Supporting dynamic access to virtualized data resources via WSRF-based services

Today grid applications require not only lots of computational power but data at a very large scale too. Although grid computing was initially conceptualized as the technology that focuses on solving compute-intensive problems, this focus has gradually shifted to applications where data is distributed over various locations. Access to these data resources stored in heterogeneous grid storage systems located at geographically distributed virtual organizations in an integrated and uniform way is a challenging problem. The Web Services Resource Framework (WSRF) has recently emerged as the standard for the development and integration of grid services. This paper proposes and presents Gravy4WS, a middleware architecture based on WSRF Web services that enables the dynamic access to virtualized grid data resources. A novel scheduling algorithm called DCE (Delegating-Cluster-Execution based Scheduling) is proposed to improve load balancing of the system. The implementation of Gravy4WS using WSRF libraries and services provided by Globus Toolkit 4 is described together with its performance evaluation.     

电信运营商环节中的信息网络安全

在互联网时代,"信息安全"问题已经引起世界上许多国家的高度重视。在我国互联网基础设施发展迅速,"网民"每年都以几何数增加,信息安全也成为一个亟待解决的问题。在实行"依法治国"的今天,这一问题的解决一方面必须靠法律手段和依靠运行商等环节。本文从运营商环节探讨如何促进信息网络的健康发展,并提出一些建议。     

基于Web服务的电信网络管理架构研究和实现*

为解决电信领域中异构网络管理系统间的动态协作问题,满足快速、高效地向客户提供综合业务和保证业务质量的需求,采用面向服务的思想并结合Web服务技术和技术无关体系结构(TNA)的原则,提出了基于Web服务的电信网络管理架构,并定义基于该架构的网络管理服务动态协作流程。通过原型系统对提出的电信网络管理架构进行了验证,该原型系统表明所定义的架构模型具有一定的有效性和适用性。     

Proactive workload management in dynamic virtualized environments

Recently, with the improvement of Cloud systems technologies and the essential advantages they can provide such as availability, scalability, and costs saving; massive domains in the IT industry are directing their business to the Cloud. To fit the computing demands of this trend along with nowadays fluky applications (e.g. social networks, media contents), Cloud systems require rapid resource changes. As a result, the workload management in a virtualized environment becomes a complex task. In this paper we propose a new proactive workload management model for virtualized resources to inspect the workload behavior of the running Virtual Machines, and to assent an appropriate scheduling and resource consolidation schema in order to improve the system efficiency, utilization, and throughput. We have carried out our model by modifying Xen Cloud Platform, then we tested the model performance through different representative benchmarks. The results show that the Proactive model can decrease the average response time remarkably.     

Optimal network locality in distributed virtualized data-centers

Cost efficiency is a key aspect in deploying distributed service in networks within decentralized service delivery architectures. In this paper, we address this aspect from an optimization and algorithmic standpoint. The research deals with the placement of service components to network sites, where the performance metric is the cost for acquiring components between the sites. The resulting optimization problem, which we refer to as the k-Component Multi-site Placement Problem, is applicable to service distribution in a wide range of communication networking scenarios. We provide a theoretical analysis of the problem’s computational complexity, and develop an integer programming model for providing reference results for performance benchmarking. On the algorithmic side, we present four approaches: an algorithm with approximation guarantee and three heuristics algorithms. The first heuristic is derived from graph theory on domatic partition. The second heuristic, built on intuition, admits distributed computation. The third heuristic emphasizes on fairness in cost distribution among the sites. We report simulation results for sets of networks where cost is represented by round-trip time (RTT) originating from real measurements. For small networks, the integer model is used to study algorithm performance in terms of optimality. Large networks are used to compare the algorithms relatively to each other. Among the algorithms, the heuristic based on intuition has close-to-optimal performance, and the fairness heuristic achieves a good balance between single-site cost and the overall one. In addition, the experiments demonstrate the significance of optimization for cost reduction in comparison to a the random allocation strategy.     

Toward an interoperable dynamic network analysis toolkit

To facilitate the analysis of real and simulated data on groups, organizations and societies, tools and measures are needed that can handle relational or network data that is multi-mode, multi-link and multi-time period in which nodes and edges have attributes with possible data errors and missing data. The integrated CASOS dynamic network analysis toolkit described in this paper is an interoperable set of scalable software tools. These tools form a toolchain that facilitate the dynamic extraction, analysis, visualization and reasoning about key actors, hidden groups, vulnerabilities and changes in such data at varying levels of fidelity. We present these tools and illustrate their capabilities using data collected from a series of 368 texts on an organizational system interfaced with covert networks in the Middle East.     

