An architecture for IP over WDM using time-division switching

This paper proposes an architecture for routing Internet protocol (IP) packets directly on optical networks. The use of label switching is assumed in the IP routers, while a new routing architecture is introduced to transport IP packets across an optical backbone network. The architecture is based on a two-tier multiplexing approach with wavelength division multiplexing (WDM) addressing the number of regional exchanges and time-division switching communicating among the hubs. Such an architecture not only has the advantages of simple network management and high efficiency with low latency; it also is scalable by addition of regional exchanges, hubs, and fibers     

全光包交换系统的实现原理

描述了光包交换节点的结构,分析了网络的物理和逻辑的可行性,介绍了一个由40个网络节点组成的节点流量达160Gbit/s的物理网络,网络能提供较好的服务质量（包丢失率和包传输延迟）并兼容多种业务,这一结果为基于全光包交换技术的灵活性网络的研究铺平了道路。     

Fast tunable wavelength conversion for all-optical packet switching

We demonstrate a simple scheme to achieve fast tunable wavelength conversion over a wide spectral range. The wavelength conversion is obtained by four-wave mixing in a semiconductor optical amplifier using a double-pump scheme, 2048-bit sequences at 2.5 Gb/s, incoming at a given wavelength, are alternatively converted toward two different wavelengths for a total conversion interval of 20 nm. With this method, the time needed to change the destination wavelength is much shorter than the bit duration. This feature makes any guard-time spacing between packets unnecessary. Bit-error-rate measurements show that the process occurs with negligible penalties (less than 0.3 dB).     

IP over WDM技术

文章介绍了IPoverWDM技术及其发展进程,论述了IPoverWDM技术的研究热点,包括IPoverWDM的网络控制技术、多协议标记交换在光网络中的应用以及自动交换光网络(ASON)等方面的内容.     

基于IP over WDM的光城域网

提出了基于IP over WDM的光城域网方案,详细阐述了波长选路WDM光城域网的多级网络拓扑及波长配置方式,并分析了波长配置方式对波长选路由策略的影响。     

中兴通讯IP over WDM解决方案

介绍了IP网络的发展趋势,承载电信级业务的IP承载网的3种组网方式,着重介绍了IP over WDM解决方案的优势和特点。     

电信辞库

ATM上的IP传输ATM上的IP传输（IPOA）技术,即只对数据流的第一个数据包进行路由地址处理,按路由转发,随后按已计算的路由在ATM网上建立虚电路（VC）,以后的数据包沿着VC以直通（Cut－through）方式进行传输,不再经过路由器,从而将数据包的转发速度提高到第二层交换的速度。目前IP与ATM的结合方式主要有重叠模型和集成模型两类。重叠模型有Internet工程任务组（IETF）推荐的CIPOA、ATM论坛（ATMF）推荐的局域网仿真（LANE）和ATM上的多协议规范（MPOA）等,集成模型有IPSwitching、多协议标记交换（MPLS）等…     

Dynamic circuit provisioning in all-optical WDM networks using lightpath switching

In this paper we investigate the problem of provisioning holding-time-aware (HTA) dynamic circuits in all-optical wavelength division multiplexed (WDM) networks. We employ a technique called lightpath switching (LPS) wherein the data transmission may begin on one lightpath and switch to a different lightpath at a later time. Lightpath switches are transparent to the user and are managed by the network. Allowing LPS creates a number of segments that can use independent lightpaths. We first compare the performance of traditional routing and wavelength (RWA) assignment to routing and wavelength assignment with LPS. We show that LPS can significantly reduce blocking compared to traditional RWA. We then address the problem of routing dynamic anycast HTA dynamic circuits. We propose two heuristics to solve the anycast RWA problem: anycast with continuous segment (ACS) and anycast with lightpath switching (ALPS). In ALPS we exercise LPS, and provision a connection request by searching for the best candidate destination node is such a way that the network resources are utilized efficiently. In ACS we do not allow a connection request to switch lightpaths. The lightpaths to each candidate destination node of a request are computed using traditional RWA algorithms. We first compare the performance of ACS to ALPS and observe that ALPS achieves better blocking than ACS. Furthermore, we also compare the performance of these two anycast RWA algorithms to the traditional unicast RWA algorithm. We show that the anycast RWA algorithms presented here significantly outperform the traditional unicast RWA algorithms.     

基于GMPLS的IP over WDM

GMPLS(通用多协议标记交换)是MPLS技术向光网络发展的产物。它有效地实现了IP和WDM光网络的无缝结合,是IPoverWDM发展的一种趋势。本文主要介绍了GMPLS通用标记的特点及实现形式,LSP(标记交换路径)技术,以及链路管理协议LMP的特点及实现方法。     

基于GMPLS的IP over WDM

GMPLS(通用多协议标签交换)是MPLS技术向光网络发展的产物。它有效地实现了IP和WDM光网络的无缝结合,是IP over WDM发展的一种趋势。本文主要介绍了GMPLS通用标签的特点及实现形式,LSP(标签交换路径)技术,以及链路管理协议LMP的特点及实现方法。     

Optical packet switching and buffering by using all-optical signal processing methods

We present a 1 /spl times/ 2 all-optical packet switch. All the processing of the header information is carried out in the optical domain. The optical headers are recognized by employing the two-pulse correlation principle in a semiconductor laser amplifier in loop optical mirror (SLALOM) configuration. The processed header information is stored in an optical flip-flop memory that is based on a symmetric configuration of two coupled lasers. The optical flip-flop memory drives a wavelength routing switch that is based on cross-gain modulation in a semiconductor optical amplifier. We also present an alternative optical packet routing concept that can be used for all-optical buffering of data packets. In this case, an optical threshold function that is based on a asymmetric configuration of two coupled lasers is used to drive a wavelength routing switch. Experimental results are presented for both the 1 /spl times/ 2 optical packet switch and the optical buffer switch.     

