光纤综合业务环形网的故障管理

故障管理在网络管理中占有重要位置，尤其在环形网中结点之间相互串接情况下显得特别重要。综合业务区域网的故障管理是当今国际上研究的一个热门话题。本文对一个具有３４Ｍｂ／ｓ传输速率的ＩＳＲ（ＩｎｔｅｇｒａｔｅｄＳｅｒｖｉｃｅｓＲｉｎｇ）的故障管理进行了研究，对两类故障的检测处理分别用不同的方法实现。     

一个光纤综合业务环网的故障自动恢复

研究一个具有34Mb／s速率，可传输计算机数据、话音、传真和会议电视的光纤综合业务环网（ISR）故障的自动隔离。分析了ISR的故障，讨论了故障的检测、定位和隔离的方法。为了适应综合业务的混合电路交换和分组交换技术，提出了采用二分搜索法来定位故障．     

广州B－ISDN示范网简介

广州Ｂ－ＩＳＤＮ示范网简介广州市电信局李秉权广州宽带综合业务数字示范网于１９９５年６月正式建成并开放示范业务，是具有一定实用意义的示范网。Ｂ－ＩＳＤＮ可以把电话、图片、视像、数据等通信业务集成在一个平台上讲行交换、传输。广州Ｂ－ＩＳＤＮ示范网是我国第...     

上海开放窄带ISDN业务

上海开放窄带ＩＳＤＮ业务上海市内电话局已于今年１月中旬向社会开放窄带综合业务数字网（Ｎ－ＩＳＤＮ），并接纳了首批用户。Ｎ－ＩＳＤＮ业务是以现有程控交换网为基础，经过技术改进开放的新通信业务。上海局开发的Ｎ－ＩＳＤＮ功能允许对普通电话线连接８个不同的终...     

利用数字程控用户交换机实现计算机联网

利用数字程控用户交换机实现计算机联网舒劲松综合业务程控用户交换网（ＩＳ─ＰＡＢＸ网）是清华大学校园网的重要组成部分，它以电路交换方式向用户提供话音及非话业务信息的通路，实现全校范围内的电话通信和数据通信。ＩＳ─ｐＡＢＸ网以ＳＯＰＨＯ─Ｓ２５００数字程...     

从吐哈油田HFC网的建设看有线电视的发展趋势

1　引言1993年 9月美国政府提出“信息高速公路计划” ,掀起了全球开发高速通信网的热潮 ,基于电路交换的数字数据网 (ＤＤＮ)、窄带综合业务数字网 (ＩＳＤＮ) ;基于分组交换的光纤分布数据接口网 (ＦＤＤＩ)、ＦＲ帧中继网以及ＡＴＭ等技术的出现 ,使通信网能在干线或局域网中实现高速大容量的信息传递。然而这些网络大多为共享型 ,传输量有限 ,易形成“瓶颈”现象 ,因此目前制约通信的主要障碍是接入网技术 ,即“最后 1ｋｍ”问题。ＨＦＣ有线电视网以其频带宽、容量大、低成本、双向性等优势 ,并兼顾现有的模拟信息和数字信息 ,是目前接…     

东莞市邮电通信网的信息化进程

顺应全球信息化的潮流，从“三金工程”等金字系列工程着手，我国的信息网络建设工作开始起步，广东邮电系统根据广东省委、省政府关于建设信息高速公路的总体部署，利用邮电公用网，承担起提供信息交换传输平台的任务。文章着重介绍了东莞市邮电局开展的一些信息化的新业务，具体有：建设光纤用户接入网、组建东莞市宽带试验网、组建“视聆通”多媒体信息服务网，大力发展数据通信业务，组建本地ＩＳＤＮ网，广州ＩＳＤ国际局接口。     

现代通信网技术讲座(6)

