Evolution of metropolitan area networks to broadband ISDN

Broadband architecture and network evolution strategies based on interface standards emerging from the IEEE 802.6 MAN Committee and the American National Standards Institute (ANSI) T1S1 and CCITT Working Groups on broadband integrated services digital networks (BISDN) are outlined. The recent history of both the MAN and BISDN standards activities is traced, and some of the motivations behind specific developments are discussed. In the context, local area networks (LANs) and MANs are compared and contrasted, with special attention given to requirements specific to a public MAN. The convergence of the MAN and BISDN protocols is examined. The benefits of commonality between these two standards are described in terms of lower-cost network architectures, and terminal equipment is examined. It is shown that broadband networks can exploit the synergy between 802.6-based MANs and wider-area BISDN networks, and that 802.6-based MANs can gracefully evolve into countrywide networks using BISDN asynchronous transfer mode (ATM) switching. Example networks are used to illustrate the evolution proposals     

Protocols for ATM access networks

The development and standardization of ATM (asynchronous transfer mode) and signaling protocols for BISDN (broadband integrated services digital network) are considered. A view of both ATM and signaling protocols in which the key design guideline is service flexibility is presented. The approaches suggested are intended to create a service-independent broadband facility that is also sensitive to both service performance and network efficiency. Key issues are raised that will require serious consideration by standards groups, manufacturers, and service providers as BISDN moves toward production     

Comparison of ATM switching architectures

Clear examination of work currently done within CCITT indicates the importance of a broadband telecommunication network. As this network should be capable of integrating all services in an efficient way—in order to reduce cost—the asynchronous transfer mode (ATM) was selected by CCITT as the target transfer mode for implementing the broadband integrated services digital network (BISDN). This selection implies that the switching nodes in the BISDN network are capable of supporting this high-speed packet and connection-orientated technique. Within the literature different switching node architectures based upon ATM have been proposed. All of these architectures should meet the high-speed and high-throughput requirements so as to cope with the delay and jitter performance objectives. In a first step this paper describes alternative switching techniques for the basic building block (switching element) of a switching node. A common model architecture of the switching element is drafted. A classification of switching elements described in the literature is derived and the influence on the complexity and performance is weighted. In a second step the switching node architecture is further elaborated according to the control and flexibility requirements. Core (switching) and edge (switching related) functions are listed, and possible functional partitionings are discussed. Finally, these ATM switching architectures are compared according to a background frame consisting of several straightforward comparison points such as the buffering strategy, the internal routeing method, the switching overhead, the connection-orientated or connectionless operation, etc.     

The role of satellite communication in the ISDN era

Satellite communications can play an important role in provisioning the next-generation telecommunications services and networks, provided that the protocols specifying these services and networks are satellite-compatible. After a brief discussion of narrowband circuit and packet mode integrated service digital network (ISDN) services, the paper focuses on emerging standards in frame relay, broadband ISDN (BISDN) and universal personal telecommunications (UPT). The specific parameters and procedures of frame relay and BISDN protocols which are affected by a satellite delay are identified, and congestion and resource management functions for frame relay and BISDN are discussed in detail. Specific ground functions and possible on-board functions are identified as potential candidates for implementation via neural network technology. Finally, the implication of UPT standards on satellite networks is discussed.     

The infrastructure for gigabit computer networks

The key features of the synchronous optical network (SONET) and asynchronous transfer mode (ATM) standards for the broadband integrated services digital network (B-ISDN) public network, which is expected to provide a powerful and ubiquitous infrastructure to support the emerging gigabit-per-second data and multimedia applications, are reviewed. The advantages of ATM, the ATM cell format, the B-ISDN protocol reference model and the ATM layer, the ATM adaptation layer, and ATM traffic management and signaling are discussed. An experimental high-performance parallel interface (HIPPI)-ATM-SONET interface is presented as an example to illustrate how the SONET and ATM techniques can be used to provide end-to-end transport for applications requiring a bandwidth of 800 Mb/s and possibly 1600 Mb/s     

A guide to data communications: B-ISDN and how it works

The capabilities of the emerging broadband integrated services digital network (B-ISDN) are examined. Fundamental differences between broadband and narrowband ISDN are identified. The basics of asynchronous transfer mode (ATM), the switching technique used by BISDN networks, are discussed. Channel identification, generic flow control, using ATM, and connectionless service are considered. The first services expected to make use of ATM are briefly described     

Distributed network computing over local ATM networks

Communication between processors has long been the bottleneck of distributed network computing. However, recent progress in switch-based high-speed local area networks (LANs) may be changing this situation. Asynchronous transfer mode (ATM) is one of the most widely-accepted and emerging high-speed network standards which can potentially satisfy the communication needs of distributed network computing. We investigate distributed network computing over local ATM networks. We first study the performance characteristics involving end-to-end communication in an environment that includes several types of workstations interconnected via a Fore Systems' ASX-100 ATM switch. We then compare the communication performance of four different application programming interfaces (APIs). The four APIs were Fore Systems' ATM API, the BSD socket programming interface, Sun's remote procedure call (RPC), and the parallel virtual machine (PVM) message passing library. Each API represents distributed programming at a different communication protocol layer. We evaluated two popular distributed applications, parallel matrix multiplication and parallel partial differential equations, over the local ATM network. The experimental results show that network computing is promising over local ATM networks, provided that the higher level protocols, device drivers, and network interfaces are improved     

Digital transport of HDTV on optical fiber

An overview of the broadband integrated services digital network (BISDN) is given. A codec that compresses high-definition television to fit within the roughly 135-Mb/s capacity of a synchronous optical network synchronous transport signal level 3c (SONET STS-3c) signal carrying BISDN asynchronous transfer mode (ATM) cells, thus requiring compression of roughly only 6:1, is described. The order and format of the transmitted HDTV data is considered. ATM adaption and user layer information are discussed. Error control in the user layer is addressed     

