Dynamic Multicast Session Provisioning in WDM Optical Networks with Sparse Splitting Capability

In this work, we study dynamic provisioning of multicast sessions in a wavelength-routed sparse splitting capable WDM network with an arbitrary mesh topology where the network consists of nodes with full, partial, or no wavelength conversion capabilities and a node can be a tap-and-continue (TaC) node or a splitting and delivery (SaD) node. The objectives are to minimize the network resources in terms of wavelength-links used by each session and to reduce the multicast session blocking probability. The problem is to route the multicast session from each source to the members of every multicast session, and to assign an appropriate wavelength to each link used by the session. We propose an efficient online algorithm for dynamic multicast session provisioning. To evaluate the proposed algorithm, we apply the integer linear programming (ILP) optimization tool on a per multicast session basis to solve off-line the optimal routing and wavelength assignment given a multicast session and the current network topology as well as its residual network resource information. We formulate the per session multicast routing and wavelength assignment problem as an ILP. With this ILP formulation, the multicast session blocking probability or success probability can then be estimated based on solving a series of ILPs off-line. We have evaluated the effectiveness of the proposed online algorithm via simulation in terms of session blocking probability and network resources used by a session. Simulation results indicate that our proposed computationally efficient online algorithm performs well even when a fraction of the nodes are SaD nodes.     

新一代智能城域光网络

本提出了一种标准化的光控制平面。阐明了开了用于光传输网的控制平面所遇到的选择与挑战。光控制平面被分解成邻居发现、服务发现、连接控制和拓扑、资源发现等几个基本的过程。不同的网络组织和分割导致了几个不同的自动配置模型：软性持久链路模型、用户接口模型和对等模型。这是构成以IP为中心的光传输网的控制和管理基础。同时也介绍了基于SDH光交换的新一代CIENA公司智能光网络，它具有大容量光交换能力和网络拓扑结构自动发现、端对端电路配置、带宽动态分配等功能及特点，将大大提高数据、电路业务的服务质量，新一代智能光网络是干线和城域网络交换传输最佳的选择。     

云计算下基于CRP算法的资源提供策略

云计算资源管理系统是用于接收来自云计算用户的资源请求,并且把特定的资源封装为服务提供给资源请求者。在云计算环境下,如何为资源请求者选择合适的资源是一个值得研究的课题。文中通过对云计算下现有的资源提供策略的分析,同时根据不同云提供者提供的计算资源的成本不同的特点,综合考虑资源的计算能力、可靠性和单位成本三点因素,提出了云计算下基于CRP算法的资源提供策略。这种资源提供策略既能提供满足用户资源请求的服务,也能降低云服务提供者的运营成本,从而获得更大收益。     

基于势能导向多下一跳路由的服务承载网构建方法

服务承载网络是基于服务构建的以满足服务端到端QoS保障为出发点的覆盖网络,是满足可重构柔性网络对业务需求支撑的有效的网络架构。基于可重构柔性网络体系框架,分析服务承载网构建的主要问题,提出了可重构柔性网络下服务承载网的构建原则,在此基础上给出了基于势能导向多下一跳路由的服务承载网构建算法,并对其进行了性能分析及仿真。仿真结果表明,该算法具有较高的构建成功率。     

Resource-aware hybrid scheduling algorithm in heterogeneous distributed computing

Today, almost everyone is connected to the Internet and uses different Cloud solutions to store, deliver and process data. Cloud computing assembles large networks of virtualized services such as hardware and software resources. The new era in which ICT penetrated almost all domains (healthcare, aged-care, social assistance, surveillance, education, etc.) creates the need of new multimedia content-driven applications. These applications generate huge amount of data, require gathering, processing and then aggregation in a fault-tolerant, reliable and secure heterogeneous distributed system created by a mixture of Cloud systems (public/private), mobile devices networks, desktop-based clusters, etc. In this context dynamic resource provisioning for Big Data application scheduling became a challenge in modern systems. We proposed a resource-aware hybrid scheduling algorithm for different types of application: batch jobs and workflows. The proposed algorithm considers hierarchical clustering of the available resources into groups in the allocation phase. Task execution is performed in two phases: in the first, tasks are assigned to groups of resources and in the second phase, a classical scheduling algorithm is used for each group of resources. The proposed algorithm is suitable for Heterogeneous Distributed Computing, especially for modern High-Performance Computing (HPC) systems in which applications are modeled with various requirements (both IO and computational intensive), with accent on data from multimedia applications. We evaluate their performance in a realistic setting of CloudSim tool with respect to load-balancing, cost savings, dependency assurance for workflows and computational efficiency, and investigate the computing methods of these performance metrics at runtime.     

基于IEEE 802．16的QOS研究

在固定宽带接入系统中,如何为具有不同QOS要求的多种类型业务流提供服务质量(QOS)保证是一个很重要并且很有挑战性的课题。尽管IEEE 802.16 MAC协议支持对各种类型应用的QOS保证,但是它没有给出具体的流调度方案来实现QOS要求。要为各种应用提供不同级别的QOS并且保证较高的系统吞吐率,必须在此MAC协议中集成一个QOS架构。这篇论文针对应用于802.16 MAC协议中的QOS架构进行深入的讨论和研究。     

Web服务图及其在服务发现中的应用研究

Web服务是一种崭新的Web应用.随着Web 环境下服务数量的快速增长,要在海量的服务中发现所需的服务是非常耗时的.UDDI V2 增加了一个新特性publisherAssersion来描述UDDI注册中心里的商业实体间的关系,类似于网页之间的超链接,这样就产生了Web服务图.首先研究Web服务的新特征,然后提出并分析构建Web服务图的原理和算法,最后利用Web服务图进行服务发现.从仿真实验可看出提出的Web服务图对组合的Web服务发现是有效的.     

IP over ATM模型上集成服务的实现技术

文章对 Ｉｎｔｅｒｎｅｔ的集成服务和 ＡＴＭ的 ＱＯＳ要求进行了分析,并讨论了将基于 ＩＰ协议的 ＲＳＶＰ与 ＡＴＭ的 ＱＯＳ控制和管理相结合,以实现 Ｉｎｔｅｒｎｅｔ与 ＡＴＭ集成中的多业务 ＱＯＳ的主要技术。     

IPOA中服务优先权技术的实现

本文分析了Classical IP Over ATM的基本思想,提出并讨论了在IPOA中提供有保证的QOS服务的基本策略,主要阐述了多路复用策略和用户优先权方案。     

Equilibrium analysis through separation of user and network behavior

Internet complexity makes reasoning about traffic equilibrium difficult, partly because users react to congestion. This difficulty calls for an analytic technique that is simple, yet have enough details to capture user behavior and flexibly address a broad range of issues.This paper presents such a technique. It treats traffic equilibrium as a balance between an inflow controlled by users, and an outflow controlled by the network (link capacity, congestion avoidance, etc.). This decomposition is demonstrated with a surfing session model, and validated with a traffic trace and NS2 simulations.The technique’s accessibility and breadth are illustrated through an analysis of several issues concerning the location, stability, robustness and dynamics of traffic equilibrium.