采用ATM技术对我省DDN网络进行优化整合思路的探讨24

本文论述了利用ATM技术整合DDN网络的诸多优点,并提出了如何利用此技术整合DDN骨干网、融合DDN接入节点、进行网络管理的具体方案。     

采用ATM技术对我省DDN网络进行优化整合思路的探讨

本文论述了利用ATM技术整合DDN网络的诸多优点,并提出了如何利用此技术整合DDN骨干网、融合DDN接入节点、进行网络管理的具体方案.     

多业务交换机改造DDN网络一例

DDN是为用户提供数据专线服务的网络，随着数据业务的发展和网络规模的扩大，DDN网络暴露出一些难以克服的问题。随着ATM和帧中继PVC业务的发展，由于其可提供的速率更高，技术更灵活，价格相对DDN更为便宜，未来五年，将会有越来越多的DDN用户转向帧中继的PVC业务，而将来相当一部分帧中继用户将出自于目前的DDN用户群。因此，云南省电信在综合考虑了网络业务的发展和现有网络的平滑过渡等多方面因素的基础上，决定采用多业务网络对现有的DDN网络进行整合，从而解决DDN骨干中继电路不足的问题，同时为专线网络向宽带化、智能化…     

迈普MP9710:开启数据网络融合的“标兵”

随着高速数据专线需求的增长,国内运营商在近两年加大了ATM网络的建设。但是,因为ATM网络投入大、用户接入能力弱,运营商普遍面临着前期投资无法回收、网络盈利能力低等问题。针对这些问题,国内著名数据通信厂商迈普近日推出了全新的Mp9710多业务接入平台(MSAP),首要目标就是实现ATM网络的延伸,整合ATM网络和DDN网络的优势,让运营商能够挖掘现有网络价值,以低成本提供灵活多样的数据专线业务,达到投资快速回收和网络的持续可盈利目标。作为一款功能强大的宽窄带多业务接入设备,MP9710主要提供宽、窄带多业务接入,也可以作为ATM边缘接入设备。该设备景大的创新在于以DDN设备的价     

MP9710:实现ATM、DDN合璧

随着高速数据专线需求的增长,国内运营商在近两年加大了ATM网络的建设。但是,因为ATM网络投入大、用户接入能力弱,运营商普遍面临着前期投资无法回收,网络盈利能力低等问题。针对这一问题,国内数据通信厂商迈普推出了全新的MP9710多业务接入平台(MSAP),其首要目标就是实现ATM网络的延伸,整合ATM网络和DDN网络的优势,让运营商能够挖掘现有网络价值,以低成本提供灵活多样的数据专线业务,达到投资快速回收和     

电路仿真在江苏省宽带网上的应用

为解决DDN骨干网中继带宽日益紧张的局面，江苏省拟利用现有的ATM宽带网的资源，采用电路仿真技术，在ATM网上实现省内DDN骨干网中继汇接的功能。通过在江苏省宽带网上进行电路信真测试，结果均达到要求。     

互连网发展过程

互连网在近几年已经得到飞速发展，从早期的用DDN专用线路互连路由器阶段发展到ATM交换网互连带ATM SAR（分割及拼接）接口的路由器阶段，目前已经进入MPLS网络阶段，本简要介绍了互连网经历的这三个发展阶段，讨论了它们的性能特点。     

上海电信大客户网络管理系统

文章介绍上海电信大客户网络管理系统(CNMS,customnetworkmanagementsystem)是基于TMN开发的数据网网络管理系统。该项目第1期完成了DDN网的管理,第2期将逐步实现DDN网、X.25网、帧中继网和ATM网的统一管理。     

网络互联业务的实现

随着近几年信息产业的迅速，人们对通信的需求已从传统的电话、传真、低速数据等逐渐向高速Internet接入、网络互联、电视电话会议、远程教育、远程医疗、VOD等宽带业务领域延伸。其中,网络互联业务对于企业或行业集团各分支机构实现内部信息的交换变得越来越重要，他们迫切需要电信运营商提供一种高速、安全、经济、扩展性好的网络。实现网络互联的方式一般基于两种，一种是基于DDN、FR、ATM的传统网络，通过专线实现互联。典型的网络互联是通过DDN采用点到多点的方法实现；也可以基于FR、ATM网络，采用二层技术实现；有时也往往采…     

