GMPLS技术及其路由算法

通用多协议标签交换（ GMPLS）是由多协议标签交换（MPLS）发展而来,它是MPLS向光层扩展的必然产物.GMPLS将时隙、波长和光纤端口作为标签用子数据转发,通过采用扩展的信令、路由协议和新增的链路管理机制以适应对智能光网络进行动态控制和传送信令的要求,动态提供网络资源并增加网络的存活性.本文着重比较了GMPLS与MPLS,说明其如何改进MPLS,并提供了GMPLS在光控制平面的应用解决方案.最后,谨慎分析了GMPLS的前景及其需要解决的问题     

基于OSPF的ASON路由的一种加密方案

自动交换光网络(ASON)控制协议采用通用多协议标签交换(GMPLS)控制协议族,其路由部分主要为开放式最短路径优先(OSPF)协议.文章分析了OSPF协议加密措施存在的安全隐患,并对现有的加密方案进行了改进.针对OSPF协议的安全模式,提出了一种可以应用于ASON中路由技术的新的安全性方案.基于数论算法,实现S盒动态调整,通过动态产生的子密钥,在迭代过程中对分组进行加密.     

GMPLS技术及其在下一代网络中的应用

文章介绍了通用多协方标签交换技术的产生背景、主要技术特点，对通用多协议标签交换技术在下一代网络中的可能应用做了分析比较，并指出了通用多协议标签交换技术的未来发展趋势。     

GMPLS域间路径建立相关路由和信令技术研究

通过对IETF相关文稿的研究,讨论了域间多协议标签交换(MPLS)和通用标签交换(GMPLS)的标签交换路径(LSP)的建立和维护,并给出了相关方面的最新研究成果以及发展趋势.     

MPLS技术发展及应用

随着网络设施的持续发展,网络规模越来越大,需要交换的数据量也与日俱增,因此一个高速传输和交换的网络技术就显得尤为重要.作为下一代网络的关键技术,多协议标签交换(MPLS)技术在改善和提高网络性能方面扮演着越来越重要的角色.因此,网络界很大一部分重点已经转向采用多协议标记交换.这为简化虚拟专用网(VPN)链路,实现服务融合和流量工程提供了极具吸引力的机会,同时最大限度地降低了与早期方法有关的复杂度和开销.重点介绍了多协议标签交换技术的发展方向和一些主要应用.     

基于GMPLS的光突发交换体系及其关键技术

文章给出了基于通用多协议标签交换(GMPLS)的光突发交换(OBS)对等体系(GLOBS)的功能结构和分层视图.在此范畴内,针对标签空间减小和流量工程两方面,结合国内外最新的研究动态,比较了各种已有技术的优缺点,并提出了适合于GLOBS体系的可能的解决方案以及今后工作的重要技术问题.     

超高频RFID阅读器多相接收防碰撞技术

防碰撞处理是超高频RFID多标签识别的关键技术,多年来已经有很多研究,研究方法基本上都是采用时分的方法,解决碰撞问题。本文提出并实现了一种全新的基于多相位的防碰撞处理方法,可以和现有的标签协议兼容,并在ISO18000-6C协议的阅读器上进行了测试,测试结果表明:采用了多相位解调技术的阅读器,其多标签处理性能提升了13.56%。     

T-MPLS技术中的QoS管理控制策略

传送多协议标签交换(T-MPLS)技术作为下一代光网络技术,需要满足用户对服务质量(QoS)的要求.文章介绍了QoS的定义,并对实现QoS采取的方法进行了描述,具体分析了使用漏桶算法的流量监管和整形,并说明了调度应用的方法.最后对改善QoS性能进行了仿真实验.     

基于GMPLS的自动交换光网络生存性技术研究

能够提供高效快速的生存性是自动交换光网络的重要特点.介绍了自动交换光网络的生存性实现的过程和各种生存性机制,提出了基于通用多协议标签交换的自动交换光网络中标签交换路径端到端生存性的实现方案,并对恢复的时间具体的分析.     

