2. TOPIC Data Communication 3 March 2004 © PETER KOMISARCZUK & VUW, 2004. 2

3. Group Member Kaleem ullah Dilawar Gull Sufyan Maqsood. 3

4. TRANSMISSION MODES 4 Simplex Half Duplex Full Duplex

5. A NETWORK MODEL 5 Source Transmitter Carrier Receiver Destination

6. NETWORKS How do we categorise?  Topology, geography  Technology Geographic  Wide area networks  Metropolitan networks  Local area networks  Personal networks Technologies  Circuit switched  Packet switched. 6

7. WHAT'S A NETWORK? CONSIDER THE PHYSICAL TOPOLOGY 7 Point-to-Point Connections:

8. WHAT'S A NETWORK? CONSIDER THE PHYSICAL TOPOLOGY 8 Point-to-Multipoint Connections:

9. WHAT'S A NETWORK? CONSIDER THE PHYSICAL TOPOLOGY 9 Topology Types: Topology = The map or plan of the network. The physical topology describes how the wires or cables are laid out, and the logical topology describes how the information flows.

10. . 10 MESH NETWORKS Partial Mesh A BC DE Full Mesh A B C DE

11. STAR TOPOLOGY. 11

12. BUS TOPOLOGY. 12

13. RING TOPOLOGY. 13

14. CLASSIFICATION OF NETWORKS BY SIZE AND COMMUNITY 14 A company or home A city wide network A country wide network

15. . 15 SINGLE TO MULTIPLE LANS

16. METROPOLITAN AREA NETWORK 16

17. WIDE AREA NETWORK 17

18. EXAMPLE NETWORK 18 modem end office end office Modem = Modulator - Demodulator COM port Copper Cable Analog Signal (voice band) Asynchronous RS-232C Digital Inside the PSTN Network Telephone Exchange Digital Signal

19. INTERNET CONNECTIONS 19 Global Backbone GW Campus LAN ISP GW Access via PSTN, ADSL or cable GW LAN Private Backbone University Large/ Medium Enterprise Access via Leased Lines (high speed)

20. WHAT IS THE MODE OF TRANSMISSION FOR COMPONENTS OF A COMPUTER? 20 Internal view / External View? Lets use an external view: Keyboard, mouse, monitor? Printer port (LPT#)? Serial port (COM#), modem, USB, LAN (Ethernet)? Firewire, SCSI, etc? Sound cards?

21. 21