共查询到19条相似文献,搜索用时 109 毫秒
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光突发交换研究综述与应用展望 总被引:5,自引:1,他引:4
介绍了OBS概念与网络结构,总结了国内外研究OBS的热点问题,给出实现OBS的关键技术与方法。通过讨论OBS在Grid网络环境中的潜在应用,给出了相应的模型结构。最后对光突发交换的发展前景做了初步展望。 相似文献
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业务驱动的光子网格关键技术研究 总被引:2,自引:0,他引:2
通过对光子网格资源管理新机制、光子网格中间件和光子网格用户网络接口等关键技术的研究,建立业务驱动的光资源动态调度方法,给出大块数据传输及视频点播(VOD)服务在可控光路与基于OBS的网格(Grid over OBS)模式下的业务应用模式。理论与实验证明业务驱动的光子网格关键技术的实现,使得光子网格能很好地为密集数据业务服务。 相似文献
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在无缓存的全光OBS网络中由于相互竞争而被丢弃的数据突发是造成其高丢包率的主要原因,而分组调度策略可以从整体上改善OBS网络的这种缺点。本文建立了一种改进的分组调度映射模型,并提出了一种基于完全图的分组调度算法,该算法相对简单且容易实现,能够较好地解决OBS网络中由于数据突发的无序竞争所致的丢包问题,从而进一步提高网络的服务质量及其信道利用率。 相似文献
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讨论了OBS网络管理的需求和网管信令的传输方式,并且提出了基于SNMP的OBS网络管理体系结构及相关网管软件的设计方案。 相似文献
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光突发交换(OBS)网络的城域网应用需要解决与接入网的互连问题。针对基于集成节点的PON与OBS网络互连方案,研究了集成节点的功能与组成结构,分析了模块之间的信息交互,给出了集成节点结构的一种设计方案,并简单讨论了基于这一方案的汇聚机制和动态带宽分配算法。 相似文献
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光突发交换网络中的闭环竞争解析 总被引:2,自引:0,他引:2
为改善光突发交换网络(OBS)的性能,深入探讨了光突发交换网络中的闭环竞争解析,提出了OBS网络中的主动资源预留方案OBS—RED和显式竞争通知方案OBS—ECN。OBS—RED采用随机早期丢弃策略,即根据数据信道拥塞情况,随机早期地丢弃控制分组。OBS—ECN的实现需要OBS—RED的支持。在OBS—ECN中,不是随机丢弃控制分组,而是将这一信息显式地通知边缘节点,边缘节点再作相应的处理。OBS—RED与OBS—ECN的应用,有利于提高网络吞吐量和链路带宽资源利用率,大大减少数据突发的阻塞概率。 相似文献
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《Optical Switching and Networking》2008,5(2-3):94-106
This paper presents some instantiations of novel application-aware network architectures for emerging IT services and future Internet applications. It proposes and analyses network architectures where the Control and Service Planes are closely and seamlessly interacting with the applications. One instantiation, the Grid-GMPLS (G2MPLS, as defined by the Phosphorus project) is presented, which implements the Network Control Plane (NCP) architecture for the support of Grid Network Services (GNS). The GNS allows the provisioning of network and HPC/Grid resources in a single-step through a set of seamlessly integrated procedures. In a second example of instantiation, a quite popular application in signalling, i.e. the Session Initiation Protocol (SIP), is integrated with the Optical Burst Switched (OBS) network technology. The SIP-enabled OBS network can be used to manage application sessions and provide network and IT services according to application requirements. This paper investigates the requirements that these new integrated architectures impose on supporting network Control and Service Planes, and technologies, and discusses their possible implementations. 相似文献
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Biao Chen Jianping Wang 《Selected Areas in Communications, IEEE Journal on》2003,21(7):1071-1080
One promising switching technology for wavelength-division multiplexing optical networks is optical burst switching (OBS). However, there are major deficiencies of OBS. (1) The delay offset between a control message and its corresponding data burst is based on the diameter of a network. This affects network efficiency, quality-of-service, and network scalability.( 2) OBS adopts one-way resource reservation scheme, which causes frequent burst collision and, thus, burst loss. We address the above two important issues in OBS. In particular, we study how to improve the performance of delay and loss in OBS. To reduce the end-to-end delay, we propose a hybrid switching scheme. The hybrid switching is a combination of lightpath switching and OBS switching. A virtual topology design algorithm based on simulated annealing to minimize the longest shortest path through the virtual topology is presented. To minimize burst collision and loss, we propose a new routing algorithm, namely, p-routing, for OBS network. The p-routing is based on the wavelength available probability. A path that has higher available probability is less likely to drop bursts due to collision. The probability-based p-routing can reduce the volatility, randomness, and uncertainty of one-way resource reservation. Our studies show that hybrid switching and p-routing are complementary and both can dramatically improve the performance of OBS networks. 相似文献