出租数据电路故障分析及解决办法

1概述20世纪90年代中期,分组、DDN和FR/ATM电路逐步在我国银行、证券、保险等行业业务网建设中得到广泛应用,特别是1998～2001年,DDN和FR/ATM电路需求量迅速增加。客户对网络的依赖性的增强,意味着用户对电路质量的要求越来越高。中国网通和中国电信是目前向客户提供数据专线出     

一种基于SDH光网络的DDN实现方案

DDN网络为专线业务的发展做出了较大的贡献,但是,其网络的持续发展却遇到了诸多困难.文中分别论述了DDN网络和SDH网络的发展,充分考虑到SDH(MSTP)光网络的发展现状,综合DDN网络以及DDN业务自身的特点和实际情况.提出一种基于SDH(MSTP)光网络的DDN业务实现方案.该方案实现了高性价比的DDN网络的升级和扩容,解决了DDN网络的发展中遇到的诸多困难,在一定程度上又丰富了MSTP的内容.     

Broadband satellite networks-the global IT bridge

Next-generation broadband satellite networks are being developed to carry bursty Internet and multimedia traffic in addition to the traditional circuit-switched traffic (mainly voice) on a global basis. These satellites provide direct network access for personal applications as well as interconnectivity to the terrestrial remote network segments. The main requirement in success of these networks is that they should be able to transmit high data rate traffic with prescribed quality of service (QoS). Thus, the broadband satellite network has no choice other than the rise of ATM technology and to be optimized for Internet-based traffic. ATM is the promising technology for supporting high-speed data transfer potentially suitable for all varieties of private and public telecommunications networks. IP, on the other hand is the fast-growing Internet layer protocol that is applicable over any data link layer Internet-based applications are the emerging source of traffic in the future wireless networks and broadband satellite networks should consider Internet as the primary service. In this paper, we discuss the traditional ATM and wireless ATM networks and explain the characteristics of the wireless IP networks. The paper then uses those concepts in defining the criteria for the broadband satellite networks such as the QoS and traffic management. Application of the broadband satellite networks is also proposed     

ATM in MPLS-based converged core data networks

Services supported by asynchronous transfer mode account for the majority of data and Internet service revenues generated by carrier networks today. This is based on ATM's ability to support high availability services with quality of service. However, the influences of the Internet and a highly dynamic telecommunications market have raised demands for increased flexibility while controlling costs. Therefore, future carrier networks are likely to continue to be based on established technologies, such as ATM, as well as IP. In many cases, this is achieved through maintaining separate ATM and IP core networks, with the IP network supporting Internet services, while the ATM network continues to support guaranteed services such as private lines, broadband access, and video. In some cases, however, it can be advantageous for a carrier to transport segments of their ATM network over their IP network core; for example, to transport ATM traffic currently carried on leased facilities onto an IP network where the service provider owns the facilities. Developments in IP and MPLS-based traffic engineering and QoS may increase the ability of IP-based networks to support ATM services using MPLS. This article provides an overview of approaches enabling a network based on MPLS that naturally supports IP services to also support ATM services. The drivers and requirements for convergence on an IP/MPLS core network are presented, followed by an overview of the different approaches and associated challenges currently being debated in the standards bodies.     

