Chapter 26. Basic Network Concepts

   

Chapter Syllabus

26.1 Network Terminology

26.2 The OSI Model

This is an era of global connectivity, and it is hard to imagine any computer system not being connected to a network. All types of corporate and business communications are carried out using some type of network. A network is a set of computers connected to each other using some communication medium. Computers on a network communicate with each other using a set of rules and regulations commonly known as a network protocol. It is not necessary for the computers connected to a network to be running a common operating system; however, they must use a common network protocol to talk to each other. Depending on the geographical span of a computer network, it is either a Local Area Network (LAN) or a Wide Area Network (WAN). LANs are usually confined to a small area such as one building and owned by one organization. WANs, on the other hand, may span any geographical area and may even spread through other countries . Many business organizations have corporate networks that fall into the WAN category. LANs operate at a higher speed than WANs do. A WAN usually interconnects multiple LANs.

Networks are used for resource sharing and fast communication. A resource may be data files, applications, printers, or computing facilities. They increase productivity and decrease the overall cost of information management.

This chapter is an introduction to network terminology and a reference network model proposed by the International Standard Organization (ISO) called Open Systems Interconnects (OSI). This model is commonly known as ISO-OSI. This is a layered model, where the functions of a network are divided into seven layers. Each layer in a network is responsible to carry a specific type of function and communicate to its adjacent layers in the network model. The functions of all seven OSI layers will be discussed in this chapter. Although ISO-OSI is not implemented in its original form in any current network protocol, it provides guidelines for designing network protocols. The most commonly used network model is TCP/IP, which is a five-layer network model, and it will be discussed in Chapter 28.

The last part of this chapter contains an introduction to how data transfer takes place between two computers connected through a network.


   
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HP Certified
HP Certified: HP-UX System Administration
ISBN: 0130183741
EAN: 2147483647
Year: 2000
Pages: 390
Authors: Rafeeq Rehman

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