POS技术在实时测控系统中的应用

POS又称IP Over SDH，即Packet Over SONET／SDH．顾名思义，即通过SDH提供的高速传输通道直接传送IP分组。其基本思路是：通过点到点协议(PPP)将数据包映射进SONET／SDH帧结构净负荷区，用SDH和高速路由器组网，将路由计算与数据包转发分别处理，采用缓冲技术、硬件芯片快速处理技术及交换路由     

在SONET／SDH架构上实现以太网透明传输的方案

引言 本文介绍了通信半导体供应商安捷伦科技与中国武汉邮电科学院共同开发的在SONET/SDH架构上提供IP业务的IC解决方案:多协议芯片(MPIC,Multi-Protocol IC)系列中的EoS(Ethernet over SONET/SDH)芯     

安捷伦科技创新产品--以太网到SONET/SDH映射芯片

安捷伦科技公司 ( Agilent Technologies)日前宣布推出其创新产品 HDMP- 30 0 1—以太网到SONET/SDH ( Eo S)映射芯片。HDMP- 30 0 1是一款通用芯片 ,运用该创新产品 ,网络和电信设备可为既有的 SONET/SDH网络同时提供局域网和广域网的接口 ,大大降低了覆盖多个地域的企业网络的运营维护成本。HDMP- 30 0 1是由安捷伦科技与武汉邮电科学研究院共同研究开发的 ,也是安捷伦科技的SONET/SDH多协议芯片 ( MPIC)系列中的第一款。MPIC可以将各种协议的信息映射到 SONET/SDH中 ,为企业级用户将数据业务传送到 SONET/SDH…     

MSR下一代光城域网架构

作为骨干网络到业务界面的桥梁，光城域网在整个电信网的作用越来越重要，其业务主体正在发生深刻变化。一方面，在已建成的传统骨干网和城域网中，SDH／SONET毫无疑司占据了绝大部分份额．是传送语音的最好技术。另一方面，经过多年的应用实践证明．以太网是传送IP的最好技术之一。现有城域网为了承载和支持与IP相关的业务．绝大多数基于包的传输和交换需要经过SDH／SONET网。在此方面，烽火网络已根据自己提出的国际标准X.86(EOS：Ethernet over SDH／SONET)开发了EOS芯片及系统设备，为以太网和SDH网络的融合以及实现数据和语音的一体化传输提供了一种简洁、高效的二层技术。     

在SDH/SONET 155Mbit/s上承载 IP包的解决之道

1前言随着近年来Internet的发展，IP网络将成为未来通信网络的重要应用平台。各大通信运营商为了传送话音业务已经铺设了采用SDH/SONET技术的庞大的光纤通信基础网络。在向统一的通信网———IP网络演变过程中，保护现有投资就成了各大通信运营商首先考虑的问题。服务供应商需要一些价格经济的解决方案，通过他们现有的SDH/SONET网络传输以太网业务。CCOM推出了基于EOS（Eth-ernetoverSDH/SONET）技术的应用产品，它能将现有的通信网中的两大技术：以太网技术和SDH/SONET技术有机地结合起来，因而保护了广大用户和通信运…     

广电IP over SDH的应用探讨

分析了SONET/SDH网络的现状和IP over SDH的优势及工作原理,提出了IP over SDH技术在泰州广电网中的应用方案,并探讨了相关技术.     

在SONET/SDH架构上实现以太网透明传输的方案

介绍了在SONET／SDH架构上提供IP业务的IC解决方案：多协议芯片（MPIC，Multi-Protocol 1C）系列中的Eos(Ethernet over SONET/SDH）芯片。此款在SONET／SDH架构上实现以太网透明传输的方案较之现有的其他方案，具有高带宽利用率（虚级联）、低成本（二层处理）、易实现（标准以太网GMII和MII接口）等优势。     

广电IP over SDH的应用探讨

分析了SONET/SDH网络的现状和IP over SDH的优势及工作原理,提出了IP over SDH技术在泰州广电网中的应用方案,并探讨了相关技术.     

