Investigation of the influence of key parameters on system performance in all-optical label switching based on FSK/ASK orthogonal modulation format

The transmission characteristics of the optical label switching system based on the FSK/ASK orthogonal modulation format is investigated. The factors that affect the transmission performance, such as the FSK tone space, dispersion compensation and coupler split ratio, are studied by numerical simulation. The proposed scheme is also experimentally demonstrated with a transmission of 155 Mbit/s FSK label combined with 10 Gbit/s ASK payload.

Performance Evaluation of an Internet Protocol Security (IPSec) Based Multiprotocol Label Switching (MPLS) Virtual Private Network

This paper evaluates the performance of Internet Protocol Security (IPSec) based Multiprotocol Label Switching (MPLS) virtual private network (VPN) in a small to medium sized organization. The demand for security in data networks has been increasing owing to the high cyber attacks and potential risks associated with networks spread over distant geographical locations. The MPLS networks ride on the public network backbone that is porous and highly susceptible to attacks and so the need for reliable security mechanisms to be part of the deployment plan. The evaluation criteria concentrated on Voice over Internet Protocol (VoIP) and Video conferencing with keen interest in jitter, end to end delivery and general data flow. This study used both structured questionnaire and observation methods. The structured questionnaire was administered to a group of 70 VPN users in a company. This provided the study with precise responses. The observation method was used in data simulations using OPNET Version 14.5 Simulation software. The results show that the IPSec features increase the size of data packets by approximately 9.98% translating into approximately 90.02% effectiveness. The tests showed that the performance metrics are all well within the recommended standards. The IPSec Based MPLS Virtual private network is more stable and secure than one without IPSec.

Optimization of Key Parameters in 622-Mb/s Amplitude Shift Keying Labeled 40-Gb/s Return to Zero Differential Phase Shift Keying Optical Switching Network

Optimized are the label extinction ratio and dispersion compensation of an optical label switching transmission system,which employs 40-Gb/s return to zero differential phase shift keying(RZ-DPSK)payload labeled with 622-Mb/s amplitude shift keying(ASK)control data.In our scheme,the receiver sensitivities of payload and label achieves-27.8dBm and-33.5dBm,respectively.After transmitted over 40km,60km and 80km single mode fiber(SMF)(with dispersion compensation)respectively,the payload can be recovered with no power penalty,while the label can be recovered with less than 2dB penalty.

Genetic algorithm for multi-protocol label switching

A new method for multi-protocol label switching is presented in this study, whose core idea is to construct model for simulating process of accommodating network online loads and then adopt genetic algorithm to optimize the model. Due to the heuristic property of evolutional method, the new method is efficient and effective, which is verified by the experiments.

A coarse-grained differentiated routing algorithm in multi-protocol label switching traffic engineering

A new coarse-grained differentiated least interference routing algorithm(CDLI) with DiffServ-Aware was presented.This algorithm is composed of off-line and on-line stages,taking into account both real-time traffic and best-effort traffic.Off-line stage is to determine the shortest path set disjointed path(DP) database for real-time traffic,and to identify link critical value by traffic profile information of real-time traffic and DP database.On-line stage is at first to select route in the DP database for real-time traffic,if there is no path to meet the needs,the dynamic routing will be operated.On-line routing algorithm chooses the relatively short path for real-time traffic to meet their bandwidth requirements,and for best-effort traffic it chooses a lighter load path.The simulation results show that compared with the dynamic online routing algorithm(DORA) and constrained shortest path first(CSPF) algorithm,the new algorithm can significantly improve network throughput and reduce the average path length of real-time traffic.This guarantees quality of service(QoS) of real-time traffic while improving the utilization of network resources.

A NEW SERVICE ARCHITECTURE OF FAST LABEL SWITCHING

Implementing QoS, one of the eternal research subjects, on Internet has been attracting a lot of attentions although several schemes are already available. This letter proposes a new service architecture-Scalable Tri-tier Service Architecture (STSA) and a fast label switching scheme, which can reduce the overhead of signaling and suit the applications of access demand for a great number of end users with QoS guarantee. Also presented in the letter is an implementation of STSA in MPLS scenario.

Optical Packet Switching Scheme Using Multi-optical-code Labels

Proposed is a novel optical code(OC) label switching scheme in which an optical label is constructed by multiple parallel optical codes.The performances of splitting loss and BER are simulated and analyzed.Simulation results show that the proposed label can be correctly recognized to perform packet switching.Compared with reported schemes using one OC as a label,the splitting loss in our proposal is lowered.

