共查询到15条相似文献,搜索用时 125 毫秒
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文章提出一种基于移动代理和光突发交换(OBS)的光链路信令建立方法和协议方案.将主动包的结构应用于移动代理,使信令消息和数据流概括到一个突发包头(BHP)中,以此来缩短一个光路的建立时间.该方案可以实现分布式处理链路,以减轻网络中一个节点的工作量和加强每个网络节点的并行运算能力. 相似文献
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GMPLS(通用多协议标签交换)是MPLS技术向光网络发展的产物。描述GMPLS和MPLS控制平台的区别,介绍引用GMPLS协议作为控制平面的OBS网络。提出的网络结构是在OBS的突发控制包中用通用标签代替源节点和目的节点地址,并使用GMPLS协议栈对路由协议、信令功能以及链路管理协议进行增强和扩展以便更好地支持OBS网络。 相似文献
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针对光突发交换(OBS)网络中已有的包括抢占和波长分离等服务质量(QoS)保证机制的不足,提出了一种改进的基于QoS的标签交换路径共享(QLS)算法。算法通过链路波长资源的统计复用,在保证高优先级业务传送的可靠性和有效性的同时,提升低优先级业务的QoS性能。使用开源离散事件仿真软件OMNeT++搭建了OBS/GMPLS仿真平台,对4×4对称型MESH网络和NSFNET网络分别采用WP算法和QLS算法进行了仿真。结果表明,QLS算法对于高QoS等级业务性能影响极小,MESH和NSFNET网络中class3业务的丢包率分别减少了近0.2和0.3,平均丢包率分别减少了约0.05和0.1。 相似文献
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在通用多协议标记交换协议(GMPLS)控制面体系结构下,OBS网络组播的实现面临着一些技术问题.首先分析并解决了其中两个关键问题,即IP组播树与组播标记交换路径(LSP),以及组播LSP与光树间的映射问题;然后提出了支持组播的OBS边缘节点与核心节点的功能模型;并在OPNET仿真环境下,设计和开发了节点仿真模块,验证了OBS组播功能.仿真结果表明:在基于GMPLS的OBS网络体系结构下,光组播树建立时间普遍较短,而且在实现方式上,与光路相比,光树型方式具有较高的链路利用率. 相似文献
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作为下一代互联网关键技术之一的光突发交换(OBS)技术已经受到业界的广泛关注.但是在网络中还需要一个成熟的控制面技术支持,为此提出了了基于GMPLS控制面的OBS网络体系,并对GMPLS体系结构的关键技术进行了介绍. 相似文献
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GMPLS技术的提出代表了人们对下一代网络的期待,也代表了未来网络向简化层次和广泛融合的趋势,同时也是IP化向光传输领域的真正迈进。通过GMPLS,运营商可以在提高网络资源利用效率的同时大幅降低运营成本,并可以提供多样化的业务来开辟新的利润来源,因而受到了广大运营商的关注。前一篇文章深入浅出地介绍了GMPLS的工作原理,并从资源的利用、业务提供、流量控制、故障保护恢复、带宽分配、SLA服务等方面进行了GMPLS优势的介绍。后一篇文章主要针对GMPLS链路的保护与恢复技术进行了详细讨论。 相似文献
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Network dimensioning should be progressed for pursuing the ultimate efficiency of network system resources in order to satisfy
target performance. This article studies node dimensioning as a method of resource optimization in optical burst switching
(OBS) networks. OBS is a new switching technology for pursuing bufferless transparent optical networks by sending control
packets prior to data burst in order to provision resources for the burst. However, the basic assumption of a bufferless node
implies burst contention at a core node when more than two bursts attempt to move forward the same output simultaneously.