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光突发交换是光路交换和光分组交换的一个有效折衷方案,避免了两者的缺点,能很好的适应未来业务量爆炸式增长及业务的多样性和多变性的要求。光虚拟专用网业务使得企业能够在公网内部灵活地组建自己的网络拓扑,避免支出建设专用网络的学生费用,同时使得运营商优化带宽的利用率,通过较少的投资获得更多的商业机会从而增加收入,把OBS技术应用于OVPN网络将使其具有更大的灵活性,安全性和可扩展性。这里介绍了OBS原理和功能,阐述了OVPN体系结构及参考模型,对采用OBS技术组建动态OVPN进行了探讨性研究。 相似文献
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基于对象存储的Lustre文件系统的研究 总被引:1,自引:0,他引:1
随着高性能计算网络集群系统的高速发展,传统的网络存储架构——网络附加存储NAS和存储区域网SAN已越来越不能够满足系统对存储性能的要求。针对SAN和NAS的不足,新一代的网络存储技术——基于对象存储OBS成为了研究的热点。重点论述了基于对象存储的架构和特点,并针对基于对象存储的Luster文件系统进行了初步测试,通过和传统的NFS文件系统对比,分析了对象存储文件系统在可扩展性、性能、易用性和安全性等方面的优越性能。 相似文献
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Qiong Zhang Neal Charbonneau Vinod M. Vokkarane Jason P. Jue 《Photonic Network Communications》2011,22(3):299-312
For optical burst-switched (OBS) networks in which TCP is implemented at a higher layer, the loss of bursts can lead to serious
degradation of TCP performance. Due to the bufferless nature of OBS, random burst losses may occur, even at low traffic loads.
Consequently, these random burst losses may be mistakenly interpreted by the TCP layer as congestion in the network. The TCP
sender will then trigger congestion control mechanisms, thereby reducing TCP throughput unnecessarily. In this paper, we introduce
a controlled retransmission scheme in which the bursts lost due to contention in the OBS network are retransmitted at the
OBS layer. The OBS retransmission scheme can reduce the burst loss probability in the OBS core network. Also, the OBS retransmission
scheme can reduce the probability that the TCP layer falsely detects congestion, thereby improving the TCP throughput. We
develop an analytical model for evaluating the burst loss probability in an OBS network that uses a retransmission scheme,
and we also analyze TCP throughput when the OBS layer implements burst retransmission. We develop a simulation model to validate
the analytical results. Simulation and analytical results show that an OBS layer with controlled burst retransmission provides
up to two to three orders of magnitude improvement in TCP throughput over an OBS layer without burst retransmission. This
significant improvement is primarily because the TCP layer triggers fewer time-outs when the OBS retransmission scheme is
used. 相似文献
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基于保护资源的混合光交换网络 总被引:1,自引:1,他引:0
提出一种基于保护资源的混合光交换方案P_HyLABS。该方案利用光电路交换(OCS)网络中的保护资源(波长信道),构建光突发交换(OBS)网络层,与OCS工作光路组成的OCS网络层一起,组成OCS/OBS混合交换网络。仿真结果表明,由于将OCS传送的电路交换的优势与OBS传送的统计复用能力进行了较好的结合,与单一的OCS网络和OBS网络相比,P_HyLABS混合交换在保证数据高效传输的同时,可应对呈高突发性的数据传送,在多失效的网络环境下也能部分恢复数据传送。 相似文献
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In this article, we study the blocking probability in a wavelength division multiplexing (WDM) based asynchronous bufferless
optical burst switched (OBS) network, equipped with a bank of wavelength converters. Our analysis encloses two wavelength
reservation schemes JIT (just-in-time) and JET (just-enough-time), and two-class data rate. The contribution of our work includes:
(i) derivation of an accurate model for blocking probability of lower priority bursts in case of a non-preempted model; (ii) provision of the analytical model for blocking probability calculation in the OBS network, which includes these
variables: two signaling schemes, partial wavelength conversion, two-class data, traffic intensity, cross-connect speed, number
of wavelengths in WDM fiber, number of fibers in the node, number of wavelength converters, and number of nodes in the path;
(iii) simulation results, which show that partial wavelength conversion provide quite satisfactory quality of service. We
compare performance in a single OBS node, under various sets of parameter values. The OBS network shows great flexibility
in terms of used multiclass data, and there is no dependence on the used higher layer protocol. 相似文献