Open Systems Interconnection Model Research Articles

OSI service specification: SAP and CEP modelling

Within the effort of ISO standarization, service specifications have been thought to be an important tool for formal verification of protocols. The paper discusses the modelling of some concepts quite related with the service: service access points and abstract service primitives. Firstly, ISO concepts are explained. Then, a service architectural model is developed as a refinament of the service access point idea using the connection end point concept. A finite state machine approach is shown to specify the behavior of the modules of such architecture. This lead us to consider the service access point represented as a single state automaton that consists of several connection end point automata. Thus, service access points allow the specification of services, and provide an abstraction of interfaces between adjacent layers of the Open System Interconnection model of ISO.

Dialogue management reference model

I would like to review and extend the discussion of the layered structure model similar to the ISO Open Systems Interconnect model in the Report on the SIGCHI Workshop on Planning for User Interface Standards published in the October, 1985 SIGCHI Bulletin . First, I would like to compliment the people who worked on the report. They produced a document which I regard as correct, however incomplete. Bullinger and Faehnrich in Germany have published papers on what they regard as the User Interface Management System. I have integrated Figure 3 and Figure 4 from the CHI '85 Report with the diagrams from Bullinger et al to produce Figure 1. The layers added---semantic, syntactic and lexical---are commonly used in the implementation of compilers and interpreters and are supported by many tools referred to as compiler compilers i.e., yacc and lex from the UNIX system. In the ISO OSI reference model, interfaces exist at the vertical arrows between adjacent layers, protocols exist between peer layers. The term "user interface" conflicts with the ISO usage of "interface." I will instead refer to "human-computer dialog rules." Human-computer dialog rules are the set of peer layer protocols along with the user feedback rules, and appear as horizontal arrows on Figure 1. It is the set of human-computer dialog rules that should be standardized by SIGCHI members. Interfaces between the adjacent layers are implementation details and should be standardized by implementors.

A formal method for composing a network command language

A formal method is introduced for the development and definition of command languages for heterogeneous computer networks. The network command languages are developed from the command languages of the systems constituting the network. This is done by defining a common presentation model for the system command languages and constructing the network command language by applying a composition principle to the commonly represented languages. The common presentation model is defined as a Vienna Development Method (Meta IV) abstract processor for command languages. System command languages are represented by means of predicate functions which are defined on the abstract domains of the abstract processor. This allows a straightforward formulation of the composition principle as a function for the logical combination of predicate functions. Two sample network command languages are composed out of two hypothetical command languages. The results are related to the International Organization for Standardization Open Systems Interconnection model (ISO OSI).

Helping computers communicate: The Open Systems Interconnection model promises compatibility for a variety of computer systems, although not all its functions are yet defined

The possibilities opened up by the Open Systems Interconnection (OSI) model are discussed. It is noted that many of the protocols to implement OSI are now complete, and manufacturers offer products to implement some of the standards. The International Organization for Standardization will continue to expand the functions covered by OSI as new communications network architectures and technologies emerge. Each of the seven layers making up the model is described. Prospects for the model's success are then surveyed.

ISDN Architecture

Modern communications-based applications require a degree of flexibility, user control, responsiveness, and integrative capability beyond that provided in traditional networks. Solutions founded on digital connectivity implemented in a distributed processing environment have begun to meet these needs. These solutions have been constrained, however, by limits to the extent in which systems could communicate with each other across network boundaries. The Integrated Services Digital Network architecture defines key interfaces that support and extend this distributed processing capability and do this in an environment of internationally defined interface standards. These interfaces are channelized into two broad categories: information-bearing channels and signaling channels. Protocols for the latter have been defined using the layered architecture of the open systems interconnect reference model. Two specific ISDN access arrangements have been specified and are planned for systems within an overall ISDN architecture. Applications for such an architecture and future directions are discussed.

Security services for applications of OSI in banking

The protection of financial information has always been critical to success in banking. Security has become much more visible now that the automation and interconnection of banking processes is becoming widespread. Most financial institution are moving towards international systems interworkng, eventually using products based on the Open Systems Interconnection model. Thus, it is essential that basic security services be incorporated into the OSI architecture. This paper reviews security needs for banking communications, surveys on-going standardization work in TC68 (Banking) and TC97/SC21, and concludes that the planned security services in OSI should satisfy banking requirements if completed quickly.

