ISDN——带您进入数字时代

近两年来,ISDN在我国蓬勃发展起来,各省市的电信部门相继开通ISDN业务。尤其在上海、广州、福州、北京等地,ISDN的发展趋势更是势不可挡。就上海来说,到今年5月份,ISDN用户已达32,000。ISDN凭借其连接速度快、传输质量高等优势正吸引着越来越多的用户。     

我国公用网ISDN标准制定成果显著

近几年来ISDN从低谷走出,多媒体桌面办公系统和接入In-ternet使ISDN有了广泛市场前景。我国北京、上海、广州、深圳、南京等地区在进行ISDN现场试验,使ISDN在信息服务的领域发挥作用。邮电部传输所在部科技司的部署下,拓展国家“七五”和“八五”ISDN攻关项目的多年实践和ITU-T以及ETSI相关国际标准分链与多个厂家的技术谈判,在我国公用网ISDN标准制定方面取得了显著的成果。目前已经制定了《ISDN技术体制》;《ISDN用户—网络接口技术规范》,简称DSSI(包括物理层,链路层、网络     

北京通信ISDN业务预测及停止促销利弊分析

1 背景介绍 ISDN业务是北京通信2002年度,特别是上半年发展的重点。从2001年开始ISDN业务就一直在有力度的促销中,截止到4月份,ISDN用户总数已突破30万户,达30.1万户,位居全国第一。在ISDN发展如火如荼的时候,北京通信毅然决定从2002年4月1日开始,停止ISDN的促销,将重点向宽带网转移。此次营销政策的调整,引发出不少争议。因此,对该调整给ISDN业务发展和收入所造成的影响做出合理预测,并针对预测结果进行一些学术探讨是非常必要的。     

最新会议电视产品及国际ISDN应用研讨会举办

由邮电部电信总局和美国视讯公司(CLI)联合举办的“最新会议电视产品及国际ISDN应用研讨会”8月21日在京召开。出席会议的有邮电系统、各部委通信部门及有关专家和技术人员共300余人。北京电信为此提供了国际ISDN线路。     

中兴视讯产品在“全国可视电话及会议终端设备展览会”上受瞩目

目前在全国电信业尚属空白的家庭便携式可视电话业务 4月 17日于深港两地同时推出。与此同时，深大电话公司在深圳市举办了“全国可视电话及会议终端设备展览会”，中兴通讯 ISDN会议电视系统参加了展览。展会期间，利用中兴通讯视讯系统同时在北京、上海、广州、深圳召开电视会议，向公众展示技术先进、性能优良的中兴通讯 ISDN会议电视终端和 MCU多点视讯控制单元。 ISDN会议电视以拨号方式连接 ,与专线会议电视相比使用方便，费用低廉。 ISDN会议电视能方便地与国外进行会议电视的通信。 ISDN会议电视的普及，将使越来越多的单…     

有关ISDN网的技术知识

ISDN网称之为综合业务数字网,又叫做“一线通”。到目前为止,全国26个省会城市在原有26部PSTN长途交换机的基础上通过软件版本升级和硬件改造,均已具备ISDN的功能,其中北京、广州、南京和上海之间已经开通了长途ISDN业务,郑州、济南、成都和天津之间也加入了全国联网,北京国际局已与美国、德国、新加坡、日本、英国、澳大利亚、韩国、瑞士、芬兰和香港、澳门、台湾等国家和地区之间开放了ISDN业务。 开通“一线通”有什么好处呢？一是速率快,线路传输稳定,不易掉线。二是功能强。ISDN是一个数字化的通信网,可以为用户提…     

ISDN专利技术综述

本文以“数字通信专利技术”及大量涉及ISDN专利技术的文献为基础,从ISDN的用户-网路接口、ISDN 的二线传输技术、ISDN 的交换组网控制技术及ISDN 通信的保密性等方面进行综合分析,并提出ISDN 的发展趋势。     