Investigation of Dispersion Compensation in 2.5 Gbit/s OOK Label and 40 Gbit/s RZ-DPSK Payload Optical Label Switching System Based on Optical Carrier Suppression and Separation

Three dispersion compensation schemes of an optical label switching transmission system were investigated, which employs 40 Gbit/s return zero differential phase-shift keying（RZ-DPSK） payload labeled with 2.5 Gbit/s on-off keying（OOK） signal based on the optical carrier suppression and separation（OCSS） techniq ue, In the system, proposed are the receiver sensi ti vity oS payload and label, achieving -- 32. 4 dBm and --38.5 dBm, respectively. Using the optimal dispersion compensation scheme, after transmitted over 160 km and 320 km SMF respectively, the label can be recovered without power penalty, while the payload can be recovered with less than 2 dB and 5 dB penalty, respectively.

Switching,explosion,and chaos of multi-wavelength soliton states in ultrafast fiber lasers

Because of the complexity and difficulty of realizing a multi-wavelength soliton state,reports on its internal dynamic characteristics are scarce.In this study,the switching and periodic soliton explosion processes of the multi-wavelength soliton state in a negative dispersion passively mode-locked fiber laser are realized.The generation of the multi-wavelength soliton state undergoes the process of noise,oscillation,and stable mode-locking,and the splitting and annihilation of solitons with different group velocities directly impact the generation and disappearance of three wavelengths.Positive and negative dispersion lead to different group velocities of solitons.The presence and displacement of solitons with different group velocities cause soliton collisions,which lead to soliton explosions.A soliton experiences relative phase oscillation,chaos,and oscillation,as well as convergence and separation before and after an explosion.With an increase in parameters related to pump power,single-soliton oscillation,multi-wavelength solitons,and chaos are found in experiments and simulations,proving the relevance and reliability between simulation and experimental results.This work promotes the dynamical study of multi-soliton collisions in nonlinear science and the development of chaos theory in multi-comb lasers.

Some Switching Invariant Prime Graphs

We investigate prime labeling for some graphs resulted from switching of a vertex. We discuss switching invariance of some prime graphs and prove that the graphs obtained by switching of a vertex in Pn and K1,n admit prime labeling. Moreover we discuss prime labeling for the graph obtained by switching of vertex in wheel Wn.

A rapid switching technology of IP data packet based on Multi-Protocol

The rapid development of network raise the role of WAN. As a large-scale backbone network, the failure of network components can lead to huge loss of data and revenue. How to improve the data switching speed and Quality of Service of network data is more and more important problem which Internet Server Provides cared. Multi-Protocol Lable Switching （MPLS） is a new WAN technology which is currently being standardized by IETF. This paper analysise the architecture of MPLS and describe the mechanism of label switching protocol. In addition, this study analyses the encapsulation of data packet at the Label Switching Routers which is on the boundary of MPLS network. A Label Switching Path （LSP） is built by Label Distribute Protocol in core network. A conclution of ＂one time routed, more times switching＂ routed was reached.

基于FPGA的千兆以太网端口通信设计

针对嵌入式领域中以太网传输速率以及实时性问题,文中提出了一种基于FPGA(Field Programmable Gate Array)的千兆以太网端口通信的设计方案。设计了千兆以太网交换机的转发功能,基于标签转发实现了端对端数据通信。CPU(Central Processing Unit)发出带有标签的数据报文,通过千兆网口输出数据报文,经过RGMII(Reduced Gigabit Media Independent Interface)接口将带标签的数据报文发送给FPGA,FPGA通过内部逻辑判断标签中的输出端口号域并去除标签,从相应千兆网口向连接设备输出数据报文。外设通过千兆网端口输入数据报文,通过SGMII(Serial Gigabit Media Independent Interface)协议将数据报文发送给FPGA,FPGA通过内部逻辑添加标签并轮询输出给CPU,从而实现多个千兆网口连接设备互通。实验结果验证了FPGA逻辑的可行性和有效性,传输速率达到1 Gbit·s-1,报文转发延时小于100μs,报文丢包率为0%,数据传输稳定性较高,满足现有项目的实际需求。

BGP MPLS VPN中CE双归属场景下路由优化研究

BGP MPLS VPN网络架构是一种由MP-BGP技术和MPLS技术相结合的新型VPN网络架构。为了提高BGP MPLS VPN网络架构中接入层PE的可靠性,通常部署CE双归属架构,然而该方案在特殊组网下,可能会存在次优路径。详细分析了一种基于CE双归属的特殊组网场景,针对存在的问题部署了OSPF虚连接优化方案,并使用ENSP软件进行模拟仿真,验证该方案的可行性。

