【作者】 齐宁；

【导师】 汪斌强；

【作者基本信息】 解放军信息工程大学 ， 通信与信息系统， 2011， 博士

【摘要】 由于网络业务的规模化、差异化趋势,采用单一网络体系结构或者服务模式支撑多样化的网络业务运营显得非常困难。为此,可重构柔性网络技术体系通过构建可重构服务承载网(Reconfigurable Service Carrying Network,RSCN)的方式,能够共享不同底层物理资源,支持多个异质网络体系结构并存,从而为用户提供多样化的网络服务。由于网络的不稳定性,如何构建具有强网络生存性的RSCN是可重构柔性网络研究的关键问题之一,其过程涉及如下关键环节:首先,对网络资源状况和故障信息的掌握是构网和故障发现的前提,面对可重构柔性网络中数量庞大的资源以及资源状态的动态性,必须建立有效的资源信息管理机制。其次,构建策略的制定决定了RSCN对网络资源利用的有效性,对网络资源的均衡利用可以减少瓶颈资源,提高资源利用率,必须设计满足构网需求且均衡配置利用网络资源的RSCN构建算法。再次,由于管理域的划分,通过集中式的服务器下发全网范围的RSCN构建策略和故障处理策略并进行命令下发不利于工程实现,为解决跨域构建问题,必须设计跨域的分布式协同的RSCN构建命令管理机制。最后,在网络出现故障或发生重大意外时,为提高RSCN的生存性,必须设计RSCN的故障恢复和故障保护机制。结合863项目可重构路由器构件组研制和可重构柔性试验网组网设备工程化实施子课题,本文基于可重构柔性网络技术体系在RSCN资源管理方法、RSCN构建管理机制以及RSCN容错构建技术等方面进行了较为系统的研究。本文的创新点和主要贡献包括以下几个方面:1.针对RSCN资源管理的可扩展性和高效性,设计了可重构柔性网络的分布式分层管理体系和资源管理协议运行机制,分别提出了域内和域间资源管理机制,建立了RSCN的资源管理模型,分析了高频属性子集和推送门限对系统管理代价的作用,通过自适应地调节资源信息结构和管理模式,以系统管理代价最小为目标,设计了资源管理优化算法(Resouce Management Optimization Algorithm,RMOA)。仿真结果表明,RMOA能够根据请求和系统状态自适应设置高频属性集和推送门限,具有比单一推送或查询模式更小的系统代价。2.针对RSCN构建管理技术,设计了RSCN分布式协同构建机制,基于令牌传递的方式设计了分布式域间RSCN构建管理方法,有效解决了大范围跨域的RSCN构建问题。为解决管理服务器单点失效问题,设计了令牌发放系统容错选举算法(Token Providing Server Resilient Election Algorithm,TREA)。理论分析和仿真结果表明,令牌传递算法ImprovedSA既能够高效地求解出令牌传递回路,又能够保证求解结果的优越性;TREA能够保证整个管理平面的有序运行,提高可重构柔性网络管理系统的容错性。3.针对RSCN构建过程的不均衡性和动态性,在构网时充分考虑底层物理网络的负载均衡,以网络构建代价最小为原则进行优化,分别提出基于链路负载均衡和节点负载均衡的构建机制,设计了负载均衡的自适应可重构服务承载网构建算法(Balanced Adaptive RSCN Construction Algorithm,BACA)。仿真结果表明,与传统构建算法相比,BACA能够较好的提高RSCN构建请求的接收率,并且对网络链路均衡度和节点均衡度都有很高的保证。为解决由于网络动态性而造成部分资源拥塞的问题,提出了基于拥塞避免的RSCN构建算法,在链路资源不能满足用户构建请求时,按照迁移策略调整部分RSCN占用的网络资源,消除瓶颈链路,均衡物理网络,从而能进一步提高RSCN构建请求接收率,为更多的用户请求提供服务。4.针对故障发生后的RSCN恢复机制,设计了资源紧迫度感知的RSCN构建算法(RSF-aware Construction Algorithm, RSF-awareCA),该算法以资源的重要程度为衡量指标,通过在构建过程中避让紧迫程度较高的资源,最小化了重要资源发生故障给网络带来的影响。为提高RSCN的运行成功率,设计了发生网络故障时的RSCN恢复算法(RSCN Single Link Failure Recovery Algorithm, RSLFRA)。仿真结果表明,RSLFRA算法在构建RSCN时充分考虑了资源的紧迫程度,在故障发生时能够恢复部分RSCN的故障链路,RSCN成功运行率和物理链路利用率明显优于其他构建方法,且长期运行后瓶颈资源产生的几率有所降低。5.针对RSCN故障保护机制,为了提高RSCN的运行成功率并降低网络链路故障损失,设计了RSCN主动保护构建算法(RSCN Active Protection Algorithm, RAPA),该算法在构建RSCN的同时备份保护路径,采用资源紧迫度感知的主路径构建子算法(RSF-aware Main Link Construction Algorithm, RSF-awareMLCA)进行主路径构建,采用RSCN保护链路构建子算法(RSCN Protection Link Construction Algorithm, RPLCA)进行备份路径构建。仿真结果表明,RAPA在构建RSCN主路径时充分考虑了资源的紧迫程度,并且为RSCN主路径映射了相应的保护路径;在故障发生时RAPA能够将RSCN故障链路快速切换到保护路径,其RSCN成功运行率、主链路利用率和平均网络链路故障损失明显优于其他构建算法。更多还原

