在它们的放置之前是未知的。到目前为止,CDN VAS VNF-FG放置的提案仅考虑了离线放置,其中VNF-FG在最终用户流量转向网络之前放置。然而,在具体情况下,可能发生服务使用模式的变化,这种情况可能需要以在线方式放置VNF-FG。本文解决了CDN中VAS的在线VNF-FG放置问题,考虑到已部署VNF的最终重用和迁移。考虑成本模型,包括多个成本;即,新的VNF实例化、迁移、托管和路由成本。目标是最佳地放置VNF-FG,使得在满足QoS的同时最小化总重新配置成本。一个非线性规划(ILP)制定和评估在一个小规模的情况下。
英文摘要:
Value-added Services (VASs) (e.g. dynamic site acceleration, media management) play a critical role in Content Delivery Networks (CDNs). Network Functions Virtualization (NFV) enables the agile provisioning of VASs. In NFV settings, VASs are provisioned as ordered sets of Virtual Network Functions (VNFs), forming VNF-Forwarding Graphs (VNF-FG) which are deployed in the CDN infrastructure. The CDN VAS VNF-FGs have a specific characteristic: they have one end-point (corresponding to the content server) that is unknown, prior to their placement. The proposals for CDN VAS VNF-FG placement, so far, have only considered offline placement, where the VNF-FGs are placed before end-user traffic steers into the network. However, in concrete cases, a change in service usage patterns might occur, a situation that could require a VNF-FG placement in an online manner. This paper tackles the problem of online VNF-FG placement for VASs in CDNs, taking into account the eventual reuses and migrations of already-deployed VNFs. A cost model is considered, including multiple costs; i.e. new VNF instantiations, migration, hosting and routing costs. The objective is to optimally place the VNF-FGs such that total reconfiguration costs are minimized while QoS is satisfied. An Integer Linear Programming (ILP) formulation is provided and evaluated in a small-scale scenario.
Load-balanced Service Function Chaining in Edge Computing over FiWi Access Networks for Internet of Things
服务功能链(SFC)有望为物联网(IoT)实现灵活且可扩展的虚拟网络基础设施。边缘计算被认为是处理大量物联网应用数据的有效解决方案。为了在分布式边缘计算节点(ECN)之间统一为物联网应用提供服务,提出了一种基于SDN和NFV协调的统一SFC编排框架,该框架通过利用FiWi接入网络的连接性提供协同边缘云平台。此外,我们研究的VNF部署问题在我们的协同框架下,我们制定了一个混合整数非线性规划(MINLP)问题,共同考虑负载均衡的网络和计算链VNF。我们还提出了两个近似的最优部署算法贪婪二分多路径(GBMP)和KSP多路径(KSMP)利用部署在ECN的多实例虚拟网络功能(VNF)和FiWi接入网络的多路径能力。在两种类型的物联网应用场景中进行了广泛的仿真,在EC over FiWi接入网络。数值结果表明,在两种典型场景下,我们提出的算法在负载均衡、业务接受率和网络利用率方面均优于单路径和基于ECMP的部署算法.
Multi-Timescale Online Optimization of Network Function Virtualization for Service Chaining
Fudan University(复旦大学);Macquarie University(麦考瑞大学);Commonwealth Scientific and Industrial Research Organization (CSIRO)(联邦科学与工业研究组织);University of Minnesota(明尼苏达大学);University of Technology Sydney(悉尼科技大学)
An NFV and Microservice Based Architecture for On-the-fly Component Provisioning in Content Delivery Networks
内容分发网络(CDN)通过互联网向地理上分布的终端用户分发内容(例如,网页、视频)。有些内容有时确实会吸引一大群最终用户的注意。这通常会导致快速拥挤,这可能会导致CDN中断等重大问题。微服务架构风格旨在将整体系统分解为更小的组件,这些组件可以独立部署,升级和部署。网络功能虚拟化(Network Function Virtualization,NFV)是一种新兴技术,其目的是通过将网络功能与底层硬件解耦来降低成本并带来灵活性。本文利用NFV和微服务架构风格提出了一种用于动态CDN组件配置的架构,以解决闪存拥挤等问题。在所提出的架构中,CDN组件被设计为通过RESTFul Web服务进行交互的微服务集,并被配置为虚拟网络功能(VNF),这些功能是动态部署和编排的。我们已经构建了一个原型,其中CDN代理服务器被设计为一组微服务,被动态部署。该原型部署在SAVI,加拿大未来的互联网应用的分布式测试床。性能也进行了评估。