GMPLS——IP与WDM无缝融合的关键

1 GMPLS的概念 CMPLS(通用多协议标签交换)是IETF提出的可用于光层的一种通用多协议标签交换技术,为了实现IP与WDM的无缝结合,GMPLS对MPLS标签进行了扩展,使得标签不但可以用来标记传统的数据包,还可以标记     

Optical CDMA for All-Optical Sub-Wavelength Switching in Core GMPLS Networks

Generalized multi-protocol label switching (GMPLS) is a multipurpose control-plane paradigm that extends the MPLS scheme allowing switching without recognizing packet boundaries. In this paper, we present a novel extension that exploits a new physical layer for switching in optical GMPLS. The proposed extension is achieved through adding an optical code switching layer, or code switch capable (CSC) layer, to the existing label mapping layers. Our proposal enables finer granularity at sub-wavelength level in all-optical GMPLS core switches, resulting in significant enhancements to traffic isolation capabilities for all-optical GMPLS core switches. We employ mathematical analysis to derive performance bounds for the proposed scheme, from both the labeling capacity and network throughput points of view. We use our analytical model to derive several optimum operating points for the network, and show that our techniques significantly improve the overall performance of all-optical core networks     

GMPLS operations and management: today's challenges and solutions for tomorrow

This article examines the technical challenges involved in the delivery of GMPLS, and in particular the challenges in managing these networks. This article focuses first on requirements gathered from customers who are deploying GMPLS in their networks, or will be doing so in the near future. The motivations for these requirements are often based on a service provider's next-generation network designs that are motivated primarily by network convergence, and the promised operational and capital expense reductions and architectural simplifications over existing segregated network designs. This article then considers various solution options to manage GMPLS networks based on these requirements. The key areas examined include provisioning/configuration, performance monitoring and operations and management, and tools that can be used for these purposes. We conclude with a recap of standardization issues and opportunities.     

Layer-preference policies in multi-layer GMPLS networks

We address the problem of routing Label Switched Paths (LSPs) in multi-layer networks based on the Generalized MultiProtocol Label Switching (GMPLS) paradigm. In particular, we pursue policies for choosing the appropriate layer to host a new LSP request, as we find that such layer-preference policies have significant impact on network performance. We discuss several simple layer-preference policies and we reveal why these simple policies ruin network performance in the long run. Consequently, we develop an efficient heuristics, the Min-phys-hop routing and wavelength assignment algorithm, to govern the selection of the best layer of a multi-layer network in which to host new LSP requests. We discuss the applicability of this algorithm with respect to the state-of-the-art GMPLS standards, above all, the GMPLS routing extensions to OSPF-TE. By extensive simulations, we justify that the Min-phys-hop algorithm produces close-to-optimal blocking and resource consumption under almost all possible selections of input parameters, and this is regardless of the wavelength and Optical-Electrical-Optical (OEO) conversion capability present in the network.     

Mesh network resiliency using GMPLS

The generalized multiprotocol label switching (GMPLS) is being developed as the control plane for the evolving photonic network. We describe how GMPLS can be used with mesh networks to provide efficient network resiliency. In particular we examine the key aspects of GMPLS that are used to support protection and restoration. We also study the various protection and restoration techniques, and we highlight the tradeoffs between recovery time and resource redundancy     

GMPLS user-network interface in support of end-to-end rerouting

Carriers are enhancing their transport networks and improving their daily operations to address the increasing demand for (new) IP-based services. They require more scalable support for the increasing traffic demand and more flexible operations for connection provisioning. They are also seeking optimized resource utilization and time performance using faster and more robust recovery schemes while maintaining overall network costs. With advances in the GMPLS protocol suite including its user-network interface support, the possibility for better cooperation between transport and IP/MPLS networks is now possible. This article addresses this question by positioning and comparing the capabilities of the optical interworking forum's UNI with the Internet engineering task force's GMPLS UNI. Through three recovery scenarios, a quantitative analysis is provided that determines the gain obtained in deploying the GMPLS UNI over its OIF counterpart. Finally, a testbed demonstrating the feasibility and practicability of the GMPLS UNI implementation (which enables end-to-end connection rerouting) is presented.     

RETRACTED ARTICLE: Research on Energy Saving Design of Intelligent Building Based on Genetic Algorithm

Generalized Multiprotocol Label Switching (GMPLS) networks is capable of allocating suitable route based on the size of the network and computational constraints. In this paper, we propose a connection provisioning strategy for updating the Traffic Engineering Database of Path Computation Element (PCE) in GMPLS optical networks. Control and management plane are used for resource optimization in PCE-based centralized network. We have also proposed connection provisioning for Label Switched Path (LSP) to optimize the resources and to maximize the connection establishment. For provisioning a connection with LSP requests, we have formulated the Integer Linear Programming and constraints to minimize the blocking of connections and network performance. The results obtained shows that the proposed strategy has better network resource utilization with minimum blocking of connections.     

