Showing papers on "Heterogeneous network published in 1990"

Interconnection system and method for heterogeneous networks

Abstract: In a network system in which an interconnection is achieved between an LAN terminal connected to an LAN and an ISDN terminal linked with an ISDN via at least an LAN/ISDN inter-working unit coupling the LAN with the ISDN, the ISDN terminal develops a function to multiplex data link connections (communication paths) identified with respective data link connection identifiers (DLCIs) on ISDN channels. After conducting a call establishment to the ISDN terminal, the inter-working unit supplies the LAN terminal with an ISDN channel number and a DLCI designating an ISDN communication path. Thereafter, the LAN terminal sends an LAN frame having an OSI layer 2 header loaded with the communication path information to the inter-working unit. On receiving the LAN frame, the inter-working unit executes a format conversion to convert the LAN frame into an ISDN frame based on the ISDN communication path information.

A cooperative LAN diagnostic and observation expert system

Abstract: The author describes a LAN diagnostic expert system called the Large Internetwork observation and Diagnostic Expert System (LODES), which has transport control protocol/internet protocol-(TCP/IP-) related and troubleshooting knowledge, and can handle problems occurring in a complex and heterogeneous network environment. Each constituent network has its own expert system containing management information about the local network. TCP/IP-related problems are thus resolved singly or cooperatively, depending on their type. This system also includes a network observer, which monitors packets flowing in the network and can find a number of problems and problem indicators for automatic problem detection and troubleshooting. The configuration of LODES is described, as well as the knowledge and control methods for cooperative diagnosis, especially the method for cooperative diagnostic task scheduling. >

A platform for heterogeneous interconnection network management

Abstract: A comprehensive network management function built into the interconnection network provides a means of meeting user needs of fault tolerance, performance, accounting, and security. However, meeting these needs on a heterogeneous interconnection network is several levels more complex than on a homogeneous network because of the existence of multiple protocol stacks for communication. An architecture that will solve this problem by analyzing the heterogeneous interconnection network as a single entity is proposed. The authors present the design issues evaluated in choosing this approach and establish the need for the various components in this architecture. An overview is presented of each of the components, and their place in the architecture is pointed out. >

Achieving multimedia communications on a heterogeneous network

Abstract: A heterogeneous intelligent network has been designed and implemented to allow multimedia real-time communications and messaging among local area network workstations with logically associated speakerphones and among ISDN voice/data terminals with transparent tablets on top of bitmap screens and stylus pens The architecture, presentation, editing, storage, and retrieval of multimedia documents in these two different kinds of terminals are described The messages and protocol conversion facilities used for multimedia communications are presented, as are the lessons learned in internetworking a local area network with ISDN >

A language for distributed applications

Abstract: Durra is a language designed to support the development of distributed applications consisting of multiple, concurrent, large-grained tasks executing in a heterogeneous network. An application-level program is written in Durra as a set of task descriptions that prescribes a way to manage the resources of a heterogeneous machine network. The application describes the tasks to be instantiated and executed as concurrent processes, the intermediate queues required to store the messages as they move from producer to consumer processes, and the possible dynamic reconfigurations of the application. The application-level programming paradigm fits a top-down, incremental method of software development very naturally. It is suggested that a language like Durra would be of great value in the development of large, distributed systems. >

Simulation of heterogeneous neural networks on serial and parallel machines

Abstract: There has recently been a tremendous rebirth of interest in neural networks, ranging from distributed and localist spreading-activation networks to semantic networks with symbolic marker-passing. Ideally these networks would be encoded in dedicated massively-parallel hardware that directly implements their functionality. Cost and flexibility concerns, however, necessitate the use of general-purpose machines the simulate neural networks, especially in the research stages in which various models are being explored and tested. Issues of a simulation's timing and control become more critical when models are made up of heterogeneous networks in which nodes have different processing characteristics and cycling rates or which are made up of modular, interacting sub-networks. We have developed a simulation environment to create, operate, and control these types of connectionist networks. This paper describes how massively-parallel heterogeneous networks are simulated on serial machines as efficiently as possible, how large-scale simulations could be handled on current SIMD parallel machines, and outlines how the simulator could be implemented on its ideal hardware, a large-scale MIMD parallel machine.

A methodology for obtaining a cost estimate in a multiple media network architecture

Abstract: An approach for using multiple link parameters for determining least cost paths in heterogeneous networks is presented The procedure has been implemented in the media resource controller (MRC) advanced development model developed for the US Air Force The cost assignment approach is broken into three functional areas and then fed to a conventional routing algorithm for least cost path assignments An approach for evaluating the proposed procedure against single parameter methods is outlined The methodology holds rigorously for the homogeneous case, and is easily extended to the heterogeneous case of future tactical network environments The MRC accomplishes this by providing the network designer with a set of tools to use in specifying cost behavior >

A systematic approach for constructing gateways

Abstract: Numerous homogeneous and heterogeneous networks coexist today. Cooperation between users connected to different networks, which can only be achieved by interconnecting these networks, is necessary in many situations. After introducing the notation used, we present our approach to performing network interconnection in a systematic way. The approach is based on a set of basic components and a toolkit of solutions. The set of basic components fosters system detection of the problems one has to deal with when designing a gateway. The toolkit presents an extensive set of solutions for a large number of these problems and provides assistance in selecting the most appropriate solution. We demonstrate the use of the toolkit for the problem of interconnecting error-control mechanisms.

