软件定义网络(software-defined networking,简称SDN)技术分离了网络的控制平面和数据平面,为研发网络新应用和未来互联网技术提供了一种新的解决方案.综述了基于OpenFlow 的SDN 技术发展现状,首先总结了逻辑控制和数据转发分离架构的研究背景,并介绍了其关键组件和研究进展,包括OpenFlow交换机、控制器和SDN技术,然后从4 个方面分析了基于OpenFlow 技术目前所面临的问题和解决思路.结合近年来的发展现状,归纳了在校园网、数据中心以及面向网络管理和网络安全方面的应用,最后探讨了未来的研究趋势.;The control and data planes are decoupled in software-defined networking, which provide a new solution for research on network applications future Internet technologies. The development status of OpenFlow-based SDN...

In order to achieve requirements such as fast search of flow entries and mask matching, OpenFlow hardware switches usually use TCAM store entries. Limited by the capacity TCAM, current commercial can only support hundreds thousands entries, which makes SDN network using vulnerable threat table overflow attack. Among them, low-rate DoS (LDoS) attack against poses a serious networks due its high efficiency concealed flow, it is also difficult detect. this regard, paper analyzed two types LDoS...

The long authentication handover delay is the greatest challenge in multi-domain SDN environment. In order to solve this problem, an mechanism under multi-SDN domain (AHMMD) proposed paper. AHMMD, firstly, when mobility entity accesses network for first time, its identity and service attributes are authenticated by flow protocol, which designed based on asymmetric encryption key; secondly, moves neighbor domain, information will be delivered from current controller neighborhood through a...

Mobile Cloud Computing (MCC) enables the mobile devices to offload their applications cloud, and thus greatly enriches types of on enhances quality service applications. Under various circumstances, researchers have put forward several MCC architectures. However, how reduce response latency while efficiently utilizing idle capacities is still a challenge. This paper firstly gives definition MCC. Secondly, by extending Cloudlet architecture, Hybrid Local Model (HLMCM) presented. Thirdly, from...

High temperature superconducting flywheel energy storage system (HTS FESS) based on asynchronous axial magnetic coupler (AMC) is proposed in this paper, which has the following possible advantages: generator/motor (G/M) can be installed outside of vacuum chamber with torque being transferred by coupler, and stator liquid cooling not needed; idle loss G/M during stage maintaining eliminated disconnecting from field shielding device. Up to now, there been little research AMC for high-speed...

在新的应用模式下,传统层次结构数据中心网络在规模、带宽、扩展性和成本方面存在诸多不足.为了适应新型应用的需求,数据中心网络需要在低成本的前提下,满足高扩展性、低配置开销、健壮性和节能的要求.首先,概述了传统数据中心网络体系结构及其不足,并指出了新的需求;其次,将现有方案划分为两类,即以网络为中心和以服务器为中心的方案;然后,对两类方案中的代表性结构进行了详细的综述和对比分析;最后指出了数据中心网络未来的发展方向.;Under the new application mode, traditional hierarchy data centers face several limitations in size, bandwidth, scalability, and cost. In order to meet needs of applications, center network should fulfill requirements with low-cost, such as high low configuration overhead, robustness...

Use for reference of the great success P2P in distributed file sharing and locating, by abolishing CDN central node making all POP nodes, which adopt cluster technique, being peers to each other, a multimedia model with architecture is put forward. In order implement global load optimization, two-level balance algorithm based on network measurement proposed. Files are sliced up transmitted through mechanism satisfy requirement real time multi-media application high quality service. Results...

As the availability is an important issue of network security, it necessary to research DDoS defending mechanism Software Defined Networking (SDN) before real-world deployment. In this paper, we first measured impact attacks on SDN based a test bed. The results showed t hat resource utilization changed sharply when started. Based observation, lightweight which implemented in controller put forward. mechanism, score Shiryaev–Roberts change point detection algorithm firstly adopted detect...

Survivability evaluation index systems and models are important basis for evaluating network survivability. The Analytic Hierarchy Process (AHP) is a common system method, but it cannot reflect the mutual influence among indexes. In order to overcome defects of AHP, survivability set Wireless Sensor Network (WSN) in emergency communications selected comprehensively, establishes WSN based on (ANP). Then, model clustering semi-Markov (SMP) put forward this paper, SMP-based survival state...

Information-centric networking (ICN) aims to make the Internet more data-oriented or content-centric, thus name-based routing and universal caching are used change way users requesting fetching content, as well improve network performance. However, current implementation mechanisms define some kinds of "clean-slate" architecture certain brand new technologies need be designed implemented. In this paper, requisites reflecting ICN's essential ingredients generalized, based on OpenFlow data...

Network performance testing is one of the key components in optimizing network resource configuration and improving performance. Existing tools usually focus on single parameters, lack ability to satisfy integrated demands administrators. In this paper, a universal model based policy scheduling proposed, which integrates many kinds into system, provides uniform interface Universal Probe (UP) component such model, thus detailed study given UP, includes UP architecture, policy-based...