基于Web服务的ESB在电信网管中的应用研究

企业服务总线是在企业应用集成的基础上,为满足这一需求而提出的一个较好的解决思路.在介绍了基于Web服务的ESB技术之后,根据Web服务技术特点和ESB的基本功能要求,提出了该技术的一种嵌入式服务管理ESM（embedded setvices management）模型,并应用于电信网管系统中.阐述了基于该模型的网管系统的总体结构和业务系统之间的服务调用过程;最后通过实验,说明了该ESM模型应用于实际网管系统的可行性.     

The dynamic competitive recommendation algorithm in social network services

As the number of Twitter users exceeds 175 million and the scale of social network increases, it is facing with a challenge to how to help people find right people and information conveniently. For this purpose, current social network services are adopting personalized recommender systems. Existing recommendation algorithms largely depend on one of content-based algorithm, collaborative filtering, or influential ranking analysis. However, these algorithms tend to suffer from the performance fluctuation phenomenon in common whenever an active user changes, and it is due to the diversities of personal characteristics such as the local social graph size, the number of followers, or sparsity of profile content. To overcome this limitation and to provide consistent and stable recommendation in social networks, this study proposes the dynamic competitive recommendation algorithm based on the competition of multiple component algorithms. This study shows that it outperforms previous approaches through performance evaluation on actual Twitter dataset.     

An efficient and coordinated mapping algorithm in virtualized SDN networks

Software-defined networking (SDN) enables the network virtualization through SDN hypervisors to share the underlying physical SDN network among multiple logically isolated virtual SDN networks (vSDNs), each with its own controller. The vSDN embedding, which refers to mapping a number of vSDNs to the same substrate SDN network, is a key problem in the SDN virtualization environment. However, due to the distinctions of the SDN, such as the logically centralized controller and different virtualization technologies, most of the existing embedding algorithms cannot be applied directly to SDN virtualization. In this paper, we consider controller placement and virtual network embedding as a joint vSDN embedding problem, and formulate it into an integer linear programming with objectives of minimizing the embedding cost and the controller-to-switch delay for each vSDN. Moreover, we propose a novel online vSDN embedding algorithm called CO-vSDNE, which consists of a node mapping stage and a link mapping stage. In the node mapping stage, CO-vSDNE maps the controller and the virtual nodes to the substrate nodes on the basis of the controller-to-switch delay and takes into account the subsequent link mapping at the same time. In the link mapping stage, CO-vSDNE adopts the k-shortest path algorithm to map the virtual links. The evaluation results with simulation and Mininet emulation show that the proposed CO-vSDNE not only significantly increases the long-term revenue to the cost ratio and acceptance ratio while guaranteeing low average and maximum controller-to-switch delay, but also achieves good vSDN performance in terms of end-to-end delay and throughput.     

A network flow based approach for network selection in dynamic spectrum access networks

In this paper, we present a network flow based approach for dynamic network and channel selection for secondary users in dynamic spectrum access networks. Most approaches in the current literature on dynamic spectrum access networks do not consider dynamic network and channel selection. We present a network flow framework for network selection. We show that our approach can enable re-assignment of networks to secondary users and also re-assignment of channels to secondary users within the same network. The assignments and re-assignments take into account, the interference caused to primary users, the price each secondary user is willing to pay and the quality of service (QoS) obtained by each secondary user. We obtain a bound for the maximum number of re-assignments.     

Toward in vivo nanoscale communication networks: utilizing an active network architecture

A safe and reliable in vivo nanoscale communication network will be of great benefit for medical diagnosis and monitoring as well as medical implant communication. This review article provides a brief introduction to nanoscale and molecular networking in general and provides opinions on the role of active networking for in vivo nanoscale information transport. While there are many in vivo communication mechanisms that can be leveraged, for example, forms of cell signaling, gap junctions, calcium and ion signaling, and circulatory borne communication, this review examines two in particular: molecular motor transport and neuronal information communication. Molecular motors transport molecules representing information and neural coding operates by means of the action potential; these mechanisms are reviewed within the theoretical framework of an active network. This review suggests that an active networking paradigm is necessary at the nanoscale along with a new communication constraint, namely, minimizing the communication impact upon the living environment. The goal is to assemble efficient nanoscale and molecular communication channels while minimizing disruption to the host organism.     