３窄带综合业务数字网 (Ｎ -ＩＳＤＮ)建立综合业务数字网 (ＩＳＤＮ)的目的是将现有的各种通信网综合成一个网 ,即将所有业务综合到一个数字网中进行传输、交换与处理。引入ＩＳＤＮ后用户只需使用一对双绞线 ,就可将多种业务终端接入网内 ,并按统一的规程进行通信 ,故ＩＳＤＮ又称“一线通”。原ＣＣＩＴＴ对ＩＳＤＮ的定义包括以下几点 :(１)ＩＳＤＮ是以综合数字电话网 (ＩＤＮ)为基础发展而成的通信网 ;(２)ＩＳＤＮ提供端到端的数字连接 ;(３)ＩＳＤＮ支持话音及非话音等多种通信业务 ;(４)用户通过有限的一组标准多功能用户／网络接…     

新型CATV光传输设备

随着光纤传输技术和综合业务接入技术的不断发展,光纤到乡村、光纤到大楼、光纤到路边,实现用户端的电视、电话、数据三网融合,完成综合业务接入的技术方案正在推广应用之中,ＣａｂｌｅＳｅｒｖｅ就是实现这种技术方案的设备。Ｃａ－ｂｌｅＳｅｒｖｅ作为ＨＦＣ组网设备之一,具有模块化的设计结构,能够按需进行设备组合,提供多种用户接口、灵活的用户综合业务接入方式、可靠的网络管理、实时的监控与故障处理等功能。１系统组成 ＣａｂｌｅＳｅｒｖｅ设备主要由位于有线电视台或交换中心的前端设备、光纤传输分路设备、按用户数量及…     

5种数据通信网的特点与应用

数据通信网主要完成数据传输与交换任务,并为广域网和城域网提供网络互连技术。按ＯＳＩ－ＲＭ七层协议分析,数据通信网提供的是低３层功能,即网络层、链路层、物理层的功能。目前的数据通信网主要有分组交换网、帧中继（ＦＲ）网、ＤＤＮ网、ＡＴＭ网。Ｎ－ＩＳＤＮ网等。其中,ＤＤＮ网、帧中继、分组交换网和ＡＴＭ网,也被称为是广域网的互连技术,而Ｎ－ＩＳＤＮ主要是面向用户提供话音和非话音业务的窄带电信业务网。表１比较了各种数据网的特点。 １．分组交换网 分组交换网是最早的数据交换技术,它的基本原理是：将用户信息封装…     

Integrated voice and data communications overview

The author reviews architectures and traffic characteristics for voice and data communications, and addresses important issues in integrated voice and data communications. He discusses some possible methods of integrating voice and data and presents an example of implementing integrated voice and data communications. He considers ISDN (integrated services digital network) as a vehicle for supporting integrated services including voice and data as well as image and video. Although the concern is mainly with switched networks, some of the concepts discussed are applicable to both switched and special-services networks     

Diagnosis of single faults in bitonic sorters

Bitonic sorters have recently been proposed to construct along with banyan networks the switching fabric of future broadband networks. Unfortunately, a single fault in a bitonic sorter may have disastrous consequences for the switching system. Therefore, a bitonic sorter must be proved to be free of faults before it can be used. We study the topological properties of bitonic sorters and present an efficient fault diagnosis procedure to detect, locate, and identify the fault type of single faults. Our diagnosis procedure can detect most single faults in two tests. Faults which cannot be detected in two tests can always be detected in four tests. Several binary search techniques are developed to locate a faulty sorting element (i.e. a 2×2 sorter)     

FB-banyans and FB-delta networks: Fault-tolerant networks for broadband packet switching

Many fast packet switches for the broadband integrated services digital network (BISDN) in the literature are based on banyan networks. Although banyan networks possess nice properties such as a simple control and a low hardware cost, they are unique-path networks. Since there is a unique path from an input to an output in a banyan network, a single component failure may disrupt services of some nodes connected to such a network. Moreover, banyan networks are also blocking networks; packets can be lost within the networks. To reduce the packet loss, buffered banyan networks can be used. In an earlier work we have proposed the addition of backward links to otherwise unidirectional banyan networks to create B-banyans (and B-delta networks). Backward links not only function as implicit buffers for blocked packets, but also provide multiple paths for each input-output connection. However, the multiple paths in B-banyans may not be disjoint. In this paper, we enhance B-banyans and B-delta networks in such a way that the resulting networks can provide disjoint multiple paths for each input-output pair. The existence of disjoint multiple paths has a significant effect on the network fault-tolerance. The new networks, called FB-banyans and FB-delta networks, are k fault-tolerant, where k is the number of backward links per switch and is less than the switch size. They are also robust to more than k faults, depending on the locations of faults. The maximal fault-tolerance is achieved when k is the switch size minus 1. The performance of the new networks is analysed and compared to that of other networks of interest. FB-banyans and FB-delta networks can be used as a switch fabric for fast packet switches to provide performance comparable to that of buffered banyan networks and good fault tolerance.     

