The OSI reference model

The early successes of computer networks in the mid-1970's made it apparent that to utilize the full potential of computer networks, international standards would be required. In 1977, the International Standards Organization (ISO) initiated work on Open Systems Interconnection (OSI) to address these requirements. This paper briefly describes the OSI Reference Model. The OSI Reference Model is the highest level of abstraction in the OSI scheme. The paper first describes the basic building blocks used to construct the network model. Then the particular seven-layer model used by OSI is briefly described, followed by a discussion of outstanding issues and future extensions for the model.     

OSI management and job transfer services

An important aspect of Open Systems Interconnection (OSI) is the organization of the distributed processing activity and the resources required for its successful prosecution. The work on Application and Systems Management, and Job Transfer and Manipulation deals with the specifics of distributed processing activities. In ISO/TC97/SC16/WG4 work on OSI management protocols is defining an overall framework for specifying management standards and identifying the subset of management standards that can be developed speedily. This paper presents an overview of this work and the progress being made. In ISO/TC97/ SC16/WG5 the model of a Job Transfer and Manipulation system (JTM) has been defined into four functional components--job submission system, job processing system, job monitoring system, and manipulation submission system. The concepts of the JTM specification along with a number of considerations that are common with the OSI management protocol work are also presented in the paper. A recent upsurge of interest in these areas has led to an increase in participation and the sense of urgency for advancing the development of the draft specifications--there should now be an acceleration of activity in this important aspect of OSI.     

CCITT standardization of network node interface of synchronousdigital hierarchy

The main concepts and interfacing and multiplexing techniques for an NNI (network node interface) as set forth in CCITT (International Consultive Committee for Telephone and Telegraph) Recommendations are described. The objectives and history of the NNI standardization are reviewed together with concepts, basic requirements, and features of the NNI. The nine-row-based frame structure and the virtual container (VC) concept, which are the main features of the NNI, are introduced. The multiplexing principle and method, the detailed frame structure and overhead, and mapping methods related to the NNI are described. Applications of the NNI in the synchronous network and international interworking are presented. The future application of asynchronous transfer mode (ATM) is discussed     

Open systems cabling as a building utility

Open Systems Interconnection (OSI) is intended to facilitate interworking between data terminal equipments (DTEs) of different designs and from multiple vendors, thus providing the user community with a broad level of independence in the procurement of IT equipment. Whilst OSI local area network (LAN) standards have aimed to fulfil this objective, actual variations in data rates, media types and cabling topographies have hindered progress. The `tree and branch' cabling architecture presented in the paper provides a powerful solution to these problems. Based on twisted-pair and optical-fibre media, it could support today's industry standard LANs, point-to-point communication links such as V24, and circuit-switched telephony within an elegant, integrated cabling system     

Transition and coexistence strategies for TCP/IP to OSI

The US DoD (Department of Defense) Internet suite of protocols (commonly known as TCP/IP for transmission control protocol/internet protocol) is the de facto open (nonproprietary) standard for computer communications in multivendor and multiadministration networks. However, some feel that protocols based on the open systems interconnection (OSI) model and promulgated by the International Organization for Standardization (ISO) will eventually achieve dominance and enjoy even greater success than TCP/IP. The author explores methods for transition and coexistence between the two protocol suites. He enumerates several approaches, discusses the positive and negative aspects of each, and describes their inter-relationships. Further, although the focus is on the problems of Internet/OSI transition and coexistence, none of the approaches described are unique to this problem. Rather, they are all general solutions to the problem of changing from one protocol suite to another or of having two arbitrary protocol suites coexisting     

QoS and service interworking using constraint route labeldistribution protocol (CR-LDP)

Introducing quality of service features to the IP/TCP protocol suite has become a hot topic of research in both industry and academia. Several architectures have been proposed for QoS support at the network layer (layer 3 in the OSI model). Both integrated services and differentiated services architectures are examples of QoS models that are implementable at the IP layer. Another development at the IETF is the work related to traffic engineering using multiprotocol label switching. While traffic engineering covers a wide range of topics, QoS support is recognized as one of its necessary features. This article describes the QoS features of the constraint-route label distribution protocol and how they can be efficiently utilized to achieve service interworking between a number of different networking technologies     

计算机网络的路由算法

本文首先介绍ＯＳＩ网络层及其路由的基本概念，功能，然后着重介绍路由选择Ｄｉｊｋｓｒａ算法，并讨论了基于这一路由算法的目前在ＴＣＰ／ＩＰ网络环境（如ＩＮＴＥＲＮＥＴ）中的路由协议ＯＳＰＥ，最后对ＯＳＩ路由协议相关概念及目前发展情况作了简单介绍。     