SR技术在二层虚拟专网中基于MPLS的实现与性能分析

文章聚焦于分段路由(Segment Routing,SR)技术在多协议标签交换(Multiprotocol Label Switching,MPLS)中的应用,尤其关注其在二层虚拟专网(Layer 2 Virtual Private Network,L2VPN)中的实现和性能。SR通过标签堆栈实现路径动态引导。控制平面协同工作进行路径计算、标签分配和拓扑管理,数据平面执行实际数据包传输。然后进行性能测试,将测试结果与传统方法进行对比对比,结果表明SR在二层虚拟专网中性能优于传统的传输方式。

Orthogonal Stacked Spectral Coding Labels for Fast Packets Routing over Optical MPLS Network

Multi-protocol label switching（MPLS） has the advantage of high efficiency in the second layer, which improves the performance of data packets routing. In this paper, a new structure to implement optical MPLS is proposed. We construct a code family for spectral-amplitude coding（SAC） labels in the optical MPLS networks. SAC labels are suitable for optical packet switching because they can be constructed and recognized quickly at each router. We use the label stacking to provide hierarchical routing to avoid swapping labels at each forwarding node and reduce system complexity. However, the phase-induced intensity noise（PIIN） appears due to the incoherent property of the light source when the stacked labels set makes the correlation decoding with the local node label,which degrades system performance.

155 Mb/s-10 Gb/s combined FSK-IM/optical label-packet modulation signals 100 km transmission over standard single mode fiber using mid-span spectral inversion by four-wave mixing in an SOA

This paper introduces the mid-span spectral inversion by four-wave mixing in a commercially available semiconductor optical amplifier （SOA） with a length of about 1.5 mm to optical label switching network based on combined frequency shift keying （FSK）-intensiy modulation （IM）/optical label-packet modulation to overcome the dispersion limitation of fiber. The 155 Mb/s-10 Gb/s combined FSK/IM signal is experimentally transmitted over a 100 km standard single mode fiber. 10^-10 and 10^-9 BER （bit error ratio）, or even better, is achieved for the FSK label and IM packet, respectively. The -19 dB power conversion efficiency is obtained for -1 nm wavelength detuning.

Some Results on Prime Labeling

In the present work we investigate some classes of graphs and disjoint union of some classes of graphs which admit prime labeling. We also investigate prime labeling of a graph obtained by identifying two vertices of two graphs. We also investigate prime labeling of a graph obtained by identifying two edges of two graphs. Prime labeling of a prism graph is also discussed. We show that a wheel graph of odd order is switching invariant. A necessary and sufficient condition for the complement of Wn to be a prime graph is investigated.

基于虚拟化的跨域VPN解决方案

针对目前运营商网络中构建的跨域虚拟私有网实现复杂、自治系统边界设备负载过重、存在单点故障等问题,提出了采用虚拟化方式构建跨域虚拟私有网的解决方案。该方案包括公网隧道的建立、本地VPN实例的建立、自治系统边界设备的虚拟化、边界设备私网路由的交互4个关键步骤。为评估方案的可行性,对方案进行了测试与验证,测试与验证结果表明该方案达到了预期设计的目标。为了评估方案的优越性,与传统多跳EBGP方式构建的跨域虚拟私有网在交换容量、路由条目、标签条目等维度进行了对比分析。对比结果表明,采用该方案构建的跨域虚拟私有网增强了自治系统边界设备的数据处理能力,并减少了自治系统边界设备需处理的数据量,是一种构建跨域私有网的改进方案。

基于多协议标签交换路由宽带均衡算法的电网通信负载缓冲研究

为了解决现有方法存在的数据包延迟和时间较长的问题,提出基于多协议标签交换(multi-protocol label switching,MPLS)路由宽带均衡算法的电网通信负载缓冲方法。获取建立电网通信信息路由的目标函数与约束条件,结合基于MPLS的动态带宽调度算法,实现MPLS路由宽带均衡,完成电网通信负载缓冲。结果表明:采用所提方法数据包的延迟时间得到了降低,方法的应用性能理想,为相关领域的深入研究提供了可靠依据。

IP网络发展:从MPLS到SR

随着IP网络的不断发展,越来越多的人开始关注并选择在这个互联网时代通过各种渠道获取自己想要得到的信息资源。从2015年起,IP网络逐渐成为人们使用的主要媒介。以段路由(Segment Routing,SR)作为研究对象,分析了其发展现状及趋势。SR是一种基于节点转发的新型网络结构,它将传统的骨干网和接入层进行分离,使得每一个节点都可以独立完成数据传输任务。同时,为了提高传输效率、降低成本、减少对用户终端设备的依赖性,骨干网采用了扁平化设计,即将所有的设备都集中放置于同一个空间内,这样就能够有效避免设备之间相互影响,也便于管理维护。