1. Computers © 2005 Prentice-Hall, Inc.Slide 1

2. Computers Chapter 6 Networks and Networking © 2005 Prentice-Hall, Inc.Slide 2

3. Computers Chapter 6 – Networks and Networking Objectives Apply the concept of connectivity to your life Understand data communications hardware Identify data transmissions services Understand the various network topologies Recognize the potential of home networking © 2005 Prentice-Hall, Inc.Slide 3

4. Computers Networks and Networking Our Wired World Connectivity – the degree to which software, hardware, and databases are functionally linked © 2005 Prentice-Hall, Inc.Slide 4

5. Computers Networks and Networking Our Wired World Cooperative processing Intracompany networking – cooperation within the company Intercompany networking – cooperation with other companies and customers © 2005 Prentice-Hall, Inc.Slide 5

6. Computers Networks and Networking Our Wired World Intranet –internal network based on Internet technology Extranet – an extension of an intranet, partially available to authorized customers and suppliers © 2005 Prentice-Hall, Inc.Slide 6

7. Computers Networks and Networking Our Wired World Virtual Private Network (VPN) – network transmissions are tunneled through the Internet Tunneling – one network uses another to send data © 2005 Prentice-Hall, Inc.Slide 7

8. Computers Networks and Networking Data Communications Hardware Data communications or telecommunications – distribution of data © 2005 Prentice-Hall, Inc.Slide 8

9. Computers Networks and Networking Data Communications Hardware Server computers – central computers that control the network Client computers – computers, linked to a server, that create the network © 2005 Prentice-Hall, Inc.Slide 9

10. Computers Networks and Networking Data Communications Hardware Proxy server computers – handle some requests, hand others to the actual server computers © 2005 Prentice-Hall, Inc.Slide 10

11. Computers Networks and Networking Data Communications Hardware Telephone-link modem – converts analog signals to digital and digital signals to analog Analog – voice communication, such as over a telephone line Digital – 1’s and 0’s used to represent data in a computer © 2005 Prentice-Hall, Inc.Slide 11

12. Computers Networks and Networking Data Communications Hardware Modem Internal External Voice/data/fax modem © 2005 Prentice-Hall, Inc.Slide 12

13. Computers Networks and Networking Data Communications Hardware Cable modem – provides Internet access via cable television lines DSL (Digital Subscriber Line) – Internet access via special line provided by a telephone company Satellite modem – Internet access via communications satellite © 2005 Prentice-Hall, Inc.Slide 13

14. Computers Networks and Networking Data Communications Hardware Network interface card (NIC) – also called network card and network adapter Needed to connect a personal computer to a network Ethernet – de facto standard © 2005 Prentice-Hall, Inc.Slide 14

15. Computers Networks and Networking Data Communications Hardware Gateway – allows for communication between networks using different protocols Router – routes messages to the appropriate destination Gateway router – both functions in one device © 2005 Prentice-Hall, Inc.Slide 15

16. Computers Networks and Networking Data Communications Hardware Message Source – device that sends the message Destination – device that receives the message Handshaking – router establishes the connection between the source and the destination © 2005 Prentice-Hall, Inc.Slide 16

17. Computers Networks and Networking Data Communications Hardware Network address – assigned to each computer on a network; used to send messages to the appropriate destination Backbone – the routers, gateways, and other equipment that link the computers of the network © 2005 Prentice-Hall, Inc.Slide 17

18. Computers Networks and Networking Data Communications Hardware Hub – expands the number of nodes on a network Half-duplex – data can only be sent in one direction at a time Switch – acts like a hub for a local area network (LAN) Full-duplex – data can be sent in both directions at once © 2005 Prentice-Hall, Inc.Slide 18

19. Computers Networks and Networking Data Communications Hardware Terminals Video Display Terminal (VDT) – input/output device Thin client – smart terminal, capable of some processing © 2005 Prentice-Hall, Inc.Slide 19

20. Computers Networks and Networking Data Communications Hardware Telephony – integration of telephones and computers © 2005 Prentice-Hall, Inc.Slide 20

21. Computers Networks and Networking Data Communications Hardware Automatic Teller Machine (ATM) – used in banking Point-of-Sale (POS) terminals – used in retail © 2005 Prentice-Hall, Inc.Slide 21

22. Computers Networks and Networking The Data Communications Channel Communications channel – media a message must pass through on a network Line Link Pipe © 2005 Prentice-Hall, Inc.Slide 22

23. Computers Networks and Networking The Data Communications Channel Transmission media Measured in bits per second (bps) © 2005 Prentice-Hall, Inc.Slide 23

24. Computers Networks and Networking The Data Communications Channel Twisted-pair wire POTS (plain old telephone services) Digital Subscriber Line (DSL) Cat5 cabling – uses four twisted pairs of wire; speeds of up to 100 Mbps Cat5e cabling – speeds of up to 1 Gbps © 2005 Prentice-Hall, Inc.Slide 24

25. Computers Networks and Networking The Data Communications Channel Coaxial cable – high capacity channel, capable of speeds up to 10 M bps Fiber optic cable – carries data as laser generated pulses of light © 2005 Prentice-Hall, Inc.Slide 25