2001中国AODI&ISDN发展论坛举行

２００１中国AODI＆ISDN发展论坛（２００１ChinaAODI＆ISDNDevelopmentForum）于日前在海南三亚举行。中国电信总局领导、全国各地电信分公司的相关负责人，以及上海贝尔的代表共９０余人参加了此次论坛，与会代表就如何推动ISDN在全国范围内的进一步发展以及AODI新技术等专题展开了积极的讨论和广泛的交流。有关专家认为，基于ISDN的AODI等新业务的发展，将为ISDN注入新的活力，促进中国ISDN业务的新一轮发展。中国电信领导就“中国ISDN业务发展”进行了专题演讲。来自武汉电信、北京电信的代表则分别介绍了“武汉电信…     

V.92标准ISDN的终结者

2000年,国内电信业闹得最红火的恐怕要数号称打电话、上网两不误的ISDN了,就北京地区而言,由于申请安装的人多,以至于北京电信库存的安装ISDN所需的必要设备NT1-Plus一度出现断档,造成全国各地生产此类产品的企业全力支援北京的局面,据说为此上海贝岭的股票在二级市场上曾狂涨了好长时间.     

北京电信启动全国第一个AO/DI系统工程

日前,北京电信与上海贝尔签订了AO/DI系统设备销售协议,北京电信AO/DI业务局端系统工程正式启动,这是中国第一个AODI项目。AO/DI是基于ISDN的一项新业务。在ISDN应用中,2B D信道中的D信道仅在呼叫建立时使用,此后便处于空闲状态。AO/DI即是利用D信道来传输低速的分组数据,这样就可以通过ISDN访问分组网络资源,并且实现ISDN用户的常接在线。对于普通用户而言,AO/DI一次拨号永远在线的特点具有重要意义。电子邮件可被用户的终端直接接受,用户收发电子邮件可随时进行,不必每次拨号上网;浏览网上信息也不必经过漫…     

与国际综合业务数字网连接的京,沪,穗国际交换机工程

本文介绍了在新建的北京、上海、广州、国际交换机工程中采用新一代程控交换技术接通国际综合业务数字网，以及本工程采用的中继方式。     

Whatever happened to ISDN?

The integrated services digital network (ISDN) standard was defined in 1972 yet the progress towards its implementation has been very slow and very little is yet on offer to the consumer. The author looks at the vision where the concept of ISDN transforms the telephone network into a transport mechanism for all communications needs. Services offered by ISDN are discussed as are implementation and tariffs     

N-ISDN的建设和业务开放(下)

介绍了综合业务数字网 (ISDN)及我国窄带综合业务数字网 (N - ISDN )的建设、组网及业务发展情况 ,对比了七号信令 TU P(电话用户部分 )与 ISU P(综合业务用户部分 )的差异和发展窄带综合业务数字网面临的问题     

Interworking IEEE 802/FDDI LANs via the ISDN frame relay bearerservice

The author presents a generic architecture for interconnecting LANs (local area networks) through the ISDN (integrated services digital network) bearer services, particularly the frame relay bearer service. The architecture is derived from the IEEE 802.1 MAC (medium access control) bridge and ISDN frame relay standards. An algorithm for MAC/ISDN address resolution that makes minimal use of the WAN (wide area network) bandwidth (which is potentially the most expensive resource) is presented. The algorithm uses a MAC/ISDN address resolution server to resolve addresses for new stations, the resolution in all other cases (e.g. stations moving from the ISDN address to another) being fully distributed. To prevent a server failure from inhibiting communication to new stations, a backup server may be provided. A practical implementation of the architecture has been found capable of supporting full throughput at ISDN hyperchannel rates (384-1920 kb/s) for all IEEE 802.3 frame lengths. Frame relay is seen as having a number of important advantages for LAN interconnection, including the following: a large number of virtual circuits available, giving the potential for a rich interconnection architecture with single-hop connections across the ISDN; and low processing overhead enabling efficient use of ISDN channels, including ISDN hyperchannels (384-1920 kb/s)     