还能“风光”多久

20世纪70年代后期，第一个光纤通信现场试验系统问世以来，技术不断进步，应用规模愈来愈大。90年代初期。SDH/SDNET问世之后，把光通信技术推向了一个新的阶段。因特网的推广应用，使光通信可以大显身手。然而，经过IP over ATM/SDH/Optical之类的“舌战”之后，似乎在业界出现了SDH/SONET不再“风光”的断言。究竟SDH/SONET能否“风光”再现？本从技术、应用和市场的不同角度，分析了SDH/SONET还能有相当一段生命期，至少在未来3-5年内还是传送网采用的主流技术。     

POS信号中IP包的提取及FPGA实现

针对目前广泛应用的通过同步数字体系(Synchronous Digital Hierarchy,SDH)提供的高速传输通道直接传送IP分组(IP Over SONET/SDH,POS)技术,主要研究了POS的封装过程,分析了从POS信号中提取出IP包的实现过程,并提出了IP包提取的方法,使用Altera FPGA进行了设计实现。通过FPGA验证表明,设计能够完成从POS信号中提取IP包的功能,满足光纤通信中POS信号IP包提取的需求。     

ATM交换机POS接入技术研究

POS即为Packet over SONET/SDH,是一种在同步光网络上承载IP数据的技术,也是当前因特网上一种重要的传输技术,该技术具有费用低、带宽利用率高、网络简单的优点,因此有广泛的应用前景。讲述了POS技术的原理,并结合ATM交换机,详细讨论了POS技术在硬件方面实现的原理及方法,在软件实现方面给出了功能单元、工作流程及设计要点。     

广电IP over SDH的应用探讨

分析了SONET/SDH网络的现状和IPoverSDH的优势及工作原理 ,提出了IPoverSDH技术在泰州广电网中的应用方案 ,并探讨了相关技术。     

实现下一代SONET/SDH新业务的关键技术

本首先分析了SONET/SDH的现状，由此引出下一代SONET／SDH的新业务—DoS，接着指出几种现有的IP over SDH的缺点，在此基础上介绍实现DoS的关键技术——GFP、VC、LCAS，最后分析讨论了这些新技术相对于现有技术的优势。     

利用DWDM实现核心网络的光网络互联

光网络互联实现了综合ＩＰ、ＡＴＭ、ＳＯＮＥＴ／ＳＤＨ和ＤＷＤＭ技术的低成本网络。ＤＷＤＭ技术彻底改变了核心网络,在ＤＷＤＭ配置的第二阶段,ＩＰ路由器和ＡＴＭ设备直接连接到ＤＷＤＭ,省去了ＳＯＮＥＴ／ＤＳＨ和ＡＴＭ,降低了成本,简化了扩容。光网络互联多数利用了现有标准,但新技术、新网络元素的引入同多带来了互操作问题,因此必须建立开放的ＤＷＤＭ系统,这也将推动光网络互联标准的发展。     

On IP-over-WDM integration

Expanding Internet-based services are driving the need for evermore bandwidth in the network backbone. These needs will grow further as new real-time multimedia applications become more feasible and pervasive. Currently, there is no other technology on the horizon that can effectively meet such a demand for bandwidth in the transport infrastructure other than WDM technology. This technology enables incremental and quick provisioning up to and beyond two orders of magnitude of today's fiber bandwidth levels. This precludes the need to deploy additional cabling and having to contend with right-of-way issues, a key advantage. Hence, it is only natural that over time optical/WDM technology will migrate closer to the end users, from core to regional, metropolitan, and ultimately access networks. At present, WDM deployment is mostly point-to-point and uses SONET/SDH as the standard layer for interfacing to the higher layers of the protocol stack. However, large-scale efforts are underway to develop standards and products that will eliminate one or more of these intermediate layers (e.g., SONET/SDH, ATM) and run IP directly over the WDM layer. IP over WDM has been envisioned as the winning combination due to the ability of the IP to be the common revenue-generating convergence sublayer and WDM as a bandwidth-rich transport sublayer. Various important concerns still need to be addressed regarding IP-WDM integration. These include lightpath routing coupled with tighter interworkings with IP routing and resource management protocols, survivability provisioning, framing/monitoring solutions, and others     