Challenges for GMPLS lightpath provisioning in transparent optical networks: wavelength constraints in routing and signaling - [Topics in optical communications]

GMPLS has introduced several enhancements to the MPLS-TE routing and signaling control plane protocols to handle dynamic lightpath provisioning in wavelength-routed networks. Specifically, the GMPLS signaling protocol has been enhanced to support two new provisioning functionalities, namely, the minimization of the setup delay, and the setup of bidirectional connection requests. In both cases, the source node must perform a wavelength allocation for either minimizing the setup delay (i.e., the suggested label) or requesting a bidirectional connection (i.e., the upstream label). However, these GMPLS provisioning functionalities present important deficiencies when applied to wavelength-routed networks with the wavelength continuity constraint, degrading the network performance considerably. The reason is that the standard GMPLS routing protocols flood link attributes only at bandwidth granularity, that is, no per-wavelength channel granularity is disseminated. Therefore, the source node is unable to perform an optimal wavelength assignment that fulfils the wavelength continuity constraint along the complete route toward the destination. In this article we present and experimentally evaluate an enhanced routing-based solution in the ADRENALINE testbed to handle the wavelength continuity constraint.     

Efficient distributed restoration path selection for shared mesh restoration

In MPLS/GMPLS networks, a range of restoration schemes will be required to support different tradeoffs between service interruption time and network resource utilization. In light of these tradeoffs, path-based end-to-end shared mesh restoration provides a very attractive solution. However, efficient use of bandwidth for shared mesh restoration strongly relies on the procedure for selecting restoration paths. We propose an efficient restoration path selection algorithm for restorable connections over shared bandwidth in a fully distributed MPLS/GMPLS architecture. We also describe how to extend MPLS/GMPLS signaling protocols to collect the necessary information efficiently. To evaluate the algorithm's performance, we compare it via simulation with two other well-known algorithms on a typical intercity backbone network. The key figure of merit for restoration bandwidth efficiency is restoration overbuild, i.e., the extra bandwidth required to meet the network restoration objective as a percentage of the bandwidth of the network with no restoration. Our simulation results show that our algorithm uses significantly less restoration overbuild (63%-68%) compared with the other two algorithms (83%-90%).     

STOLAS: switching technologies for optically labeled signals

GMPLS-based labeled optical burst switching (LOBS) networks are being considered as the next-generation optical Internet. GMPLS includes wavelength switching next to label and fiber (space) switching. We present a new concept of optically labeling bursts of packets suitable for LOBS networks supported by GMPLS. It is based on angle modulation, which enables control information to modulate the phase or frequency of the optical carrier, while payload data are transmitted via intensity modulation (IM). In particular, the optical label is orthogonally modulated, with respect to the payload, using either frequency shift keying or differential phase shift keying. We present a performance analysis of the modulation schemes by means of simulations where the influence of the payload IM extinction ratio and laser linewidth are investigated. In addition, the transmission performance of an IM/FSK combined modulated signal is experimentally validated at 10 Gb/s, demonstrating at the same time an FSK label swapping operation. Finally, a suitable optical label-controlled switch design is proposed that takes advantage of these novel labeling techniques, and efficiently combines widely tunable, fast switching lasers and SOA-MZI wavelength converters with an arrayed waveguide grating router.     

Extending generalized multiprotocol label switching (GMPLS) for polymorphous, agile, and transparent optical networks (PATON)

This article presents a vision for the emerging integrated optical networks to meet various traffic requirements and design criteria. To address the shortcomings in today's GMPLS over wavelength-routed optical networks, a new network architecture called polymorphous, agile, and transparent optical networks (PATON) is proposed. PATON uses polymorphous optical burst switching (POBS) to seamlessly integrate different signaling, switching, and reservation schemes. The main features of PATON, along with its benefits as well as design and implementation challenges, are also described. Finally, both qualitative and quantitative performance comparisons of POBS with the two representative IP/GMPLS/OCS approaches are provided