Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice HallChapter One 1 Business Data Communications Chapter One Introduction to Data Communications

Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall Chapter One 2 Changing our World

Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall Chapter One 3 Primary Learning Objectives Identify five data communications phases Understand the importance of protocols and standards Be familiar with the OSI and TCP/IP networking models Describe the benefits of a layered architecture Recognize the general categories of networks

Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall Chapter One 4 Five Data Communications Phases 1960s - Digitization of Data 1970s - Growth of Data Communications 1980s - An Era of Deregulation 1990s - The Internet as a Common Tool 2000s - Pervasive Computing

Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall Chapter One s – Digitization of Data Digitization transcribes data into binary form First large-scale, mainframe computer systems are proprietary and they use a closed architecture technology The trend today is for open architecture technologies

Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall Chapter One s – Digitization of Data

Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall Chapter One s – Growth of Data Communications With greater frequency, businesses automate their previously manual processes, using computer technology As a result, computers become more prevalent Increasingly, computers need to communicate with each other so that their data and resources can be shared Data communication infrastructures evolve in response to this need, particularly packet-switching networks

Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall Chapter One s – Growth of Data Communications

Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall Chapter One s – An Era of Deregulation Initially, the telecommunications industry in the United States runs as a monopoly under Bell Telephone/AT&T In 1984, the United States deregulates long distance telecommunication resulting in the breakup of Bell Telephone/AT&T Deregulation’s intent is to provide greater competition in a given market

Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall Chapter One – Internet as Common Tool In 1969, ARPA evolves into ARPANET, which eventually evolves into today’s Internet IPv4, the original protocol version for the Internet Not designed with multimedia data in mind Today, hundreds of millions of people worldwide connect to the IPv4 Internet IPv6, the latest version of the Internet, will gradually replace IPv4

Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall Chapter One – Internet as Common Tool

Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall Chapter One s – Pervasive Computing Pervasive Computing A technology so commonly used it can be taken for granted Essential to future pervasive computing will be wireless technologies For example, telemetry allows the wireless transmission and reception of data for monitoring equipment and environmental conditions

Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall Chapter One s – Pervasive Computing

Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall Chapter One 14 Acme’s use of Telemetry

Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall Chapter One 15 Data Communications Currently a subset of telecommunications, although the differences are beginning to blur Telecommunications includes television, telegraphy, and telephony Data communications focuses primarily on the transmission of data between computing devices

Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall Chapter One 16 Encoding Schemes Data is transmitted using binary encoding schemes Binary encoding schemes, of which there are several, use the binary digits 0 and 1 A new binary encoding scheme called Unicode will allow for the encoding of more than 64,000 unique characters Traditional encoding schemes, such as EBCDIC and Extended ASCII, allow for only 256 unique characters

Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall Chapter One 17 Protocols Data communications also depend on protocols Protocols determine the rules for how something is performed or accomplished Protocols become established or defined through a standards process

Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall Chapter One 18 Standards Standards may be formal or informal Informal standards are also called “de facto” standards Standards can be proprietary or open The trend is toward open standards There are numerous standard-setting bodies ISO, ANSI, IEEE, IETF, to name a few

Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall Chapter One 19 Networking Models Models are logical and based on theory In data communications, two important models are: OSI – Open Systems Interconnection TCP/IP – Transmission Control Protocol/Internet Protocol The OSI and TCP/IP models are both open system models that use a layered architecture The OSI has seven Layers The TCP/IP has four or five layers, depending on the source

Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall Chapter One 20 The Layering Approach In a layered model, each layer is responsible for specific functions A layer must be able to communicate with the layer immediately above or below it However, a layer does not have to “understand” how a layer above or below works Designers of networking technologies can create products that function within a specific layer

Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall Chapter One 21 The OSI Layers Application Presentation Session Transport Network Data Link Physical

Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall Chapter One 22 The TCP/IP Layers Application Transport Network Data Link Physical The application layer of the TCP/IP model includes the application, presentation, and session layers of the OSI model.

Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall Chapter One 23 OSI and TCP/IP These models have several similarities Both offer layered architectures Both are open models They have similar data link layer functions They have similar physical layer functions Of the two, TCP/IP is the older and the more popular

Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall Chapter One 24 Networks Standards and protocols are critical in data communications when creating a network Networks have four general classifications Local Area Network – LAN Backbone Network – BN Metropolitan Area Network – MAN Wide Area Network – WAN Networks are based on models

Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall Chapter One 25 A Local Area Network

Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall Chapter One 26 A Possible Backbone Network

Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall Chapter One 27 A Metropolitan Area Network

Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall Chapter One 28 A Wide Area Network

Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall Chapter One 29 In Summary Data communications is a multifaceted field Many technologists end up specializing in specific areas Many standard-setting bodies affect its direction Pervasive computing will transform how the average person uses and experiences data communications technology