New transport services for next-generation SONET/SDH systems

SONET/SDH systems have been the preferred transport technology over fiber optics for almost two decades now. Carriers have developed extensive expertise in operating, managing, and developing business models for these systems. Manufacturers' technical expertise in such systems has increased to a deep understanding of what transport over fiber is about. In short, SONET/SDH can be called a mature transport technology. Out of this mature expertise, new techniques for bettering transport over fiber services have appeared. These techniques are likely to considerably reshape the next generation of SONET/SDH systems in many aspects: new transport techniques, new transport services, new management systems and business models. We describe several new transport techniques, and discuss their impact on the creation of new transport services for next-generation SONET/SDH systems     

Future transport network architectures

The architecture of today's long distance transmission networks, which we call the baseline architecture, is a complex and multilayered hierarchy of TDM circuits. One premise of the baseline architecture is that restoration from network failures is provided mostly by SONET/SDH rings. This article presents an alternative architecture that uses ATM and optical layer cross-connect technology for TDM services. Using a sophisticated set of network design tools developed at AT&T Labs-Research, we show that the alternative architecture offers dramatic capital savings and improved network efficiency over the baseline architecture. Most of this savings can be attributed to use of OLXC mesh network restoration, which makes more efficient use of capacity than SONET/SDH rings, and use of ATM switching for transport of TDM circuits, which consolidates the numerous TDM equipment layers inherent to the baseline architecture. In addition, motivated by the rapid growth of IP services, we analyze in the alternative architecture whether to provide restoration for IP services in the IP layer itself, by rerouting packets over precalculated restoration paths with MPLS, or to alternatively provide restoration of failed IP layer links in the OLXC layer. One potential advantage of IP layer restoration is that network operators may choose to only restore a fraction of the services, in particular the “priority” services, affected by a network failure. This article gives some methodology of how to determine this fraction at which IP layer restoration is cost-competitive with OLXC restoration     

Carrier ethernet

This article sets out the opportunity and the role of Ethernet within large-scale carrier networks. Carrier Ethernet can greatly reduce the consequences of the complexity associated with the large scale and broad scope of carriers' networks by being a cost-effective replacement for SONET/SDH. However, in order to achieve this, carrier Ethernet needs to provide the equivalent level of transparency, simplicity, and reliability currently achieved by SONET/SDH, and the emerging IEEE Ethernet standards for PBB and PBB-TE are well suited to this role. These technologies are an ideal complement to IP/MPLS for which they can provide highly cost-effective managed and guaranteed bit pipes.     

新型协议及设备架起连通以太网与SONET世界的桥梁

通信领域受控于两种截然不同的技术，即用于局域网（LAN）中内部业务通信的以太网及广域网（WAN）中的SONET/SDH。在网络可靠性至关重要的企业环境中，以太网已经成为普遍使用物数据网络协议，以太网具有简单，高效和可靠性极高等优点，适用于LAN环境，本介绍了虚级联和通用成帧规程。     

Survivable virtual concatenation for data over SONET/SDH in optical transport networks

Next-generation SONET/SDH technologies-namely, generic framing procedure, virtual concatenation, and link-capacity-adjustment scheme-enable network operators to provide integrated data and voice services over their legacy SONET/SDH infrastructure to generate new revenue. An important open research problem on data over SONET/SDH (DoS) is survivability: SONET automatic protection switching is too resource inefficient for data services, and the protection mechanisms of data networks are too slow for mission-critical applications. We propose two approaches for provisioning survivable DoS connections. Our approaches exploit the tradeoff between resource overbuild and fault-recovery time while utilizing the inverse-multiplexing capability of virtual concatenation to increase backup sharing. Our results show that one approach achieves low resource overbuild and much faster fault recovery than that of data networks, and the other approach achieves fast fault recovery comparable to SONET 50-ms protection (for typical U.S. backbone networks) while still achieving modest backup sharing. We further investigate the tradeoff between network blocking performance and network control and management complexity resulting from the number of paths M a connection can be inversely multiplexed onto: larger M leads to more freedom in routing and better network performance but increases network control and management complexity. Our results indicate that the network blocking performance for small values of M (e.g., M=2 for some representative backbone network topologies) is almost as good as the case in which M is infinity.