International standards for the broadband ISDN user-network interface

Recently, a series of international standards on broadband ISDN were approved in CCITT Study Group XVIII. These standards establish fundamental details on transmission, multiplexing and switching for broadband aspects of ISDN. This article reports on the current definition of the BISDN user-network interface. The UNI reference configuration, physical medium, rates, structure, ATM functions, and operations and maintenance functions are addressed with consideration given to open issues and the direction of future standards activities. Objectives for the UNI capabilities have generally been met with the current CCITT specifications. Some of the UNI physical layer ‘options’, however, potentially impose networking cost penalties.     

ISDN user-network interface management protocol

The author discusses an ISDN user-network interface management protocol. The protocol enables users to manage network services, operation (such as network reconfiguration and routing change), and maintenance. That the user equipment should be looked at from both user-of-service and manager-of-service perspectives is emphasized in a discussion of the relation of the user equipment to the Telecommunication Management Network (TMN). The current status of the ISDN UNI management protocol architecture studies in CCITT is reviewed, and problems specific to the ISDN environment are identified. The need to strengthen the convergence function to solve ISDN-specific problems is stressed. Examples of ISDN UNI management protocol applications are given     

GMPLS user-network interface in support of end-to-end rerouting

Carriers are enhancing their transport networks and improving their daily operations to address the increasing demand for (new) IP-based services. They require more scalable support for the increasing traffic demand and more flexible operations for connection provisioning. They are also seeking optimized resource utilization and time performance using faster and more robust recovery schemes while maintaining overall network costs. With advances in the GMPLS protocol suite including its user-network interface support, the possibility for better cooperation between transport and IP/MPLS networks is now possible. This article addresses this question by positioning and comparing the capabilities of the optical interworking forum's UNI with the Internet engineering task force's GMPLS UNI. Through three recovery scenarios, a quantitative analysis is provided that determines the gain obtained in deploying the GMPLS UNI over its OIF counterpart. Finally, a testbed demonstrating the feasibility and practicability of the GMPLS UNI implementation (which enables end-to-end connection rerouting) is presented.     

The broadband call control demonstrator — a platform for ITU-T, DAVIC and TINA-C implementations

The paper firstly provides an introduction to the broadband call control demonstrator platform developed at BT Laboratories. It describes the basic connection level functionality used to give point-to-point and point-to-multipoint call demonstrations. It then describes the introduction of a Digital Audio-Visual Council (DAVIC)-conformant session control capability and how this is used as the basis of a more comprehensive demonstration. The paper also examines how future networking concepts such as object orientation and distributed processing environments are being introduced, in particular the interworking between DAVIC and Telecommunications Information Network Architecture Consortium (TINA-C) approaches. Finally, some of the evolutionary aspects of the broadband call control demonstrator platform are introduced.     

分布式宽带网络病毒预警系统

对比于传统的主机病毒，在开放式网络环境中，网络病毒攻击能力更强、传播范围更广、破坏力度更大。所以有必要通过建立我国的病毒预警系统，全面监控各地的网络病毒疫情状况。本文研究分布式宽带网络病毒预警模型，实时检测网络病毒疫情。在病毒监控系统中充分采用未知病毒的检测技术，可以及时发现新爆发的病毒疫情，及疫情的发展趋势，制定有效的控制策略，从而减少病毒的危害，并能够及时为国家计算机安全机构提供最新发现的未知病毒样本。     

广电宽带网上的虚拟专用网络服务

随着广电网数据业务的扩大,很多用户提出在城域范围建立内部人员的Internet访问, 而且要有服务质量、权限和安全机制保证, 这样VPN的应用就显得十分突出.那么VPN究竟怎样应用?需要注意什么问题?技术上怎样设计?现根据初步的实践总结如下.     

The ATM Forum's private network/network interface

The ATM Forum completed the first version of its private network/network interface (PNNI) in March 1996 and many ATM switch manufacturers are now offering early implementations. PNNI offers a different type of internetwork or internodal interface from the traditional Signalling System No 7 based approach favoured to date by 'public' network operators, such as BT. In spite of its name, however, PNNI may find its place in network service provider networks as well as in 'private' or customer networks. Some of the perceived limitations of the current specification for such an environment are currently being addressed in version 2, tentatively due for completion in the second half of 1998.The PNNI really consists of two parts, a signalling protocol based around the ATM Forum's UNI signalling specification, and a dynamic source routeing protocol. This paper aims to provide an overview of the functionality and mechanics of PNNI, and to compare and contrast with the functionality offered by ITU-T's B-ISUP.     