Switching integrated broadband services by sort-banyan networks

Substantial attention has recently been given to the implementation of sort-banyan networks for switching asynchronous transfer mode (ATM) transmission links in a BISDN (broadband integrated service digital network) network. The author gives a three-dimensional view of the theory and implementation of switching, as well as variations of the basic scheme. ATM switches are classified as blocking versus nonblocking, unicast versus multicast, and input queued versus output queued. Sorting networks structured by a three-dimensional interconnection topology are studied. A sorting network, when coupled with a banyan routing network structured in three dimensions, becomes a self-routing and nonblocking switching network. This three-dimensional topology allows CMOS VLSI implementations of the subnetworks and interconnection of these subnetworks at a speed of 150 Mb/s and beyond. The sorting mechanism can also be used for output conflict resolution, subsequently making the switch suitable for ATM switching. Recent enhancements, which provide features such as parallelism, trunk grouping, and modularity, are also described. These features enhance the throughput/delay performance, provide better fault and synchronization tolerance, and enable more economical growth for switch size     

Fiber-based local access network architectures

The attributes of the various architectural alternatives are discussed. Several systems proposed for the delivery of telephone service and/or distributive video services in the local access network are described. The status of the standardization of interfaces for the broadband integrated services digital network (BISDN) based on the synchronous optical network (SONET) and asynchronous transfer mode (ATM) is examined     

ATM交换机设计

本文提出一种宽带交换的新设计思想,它以异步传送模式为前提,能够保证各种宽带和窄带业务的综合交换。     

PERFORMANCE EVALUATION OF NON-BLOCKING ATM SWITCHES UNDER VARIOUS TRAFFIC AND BUFFERING SCHEMES

Broadband integrated services digital networks (BISDN) are designed to offer a variety of services with bit rates ranging from several kb/s (e.g. teleactions) to hundreds of Mb/s (e.g. HDTV), and in some cases approaching Gb/s (e.g. in interconnections of high-speed LANs). A multiplicity of rates and the burstiness of traffic sources lead naturally to systems based on the fast packet switching (or asynchronous transfer mode) concept. The requirements of data buffering and high-speed processing of packet headers have resulted in a plethora of proposals for ATM switching nodes and an equal number of ways for evaluating them. In particular, the class of non-blocking architectures of ATM switches has received the most attention from the research community. This paper reviews this class of architecture with emphasis on contention resolution methods and communication traffic performance. The contention resolution methods are divided into four categories: input buffering, output buffering, shared buffering, and hybrid buffering. The communication traffic characteristics are divided into two categories: uniform traffic and bursty traffic.     

A promising application for broadband ISDN: Hypermedia teleconference

The optimum BISDN teleconference service for business, called hypermedia teleconference, is designed based on research into typical business activities and ATM, the most promising BISDN architecture. Service characteristics are determined by analysing the daily work practices of a large set of businessmen. It is shown that communication tasks occupy 44 per cent of the working day. The analysis further shows that some 60 per cent of all communication tasks could be performed through an advanced digital teleconference service. Hypermedia teleconference is designed to satisfy the needs of business through personal communication terminals and ATM public networks. The terminals effectively allocate the BISDN's high-speed transmission capability between a number of subchannels that realize distributed multipoint connection links and multimedia paths. The terminals use a new variable-bit-rate ATM codec created to realize high quality video. Users can easily create full featured teleconferences without a centralized connection facility. Terminals allow the synergistic combination of video, voice, telewriting, telepointing and document transmission services.     

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     

OAM mechanisms for BISDN UNI and access networks

This paper clarifies operation and maintenance (OAM) requirements for broadband integrated services digital network (BISDN) customer access systems including user-network interface (UNI), and proposes basic OAM mechanisms. Access networks employ a logical networking architecture based on the asynchronous transfer mode (ATM) virtual path (VP) concept to provide all services efficiently, economically. Services are independent of the network's physical configuration. Thus, OAM functions for the access network are required to support physical and ATM layer capabilities. UNI physical performance and failure information flows to ensure user service quality are described. A fault localization mechanism is introduced that determines whether the failure lies on the network provider side or customer side. It uses failure information flows and loop back testing at the network terminator 1 (NT1). As connection-related virtual path connection (VPC) availability indication is necessary for user-to-network applications and user-to-user applications, two alternative VPC-related availability indication mechanisms are studied. Furthermore, basic performance monitoring mechanisms for ATM layer are described.     

B—ISDN的基本概念与标准化

本文首先介绍了宽带综合业务数字网(B—ISDN)的概念,继而引入ATM的概念;阐述了B—ISDN的基本原理、特点及标准化;最后明示了B—ISDN有待研究解决的几个问题。     

PCS mobility support over fixed ATM networks

As broadband multimedia services and wireless services become popular, there is growing interest in the industry to support ATM over a wireless link, and wireless access to fixed ATM networks. We focus on the internetworking of PCS and ATM networks, in which the air interface remains one of the PCS standards and the backbone is an ATM network with mobility support. It is desirable to minimize the impact of the internetworking and mobility support on the existing/emerging PCS and ATM specifications. A network architecture, a protocol reference model, and signaling protocols for PCS mobility support over fixed ATM networks are described. They are compared against other implementation alternatives and the trade-offs are discussed. Some performance results of the proposed architecture are also presented     

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     

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     

A survey of research and standards in high-speed networks

This paper surveys research and standards in high-speed networks. It first classifies high-speed networks according to the area of coverage. Secondly, it discusses the switches. Then, it examines network management protocols: media access control, routeing, flow control and error control. Finally, it investigates current hig-speed network standards: DQDB, FDDI, ATM, and SONET.