McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Overview of Data Communications and Networking PART I

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Overview

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Chapters Chapter 1 Introduction Chapter 2 Network Models

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Chapter 1 Introduction

McGraw-Hill©The McGraw-Hill Companies, Inc., Data Communication Components Data Representation Direction of Data Flow

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 1.1 Five components of data communication

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 1.2 Simplex

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 1.3 Half-duplex

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 1.4 Full-duplex

McGraw-Hill©The McGraw-Hill Companies, Inc., Networks Distributed Processing Network Criteria Physical Structures Categories of Networks

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 1.5 Point-to-point connection

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 1.6 Multipoint connection

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 1.7 Categories of topology

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 1.8 Fully connected mesh topology (for five devices)

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 1.9 Star topology

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 1.10 Bus topology

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 1.11 Ring topology

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 1.12 Categories of networks

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 1.13 LAN

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 1.13 LAN (Continued)

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 1.14 MAN

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 1.15 WAN

McGraw-Hill©The McGraw-Hill Companies, Inc., The Internet A Brief History The Internet Today

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 1.16 Internet today

McGraw-Hill©The McGraw-Hill Companies, Inc., Protocols and Standards Protocols Standards Standards Organizations Internet Standards

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Computer communications and standards Why standards? Required to allow for interoperability between equipment Advantages Ensures a large market for equipment and software Allows products from different vendors to communicate Disadvantages Freeze technology May be multiple standards for the same thing Defacto and Dejure standards

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Key Organizations Standards organizations provide forums for discussion, help turn discussion into formal specifications Most standards organizations have specific processes for turning ideas into formal standards. They all iterate through several rounds of organizing ideas, discussing the ideas, developing draft standards, voting on all or certain aspects of the standards, and finally formally releasing the completed standard to the public.

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Key Organizations (con’t) Some of the better-known standards organizations follow: International Organization for Standardization (ISO)—An international standards organization responsible for a wide range of standards, including those relevant to networking. This organization is responsible for the OSI reference model and the OSI protocol suite.

McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Key Organizations (con’t) American National Standards Institute (ANSI)— The coordinating body for voluntary standards groups within the United States. ANSI is a member of ISO. ANSI’s best-known communications standard is FDDI. Electronic Industries Association (EIA)—A group that specifies electrical transmission standards. EIA’s best-known standard is EIA/TIA-232 (formerly RS-232).

McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Key Organizations (con’t) Institute of Electrical and Electronic Engineers (IEEE)—A professional organization that defines network standards. IEEE LAN standards (including IEEE and IEEE 802.5) are the best-known IEEE communications standards and are the predominant LAN standards in the world today.

McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Key Organizations (con’t) International Telecommunication Union Telecommunication Standardization Sector (ITU-T) (formerly the Committee for International Telegraph and Telephone [CCITT])—An international organization that develops communication standards. The best-known ITU-T standard is X.25.

McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Key Organizations (con’t) Internet Activities Board (IAB)—A group of internetwork researchers who meet regularly to discuss issues pertinent to the Internet. This board sets much of the policy for the Internet through decisions and assignment of task forces to various issues. Some Request for Comments (RFC) documents are designated by the IAB as Internet standards, including Transmission Control Protocol/Internet Protocol (TCP/IP) and the Simple Network Management Protocol (SNMP).