This document provides an overview of data communications and networking. It discusses the components of data communication including data representation and direction of data flow. It also describes different network models like point-to-point, multipoint, bus, star, ring and mesh topologies. Additionally, it differentiates between local, metropolitan and wide area networks. The document also provides a brief history of the Internet and discusses protocols, standards and standards organizations that are important to data communication and networking.

1. McGraw-Hill ©The McGraw-Hill Companies, Inc., 2004
Overview ofOverview of
Data CommunicationsData Communications
andand
NetworkingNetworking
PART IPART I

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

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

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

5. McGraw-Hill ©The McGraw-Hill Companies, Inc., 2004
1.1 Data Communication
Components
Data Representation
Direction of Data Flow

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

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

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

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

10. McGraw-Hill ©The McGraw-Hill Companies, Inc., 2004
1.2 Networks
Distributed Processing
Network Criteria
Physical Structures
Categories of Networks

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

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

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

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

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

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

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

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

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

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

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

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

23. McGraw-Hill ©The McGraw-Hill Companies, Inc., 2004
1.3 The Internet1.3 The Internet
A Brief History
The Internet Today

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

25. McGraw-Hill ©The McGraw-Hill Companies, Inc., 2004
1.4 Protocols and Standards1.4 Protocols and Standards
Protocols
Standards
Standards Organizations
Internet Standards

26. 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

27. 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.

28. 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.

29. 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).

30. 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 802.3 and IEEE 802.5) are the best-known
IEEE communications standards and are the
predominant LAN standards in the world today.

31. 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.

32. 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).