Thus, burst contention is a critical performance metric and this article takes it into account as a constraint on node dimensioning
and target performance. In this article, we first present node dimensioning issues for OBS networks. Two constraints from
the transport plane and the control plane which affect burst contention are then introduced. The effect of the burst assembly
process on node dimensioning is also presented. From numerical analysis, the optimal number of wavelengths in a link, which
provides the lowest blocking probability, is obtained to suggest a guideline for node dimensioning. 相似文献
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Because pure electrical routers with their bandwidth limitations can hardly keep up with the tremendous traffic growth in the Internet, optical routers based on various optical switching techniques including optical wavelength switching (OWS), optical burst switching (OBS), and optical packet switching (OPS) have been suggested to cope with this problem. However, because OBS and OPS are both in their early experimental phase and OWS only provides coarse granularity switching, a hybrid-switching optical router with combined OWS and electrical packet switching is a necessity in order to accommodate the entire multi-granularity traffic with multi-service requirements in a cost-effective manner. Its coordination capability of optical circuit switching and electrical packet switching enables efficient/intelligent usage of network resources. In this paper, we first review research and developments of such IP routers employing optical switching/interconnection techniques and examine how these techniques can be used inside routers to scale node capacity and to improve optical Internet performance. We also present and study the performance of a terabit optical router with an optical-electrical hybrid-switching fabric. The node architecture is based on the idea of IP over WDM integration with Generalized Multi-Protocol Label Switching (GMPLS). The network-level performance evaluations show that the proposed hybrid-switching optical router is a cost-effective solution for building the next generation GMPLS-based multi-granularity optical Internet. 相似文献
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Efficient multiple-token-based MAC protocols have been proposed for optical burst-switched (OBS) unidirectional ring networks
using a TT-TR-based node architecture in our previous research. However, the unidirectional OBS ring network is difficult to scale to larger
networks. As wavelengths accessibilities are dominated by tokens, network performance is restricted by the frequency of capturing
a token. If the network is too large, it takes a long time for tokens to rotate. Thus, a destination queue may wait for a
long time to be served, which results in large queuing delays and inefficiency of network resource utilization. In order to
improve network efficiency and scalability for OBS ring networks using multiple tokens, this work is extended to a bidirectional
ring system that uses the tunable transmitter and tunable receiver (TT-TR)-based node architecture with two pairs of transceivers, so that each queue can be served by tokens from both directions.
Furthermore, two kinds of node architectures differing in sharing the two pairs of transceivers, either shared or not, are
proposed. Then, two MAC protocols considering different queue scheduling algorithms are proposed for the ring network using
the proposed node architectures, in order to use the network resources more efficiently. They are improved from general round-robin
(GRR) and termed as half-ring round-robin (HfRR) and co-work round-robin (CoRR), respectively. The network performance of
the two proposed node architectures and the two proposed MAC protocols for the networks using them as well as the network
scalability are evaluated with the OPNET simulator. 相似文献
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OBS网络中的多BHP延迟调度算法 总被引:2,自引:0,他引:2
光突发交换 (Optical Burst Switching,OBS) 是下一代光网络中的有效核心交换技术之一。在OBS网络中,核心节点的调度方案是影响网络交换性能的重要因素。如何有效地对突发分组 (Burst) 进行合理调度,以减少丢包率正是关键问题所在。该文提出了一种多控制分组 (Burst Header Packet,BHP) 延迟调度算法,对于一个收集周期内到达的多个BHP所对应的突发数据,按照一定的方式对它们进行集中调度,实现对已预约资源的更改,使调度结果得到了优化。该算法根据不同的网络应用,可细化为4种具体的算法实现,以适用于不同的应用场景。仿真结果表明,该文提出的调度算法和已有算法相比,能够优化对突发分组的调度,提高对信道资源的有效使用,从而降低交换网络的丢包率。 相似文献
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OBS网络中一种基于突发包优先级分割的可控重传方案 总被引:2,自引:2,他引:0
在光突发交换(OBS)网络中,突发包会由于竞争OBS核心节点输出端口的有限波长资源而发生冲突。突发包重传能够在一定程度上减少由于突发包在核心节点冲突而导致的数据损失,但重传次数的增加可能会加重网络负荷,反而增加数据丢失率。并且,在多业务存在的OBS网络中,重传方案需要能够实现区分服务以保证网络的服务质量(QoS)。据此,本文提出一种基于突发包优先级分割的可控重传方案,在实施优先级分割的同时,根据网络负荷赋予每次重传不同的概率,并对重传次数加以控制。最后,仿真分析了路径阻塞率和不同优先级业务的字节丢失率(ByLP,byte loss probability)性能。 相似文献