Business Data Communications

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

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

1960s – 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

1970s – 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

1980s – 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

1990 – 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

2000s – 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

0110010101110001010101 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

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

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

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

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

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

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. The TCP/IP Layers Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall

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

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

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 Business Data Communications, by Allen Dooley, (c) 2005 Pearson Prentice Hall

Business Data Communications