MPLS—宽带网络新技术

依据当前Internet网络技术的发展趋势,介绍了一种新兴的宽带网络技术-多协议标签交换（MPLS）技术,重点介绍了MPLS技术的原理和主要特点,指出MPLS是未来网络传输交换技术的融合点,将成为最有竞争力的宽带网络技术。     

TMN-based broadband ATM network management

ATM has rapidly transitioned from a standards and prototyping concept to become the next-generation switching technology used in products available on the market. With the rapid introduction of ATM switches into networks, there is an urgent need to manage them. The article discusses the telecommunication management network (TMN) interfaces being defined for management systems to communicate with ATM network elements (NEs) and other management systems. ATM management systems will have to communicate with ATM NEs in their jurisdiction using TMN interfaces. Networks will usually contain equipment from different suppliers. Thus, it is vital that there be standard management interfaces so that these different NEs can be managed. Some standard interfaces for ATM networks are defined, while others are being defined. The status of these interfaces is reviewed in the article. Communication between different networks is also needed, both between public networks and between public and private networks. Management personnel of one network need to exchange information with other networks for certain functions (e.g., initial service provisioning), and so management systems of different networks will exchange information through a combination of mechanized and manual interfaces. The status of these interfaces is also reviewed in the article     

Cable television broadband network architectures

Fiber-deep network topologies will allow broadband service delivery to become a reality. This article discusses optical technology being deployed by the cable industry to support broadband. Included is a discussion of the current network and plans for the next-generation network, driving fiber even closer to the-subscriber     

Global seamless network demonstrator: a comprehensive ASON/GMPLS testbed

This article reports on the continuous activities of Deutsche Telekom in setting up comprehensive ASON/GMPLS network demonstrators. The goal is to enable practical evaluations and early experiences with prototype implementations related to new standards and specifications from ITU-T, IETF, and OIF. Evolving from the GSN Demonstrator toward the current GSN+ Demonstrator configuration, this field testbed comprises ASON/GMPLS-based backbone network domains, as well as key client networks such as IP, Ethernet (metro and access networks), storage area networks, and broadband video applications to exemplify the wide range of network functions enabled by these new technologies. These ASON/GMPLS demonstrator activities were embedded in the OIF World Interoperability Tests and Demonstration in 2004, and are linked with the German national (VIOLA) and pan-European (MUPBED) project activities ensuring the highest level of interoperable implementations.     

HFC宽带网络运营的几个问题

怀化铁路有线电视台于 2 0 0 1年对全网络进行了ＨＦＣ双向改造 ,经过一年来的运营 ,我们认为改造是成功的 ,ＣａｂｌｅＭｏｄｅｍ网络接入业务成为新的经济增长点 ,同时我们对双向网络运营中的一些问题有了进一步的认识。1　星型结构集中分配方式能有效消除汇集均衡 ,但对消除汇集干扰作用有限由于全网络的同轴电缆全部采用星型拓扑结构 ,没有采用分支器 ,传送到光节点处的上行信号的电平基本一致 ,加上楼道的集线器能对上下行电平进行微调 ,有效地消除了汇集均衡。每台ＣａｂｌｅＭｏｄｅｍ的上行电平规定在 - 15～ + 15ｄＢｍＶ之间 ,经…     

The role of the broadband integrated services digital network

An overview of the services andnetworking technologies under consideration for BISDN is provided. Future directions and challenges for broadband research and development are outlined. Some of the key technology issues, particularly those concerned with the administration and control of broadband networks, are discussed     

EPON:下一代宽带光接入网

介绍了EPON（以太网无源光网络）的体系结构，国内外的研究现状以及市场和应用，并对其前景进行了展望。     

宽带综合业务数字网的ATM技术

目前宽带综合业务数字网(B—ISDN)已成为各国研究与开发的重要内容。本文简述了信息传输技术的发展趋势,着重介绍了ATM技术的概念、ATM信元结构和传输帧结构、ATM交换技术和ATM系统参考模型。     

新一代I P宽带接入网

前言在成功实现为宽带接入提供高速Internet接入技术之后,宽带系统供应商开始转向更广阔的IP服务.第二代宽带接入产品凝结了更多的高端技术.以多层QoS(服务质量)为基础的通信优先权,首次成功地解决了带宽资源不足的问题. 　　……     

Crosstalk in a fibre access network demonstrator carryingtelevision and interactive digital services

An optical access network is being constructed as part of the RACE programme to demonstrate the feasibility of providing both interactive broadband and television distribution services over a single, shared fibre to a residential subscriber. The interactive and distributive services will be transmitted in the 1.3 μm and 1.5 μm optical windows, respectively, of the fibre. To prevent crosstalk between the two services a wavelength division demultiplexer which gives adequate isolation between the two optical carriers must be provided at the subscriber receiver. Performance deterioration due to mutual crosstalk is calculated and measurement results presented. Theory and measurement show that the deterioration of the interactive signal caused by the distributive signal sets the most demanding isolation requirement. For an interactive signal penalty of 0.5 dB the isolation has to be 40 dB, which is at the limit of the performance achieved by commercially available wavelength division demultiplexers     

Air interface access schemes for broadband mobile systems

High bandwidth everywhere is a key requirement of future communication systems. The big challenge is that the mobile user also be able to benefit. The UMTS, a member of the IMT-2000 family of systems, will offer global universal services up to 2 Mb/s for the mass market in the near future. For users demanding more capacity for “bit-hungry” high-quality applications, broadband mobile radio access systems are being developed, such as wireless LANs and the Mobile Broadband System. In this article broadband mobile systems are classified, taking into account services and quality, spectrum, and standardization issues. The practical experiences gained in two European research projects-ATM Wireless Access Communication System (AWACS) and System for Advanced Mobile Broadband Applications (SAMBA)-are described. Finally, a realistic look at possible future deployment is given     

流媒体技术的宽带应用

流媒体技术是未来宽带网络为用户提供丰富的多媒体信息服务的主流技术,本文结合流媒体技术在麻城市广电宽带网的应用实践。就流媒体系统的技术选择,系统组成结构、应用服务功能作了具体介绍。