Simultaneous Transmission of Millimeter-Wave and Baseband Signals Using Wavelength Interleaving and Polarization Multiplexing for an Integrated Reconfigurable Access Network

A novel scheme for the simultaneous transmission of 1.25-Gb/s baseband (BB) signals and 155-Mb/s 60-GHz radio-over-fiber (RoF) signals is experimentally demonstrated. The BB and RoF signals are wavelength-interleaved and polarization multiplexed. Tunable filtering along with polarization demultiplexing are used to drop an RoF signal with the wavelength-interleaved BB signal. This scheme is suited for future reconfigurable ring/bus access networks to provide an integrated platform for BB and millimeter-wave services.     

弹性分组数据（RRR）环技术

随着各电信运营商大力开展宽带域网建设，如何提代电信级的数据服务变得越来越重要。本文详细阐述了新型的弹性分组数据环（RPR）技术的特征，以及RPR技术与SDH、以太网技术相比在环形拓扑结构上支持数据业务的优势。     

An integrated services token-controlled ring network

A ring protocol is proposed that allows voice and data traffic to coexist within the ring. This ring has the following distinct features: (1) it allows synchronous traffic such as voice and video to have a definite access to the channel within each packetization period (or frame); (2) it allows data messages to have a higher channel access priority provided that the synchronous traffic is not delayed by more than one frame; (3) it supports variable rate data circuits. Simulation results show that the data-message delay is much smaller than for other integrated services schemes. Urgent messages can be transmitted with a higher priority over voice. Since the voice packet delay is bounded within one packetization period, no time-stamping is needed and the voice loss can be completely avoided by reserving a sufficient number of slots. Continual speech reception is possible by synchronizing the speech regeneration process to the end of each frame. Since the ring is synchronized, gateway switching to external circuit-switched and packet-switched networks is very simple     

Integrating communication services

The need for communication services which span multiple communication technologies is growing. Communication services are being developed in three areas: in the public switched telephony networks, on the Internet in the form of integrated multimedia including voice-over-Internet, and in private switched telephony networks in the form of enterprise computer-telephony integration applications. This article shows it is plausible to create unified services which span the Internet and public switched telephony networks, and goes on to describe Nexus, an architecture and prototype for integrated communication services     

Error control techniques for integrated services packet networks

The design of a multiservice packet network must ensure that delays to speech packets are minimized while data and other types of packets are delivered without error. The author suggests some ways in which error detection, forward error correction (FEC), and automatic repeat request (ARQ) schemes may be utilized in integrated services packet networks (ISPNs) to ensure that satisfactory error performance and reliability standards are achieved. The results show that ARQ schemes combined with reliable error detection are the most practical way of achieving reliable error control in integrated services networks. Also, such error control schemes can have performance advantages if applied on a region-by-region basis rather than simple end-to-end     

基于二分图模型的通信信息网络故障联合定位

国家电网信息通信网络依靠两套运维系统,分别实现对信息网络与通信网络的故障定位与分析,然而通信网络故障往往会引发信息网络故障,如何高效精确地进行通信信息网络故障联合定位是亟需解决的问题.针对信息通信网络的联合故障定位问题,提出了基于二分图模型的故障联合定位算法.首先依据通信网网络节点的关联性对网络分簇,并将每一簇作为一个子域.其次在每个子域内建立基于二分图的故障关联影响模型,最终利用目标排序法并行地对多个子域内网络故障进行分析,从而实现通信信息网络关联故障高效精确的联合定位.实验结果表明,该联合故障定位分析方法的故障诊断率达85％～95％.