Scalable Quasi‐Dynamic‐Provisioning‐Based Admission Control Mechanism in Differentiated Service Networks

The architecture in a differentiated services (DiffServ) network is based on a simple model that applies a per‐class service in the core node of the network. However, because the network behavior is simple, the network structure and provisioning is complicated. If a service provider wants dynamic provisioning or a better bandwidth guarantee, the differentiated services network must use a signaling protocol with QoS parameters or an admission control method. Unfortunately, these methods increase the complexity. To overcome the problems with complexity, we investigated scalable dynamic provisioning for admission control in DiffServ networks. We propose a new scalable qDPM² mechanism based on a centralized bandwidth broker and distributed measurement‐based admission control and movable boundary bandwidth management to support heterogeneous QoS requirements in DiffServ networks.     

Failure-aware resource provisioning for hybrid Cloud infrastructure

Hybrid Cloud computing is receiving increasing attention in recent days. In order to realize the full potential of the hybrid Cloud platform, an architectural framework for efficiently coupling public and private Clouds is necessary. As resource failures due to the increasing functionality and complexity of hybrid Cloud computing are inevitable, a failure-aware resource provisioning algorithm that is capable of attending to the end-users quality of service (QoS) requirements is paramount. In this paper, we propose a scalable hybrid Cloud infrastructure as well as resource provisioning policies to assure QoS targets of the users. The proposed policies take into account the workload model and the failure correlations to redirect users’ requests to the appropriate Cloud providers. Using real failure traces and a workload model, we evaluate the proposed resource provisioning policies to demonstrate their performance, cost as well as performance–cost efficiency. Simulation results reveal that in a realistic working condition while adopting user estimates for the requests in the provisioning policies, we are able to improve the users’ QoS about 32% in terms of deadline violation rate and 57% in terms of slowdown with a limited cost on a public Cloud.     

Estimating the performance of intelligent transport systems wireless services for multimodal logistics applications

Various wireless technologies including radio frequency identification (RFID), bluetooth, cellular networks and dedicated short range communications (DSRC) might have an impact on logistics and transport operations. Among them, DSRC stands out as a broadband communications technology which has been designed to provide a general purpose Radio-Frequency (RF) link between vehicles and network infrastructure. As such, DSRC is capable of implementing the physical layer of an Internet Protocol (IP) bearer based network designed to facilitate the monitoring and coordination of portside vehicular traffic. This unprecedented application of wireless networking has the potential to greatly enhance the management of the flow of goods and resources, particularly within large, international ports whose activities comprise multimodal operations such as the use of road haulage to move cargo transported by sea. Given the need for reliable services in non-safety business applications, in this work an Intelligent Transport Systems (ITS) approach is used to address two issues. First, in wireless networks reliable data transfer transport layer services are affected where there is an apparent increase in mobility when access point coverage areas are reduced to counter the effects of path loss in the physical layer. Second, a service provisioning protocol intended for vehicle to infrastructure (V2I) data transfer is proposed to illustrate the importance of cumulative costs in wireless networks used for logistics applications. The analysis covers the average response time for requesting on-demand services within the portside network considered. The results of the analysis confirm the suitability of the approach used to provide a logistics network capable of meeting the requirements demanded in multimodal logistics.     

An Enquiry-Based Dynamic Service Provisioning Approach for Overlay IP-over-Optical Networks

Network control for IP-over-optical networks can be classified as falling under the overlay, augmented, or peer models. In the first two models, the IP layer and the optical layer only have the resource information of their respective layers. In the peer model, all the resource information is known to both layers; hence, it can potentially achieve better resource utilization. Unfortunately, the peer model approach is generally not acceptable to the operators if the IP layer and optical layer belong to two different administrations. In addition, it is much more complex and generally seen as not feasible in the near future In this paper, we propose an enquiry-based provisioning scheme based on the overlay model which can, however, utilize resources in both layers as in the peer model approach. Two simple and novel algorithms for routing labeled-switched path (LSP) requests for this provisioning scheme are proposed. Simulation results show that our proposed algorithms perform significantly better than other routing algorithms for the overlay model and are nearly as good as the integrated routing algorithm for the peer model.     

