Protection Schemes for IP-over-WDM Networks: Throughput and Recovery Time Comparison

This article presents a novel protection approach using Generalized Multi-Protocol Label Switching (GMPLS). This strategy provides protection at the Wavelength Division Multiplexing (WDM) layer, meaning that all Internet Protocol Label-Switched Path (IP LSPs) nested inside a lightpath are protected in an aggregated way. It uses resources efficiently since spare capacity of working primary lightpaths can be used for backup purposes whenever necessary. The IP and WDM layers are treated together as a single integrated network from a control plane point of view, so that network state information from both layers can be used. Besides discussing the strategy proposed and the key features of GMPLS that will allow its implementation, we mathematically formulate the maximum throughput problem. Thereafter, we propose and compare heuristic algorithms for IP-over-WDM networks using three protection approaches: WDM lightpath protection, IP LSP protection, and the proposed protection scheme. Their throughputs and recovery times are analyzed and compared. Our results show that, for a representative mesh network, the proposed aggregated protection scheme presents better protection efficiency and good scalability properties when compared with the other two schemes.     

Path-based protection in WDM mesh networks subject to double-link failures

This letter studies the protection problem in WDM mesh networks and proposes a new scheme called improved path-based shared protection (IPSP) to tolerate double-link failures. Differing from previous path-based shared protection (PSP), IPSP allows some primary and backup paths to share resources. Simulation results show that IPSP outperforms PSP.     

New results for path-based shared protection and link-based Hamiltonian cycle protection in survivable WDM networks

In this paper, we study the path-based shared protection (PBSP) and the link-based Hamiltonian cycle protection (LBHCP) schemes for tolerating single-link failures in survivable wavelength-division-multiplexing networks. Although previous work indicated that PBSP can perform better than link-based shared protection including the case of LBHCP, from theoretical analysis and simulation results in this paper, we can clearly see that this indication of previous work is not suitable for LBHCP since it can have a better resource utilization ratio and a faster recovery time than PBSP. Therefore, the new result of this paper is a modification for the previous inaccurate idea and it also can well guide future work of researchers.

Protection vs. redundancy in homogeneous parallel systems

The article considers defense resource allocation in a system exposed to external intentional attack. The defender distributes its resource between deploying redundant elements and their protection from attacks. The attacker distributes its effort evenly among all of the elements or among elements from a chosen subset. The vulnerability of each element is determined by an attacker–defender contest success function. The expected damage caused by the attack is evaluated as system unsupplied demand. The article considers both the cases without and with performance redundancy.     

Limits for survivability in frontal collisions: theory and real-life data combined

The limits for survivability in vehicle frontal collisions are unknown. This paper proposes a new hypothesis that occupant risk in frontal collisions is due to both inertial and crushing injuries and that the limits of survivability in frontal collisions are principally due to the complete crushing of vehicles at high DeltaV's. Analysis of the NASS data for the period 1982-1991 for AIS3+ injury and fatality to belted and unbelted drivers shows that the real world distributions of risk with DeltaV are asymptotic to 1.0 over similar DeltaV ranges and over a lower speed range than that predicted from intrusion/complete car crush alone. This is consistent with the proposed hypothesis as human biomechanical loading also influences survivability. While the hypothesis is supported by the presently available limited high-speed collision data, further in-depth investigations should be undertaken to confirm the ultimate limits of survivability.     

基于GMPLS的ASON生存性技术研究

自动交换光网络（ASON）是一种能够自动完成网络连接的新型网络。控制面技术是其核心,一些协议（如GMPLS）正在逐步应用到ASON控制面中。网络生存性是指网络发生故障时提供连续业务的能力。基于GMPLS的网络生存性技术对于网络的运营具有重要的意义。本文介绍了光网络的生存性技术并结合GMPLS与ASON控制平面对光网络的生存性进行了较为深入的研究。     

可生存网络系统的形式化定义

随着大规模、分布式网络系统对信息安全需求的进一步提高,其安全问题的研究重点已转移为网络系统的可生存性研究.那么,首要问题是建立统一、规范的网络系统的可生存性定义.文中从网络系统的可生存需求出发,借鉴了近年来国内外的可生存研究成果,提出了规范化的网络系统的可生存性定义,并给出其形式化的描述及其实现模型,为下一阶段的系统可生存性的定量分析提供统一、规范的可生存性定义.     

基于优化理论的复杂网络节点攻击策略

该文在分析传统复杂网络节点攻击策略不足的基础上提出一种新的攻击策略,该策略的思路是将节点攻击序列的构造问题视为一个优化问题而非传统的评估问题。为了实现该策略,设计了复杂网络抗毁性测度用以衡量节点攻击序列的攻击效果,建立了以最大化攻击效果为目标的节点攻击序列构造模型,提出了基于禁忌搜索的模型求解算法。在真实网络和模拟网络上的实验结果表明,新策略比其它复杂网络节点攻击策略更为有效和优越。     

软件定义光网络中一种时延约束的控制器生存性部署方法

控制时延、控制平面的生存性和控制平面的控制冗余程度是软件定义光网络中网络性能是否良好的重要判断依据。该文提出时延约束下的控制器生存性部署方法,该方法充分考虑时延、生存性和控制器冗余等网络性能因素,在用户指定时延的前提下,确保每个网络节点至少有两条控制链路,以提高控制平面的生存性。同时,保证使用尽可能少的部署节点完成整个网络的覆盖,以减少控制平面的控制冗余。仿真表明,该方法能够有效地减少控制时延,提高控制平面的生存性,并减少控制器的部署个数,降低控制冗余,有效地提高了软件定义光网络的整体网络性能。该方法保证至少两条控制链路与C-MPC算法起到了相同的保护作用,与MCC算法相比,使SDON网络控制平面可靠性提高了20%。同时,在指定时延10 ms的约束条件下,在NSF和COST239网络中,与C-MPC算法相比所提算法分别减少了88%和75%的控制器部署。     

带有生存性感知的低成本光无线混合网络无线功能部署策略

光无线混合网络的生存性保障程度与部署成本之间存在矛盾。为提高网络资源利用率,该文提出一种低成本的无线功能部署策略。根据网络中无线功能部署情况,综合考虑网络生存性保障程度及部署成本两方面因素,在此基础上,提出基于向量评价的二进制粒子群算法实现其优化过程,进而,由进化得到的种群粒子不断调整光网络单元选取,以较低的成本实现较强生存性的网络部署。结果表明所提出的无线功能部署策略能有效提高网络的生存性,并大幅度的降低网络成本。