TMN-based customer network management for ATM networks

Effective end-to-end management of today's globalized heterogeneous corporate customer networks, a mixture of ATM WANs and ATM LANs, is essential for customers at the cutting edge of technology. ATM WAN and ATM LAN management systems generally have different management policies and management information models. Studies on the customer network management system (CNMS) to realize end-to-end customer network management have thus adopted the telecommunications management network (TMN) interoperability concept, which is based on CNM manager and agent interoperation. This article proposes an end-to-end customer network management method that realizes interoperation. In order to realize configuration management, fault management, and performance management, the CNM agent extracts the information needed by CNMS from the ATM transport network operations system and controls the operations system accordingly     

Service convergence using MPLS multiservice networks

Enterprises are increasingly using virtual private networks to interconnect remote sites. Traditionally, service providers have used ATM core networks to deliver layer 2 services such as frame relay, ATM, or TDM private lines, which enterprise customers have then used to build their corporate network infrastructure. Such services account for the majority of data service revenues today. However, pressure has increased on service providers to combine increased flexibility with reduced costs in the context of a highly dynamic telecommunications market. Service providers also need to generate new revenues from their IP network infrastructure, through new opportunities such as IP VPNs and virtual private LAN services, while simultaneously achieving operational efficiencies through the convergence of all of their services on a common MPLS backbone. New access and metro network technologies, such as Ethernet, are also emerging that can be used to deliver these new services to enterprise customers alongside ATM and frame relay access. This must be achieved while also supporting existing technologies such as ATM, which continue to deliver highly profitable services. This article discusses the technical challenges in meeting the often conflicting requirements of delivering both traditional layer 2 services and new layer 3 services on a converged MPLS network. We show how both network and service interworking are required, and how these must operate at the user, control, and management planes to enable profitable services to be delivered over the new converged network. The different solutions being defined in the standards bodies are described, and the distinct scenarios they address are explained.     

Applications of ATM in global networks

This article describes the market drivers, objectives, and consequences of introducing ATM into public and private networks. To serve the diverse needs of environments and applications, ATM presents a broad choice of characteristics to users and providers. To harness this diversity and bring structure to the choices, this article discusses ATM transfer capabilities (ATCs) and quality of service (QoS) classes as specified in ITU-T Study Group 13. Industry aims to achieve consistency between the ITU-T and ATM Forum specifications. This article includes consideration of AALs and interworking in developing network strategies. Providers will offer a selection of the possible services defined for ATM. Also, each provider will communicate their strategy for preferred network utilization and efficient traffic through incentives to users     

ATM业务流控制技术

业务流控制是ATM的关键技术之一。业务警管和连接接纳控制构成了ATM的业务流控制。通过网络和用户共同签订并承诺履行的业务合约实现连接接纳控制。对于不同的业务类型,其业务合约参数不同,具有相应的控制机制。业务流控制的国际标准化工作正在积极开展,I-TU-T 建议的标准为1.371。     

The development of broadband signalling platforms

Mao Zedong once said: "All genuine knowledge originates in direct experience." This paper describes the experiences gained through a range of development projects, all concerned with the design, development, demonstration and maintenance of real broadband signalling systems. The authors have participated in the development of a variety of systems offering broadband capabilities, all of which support some form of broadband signalling between the service user and the service provider. The process of designing and building such systems can provide invaluable insights into issues such as development methods, signalling performance, programming interface definitions, etc, none of which are apparent from purely paper-based studies or through the standards specification process.This 'coal-face' experience covers both collaborative as well as internal BT projects, with each system being subject to a wide variety of service requirements. In addition, the period of work covered by the developments described in the paper encompasses broadband signalling systems that on the one hand predate the published ITU-T standards on broadband ISDN systems and on the other include a comprehensive testbed supporting an interworking set of broadband signalling interfaces based on the appropriate signalling standards defined by both the ATM Forum as well as the ITU-T.     

