1. Data communication คุณลักษณะ 3 อย่างที่มีผลต่อการสื่อสารข้อมูล 1.Delivery 2. Accuracy 3. Timeliness (Real time transmission)

2. Components Massage Step 1: Step 2: Step 3: ……… Step 1: Step 2: Step 3: ……… Protocol SenderReceiver Medium

3. Components 1.Massage - text- number - pictures - sound - Video 2. Sender - a computer- workstation - telephone handset - video camera 3. Receiver - a computer- workstation - telephone handset - television

4. 4. Medium - twisted pair wire- coaxial cable - fiberoptic cable- laser - radio wave or satellite microwave 5. Protocol Components

5. Basic Concepts  Line configuration  Topology  Transmission mode  Categories of networks  Internetworks

6. 1. Line configuration Line configuration MultipointPoint-to-point Two categories of line configuration

7. Link Workstation Mainframe Point-to-point

8. Multipoint Link

9. 2. Topology Topology StarMeshTreeBusRing

10. Mesh

11. ตัวอย่าง กรณีที่มีเครื่องคอมพิวเตอร์ 8 เครื่องต้องการเชื่อมต่อกันในรูปแบบ Mesh ให้คำนวณหา Number of link และ Number of point per Device Solution Number of link = n(n-1)/2 = 8(8-1)/2 = 28 Number of point per Device = n-1 = 8-1=7

12. Star Hub

13. Tree Hub

14. Bus Drop line Drop line Drop line Drop line Tap Cable end

15. Ring

16. Hybrid Topologies Hub Bus Ring Star

17. 3. Transmission Mode Transmission Mode Full-duplexSimplexHalf-duplex

18. Simplex Mainframe Monitor Direction of data

19. Half -duplex Workstation Direction of data at time 1 Direction of data at time 2 Workstation

20. Full-duplex Workstation Direction of data all the time Workstation

21. 4. Categories of network  Local Area Network (LANs)  Metropolitan Area Network (MANs)  Wide Area Network (WANs)

22. Local Area Network (LAN) Single building LAN

23. Local Area Network (LAN) Backbone Multiple building LAN

24. Metropolitan Area Network (MAN) Public city network

25. Wide Area Network (WAN)

26. 5. Internetworks WAN LAN MAN R R R R R R RR