Performance evaluation of FDDI network and interconnected heterogeneous networks

Abstract: Interconnected heterogeneous networks are presented and their performance analyzed. The interconnected networks consist of token ring, fiber distributed data interface (FDDI), and carrier sense multiple access with collision detection (CSMA/CD) networks, each of which connects a large population of users. In the interconnected networks, the local users on the token ring send intra- or internetwork packets. The internetwork packets are transmitted to the CSMA/CD network via gateways and the FDDI network. In the meantime, the local users on the FDDI and CSMA/CD networks generate intranetwork packets. Since the maximum packet sizes of these networks are different, packet fragmentation and reassembly are sometimes necessary. These functions are performed by gateways. The model focuses on the end-to-end delay between two end users on the token ring and CSMA/CD network. Analytic models for calculating the delays for the FDDI network and the interconnected networks are presented, and the measurements from the models are compared with that from the simulation models, validating the analytic models. >

Network file for ISDN

Abstract: The necessity of file-storage systems for network systems such as ISDN (integrated services digital network) and B-ISDN (broadband ISDN) is discussed. The stored information has a wide range of characteristics depending on the storage medium and it is accessed and transmitted through heterogeneous networks. Since visual services will increase with the progress of network systems, the file-storage system must provide large capacity, low storage cost, and high transfer rate. In ISDN and B-ISDN, these requirements will be met by optical-disk storage systems. In the future, the file-storage system will need to provide a huge storage capacity and an ultra-high data transfer rate sufficient for high-quality visual services at a low cost. This will require innovative technologies in memory devices and materials to surpass the real recording-density limits of present technologies. >

Supporting multimedia information presentation in a distributed, heterogeneous environment

Abstract: A design overview of a distributed object-oriented system is given which supports the distributed processing of multimedia information with special regard to information presentation in an environment of heterogeneous networks and workstations. Essential features of the system are an object model designed for the handling of multimedia information and the adaptation of presentation and transport of multimedia information to the capabilities and available resources of the workstations and underlying networks. This adaptation is done by a distributed support layer. Using environment information, this layer makes an information presentation and transport service available to the applications. >

Distributed computing in heterogeneous environments

Abstract: Distributed computing systems have received considerable attention in the last decade. Unfortunately, current research efforts are often restricted to homogeneous environments. There seems to be little attention for real-world installations, where heterogeneity is mostly the rule, rather than the exception. The Distributed Academic Computing Network Operating System, DACNOS for short, presents a general solution for running distributed applications in heterogeneous networks. The DACNOS extends local guest operating system services to provide homogeneous networking functionality. This is achieved by a virtual global object space, to which each user has access from within his native environment. This paper describes the architecture of the DACNOS network operating system, with special emphasis on its incarnation on the UNIX platform. It presents the DACNOS solutions to the problems of communication, access protection and data representation in a network of cooperating heterogeneous systems. DACNOS implementations currently exist for VM/CMS, VAX/VMS, PC-DOS, OS/2 and UNIX System V derivatives.

Applying Artificial Intelligence Techniques to the Management of Heterogeneous Networks

Abstract: In this paper, we present the main components of an intelligent system which can help users to manage a communication network. We also present our motivation as to why we chose a multi-expert system design.. This system is an administration expert capable of managing several networks of different manufacturers. It defines an administration model of distributed heterogeneous systems, which is based on the translation of different manufacturers management systems into a single reference system. More specifically, it consists of several expert systems that communicate with each other in order to solve network administration problems (asin the case of error diagnosis). The knowledge needed by the management system is organized into a hierarchy, so that it can be modelled by a layered structure. Thus, the knowledge base can be built step by step.