近期中国窄带ISDN市场需求——京、沪、穗三城市市场需求调查摘要

为了解我国对窄带ISDN业务的近期实际需求和潜在市场,有关部门在京、沪、穗三城市对ISDN业务做了缜密的调查研究。本文摘要介绍此次调查的部分结果。     

ISDN: from custom to commodity service

With a toehold in specialized applications, ISDN is poised for takeoff as the all-digital telephony service affordable by everyone. ISDN has been on the worldwide telecommunications agenda for the last decade and is one of the most important junctions of the Information Superhighway. Despite early satire of the network as the Interface Subscribers Don't Need, operators have diligently brought it to market as an outstanding telephony service capable of revolutionizing users' lives. The ISDN options added by vendors to their product lines are costly because of low installed volume. And high tariffs deter many users who could get ISDN services in their area, however much they appreciate all its technical goodies. Still, from a technological point of view, ISDN is well prepared for mass-market deployment in commodity applications. It needs only a further push by operators (lower tariffs, better geographical coverage) to become in reality the Interface all Subscribers Definitely Need     

Network and System Architecture: The Integrated Approach to ISDN in the UT Line

The paper presents an approach to ISDN suitable both for a pilot service, to be carried out in the near future in Italy, and for long-term developments with a high degree of penetration of ISDN setvices. Integration of ISDN services in the digital telephone exchange "UT" has taken place at all levels: system architecture, subscriber access structure, circuit connecting network, transmission links, call processing, and 0 & M functions. We also describe a new protocol that facilitates the dialog between exchange modules and between different exchanges for the data service. It is suitable for implementing packet transit switches with low complexity, high throughput, and low transit time. A special peripheral-handling processor handles the most repetitive functions of the protocols both in the local exchange and in other parts of the network, while the exchange central processor performs the ISDN call-handling functions; the same peripheral processors and the same module processor are used for both ISDN and telephone services. Finally, the paper shows how this architecture can evolve to include new wide-band services and new techniques to implement high-capacity fast packet switches.     

CCITT Recommendations--Network Aspects of the ISDN

This paper presents an outline of the key network standards issues addressed in CCITT as a necessary part of the development and implementation of ISDN. The results achieved in the 1981-1984 Study Period focused on ISDN network functional requirements, ISDN numbering plan, connection types to link ISDN interfaces across the network, and the relationship of the ISDN protocol model with the seven-layer ISO model. The additional network issues which must be resolved in the current (1985-1988) Study Period are identified and briefly discussed. Of particular interest are internetworking between ISDN and existing networks, numbering plan interworking, routing, and maintenance standards. The market success of ISDN depends upon early resolution of these network standards to meet the field trials scheduled for 1986-1988 and the first implementations expected in 1988-1990.     

Bell Canada ISDN Trial Plans

After years of work by the CCITT and other standards bodies, the ISDN concept has reached the stage where manufacturers are announcing the availability of ISDN network and terminal products. Bell Canada has responded to this development by planning an extensive ISDN trial program, including access-loop verification, switch hardware and software verification, and, finally, customer market trials. This trial program will permit Bell Canada to refine the technology and services to best meet customer needs. The trial program is only the most recent manifestation of the evolution towards ISDN through digital network modernization. An early move towards digital technology within Bell has already paid substantial dividends in terms of new services and revenues. These services, and the emerging ISDN-based service opportunities, are highlighted in this paper.     

The value of ISDN for banking applications

US Bank's experience with a number of applications supported by Northern Telecom's DMS-100 integrated services digital network (ISDN) is discussed. Some of the applications that US Bank has been using, as well as some applications planned for near-term implementation, are described. The current applications supported by ISDN are the centrex telephone; message desk call receptionists; systems network architecture (SNA) host access; automatic teller machines; point-of-sale network; and wide-area networking. Future ISDN applications include support of loan approvals and service kiosks