Operations standards for global ATM networks: network element view

The International Telecommunication Union (ITU) has completed work on a series of standards on asynchronous transfer mode (ATM) equipment functional operations and network element management. The objective of these standards is to enable flexible design and interoperability of network elements for use in a global ATM network, independent of any specific implementation. This article discusses these standards with respect to their development and application in planning ATM networks. Specifically, it addresses the following: the modeling approach taken in the development of the ITU standards, key operational features specified in the ATM network element functional model, and the capabilities of the ATM network element management interface. Examples of ATM equipment are provided to illustrate how the functional models specified in the ITU standards may be used by network planners and equipment manufacturers to specify and develop ATM equipment tailored to specific needs, while ensuring network interoperability. The article concludes with some points on the future enhancement of these and related ATM equipment operations standards     

Emerging technologies for fiber network survivability

Reducing network protection costs, while maintaining an acceptable level of survivability, has become an important challenge for network planners and engineers. This article will review technology and architectures that may be used to implement cost effective survivable fiber networks for each transport layer, and discuss the interworking system between survivability mechanisms across different layers and associated open issues. Standards development, product availability and the current status of deployment will also be reviewed. The first section reviews a class of survivable fiber network architectures that has been deployed or is scheduled to be deployed. Next is a review of emerging technologies for these survivable architecture implementations. These emerging technologies include SONET, ATM, and passive optical technology. Finally the issue of multiple layer interworking on SONET/ATM networks is discussed     

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.     

南京ATM宽带多媒体网络的建设

ＡＴＭ技术在经济ＩＴＵ－Ｔ和ＡＴＭ论坛多年的研究与论证后,已开始在多个领域得到广泛运用。本文介绍了南京市ＡＴＭ的网络的建设情况,包括基本组成、网络业务及网络的测试等。     

Management and control functions in ATM switching systems

As research has progressed, it has become clear that the main difficulties in ATM pertain to its operational details rather than the concept. And it seems likely that these control issues will be much more complicated and costly for ATM switches when compared with current telephone circuit switches. The asynchronous transfer mode (ATM) is the target switching technique for the future public broadband integrated services digital network (B-ISDN). The purpose of this article is to examine the management and control functions in ATM switching systems implied by current industry standards and agreements on OAM and traffic control. Until now, ATM research in the areas of switch design and traffic control have progressed essentially independently. First, we briefly review the B-ISDN Protocol Reference Model and its representation of the different information flows in ATM. Network management and traffic control principles in ATM, and in particular OAM, are overviewed. With this information as background, we attempt to infer their implications on the functional blocks of an ATM switching system. An example switch architecture model with distributed management and control functions is outlined, and some design issues are discussed     

ATM与帧中继互连技术

ＡＴＭ技术是ＩＴＵ－Ｔ推荐的Ｂ－ＩＳＤＮ交换技术，而帧中继在提供广域网业务方面很成功。因此，在ＡＴＭ发展的初期不可避免地会与帧中继技术并存。本文阐述了ＡＴＭ与帧中继网络互加和业务互连的相关技术及其存在的问题。     

Advances in data networking

This paper highlights the current approach to large-scale internetwork design using today's network layer routeing protocols. It describes how large internetworks can be constructed to provide stability, resilience and scalability, together with a set of best practice design guidelines for those involved in the design of large data networks, highlighting the key issues to be considered. The paper looks at how new technologies are likely to enhance this design approach, in particular, how the full potential of cell switching can be realised through emerging technologies such as integrated switching and routeing. The paper concludes that the model proposed for large-scale networks based on current routeing protocols and technologies can be enhanced to make optimum use of switched WAN services such as ATM, through the use of newer routeing technologies.     

Advanced internetwork design — today and in the future

This paper highlights the current approach to large-scale internetwork design using today's network layer routeing protocols. It describes how large internetworks can be constructed to provide stability, resilience and scalability, together with a set of best practice design guidelines for those involved in the planning of large data networks, highlighting the key issues to be considered. The paper looks at how new technologies are likely to enhance this design approach, in particular, how the full potential of cell switching can be realised through emerging technologies such as integrated switching and routeing. The paper concludes that the model proposed for large-scale networks based on current routeing protocols and technologies can be enhanced to make optimum use of switched WAN services such as ATM, through the use of newer routeing technologies.     