"网络好,服务更好"——上海电信致力创服务名牌

上海电信近几年来,先后获得了“全国质量效益先进单位”、“全国精神文明创建活动示范点”、“全国思想政治工作优秀企业”、“全国职业道德建设先进单位”,2001年度,上海市电信公司又荣获“全国五一劳动奖章”、“全国用户满意服务企业”和“上海市首批服务质量金奖”等荣誉称号。公司的经营管理、经济效益、通信质量、安全生产、服务工作均居全国同行业先进水平。 上海电信上下一心、坚定信心、全力拼搏,以“用户至上、用心服务”的理念,树立了“网络好、服务更好”的形象。 目前,上海电信正以与时俱进的思想,深入开展对服务工作的研究,在提供优质服务方面大力进行创新。上海电信本着以用户为中心、以市场为导向、用户满意为标准、用心服务的原则,从提高服务水平出发,将通过加强内部管理,在以下几方面做得更好:服务态度更好;服务环境更佳;服务质量更优;服务效率更高;服务内容更实。     

A QoS-based dynamic pricing approach for services provisioning in heterogeneous wireless access networks

In this paper we propose a simple QoS-based dynamic pricing approach for services provisioning in a heterogeneous wireless access network environment which attempts to increase user’s satisfaction level by firstly, maximizing the provided QoS level, and secondly, by applying dynamic pricing strategies according to the QoS. These strategies will allow service providers to maximize their profits. Simulation results demonstrate that the proposed dynamic pricing approach benefits both users and wireless service providers (WSPs). Results also suggest that users have better overall satisfaction due to a better QoS level and fairer prices. The analysis shows that our proposed pricing approach contributes to an increase in WSPs profits compared to the application of the flat-rate pricing model in a competitive market-model.     

Transport network design of integrated networks with real-time dynamic routing

Integrated real-time dynamic routing (IRR) networks provide dynamic routing features for multiple classes-of-service on an integrated transport network. In a previous Journal paper it is shown that IRR networks allow reduced network management costs since with real-time dynamic routing a number of network operations are simplified or eliminated, leading to savings in operations costs and expenses. In this paper a new algorithm is described for the transport design of IRR networks which achieves near-optimal capacity engineering. In particular, a Karmarkar Algorithm optimal solution to the linear programming flow model achieves approximately a 5 to 8 percentage point reduction in network design cost in comparison to the designs of pre-planned dynamic networks solved with heuristic design techniques. The optimization techniques described in this and the previous Journal paper attain significant capital cost reductions and network performance improvements by properly modeling the more efficient operation of IRR networks.     

Effects of dynamic isolation for full virtualized RTOS and GPOS guests

Industrial systems currently include not only control processing with real-time operating system (RTOS) but also information processing with general-purpose operating system (GPOS). Multicore-based virtualization is an attractive option to provide consolidated environment when GPOS and RTOS are put in service on a single hardware platform. Researches on this technology have predominantly focused on the schedulability of RTOS virtual machines (VMs) by completely dedicated physical-CPUs (pCPUs) but have rarely considered parallelism or the throughput of the GPOS. However, it is also important that the multicore-based hypervisor adaptively selects pCPU assignment policy to efficiently manage resources in modern industrial systems. In this paper, we report our study on the effects of dynamic isolation when two mixed criticality systems are working on one platform. Based on our investigation of mutual interferences between RTOS VMs and GPOS VMs, we found explicit effects of dynamic isolation by special events. While maintaining low RTOS VMs scheduling latency, a hypervisor should manage pCPUs assignment by event-driven and threshold-based strategies to improve the throughput of GPOS VMs. Furthermore, we deal with implicit negative effects of dynamic isolation caused by the synchronization inside a GPOS VM, then propose a process of urgent boosting with dynamic isolation. All our methods are implemented in a real hypervisor, KVM. In experimental evaluation with benchmarks and an automotive digital cluster application, we analyzed that proposed dynamic isolation guarantees soft real-time operations for RTOS tasks while improving the throughput of GPOS tasks on a virtualized multicore system.     