A High-Speed, Large-Capacity, Jukebox "Optical Disk System"

Two optical disk 'jukebox' mass storage systems which provide access to any data in a store of 10 to the 13th bits (1250G bytes) within six seconds have been developed. The optical disk jukebox system is divided into two units, including a hardware/software controller and a disk drive. The controller provides flexibility and adaptability, through a ROM-based microcode-driven data processor and a ROM-based software-driven control processor. The cartridge storage module contains 125 optical disks housed in protective cartridges. Attention is given to a conceptual view of the disk drive unit, the NASA optical disk system, the NASA database management system configuration, the NASA optical disk system interface, and an open systems interconnect reference model.

Local area networks: Local area networks — An interconnection of computers and peripherals in adjacent rooms or buildings — Can provide cost-effective communications

Local area networks are defined, and the operation of ring, bus, and star networks is described and compared. The ISO Open System Interconnection Model is also described.

Modularity in the design and standardisation of open systems

Some practical suggestions are made as to how data abstraction may be used to provide a modular framework for the design of open systems and their means of interconnection. This framework is technically advantageous in clarifying the interfaces between the parts of a large design, and would also help in planning and coordinating the work of standards committees. A reference model for languages applicable to local system function is compared with the reference model for open systems interconnection (OSI), and a clarification is suggested which would make the models compatible. Two major functional requirements are proposed for the application layer of the OSI model, namely the ability to transmit arbitrary operations to be performed on remote objects, and the option to specify whether objects or merely references to them should be transmitted.

The new CEPT-standard: Another system or a solution?

The paper gives an overview on the new standard with regard to its general structure and its relation to the ISO OSI (Open System Interconnection) model. It describes the general properties (character and colour repertoire, attributes and functions) and gives a more detailed description of the two novelties within the new standard DRCS (Dynamically Redefinable Character Set) and the dynamically redefinable colour set. Furthermore, it highlights the most important aspects of transmission and presentation with regard to codes and code extensions. Finally, it comments on the compatibility of the new standard with existing systems.

Human factors in and requirements of the OSI environment

Abstract This paper examines the ISO open systems interconnection model as promulgated, from the standpoint of human factors research rather than from the traditional telecommunications perspective. It argues that the model needs refining in its top layer and that this layer should be considered as a general ‘function’ layer oriented towards users rather than just an applications layer. The vertical relationship between layers and the horizontal relationships within a layer are discussed with regard to the implications that a small change in user behaviour has for the technical specifications of the system and vice versa. Particular stress is placed on the need for a core ‘native’ language which would operate at any level to support human factors requirements. The surface features of the system that need to be optimized.for the user are defined in the context of existing human factors research. The paper concludes by specifying the human factors requirements for OSI

Experiences with a Layered Approach to Local Area Network Design

The Nestar Plan 4000 network was designed using the ISO Open Systems Interconnection model. The Xerox Network Systems Internet Transport Protocols (XNS) were chosen for the network and transport layers, a token-passing protocol (Arcnet) for the physical and datalink layers, and existing Nestar server software for the highest layers. The physical and datalink layers are supported by a VLSI chip and their implementation was straightforward. In spite of their detailed specification, implementing the network and transport layers presented some unanticipated challenges. This paper discusses details of our experience in implementing the network with emphasis on the problems encountered and how they were solved.

Local-network database

The architecture of the Microbe distributed database management system is described, with particular emphasis on the distributed execution of user requests controlled in a fully decentralized manner by a distributed execution monitor (SER). The monitor is based on the results of a dynamic and decentralized query decomposition algorithm known as Dopage. Microbe is now being implemented on a local broadcasting network of LSI-11 machines developed at Laboratoire IMAG for scientific and administrative applications. It was designed to be used for research in the distributed data processing field particularly concerning the implementation of the ISO open systems interconnection model levels 5 and 7 (session and application layers) for a loosely coupled distributed database system.