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抗毁WDM网中单SRLG故障的共享子通路保护 总被引:3,自引:0,他引:3
该文针对抗毁WDM网中单个共享风险链路组(Shared Risk Link Group,SRLG)故障,提出了一种动态共享子通路保护(Dynamic Shared Sub-Path Protection,DSSPP)算法.DSSPP为每条业务请求选择一条工作通路后,按照参数m把工作通路划分成若干条等长的子通路,其中m为子通路的长度,并为每条子通路各选择一条SRLG分离的保护通路.如果两条子通路SRLG分离,则它们对应的保护通路可以共享相同资源.在进行路由选择时,DSSPP考虑了负载均衡度和资源共享度,因此能有效地提高资源利用率和降低业务阻塞率.仿真表明,DSSPP不仅能保护单SRLG故障,而且能灵活地在资源利用率(阻塞率)和保护切换时间之间进行性能折衷. 相似文献
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本文研究了网状WDM网中的SRLG(Shared Risk Link Groups:共享风险链路组)分离约束下的静态共享通路保护设计问题-给定网络物理拓扑、业务量需求矩阵和工作路由,为每个波长需求确定保护路由,使得所需的备份资源最小.这个问题可以用整数线形规划公式来描述.由于这是一个NP-C问题,因此,本文提出一种启发式算法MSC(Maximally Share the Capacity)加以解决,该算法的核心思想是改变链路权重使得保护路由之间尽量共享资源.仿真结果表明,本文算法能有效地降低所需的备份资源,提高了网络的资源利用率. 相似文献
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基于共享风险链路组(SRLG,shared risk link group)和P圈(P-Cycles,pre-configured cycles)的概念,研究了SRLG约束下p-Cycles的构造问题,引入SRLG完全分离p-Cycles的概念,基于SRLG的简单p-Cycles构造算法和获得更多p-Cycles的SRLG约束下的圈扩展算法提出的SRLG约束下的p-Cycles配置算法(SCAA),实现在光网络中优化配置SRLG完全分离的p-Cycles。通过计算机仿真表明,SCAA最小容量配置方案可以预留更少的网络资源,而SCAA优化容量配置方案可以实现p-Cycles快速配置容量,SCAA算法可以保障配置SRLG分离p-Cycles的高保护效能,使网络具备单SRLG故障恢复能力。 相似文献
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本文研究了WDM网状网中双链路失效的动态共享链路保护设计问题,提出了一种新的启发式算法TBP (Two Backup Paths) 和一种改进的启发式算法OBP (One Backup Path).两种保护算法都能根据当前网络状态动态地动态调整链路代价,所选路由都是最小代价的路径.文本还研究了双链路失效的保护切换时间,详细描述了保护切换过程.仿真表明,(1)两种算法都能有效地保护双链路失效;(2)TBP的性能优于OBP;(3)与其他算法相比,TBP具有最快的保护切换时间. 相似文献
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研究了基于SRLG的光层保护的各种算法,在动态负载均衡算法基础上进行了改进,把共享子通路保护方式和动态链路权重配置算法结合在一起考虑,提出了负载均衡的共享子通路保护算法,使算法在符合SRLG限制的基础上,在动态负载均衡和故障倒换时间上都具备较理想的性能。 相似文献
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WDM光网络中基于SRLG的共享通道保护策略 总被引:3,自引:1,他引:2
研究了动态业务下,WDM光网络的生存性。提出了一种单链路故障模型,并在此单链路故障模型下,考察了基于共享风险链路组(SRLG)的共享通道保护策略SRLG-SPP的保护性能,并把它同共享通道保护SPP和专用通道保护DPP的性能做了比较。 相似文献
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In this letter, a new sharing mechanism, SRLG sharing, is proposed, which allows the links of the same shared risk link group (SRLG) in a primary light tree to share protections in WDM optical networks. In previous studies, how to share spare resources with SRLG constraints has not been studied in multicast optical networks. In this letter, considering SRLG sharing, we propose a novel algorithm –multicast with SRLG sharing (MSS)– to establish a protection light tree. Finally, the algorithm MSS and the algorithm multicast with no SRLG sharing (MNSS) are compared through a simulation to show that our new sharing scheme of SRLG sharing is more efficient than that of no SRLG sharing in terms of spare resource utilization and blocking probability. 相似文献
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针对WDM光网络中单链路失效的情况,提出了一种基于链路的保护动态组播业务的优化共享保护算法(Link-based optimized shared-protection algorithm for multicast sessions,LB-OSPM).该算法在对工作树任意光纤链路失效情况寻找保护路径时,允许组播内不同保护路径共享预留波长资源,同时通过引入预留波长使用情况矩阵和波长预留矩阵记录预留波长资源的使用情况,实现了不发生冲突的不同组播的保护链路间共享预留波长资源.研究采用欧洲光网络(European Optical Network,EON)的拓扑对不同波长资源配置和网络负载情况下LB-OSPM算法的网络连接阻塞率做了仿真.结果表明,通过引入共享机制,LB-OSPM算法在对单链路失效保证100%恢复率的同时可以获得更低的连接阻塞率,提高了波长资源利用效率. 相似文献
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WDM疏导网络的共享子通路保护算法 总被引:4,自引:4,他引:0
研究了WDM疏导网络中的生存性问题,提出一种支持多粒度业务的共享子通路保护算法(GSSP)。GSSP首先根据网络当前状态动态调整链路权值,在此基础上选择一条最短路作为工作通路;然后将该通路分为互不重叠的等长子通路,分别找出它们的保护通路,并且允许共享保护资源。GSSP可以保证业务连接的可靠性,又允许网络管理者根据不同的优化策略调整子通路长度,可以在恢复时间和资源利用率之间进行折中。最后对GSSP进行了仿真研究,给出了仿真结果。 相似文献
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Xu Shao Luying Zhou Xiaofei Cheng Chava Vijaya Saradhi Yixin Wang Jianqing Li 《Photonic Network Communications》2008,16(3):221-231
For 100% shared risk link group (SRLG) failure protection, conventional full path protection has to satisfy SRLG-disjoint
constraints, i.e., its working path and backup path cannot go though the same SRLG. With the increase of size and number of
SRLGs, capacity efficiency of conventional shared full path protection becomes poorer due to SRLG-disjoint constraints and
the blocking probability becomes much higher due to severe traps. To solve these problems, we present a partial path protection
scheme where SRLG-disjoint backup paths may only cover part of the working path. Full path protection becomes a special case
of partial path protection, in which the backup path covers the full working path. By choosing the most survivable partial
backup path as backup path, we can make the impact of SRLG failures as low as possible and accept as many as possible connection
requests. Assuming every SRLG has the same probability to fail, we present a heuristic algorithm to find the most survivable
partial backup path by choosing full path protection first, iteratively computing partial backup paths and choosing the most
survivable one. The benefit of this heuristic algorithm is that it can find the optimal results within less iteration. Analytical
and simulation results show that, compared to conventional full path protection, our proposed scheme can significantly reduce
blocking probability with little sacrifice on survivability. The proposed scheme is very useful particularly when the network
contains a lot of SRLGs and the blocking probability of conventional full path protection becomes too high.
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Jianqing LiEmail: |