【Abstract】 As the diversification and discrepancy trend of network traffic, network technology has faced to flinty challenges. One size fit all is impossible. Through sharing different substrate re-sources many heterogeneous networks can coexist on the same Reconfigurable Flexible Network (ReFlexNet) by constructing Reconfigurable Service Carrying Network (RSCN). This can pro-vide various network services. How to construct high network survivability RSCN is one of key issues in the research of ReFlexNet. There are some pivotal issues in construction processes.Firstly, in control of status and failure information of network resources is the precondition of constructing RSCN and failure discovery. In the face of huge number of resources and the dynamic of these resources, how to manage these resources efficiently is a challenge problem. Secondly, the efficiency of network resource utilization rests with construction policy. Bal-anced use of network resources can reduce the number of bottleneck resources and improve re-source utilization. How to construct RSCN which satisfies user s demand efficiently under the situation of limited resources is a key issue.Thirdly, as the partition of management domains, to calculate construction policy and dis-tribute construction and failure process commands by centralized server is unpractical. The in-ter-domain RSCN construction issues must be discussed, and distributed cooperative manage-ment system and resource management mechanism must be proposed.The last but not least, as the instability of network, how to improve the survivability of RSCN under condition of network failure or fatal accidents is a key issue. Mechanisms of net-work failure recovery and protection must be discussed.Combined with the research and development of the sub-project Research and Develop-ment of Reconfigurable Router Components and Engineering Implementation of Reconfigura-ble Flexible Testbed Equipments , which are supported by the National High-Tech Research and Development Program of China (863 Program). This thesis focuses on the research of resourse management methords and construction mechanism and policies of RSCN and resilient con-struction technology of RSCN in ReFlexNet. In short, its main work and contributions are out-lined as follows:1. Aiming at improving the extensibility and efficiency of resource management of RSCN, distributed layered management system and runtime mechanisms of resource management pro-tocols are designed. Both intra-domain and inter-domain resource management principles are proposed. Resource management model of ReFlexNet is established. The impact of High Fre-quency Attributes Subset and Push Threshold on the system management cost is analyzed. To reduce system cost, Resource Management Optimized Algorithm which is called RMOA via ad-justing resource information structure and management mode adaptively is proposed. The ad-vantage of RMOA is proved via experiments in several scenarios.2. Aiming at sloving construction technology of RSCN, distributed cooperative construc-tion mechanism is proposed, which can resolve large-scale inter-domain construction problem efficiently based on the manner of token passing. To solve single node failure problem of Recon-figurable Management Systems (RMS), Token Providing Server (TPS) Resilient Election Algo-rithms (TREA) are designed. The theoretical analysis and simulation results show that token passing algorithm (ImprovedSA) can find a better circle rapidly and effectively via ameliorating the result gained by traditional algorithm, and TREA can assure regular function of management plane and improve the survivalbility of management sysetm of ReFlexNet.3. To solve the asymmetry and dynamicness of RSCN construction process, under some important principles of RSCN construction,balanced link load RSCN construction algorithm and balanced node load RSCN construction algorithm are given. Based on these two algorithms Balanced Adaptive RSCN Construction Algorithm (BACA) is proposed. The efficiency of BACA is evaluated by simulation experiment according to construction requirements acceptance ratio and link and node load balance ratio of the whole substrate network. To solve resource congestion issues due to network dynamicness, a congestion avoidance RSCN construction algo-rithm is proposed. Part of RSCN can be migrated according to migration principles when link resources cannot satisfy user s RSCN request. It can eliminate some bottleneck link and poise substrate network, and can improve RSCN construction requirement acceptance and provide ser-vice for more users requests.4. To Solve resilient construction problems of RSCN in the precondition of physical link prone to failure, mathematics model of RSCN resilient construction issues is established. To avoid enormous influence because of important resource failure, a Resource Stress Factor (RSF) awareness RSCN construction algorithm named RSF-awareCA is proposed. To improve success running ratio of RSCN, RSCN link failure recovery algorithm named RSLFRA is implemented when single link failure takes place. The efficiency of algorithms is evaluated by simulation ex-periments according to RSCN success running ratio and different RSF resource distribution and physical link utilization under several scenarios.5. Because of the blight of network failure, active protection problem of RSCN is dis-cussed. Mathematics model of RSCN active protection issues is established. To avoid enormous influence, Resource Stress Factor (RSF) awareness Main Link Construction Algorithm named RSF-awareMLCA is proposed. To improve success running ratio and reduce network link failure loss of RSCN, RSCN Protection Link Construction Algorithm named RPLCA is implemented. Considering of the two sub-algorithms, RSCN Active Protection Algorithm named RAPA is de-signed. The efficiency of algorithms is evaluated by emulation experiments according to RSCN success running ratio and main link utilization ratio and average network link failure loss under several scenarios.更多还原