China
Africa
Explore chapters and articles related to this topic
Networking Basics
Published in Vivek Kale, Parallel Computing Architectures and APIs, 2019
The OSI model has seven layers. The principles that were applied to arrive at the seven layers can be briefly summarized as follows: A layer should be created where a different abstraction is needed.Each layer should perform a well-defined function.The function of each layer should be chosen with an eye toward defining internationally standardized protocols.The layer boundaries should be chosen to minimize the information flow across the interfaces.The number of layers should be large enough that distinct functions need not be thrown together in the same layer out of necessity and small enough that the architecture does not become unwieldy.
Introduction of Computer Networks
Published in Dijiang Huang, Ankur Chowdhary, Sandeep Pisharody, Software-Defined Networking and Security, 2018
Dijiang Huang, Ankur Chowdhary, Sandeep Pisharody
The Open Systems Interconnection (OSI) modelOSI Open Systems Interconnection is a conceptual model that characterizes and standardizes the communication functions of a telecommunication or computing system without regard to its underlying internal structure and technology. OSI model is standardized by the International Organization for Standardization (ISO) and International Electrotechnical Commission (IEC) with the identification ISO/IEC 7498-1. The goal of OSI is the interoperability of diverse communication systems with standard protocols. The model partitions a communication system into abstraction layers. Shown in Figure 1.1, on the right side is the original version of the model defined using seven layers, namely Physical, Data Link, Network, Transport, Session, Presentation, and Application. The corresponding TCP/IP TCP/IP protocol layers, which is the Internet Engineering Task Force (IETF) standard is presented on the left side of the Figure 1.1. The OSI model is conceptually sound to nicely present the relations among multiple protocols and their inter-dependencies. However, the simplicity of the TCP/IP protocol framework won the competition and has been widely adopted by many networking systems, especially, the Internet.
Network Models
Published in Sunit Kumar Sen, Fieldbus and Networking in Process Automation, 2017
TCP/IP was developed by the Department of Defense before the introduction of the seven-layer OSI model. It is the de facto global standard for the Internet. The Internet (earlier known as ARPANET) was a part of a military project of the Advanced Research Projects Agency (ARPA) and the communication model based thereon is known as the ARPA model. ARPA was developed in the United States before the OSI model was developed in Europe by the ISO. Whereas the OSI model specifies exactly what function(s) each layer has to perform, TCP/IP comprises several relatively independent protocols that can be combined in several ways. Although TCP/IP and OSI were developed at different times by different bodies, they form the basis for data communications having different types and of different complexities.
The internet of things for smart manufacturing: A review
Published in IISE Transactions, 2019
Hui Yang, Soundar Kumara, Satish T.S. Bukkapatnam, Fugee Tsung
In addition, a number of IoT frameworks and architectures such as RAMI 4.0 and OPC Unified Architecture have been proposed to define the communication structure of Industry 4.0. RAMI 4.0 provides a reference architectural model to define the three-dimensional map for Industry 4.0. The first dimension is the Factory Hierarchy (i.e., product, field device, control device, station, work center, and enterprise). The second dimension is Architecture (i.e., Asset, Integration, communication, information, function, and business). The third dimension is Product Life Cycle (i.e., from the initial design to the scrapyard). Note that RAMI 4.0 is similar to the Open Systems Interconnection (OSI) model, but add two more dimensions that are critical to the industrial systems. Note also that the OSI model uses seven abstraction layers: physical layer, data link layer, network layer, transport layer, session layer, presentation layer and application layer, to compartmentalize and standardize functions in network communication (Zimmermann, 1980). As such, the OSI model enables users to communicate over the Internet without concern for electrical specifications, binary transmission, or network addressing. Similarly, RAMI 4.0 compartmentalizes and standardizes functions in three different dimensions, so as to provide the reference architecture for Industry 4.0. Also, the OPC foundation proposes the OPC Unified Architecture (UA) for data acquisition and information exchange in the RAMI 4.0 framework. As the same architecture model is used, OPC UA-enabled devices and products will speak the same language for effective and efficient communication. However, there are also other IoT architectures currently available such as the IoT standard landscape from NIST, Robot Revolution Initiative (Japan), the Industrial Internet Consortium (IIC) white paper, Platform Industrie 4.0 white paper, as well as the Cisco white paper. Note that it is difficult for all companies to use the same reference architecture of Industry 4.0, due to competition in the business world. However, such competition will accelerate the development of a comprehensive IoT framework. As with the first phase of Internet development, it is anticipated that competition and collaboration will eventually result in a widely-used IoT framework and architecture for Industry 4.0.