Open Systems Interconnection

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Open Systems Interconnection

(OSI-RM, OSI Reference Model, seven layer model) A model of network architecture and a suite of protocols (a protocol stack) to implement it, developed by ISO in 1978 as a framework for international standards in heterogeneous computer network architecture.

The OSI architecture is split between seven layers, from lowest to highest: 1 physical layer, 2 data link layer, 3 network layer, 4 transport layer, 5 session layer, 6 presentation layer, 7 application layer.

Each layer uses the layer immediately below it and provides a service to the layer above. In some implementations a layer may itself be composed of sub-layers.

OSI is the umbrella name for a series of non-proprietary protocols and specifications, comprising, among others, the OSI Reference Model, ASN.1 (Abstract Syntax Notation 1), BER (Basic Encoding Rules), CMIP and CMIS (Common Management Information Protocol and Services), X.400 (Message Handling System, or MHS), X.500 (Directory Service), Z39.50 (search and retrieval protocol used by WAIS), and many others. Apart from its actual application to real protocols, it also serves as a useful teaching model.
This article is provided by FOLDOC - Free Online Dictionary of Computing (
References in periodicals archive ?
For instance, the Open Systems Interconnection (OSI) standards are official, or de jure standards, while DOS is a de facto standard because many people use it.
An X.25 packet switched network that supports the Open Systems Interconnection Standard, the New Network provides telecommunications service to nearly 14,000 OCLC-participating libraries in 46 countries.
Here the ISO Open Systems Interconnection seven-layer model (ref.
And, some of the applications put to work on newer networks are being implemented in compliance with open systems interconnection (OSI) standards.
[2] Open Systems Interconnection Basic Reference Manual.
The new OS/400 Version 2 operating system includes implementations of networking protocols like Open Systems Interconnection, Transmission Control Protocol/ Internet Protocol, and Integrated Services Digital Network.
Networking must be based on internationally recognized standards such as the Open Systems Interconnection (OSI) reference model.
Many computer companies and network operators are gradually shifting to a standard known as the Open Systems Interconnection being developed by the International Standards Organization.
Straight 10-, 100- or 1,000-Mbps media converters operate in the Layer 1 of the open systems interconnection (OSI) model.
ONE's Foundation Product Suite provides Open Systems Interconnection (OSI) protocol solutions, agent development tools, mediation tools, and professional services.

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