A comparison between the OSI reference model and the B-ISDNprotocol reference model

The author presents views on the relationships between the Open Systems Interconnection (OSI) reference model (RM) and the broadband integrated services digital network (B-ISDN) protocol reference model (PRM), in an attempt to facilitate an interconnection between B-ISDN and data networks conforming to the OSI standards. According to the International Telecommunications Union-Telecommunications Sector (ITU-T), the exact relationship between the lower layers of the OSI RM and the B-ISDN PRM is for further study     

Implementing OSI agent/managers for TMN

The telecommunications management network (TMN) architecture defines a framework for the management of telecommunications networks and services. It is based on a set of TMN standards developed by the International Telecommunications Union (ITU-T), and is finding increased interest in the telecommunications industry, where rapid development of services and open architectures are in demand. Open systems interconnection (OSI) agent/managers as defined by the OSI systems management standards play a major role in the TMN architecture. However, the complexity of these standards, make the implementation of agent/managers and thus TMN systems a challenging task; methodologies and tools to ease the task of building agent/managers are needed. This article discusses the key difficulties in building OSI agent/managers and presents an architecture and a toolkit that can overcome them. The toolkit automates the generation of code that conforms to TMN and OSI standards, allowing the implementor to focus on the implementation of agent and manager specific components using the facilities provided by the toolkit     

Toward a unified theory of managing large networks

The growing web of computer networks has triggered a search for an organizing principle to monitor and control operations. The various system management functions are identified, and the development of network management standards is discussed. Particular attention is given to the Basic Reference Model for Open Systems Interconnection (OSI), developed by the International Organization for Standardization (ISO)     

Robot Internetworking

The aim of this paper is to present an analysis of the robot internetworking by pointing out both communication and management aspects. The proposed structure uses the concepts of the Open Systems Interconnection (OSI) architecture proposed by the International Standards Organization (ISO). The modularity and the flexibility of the proposed approach facilitate the implementation and the system expansion according to the user needs.     

Mapping the X window onto open systems interconnection standards

The issues involved in integrating X11 and open systems interconnection (OSI) are explored and potential solutions to implementation problems are given. OSI standardization issues are discussed, including naming and registration conventions and the current status of this work effort in national and international standards bodies. The direction of OSI in window management, X11's relationship to the OSI reference model and, in particular, the use of OSI association control and presentation services are briefly addressed. The potential impact on the OSI market and the global view of this work are discussed, from a research and from an international standardization perspective, along with the issues evolving from the prototype built and the likely commercial provision of X11 products supporting OSI     

帧中继承载业务的ATM传输技术

在帧中继网络协议模型的基础上,对继帧中继承载业务的ＡＴＭ传输中关网络互通,虚连接复用,参数映射等技术问题进行了讨论,并对帧中继业务与ＡＴＭ宽带业务互通问题进行了简要介绍。     

The ISO reference model entities

The functionalities and presently defined entities at the different levels of the Open Systems Interconnection reference model are discussed. An overview of standards activity by the International Organization for Standardisation (ISO), the Institute of Electrical and Electronics Engineers (IEEE), and the International Consultative Committee for Telephone and Telegraph (CCITT) is given. The ISO reference model and layer functions are described. Standards for the different layers are examined. Network security and naming and addressing issues, which were not covered by the basic reference model and earlier standards activities, are addressed. Two private-sector examples of OSI networks, the Manufacturing Automation Protocol (MAP) and the Technical Office Protocol (TOP), are considered     

High-speed transport components

An overview of research of high-speed transport components is given. High-speed protocols as well as high-speed implementations are considered. The use of parallelism to increase the performance of communication nodes is considered. A parallel implementation of Open Systems Interconnection (OSI) protocols on transputer networks based on the parallel concepts discussed is described. Selected performance values of the implementations are presented. The outlook on the design of high-speed transport components for future communication systems is examined     

Connections and connectionless data transmission

The complementary concepts of connection-mode data transfer and connectionless data transmission are the fundamental models of communication in the architecture of Open Systems Interconnection (OSI). As the names imply, connection-mode data transfer involves the establishment and maintenance of a connection, which represents a dynamically negotiated agreement concerning the transfer of a series of related units of data; connectionless data transmission relies only on the prior knowledge that peer entities have of each other to transmit independent, unrelated data units, and does not involve the establishment of a connection. The two concepts together describe all of the peer-to-peer interactions that take place in the OSI environment. The national and international organizations concerned with OSI have applied these concepts successfully in the development of OSI service and protocol standards.