Energy-efficient dynamic resource allocation with opportunistic network coding in OFDMA relay networks

Network coding is significantly able to save system resources for wireless networks, and has been widely studied for the 802.11 wireless local area network and traditional cellular networks. The relay technology was introduced in 802.16j, 802.16m, and Long Term Evolution-Advanced (LTE-A) standards. Recently, the application of network coding to multi-hop wireless relay networks has been taken into consideration. Although the introduction of relay stations (RSs) may bring more energy consumption, it provides opportunities for network coding to save spectrum resources. Nevertheless, the benefits of network coding are diminished by high multiuser diversity based on orthogonal frequency division multiple access (OFDMA). For ensuring the superiority, network coding is performed opportunistically according to the channel state. Hence dynamic resource allocation (DRA) subject to rate constraints is combined with the idea of opportunistic network coding to minimize the total transmission power in a frame. A fixed set of discrete modulation levels in an OFDMA relay system is also considered. By taking the characteristic of a half-duplex decode-and-forward (DF) mode relay, a solution is proposed for the optimal problem of each subframe after separating power-aware relay selection. Simulation results show that DRA with opportunistic network coding can improve system energy efficiency. Further, it is more efficient for saving energy than DRA with static network coding compared solely to DRA.     

Delivering relative differentiated services in future high-speed networks using hierarchical dynamic deficit round robin

With the increasing deployment of real-time audio/video services over the Internet, provision of quality of service (QoS) has attracted much attention. When the line rate of future networks upgrades to multi-terabits per second, if routers/switches intend to deliver differentiated services through packet scheduling, the reduction of computational overhead and elimination of bottleneck resulting from memory latency will both become important factors. In addition, the decrease of average queueing delay and provision of small delays for short packets are two further critical factors influencing the delivery of better QoS for real-time applications. The advanced waiting time priority (AWTP) is a timestamp-based packet scheduler which is enhanced from the well-known WTP. Although AWTP considers the effect of packet size, the latency resulting from timestamp access and a great quantity of computational overhead may result in bottlenecks for AWTP being deployed over high-speed links. Many existing schedulers have the same problems. We propose a multi-level hierarchical dynamic deficit round-robin (MLHDDRR) scheduling scheme which is enhanced from the existing dynamic deficit round-robin scheduler. The new scheme can resolve these issues and efficiently provide relative differentiated services under a variety of load conditions. Besides, MLHDDRR can also protect the highest priority traffic from significant performance degradation due to bursts of low-priority traffic. We compare the performance of AWTP with the proposed scheme. Extensive simulation results and complexity analysis are presented to illustrate the effectiveness and efficiency of MLHDDRR.     

面向电信行业网络告警系统的告警过滤算法

为了减小电信网络中海量告警数据对的告警根源分析所造成的干扰,提出一种告警过滤算法。首先,基于电信网络告警数据对告警量分布、告警持续时间等特征进行量化分析,提出告警影响力和高频瞬态告警概念。在此基础上,从告警量、平均告警时间、告警影响力以及告警实例持续时间四个维度对告警重要程度进行综合分析,并提出复杂度为O（n）（n为告警记录数）的告警过滤算法。单因素实验分析显示,告警压缩比与特定告警元的告警量、平均告警时间、告警影响力以及告警实例持续时间具有正相关关系。对比实验结果表明,在相似告警压缩比下,所提算法的准确性比FTD（Flexible Transient flapping Determination）算法最多提高18个百分点,可用于电信行业的告警数据样本分析以及在线告警过滤。     

数据流处理技术在电信网管系统中的应用

网络流量监测技术是电信运营商所关注的重点之一。随着网络传输带宽的不断增加,传统的基于磁盘的处理技术已经不能够满足运营管理的需要,数据流处理技术的出现为网络流量监测应用提供了一种新的解决方案。SMART[1,2]和RealMon[3]是将数据流处理技术应用于网络流量监测的两个应用系统。文中结合上海电信在骨干网流量监测上的应用需求,对这两个系统的设计与应用进行了介绍。SMART系统以数据流上的频繁项挖掘算法为基础,支持NetFlow数据流上长时间滑动窗口内的Top-K查询,实现了对网络流量分布的实时监测。RealMon系统采用数据流上的降维分析算法对SNMP数据流进行分析,通过监测网络链路上不同流量数据的相关性变化来发现异常流量。实验和在真实环境中的应用表明,SMART和RealMon系统能够满足骨干网流量监测应用的需要,并且极大地提高了监测系统的性能。