World-wide standardization of broadband ISDN

A growing market demand for high-performance voice, data, image and video networks, coupled with advances in high-speed technologies has heightened interest in broadband ISDN (BISDN) throughout the world. Network providers, equipment manufacturers and standards bodies are working jointly to accelerate the definition of BISDN interfaces in anticipation of emerging market opportunities. BISDN is being designed as the foundation upon which to implement very flexible, high-bandwidth, high-performance networks. A multiplexing concept called asynchronous transfer mode (ATM), which can offer bandwidth on demand at rates exceeding 150 Mb/s, high-speed packet switching, and an efficient protocol which adapts existing information streams into the ATM format are key attributes of the emerging BISDN network standards. This paper reviews the motivations behind BISDN, explains its key attributes and challenges and discusses possible strategies for evolving today's network toward BISDN.     

为IP用户提供业务的新一代智能网技术

基于ITU－T和IETF制订的最新国际,结合国内相关研究成果,系统介绍能为IP用户提供业务的新一代智能网的典型业务、网络结构和关键技术,并展望了智能网技术的未来发展趋势。     

基于TMN的ATM网络管理模型

针对ＡＴＭ网络管理中特有的一些问题,结合ＴＭＮ的概念,提出了一种基于ＴＭＮ分层结构的ＡＴＭ网络管理模型。对它的信息模型、接口、协议和功能进行了分析。     

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     

自动交换光网络的标准化现状

国际上许多标准化组织都在对自动交换光网络的相关技术和标准规范进行研究。本文介绍了ITU－T、IETF和OIF等几个主要的标准化组织在自动交换光网络标准方面的进展情况。     

Integrity of public telecommunications networks

Provides an overview of the special issue of the IEEE Journal of Communications, Volume 12, Number 1 (January 1994) which addresses open questions in network integrity, reliability and survivability. Current progress in this area is discussed. The questions addressed include user survivability perspectives on standards, planning, and deployment; the analysis and quantification of network disasters; survivable and fault-tolerant network architectures and associated economic analyses; and techniques to handle network restoration as a result of physical damage or failures in software and control systems. Special interests are devoted to the survivability of broadband networks employing the new transport/switching techniques based on the synchronous optical network (SONET) and asynchronous transfer mode (ATM) standards due to their emerging role in future B-ISDN. Network integrity due to failures of common channel signaling (CCS) systems is also very critical. The present special issue includes 22 papers and is organized into the following sections: user perspectives and planning, software quality and reliability, network survivability characterization and standards, network restoration for SONET networks, network restoration for ATM networks, traffic effect and performance enhancement for computer networks, and survivable network design methods. Network restoration methods for SONET, ATM, and computer networks correspond to those for the physical layer (SONET), ATM layer, and the network layer, defined in the CCITT broadband ISDN layer structure     

Internetworking based on cell switch router-architecture andprotocol overview

This paper describes an internetworking architecture and related protocol overview based on routers that have asynchronous transfer mode (ATM) cell switching capability in addition to conventional Internet protocol (IP) packet forwarding. The proposed architecture can provide high-throughput and low-latency switched paths for individual application flows or a group of application flows while retaining current router-based internetworking architecture. The proposed router is able to establish the switched path based on the characteristics of flows, e.g., arrival of a data packet with specific upper layer protocols or arrival of more than a certain amount of data packets in a predetermined period, as well as by the reception of an IP-layer resource reservation request, such as resource reservation protocol (RSVP). One important feature that is provided by the proposed router is interoperability with the emerging ATM network platform specified by the ATM Forum and the telecommunications sector of the International Telecommunications Union (ITU-T). The proposed routers can be interconnected with each other over the point-to-point synchronous optical network link as well as over the ATM network platform, which provides permanent virtual channel, virtual path, or switched virtual channel (SVC) services. That enables network carriers to provide Internet/intranet services as well as others, such as telephony, ATM/time division multiplexing leased line, or native ATM SVC services