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Lecture Business data communications: Chapter 1 - Behrouz A. Forouzan

Chapter 1 - Introduction. This chapter addresses four issues: data communications, networks, protocols and standards, and standards organizations. First, we give a broad definition of data communications. We then define networks as a highway on which data can travel. We also discuss different types of protocols and the difference between protocols and standards. Then, we give a brief review of the standards organizations that we refer to throughout the book. Finally, we discuss network models. | Chapter 1 Introduction Understand the difference between telecommunications and data communications. List the components of a data communications system. Understand the need for a network and distinguish between different network types. Understand the difference between a protocol and a standard. After reading this chapter, the reader should be able to: OBJECTIVES OBJECTIVES (continued) Understand the duties of the layers in the OSI model. Understand the duties of the layers in the Internet model. Be able to compare the layers in the OSI and Internet model. Be familiar with standards organizations and their duties. DATA COMMUNICATIONS 1.1 In computer information systems, data are represented by binary information units (or bits) produced and consumed in the form of 0s and 1s. Note: Figure 1-1 Data communications system components In data communications, a protocol is a set of rules (conventions) that governs all aspects of information communication. Note: NETWORKS 1.2 Figure 1-2 . | Chapter 1 Introduction Understand the difference between telecommunications and data communications. List the components of a data communications system. Understand the need for a network and distinguish between different network types. Understand the difference between a protocol and a standard. After reading this chapter, the reader should be able to: OBJECTIVES OBJECTIVES (continued) Understand the duties of the layers in the OSI model. Understand the duties of the layers in the Internet model. Be able to compare the layers in the OSI and Internet model. Be familiar with standards organizations and their duties. DATA COMMUNICATIONS 1.1 In computer information systems, data are represented by binary information units (or bits) produced and consumed in the form of 0s and 1s. Note: Figure 1-1 Data communications system components In data communications, a protocol is a set of rules (conventions) that governs all aspects of information communication. Note: NETWORKS 1.2 Figure 1-2 Network criteria Figure 1-3 LAN Figure 1-4 MAN Figure 1-5 WAN Figure 1-6 Internetwork (internet) Technical Focus: Representing Information Information stored inside the computer consists of only two symbols: 0 and 1. This is because the memory of the computer is made of electronic switches that are either on or off. When the switch is off, it stores a 0; when the switch is on, it stores a 1. This means that any type of information must be represented as a sequence of 0s and 1s for storage inside the computer. Because data communications is the process of moving information from one computer to another, data communications also uses 0s and 1s to represent information. PROTOCOLS AND STANDARDS 1.3 Figure 1-7 Categories of standards STANDARDS ORGANIZATIONS 1.4 Business Focus: Standards Organizations The following are some standards organizations: ISO ANSI ITU-T IEEE EIA Business Focus: FCC Specific FCC responsibilities include the following: Review rate and service-charge applications .