1. Data Communications ผู้สอน : ผศ. ดร. ศักดิ์ชัย ทิพย์จักษุรัตน์ (2D/1) Email: ktsakcha@kmitl.ac.th ผศ. ดร. อรฉัตร จิตต์โสภักตร์ (2D/2) Email: orachatc@yahoo.com Tel: (02) 329-8341-2 TEXTBOOK: B. A. Forouzan, Data Communications and Networking, 4 th edition McGRAW-HILL GRADING POLICY: Assignment 20% Midterm Exam 30% Final Exam50%

2. List of Studied Topics Basic of Communication: Chapter 1, 3, 4, 5, 6, 7 Introduction (1), Signal (3), Digital Transmission (4), Analog Transmission (5), Multiplexing (6), Transmission media (7) Standard Communication Protocol: Chapter 2 and Appendix C Network Model (TCP/IP) (2) and OSI model (Appendix C) Switching, Telephone network, and High Speed Digital Access : Chapter 8-9 Data flow control: Chapter 10-15 Error detection & correction (10), Flow control (11), Point-to-Point Access (12), Multiple Access (13), LAN (14), Wireless LAN (15)

3. WCB/McGraw-Hill Data Communication System Components

4. Data Representation Text ASCII (8 bits): (The American Standard Code for Information Interchange) ASCII Table -> Appendix Unicode (16 bits): Represents symbols belong to languages other than English Images Videos Audio

6. Direction of Data Flow between two devices

7. Figure 1.2 Simplex

8. Figure 1.3 Half-duplex

9. Figure 1.4 Full-duplex

10. 1.2 Networks Distributed Processing Physical Structures Categories of Networks

11. Physical Structure

12. Point-to-Point Connection Guided medium link Unguided medium

13. WCB/McGraw-Hill Multipoint Connection

14. Categories of Topology

15. Figure 1.7 Categories of topology

16. Mesh Topology - Physical Structure: point-to-point - number of link = n(n-1)/2 n = number of devices Any two devices have their own link - Advantages Transmission speed ( สูงมาก ) Reliable (damage link) ( สูงมาก ) Privacy, Security ( สูงมาก ) Fault Detection ( ง่ายมาก ) - Disadvantages Cost (Installation and Maintenance) ( สูงมาก ) Expansion and Modification ( ยุ่งยากมาก )

17. Star Topology - number of link = n n = number of devices Centralize communication - Advantages Cost (Installation and Maintenance) ( น้อย ) Reliable (damage link) ( ปานกลาง ) Expansion and Modification ( ง่าย ) Fault Detection ( ง่าย ที่ Hub) - Disadvantages Intelligent central controller Limited number of ( ตามจำนวน port ของ Hub) - Physical Structure: point-to-point

18. Tree Topology - point-to-point Multi-level star - Disadvantages Intelligent central controller Limited number of devices - number of link = n + m n = number of devices m = number of secondary hubs - Advantages Cost (Installation and Maintenance) Reliable (damage link) ( ปานกลาง ) Expansion and Modification Fault Detection Group Priority

19. Ring Topology - number of link = n n = number of devices - point-to-point Loop around - Advantages Cost (Installation and Maintenance) ( ปานกลาง ) Expansion and Modification Fault Detection ( ปานกลาง ) Multiaddressing - Disadvantages Unreliable (damage link; unidirectional ring) Extra-cost for repeater Get rid of unused data

20. Bus Topology - multipoint - number of link = 1 Share a single medium Unreliable (damage link) Expansion and Modification Fault Detection - Disadvantages Transmission speed Limited number of devices - Advantages Lowest Cost Efficient utilization of the medium

21. Performance Comparison of each network topology Cost Device, Connection, and Maintenance (Low -> High): Bus < Star < Ring < Tree < Mesh Transmission Speed (High -> Low): Mesh > Star > Tree > Ring > Bus Expansion and Modification (Easy -> Hard): Star > Ring > Bus > Tree > Mesh Fault detection (Easy -> Hard): Mesh > Star > Tree > Ring > Bus Reliable (High -> Low): Mesh > Star >Tree > Ring > Bus Privacy and Security (High -> Low): Mesh > Star>Tree > Ring > Bus

22. Categories of Networks

23. Figure 1.12 Categories of networks

24. Figure 1.13 LAN - Area < 2 mi (2-3 km) - Data rate 100, 1000 Mbps

25. Figure 1.13 LAN (Continued)

26. Figure 1.14 MAN - Area: Town, City -Example: part of the telephone company network providing High speed DSL / Cable TV

27. Figure 1.15 WAN

28. 28 Classifying Networks by Area A personal area network (PAN) refers to the small computer networks that are found in private homes. A Campus area network (CAN)

29. 1.3 The Internet A Brief History The Internet Today

30. Figure 1.16 Internet today ISP: Internet Service Providers

31. ประสิทธิภาพของการส่งผ่านข้อมูล ถูกที่หมายปลายทาง ข้อมูลที่ได้รับต้องถูกต้องแม่นยำ ปราศจาก ข้อผิดพลาด เวลาในการส่งเหมาะสม WCB/McGraw-Hill

32. Criteria ในการวัดประสิทธิภาพ ของระบบ network

33. 1.4 Protocols and Standards Protocols Standards Standards Organizations

34. WCB/McGraw-Hill - Standard not been approved by organization body - Widespread - Standard been approved by organization body

35. ตัวอย่างขององค์กรที่ทำหน้าที่ จัดทำ standard ISO -> OSI (Open Systems Interconnection) ITU-T -> V series, X series, ISDN, email ANSI IEEE -> LAN standard EIA -> physical connection interfaces & signalling FCC -> Federal Communications Commission WCB/McGraw-Hill

36. Forum Frame Relay ATM Forum ISOC & IETF