一种提升自动精简配置效能的方法研究

当前云存储已经成为IT领域的焦点,并在电信以及流媒体等领域有着广泛需求,自动精简配置是一种先进的存储虚拟化技术,能够提高存储空间的使用效率,简化存储基础架构,满足云储存基础架构设施的需要。针对当前自动精简配置存在效能低下的问题,以流媒体行业为应用背景,没计并实现I_THINP自动精简配置系统。采用模块化、分层的设计思想,将文件系统、通用块设备、iSCSI模块、精简池模块有机结合,整体提升自动精简配置的空间使用效率,并降低空间回收对系统性能的负面影响。实验结果表明,与现有主流自动精简产品相比,I_THINP自动精简配置系统的空间回收效率在97%以上、每秒处理的I/O请求数量下降16.53%、I/O平均响应时间下降22.82%,证明I_THINP自动精简配置系统在效能方面达到业界先进水平。     

基于策略路由的高校校园网络多出口配置

由于不同网络运营商之间的互联互通问题,造成网络用户访问接入在不同运营商线路上的服务器资源时,速度大受影响,甚至无法访问。为满足高校校园网络用户能利用校园网线路访问校外资源信息的速度能达到要求,实现资源共享的目的,提出基于策略路由的网络多出口配置方案,以解决网络出口数据按不同的访问目标途经不同的线路,实现各行其道,一方面提高网络的访问速度,另一方面提高网络的安全性。     

Dynamic address resolution for enhanced configurability in packet-based TDMA GPONs

Packet-oriented PONs will offer an efficient way to transfer IP traffic, providing at the same time flexible Quality of Service mechanisms to support a great variety of services. To allow provisioning of connections from customer sites to ISP sub-networks across packet-based PONs, it is necessary to correlate the Ethernet MAC address used in the customer terminals to the ISP interfaces and the MAC addresses used in the shared PON system. Automatic address resolution mechanisms are needed to allow for automatic dynamic reconfiguration without manual intervention. The address resolution mechanism impacts on the design of the MAC local address since it should allow for identification of the client interfaces on both ends of the PON. This paper investigates the relevant issues and proposes a solution extending the widely used address resolution protocol.     

Modeling and Performance Evaluation of 3G CDMA Networks with Beamforming

The second generation (2G) code-division multiple access (CDMA) IS-95A cellular network has been deployed for almost ten years. Although the system design rules and operating procedures for voice services are well established and understood, these rules and procedures need to be re-examined in light of several technology innovations. These innovations include the launch of third generation (3G) cdma2000 1× high-rate data services and the new research results in interference cancellation, antenna array and multiple-input multiple-output (MIMO) technologies.We have built a 3G cdma2000 1× cellular simulator, which simulates the physical layer using MATLAB and networking layers using OPNET Modeler, to investigate various design issues of cdma2000 1× networks. This paper explores the use of a simple beamforming model and investigates the effectiveness of deploying antenna array techniques in cdma2000 1× networks. The capacity improvement for CDMA networks using antenna array techniques is evaluated under different deployment scenarios (voice versus data services and various number of antenna elements). Based on the performance evaluation results it is proposed to utilize beamforming as one of the elements in quality of service (QOS) provisioning for data services and to couple antenna arrays with dynamic soft handoff threshold adjustment for further improvement in the system capacity.This paper was presented in part at IEEE 60th Vehicular Technology Conference (VTC), Los Angeles, CA, USA, Sep. 26–29, 2004.     

Multi-tiered service survivability in next-generation SONET/SDH networks

Rapid advances in next-generation SONET/ SDH and optical switching technologies along with dynamic generalized multi-protocol label switching control architectures have enabled many new service provisioning paradigms. In particular, a key addition is the new virtual concatenation feature that allows for inverse multiplexing of connection demands across SONET/SDH domains. This paper presents a novel tiered survivability scheme that leverages this feature to support multiple levels of service survivability and higher load carrying capability and service resiliency. Detailed simulation performance analysis results are also presented along with conclusions and directions for future work.