CPETECET 355

1
CPET/ECET 355

• 1. Introduction
• Data Communications and Networking
• Fall 2004
• Professor Paul I-Hai Lin
• Electrical and Computer Engineering Technology
• Indiana University-Purdue University Fort Wayne
• www.ecet.ipfw.edu/lin

2
Overview

• Data communications use network infrastructure to
  sent data (information) from one place to another
• Data Communications involve
• Data and Data Representation (information)
• Data Flow
• Physical Network Components

3
Overview (cont.)

• Examples of Data
• Online banking
• Airline reservation
• Medical record
• Digitized data
• Voice
• Video
• Multimedia

4
Overview (cont.)

• Networking involves
• Application protocols
• Connections of computers and programs
• Networking devices
• Media

5
Overview (cont.)

• Local Area Networks
• Application protocols
• Connections of computers and programs
• Networking devices
• Transmission Media

6
Overview (cont.)

• Wide Area Networks
• Application protocols
• Connections of computers and programs
• Networking devices
• Transmission Media

7
Overview (cont.)

• Internet
• A collection of LANs and WANs
• Standard protocols

8
Overview (cont.)

• Standards and Protocols
• HTML
• XML
• 802.3
• 802.11g
• Network Models
• TCP/IP
• OSI
• etc

9
1.1 Data Communication

• Data
• Refers to Information, Facts, Concepts,
  Instructions
• Represented by binary information units (bits
  0, 1)
• Consists of text, numbers, pictures, sound or
  video

10
1.1 Data Communication (cont.)

• Data Communication
• Exchange of data between devices via some form of
  transmission medium

11
1.1 Data Communication (cont.)

• Three Fundamental Characteristics
• Delivery source gt destination
• Accuracy error free
• Timeliness real-time

12
1.1 Data Communication (cont.)

• A Communication Model/System (5 components)
• Message
• Sender
• Medium
• Receiver, and
• Protocol

13
Five Components of a Communication System(cont.)

• Message
• Text, numbers, pictures, sound or video or any
  combination of these
• Sender
• Computer, workstation, server, telephone handset,
  video camera, etc

14
Five Components of a Communication System (cont.)

• Medium
• Twisted pair wire, coaxial cable, fiber-optic
  cable, laser, radio waves, microwaves
• Receiver
• Protocol
• A set of rules that govern data communications

15
Examples of Senders/Receivers

• Workstation
• Modem
• Public Telephone Network
• Server

16
Direction of Data Flow

• Simplex
• one direction, either as transmitter or receiver
• Half-duplex
• both direction can transmit or receive, but one
  at a time
• Full-duplex
• can transmit and receive simultaneously

17
Communications Tasks

• Message Formatting
• Encryption, or Encoding (Security)
• Addressing
• Routing
• Synchronization
• Flow Control

18
Communications Tasks (cont.)

• Exchange Management
• Error detection and Correction
• Recovery
• Network Management

19
1.2 Networks

• A Network - a set of nodes connected by media
  links for resource sharing
• A Node computer, printer, etc
• A Link communication Channel
• Resource printer, database, files, Web pages,
  records, etc

20
1.2 Networks

• Distributed Processing
• Loosely connected computer networks
• Many computers collaborating with each other
• Client-Server

21
Network Criteria

• Performance
• Reliability
• Security

22
Network Criteria

• Performance
• No of users
• Types of transmission medium
• Hardware
• Software

23
Network Criteria

• Reliability
• Frequency of failure
• Recovery time of a network after a failure
• Catastrophe

24
Network Criteria

• Security
• Unauthorized access
• Viruses
• Data protection
• System protection

25
Applications of Networks

• Marketing and sales
• Financial services
• Manufacturing
• Electronic Messaging
• Directory services

26
Applications of Networks

• Information services
• Electronic data interchange (EDI)
• Teleconferencing
• Cellular telephone
• Cable television

27
Network Configurations

• Defines the attachment of communication devices
  to a link
• Two categories
• Point-to-Point
• Multipoint

28
Point-to-Point Line Configuration

• Dedicated link with entire capacity of the
  channel reserved for communication
• Examples
• PC to PC (workstation)
• Mainframe to PC (Workstation)
• Satellite links

29
Multipoint Line Configuration

• Multi-drops
• Sharing a single link
• Spatially
• Time sharing

30
Multipoint Line Configuration

• Multi-drops
• Sharing a single link
• Spatially
• Time sharing

31
Network Topology

• Logical or physical layout of a network
• Two or more links form a topology
• Five Basic Topologies
• Mesh, Star, Tree, Bus, Ring

32
Categories of Networks

• Local Area Network (LAN)
• Metropolitan Area Network (MAN)
• Wide Area Network (WAN)
• Long distance transmission of data, voice, image,
  and video information
• Enterprise network (owned by a single company)

33
Local Area Network (LAN)

• Privately owned links and computers in a single
  office, building, or campus
• Bus, Ring, and Star topologies Topologies bus,
  ring, star, wireless, infrared
• Data rates 2 Mbps, , 10 Mbps, 100 Mbps, Gigabits

34
Metropolitan Area Network (MAN)

• City wide coverage
• LAN-to-LAN
• LAN-to-other larger network

35
Wide Area Network (WAN)

• Long distance transmission of data, voice, image,
  and video information
• Enterprise network (owned by a single company)
• Technologies
• ATM (Asynchronous Transfer Mode)
• Frame Relaying
• X.25 (Packet switching network)
• Circuit switching

36
Internet

• Internet (World Wide Web)
• Router
• Gateways
• Servers
• LANs
• WANs
• MANs
• Browsers/Computer

37
Internet Service Providers

• Internet Service Providers
• Regional Service Providers
• National Service Providers
• International Service Providers
• Application Service Providers
• Universities/Government/etc
• Telecomm. Companies
• Telephone companies

38
Protocols

• A set of rules that govern data communications
• What is communicated?
• How it is communicated?
• When it is communicated?
• Key elements Syntax, Semantics, and Timing

39
Syntax

• Structure or Format of data
• Order of data
• Example
• Address of Receiver (First 8 bit)
• Address of Sender (Second 8 bit)
• Message (rest of bits)

40
Semantics

• Meaning of each section of bits
• Bit pattern and interpretation
• Command or action

41
Timing

• When to send?
• How fast it can be sent?

42
Standards

• Provides a model for govern the PHYSICAL,
  ELECTRICAL and PROCEDURAL characteristics of
  communication equipment

43
Standards

• Advantages
• Assures that there will be a large market for a
  particular piece of equipment or software
• Allows products from multiple vendors to
  communicate (more selections)

44
Standards

• Disadvantages
• Tends to freeze the technology
• Multiple conflicting standards

45
Summary

• Data communications
• Networking
• Protocols
• Standards
• Questions?