ATM网络中实现视频业务

近年来,视频业务伴随着应用需求的增长而迅猛发展,视频业务是使用ＡＴＭ网络提供高速宽带业务的重要应用之一。本文从视频业务的编码方式,视频数据到ＡＴＭ信元的映射、视频业务的质量保证和ＡＴＭ论坛的频点播建议几方面分析了在ＡＴＭ网络中实现视频业务的主要技术热点。     

Wireless ATM—an overview

This paper sketches the requirements and possibilities of wireless ATM in local area networks. Because of the wide range of services supported by ATM networks, ATM technology is expected to become the dominant networking technology in the medium term for both public infrastructure networks and for local area networks. ATM infrastructure can support all types of services, from time-sensitive voice communications and desk-top multi-media conferencing, to bursty transaction processing and LAN traffic. Extending the ATM infrastructure with a wireless access mechanism meets the needs of those users and customers that want a unified, end-to-end networking infrastructure with high-performance, consistent service characteristics. The paper introduces ATM concepts, discusses the requirements for wireless ATM, in particular for data link control and radio functions. It closes with some notes on development of wireless ATM research systems standardization and spectrum allocations.     

Traffic management for TCP/IP over satellite ATM networks

Several Ka-band satellite systems have been proposed that will use ATM technology to seamlessly transport Internet traffic. The ATM UBR, GFR, and ABR service categories have been designed for data. However, several studies have reported poor TCP performance over satellite ATM networks. We describe techniques to improve TCP performance over satellite ATM networks. We first discuss the various design options available for TCP end systems, IP-ATM edge devices, as well as ATM switches for long-latency connections. We discuss buffer management policies, guaranteed rate services, and the virtual source/virtual destination option in ATM. We present a comparison of ATM service categories for TCP transport over satellite links. The main goal of this article is to discuss design and performance issues for the transport of TCP over UBR, GFR, and ABR services for satellite ATM networks     

Technology interworking for SMDS: from the DXI/SNI to the ATM UNI

As service providers introduce asynchronous transfer mode (ATM) into their networks, they are faced with the issue of technology interworking: for a given service, can a customer who has an ATM user-network interface (UNI) communicate with a customer who does not have an ATM UNI? For switched multimegabit data service (SMDS), technology interworking is well defined. In fact, SMDS is supported by several technology platforms that can interwork with each other. The three major platforms which support SMDS are: a frame-based platform based on the SMDS data exchange interface (DXI), a cell-based platform based on the IEEE 802.6-1990 standard, and a cell-based platform based on ATM. This article examines how SMDS is supported by each of these platforms and how these platforms interwork. Furthermore, this article presents how the major interworking functions required for these platforms appear to be straightforward for suppliers to implement,     

Survey of traffic control schemes and protocols in ATM networks

The authors survey a number of important research topics in ATM (asynchronous transfer mode) networks. The topics covered include mathematical modeling of various types of traffic sources, congestion-control and error-control schemes for ATM networks, and priority schemes to support multiple classes of traffic. Standard activity for ATM networks and future research problems in ATM are also presented. It is shown that the cell-arrival process for data sources can be modeled by a simple Poisson process. However, voice sources or video sources require more complex processes because of the correlation among cell arrivals. Due to the effects of high-speed channels, preventive control is more effective in ATM networks than reactive control. Due to the use of optical fibers in ATM networks, the channel error rate is very small. The effects of propagation delay and processing time become significant in such high-speed networks. These fundamental changes trigger the necessity to reexamine the error-control schemes used in existing networks. Due to the diversity of service and performance requirements, the notion of multiple traffic classes is required, and separate control mechanisms should be used according to the traffic classes. The priority scheme is shown to be an effective method to support multiple classes of traffic     

ATM local area networks

LAN emulation offers a best-effort, connectionless, packet transfer service at the MAC sublayer, implemented on top of a connection-oriented ATM network LAN emulation using switched virtual connections requires address resolution to locate the destination end station followed by connection establishment to the resulting ATM address. Address resolution may be implemented by a broadcast technique or by an address server. The broadcast method is the simplest for small networks but a combination of both is probably better. The use of the MAC address to identify an end station, with dynamic binding to its current physical location in the ATM network, allows the ATM LAN segment to be viewed as a virtual LAN. The virtual LAN model permits end stations to move and change physical location while maintaining connection to the same ATM LAN segment. This greatly simplifies the management of large data networks