1. Networks and Networking
Chapter 6
Copyright Prentice-Hall, Inc. 2001

2. Get Wired!!
Surfing
Online Books
Monthly
Technology
Update

3. What is it all about? Computer networks simply enhance
the efficiency and effectiveness
of interactions between people,
whether they are knowledge workers or Internet surfers.

4. Becoming digitally compatible!!
Digital Convergence
DVDs
Telephones
Televisions
Computers
Newspapers
College courses
Textbooks on CD-ROM
Banking/Finance
Becoming digitally compatible!!

5. Connectivity
Seeking ways to interface, or connect, a diverse set of hardware, software, and databases.

6. Cooperative Processing
E-commerce (electronic commerce)
Intercompany Networking
Electronic Data Interchange (EDI)
Intranets
Extranets

7. Data Communications Data Communications = Telecommunications
Special hardware transmits the digital information between computers

8. Data Communications Hardware
Modem
Digital to Analog to Digital
Internal & External
Fax Modems
Network Interface Cards (NIC)
Special Function Communications Devices
Routers (backbone hardware)

9. Data Communications Messaging
Message is distributed among:
Host or Server computer - in control
Front-end Processor - establishes handshake
Multiplexor - collects data from multiple devices and sends it along
Network Address

10. Communications Protocols
Rules that govern the way data are transmitted
Communication between networks using incompatible protocols (use of routers)
Serendipitous Surfing:
Government

11. Data Communications Channel
The medium through which digital information must pass to get from one location in a computer network to the next.
Also called the Line, Link or Pipe
Transmission Media

12. Transmission Media Wires & Wireless Media Channel Capacity (Bandwidth)
Bits per Second (BPS) vs. Baud
Types:
Twisted-Pair Wire
Coaxial Cable
Fiber Optic Cable
High-Speed Wireless
Transmission Media

13. Twisted-Pair Wire Carries data as electrical signals
POTS (plain old telephone service) 56 K bps
ISDN - Line & Modem 128 K bps
ADSL - Line & Modem 1.5 to 9 M bps
Downstream rate
Upstream rate
Will compete with cable
Transmission Media

14. Coaxial Cable Carries data as electrical signals
Hundreds of times faster than POTS
100 times faster than ISDN
Need a cable modem

15. Fiber Optic Cable Carries data as laser-generated pulses of light
Foundation transmission medium for Internet backbone
Better for data security
Courtesy of International Business Machines Corporation

16. High-Speed Wireless Carries data via microwave or radio signals
Geosynchronous Orbit Satellites
Wireless Transceivers

17. Common Carriers AT&T, MCI, Sprint, etc. Private Line (or Leased Line)
Switched Line (or Dial-Up Line)

18. Is it time to GO yet?

19. Network Topologies
Network Topology is a description of the possible physical connections within a network. It is a configuration of hardware and it shows which pairs of nodes can communicate.
Networks

20. Network Topologies
Ring
Star
Bus
Networks

21. Client/Server Computing
Centralized Computing
Trend to Decentralizing & Downsizing
Server Computer
Client Computer
Proxy Server Computer
Front-end Applications
Back-end Applications

22. Network Line Control Communications Protocols (TCP/IP)
Two Classifications:
Asynchronous Transmission (low speed)
Synchronous Transmission (high speed)

23. Metropolitan Area Network
Types of Networks
Wide Area Network
WAN
Metropolitan Area Network
MAN
Local Net
LAN
Tiny Area Network
TAN

24. Sharing Resources on a LAN
Applications software
Links to mainframes
Communications capabilities
I/O devices
Storage devices
Add-on boards

25. Local Area Networks LAN Access Methods LAN Servers Token Access Method
Ethernet
LAN Servers
File Server
Print Server
Communications Server

26. LAN Software Operating Systems Applications Software
Peer to Peer LANs
LANs with dedicated servers
Applications Software
Shared software
Groupware
Networks on the Fly

27. End of Chapter 6 Interactive Study Guide
Copyright Prentice-Hall, Inc. 2001