IP over WDM与IP over OTN组网分析

IP流量的激增不断地对核心网络的承载能力提出了新的考验,文中对IP over WDM IP over OTN两种组网方式进行了全方面的比较,从而得出具有前瞻性的观点,可为运营商建设IP核心网络提供参考。     

IP over WDM-新一代的因特网

论述了IP over WDM技术及其特点，并指出该技术面临的主要挑战是网络必须稳定可靠，且要解决服务质量保障及链路管理问题。     

IP over WDM的多层生存性

在论述IP层和光层的保护和恢复机制的基础上,提出了多层联合恢复机制的思想,针对多层联合恢复机制中各层之间如何协调进行了分析,为了获得优化的多层网络故障恢复能力,提出了利用GMPLS的基于层间协调机制的集成多层网络生存方案.     

Evaluation of IP over WDM Network Architectures

The commonly used IP-backbone network architecture of today is IP/ATM/SDH/WDM. This architecture has many redundant functionalities and is not optimized to transport IP traffic. New approaches for simplified network architectures try to eliminate redundant functionalities and to decrease the protocol overhead and thereby transport IP as efficiently as possible over WDM-based optical networks. EURESCOM project P918 Integration of IP-over-optical networks: networking and management investigated scenarios for optimized IP transport in WDM-based backbone networks. In this paper, three architectures, namely Gigabit Ethernet, Packet over Sonet/SDH and Dynamic Packet Transport are investigated and evaluated as an alternative to the IP/ATM/SDH/WDM architecture.     

IP over WDM联合路由框架

研究了IPoverWDMdirectly所面临的三大基本问题 ,重点对IP和WDM的联合路由框架进行了研究 ,分析了三种模型以及其中所用到的协议以及协议扩展。并对联合路由的控制面问题进行了研究 ,着重分析了对MPLS TE进行适当的光扩展以实现统一的控制平面。     

WDM光网络与IPoverWDM组网方式

WDM技术的出现与发展是本世纪末光纤通信发展的一个重大突破,WDM技术利用单模光纤的宽带低损耗特性,采用多个波长作为信息载波信道,各信道在一根光纤内同时传输。与单信道系统相比,密集波分复用(DWDM)不仅极大地提高了网络系统的通信容量,充分利用了光纤的带宽,而且具有扩容的灵活性和路由选择的灵活性等诸多优点,应用前景十分广阔。因此近年来,世界各国对WDM技术都进行了重点研究,新技术和新设备层出不穷,相应的光网络组网形式也随之不断改变。     

A latency-aware scheduling algorithm for all-optical packet switching networks with FDL buffers

Optical buffers implemented by fiber delay lines (FDLs) have a volatile nature due to signal loss and noise accumulation. Packets suffer from excessive recirculation through FDLs, and they may be dropped eventually in their routing paths. Because of this, packet scheduling becomes more difficult in FDL buffers than in RAM buffers, and requires additional design considerations for reducing packet loss. We propose a latency-aware scheduling scheme and an analytical model for all-optical packet switching networks with FDL buffers. The latency-aware scheduling scheme is intended to minimize the packet loss rate of the networks by ranking packets in the optimal balance between latency and residual distance. The analytical model is based on non-homogeneous Markovian analysis to study the effect of the proposed scheduling scheme on packet loss rate and average delay. Furthermore, our numerical results show how various network parameters affect the optimal balance. We demonstrate quantitatively how to achieve the proper balance between latency and residual distance so that the network performance can be improved significantly. For instance, we find that under a given latency limit and light traffic load our scheduling scheme achieves a packet loss rate 71% lower than a scheduling scheme that ranks packets simply based on latency.     

An analytical model for all-optical packet switching networks with finite FDL buffers

Signal loss and noise accumulation can cause fading in optical buffers implemented by fiber delay lines (FDLs). Optical packets that excessively recirculate through FDLs are easily dropped from their routing paths. Therefore, analytical models and packet scheduling schemes require additional considerations for FDL buffers. This work proposes an analytical model for all-optical packet switching networks with finite FDL buffers and a general class of scheduling schemes including many basic scheduling schemes. We intend to minimize the packet loss probability by ranking packets to achieve an optimal balance between latency and residual lifetime in the general class of scheduling schemes. The analytical model is based on a non-homogeneous Markovian analysis to study the effects of various scheduling schemes on packet loss probability and average latency. Analytical results show how various network parameters affect the optimal balance, and illustrate how properly balancing latency and residual distance can significantly improve network performance.     

MPLS支持移动IP技术研究

移动IP是一种在全球Internet上为移动节点提供移动功能的方案。同时,鉴于MPLS是一种基于三层边缘路由、二层核心标签交换的技术,可以较大程度地提高分组的转发速度,业界对扩展MPLS功能使其支持移动性产生了极大的兴趣。文章主要讨论MPLS支持移动IP的技术细节。