Customer network management: a service provider's view

Abstract: Experience in providing network management for the 1986 Pan American (Pan Am) Games in Indianapolis USA are described. The situation called for an integrated solution that could manage the 5000 voice, data, and video circuits residing within several different networks providing communications for 6500 data terminals and 143 computers spanning 40 locations. The scope of network management is examined, separating it into two parts: management of the specific local exchange carrier services and integrating that with the management of all other products and services. The driving forces behind the need for customer network control are discussed. A two-stage approach to achieving that control is presented. >

Protocol issues in interconnecting ISDN, IN, and LAN

Abstract: The author discusses some of the protocol design and implementation issues in interconnecting integrated services digital networks (ISDN), intelligent networks (IN), and local area networks (LAN) An internetworking architecture for a heterogeneous intelligent network that consists of network-resident intelligent peripherals and three subnetworks, a telephone network, a LAN, and an ISDN, is presented Design issues and problems encountered in the implementation of four protocol conversion facilities for a heterogeneous intelligent network testbed are analyzed The testbed allows multimedia real-time communications/messaging among LAN workstations with logically associated telephones and ISDN voice/data terminals with a stylus pen and transparent tablet on top of a bitmap screen >

Communication Terminal for Heterogeneous Network Based on BTRON HMI

Abstract: Recently, many kinds of computer network services in UNIX workstations and personal computers have become popular. However, the users have to learn a lot of knowledges to use them and there are many differences on each operation of the network services.

Requirements and prospects for multiservice business networks

Abstract: The authors address new architectural concepts for organizing heterogeneous network components into a system framework. Reference scenarios foreseeable in the following decade are given, with the interaction of market trends and technical achievements taken into account. After a requirements analysis, a multiservice business network architecture suitable for early deployment and with the possibility of evolving into a future broadband integrated services digital network is proposed. This architecture, besides exploiting the capabilities of distributed switching, typical of metropolitan area network technology, avoids capacity limitations caused by the use of single-level shared-medium topologies. >

Genesis, A Real-Time Expert System for Network Control

Abstract: A high level system design for GENESIS, a GEneric Network Expert System with Intelligent Simulation, is presented. GENESIS is a real-time expert system which will monitor and control the public voice telephone network. The design includes a human interface for display and user input, a realistic simulation of the network with expert heuristics to drive and test the expert system in real-time, an interface to required data bases and a blackboard for intermodule communications and control. The system is generic in that it was designed to reside above any network monitoring or data-collection system and to handle heterogeneous networks consisting of switching equipment from different manufacturers and a mix of product release levels. Key features of the design are flexibility and expandability to handle a growing network and changing needs.

A new type of hierarchical neural-like networks: representation

Abstract: Presents a new kind of hierarchical binary network which may be considered as a specific case of cellular networks. Such networks are defined by primitives or processes which are personalised for network implementation in specific applications. The way in which a network may be described is provided by a process (network process) which may be used both for simulation software and for deducing the general hardware architecture of the network. Following a description of the algorithms of different simulation primitives, a network example for noise elimination in images is included to illustrate the potential of this kind of network. >

Real time networking of control systems

Abstract: Applications and implementation considerations when working with real-time local area networks with bandwidths of 1 Mb/s and above are discussed. The following networking issues are discussed: industrial peer-to-peer networks, applications, network characteristics, network performance, network components, designing networks, installing networks, software programming network, and host computer connectivity. >

Implementing Integrated Monitoring Systems for Heterogeneous Networks

Abstract: The increased use of multiple technologies and multi-vendor equipment in today’s networks has made the task of network monitoring more complex. Since these networks integrate different technologies to provide communication services, failures in any one component of the network can affect many others. To effectively diagnose problems in the network requires the ability to collect, integrate, and correlate monitoring data from all network components. Collecting and integrating monitoring data is complicated by the lack of a standard network management interface available across different technologies and vendors.

Packet communication technology for advanced wireless networks

Abstract: Two techniques for future (third-generation) wireless networks are described They are a switching architecture, referred to as a cellular packet switch, and a packet transmission technique, referred to as packet-reservation multiple access It is shown how the two can work together to meet the demands of third-generation wireless networking As a network design example, a dual-bus metropolitan area network to be standardized as IEEE 8026 is considered >

PRAIS: Distributed, real-time knowledge-based systems made easy

Abstract: This paper discusses an architecture for real-time, distributed (parallel) knowledge-based systems called the Parallel Real-time Artificial Intelligence System (PRAIS). PRAIS strives for transparently parallelizing production (rule-based) systems, even when under real-time constraints. PRAIS accomplishes these goals by incorporating a dynamic task scheduler, operating system extensions for fact handling, and message-passing among multiple copies of CLIPS executing on a virtual blackboard. This distributed knowledge-based system tool uses the portability of CLIPS and common message-passing protocols to operate over a heterogeneous network of processors.

Intelligent gateways for unified computing environments

Abstract: The use of gateways to integrate heterogeneous networks is investigated. The goal is to extend the unified environments across network boundaries transparently so that services provided by one environment are available to other networks. This approach is most effective if the connected networks have incompatible environments which provide similar services. Intelligent gateways have the advantages of low cost, modularity, resource sharing across the networks and minimal modification to the existing systems. The basic concept of an intelligent gateway is introduced. A case study in which an intelligent gateway supports a network file system between a SUN network and a PC network is presented to demonstrate the basic ideas. >