1. THE OSI MODEL ISO is the organization.OSI is the model. ISO  International Standards Organization OSI  Open Systems Interconnection

2. THE MODEL Application Presentation Session Transport Network Datalink Physical 76543217654321

3. Layered Architecture Application 7-6 Interface Presentation 6-5 Interface Session 5-4 Interface Transport 4-3 Interface Network 3-2 Interface Datalink 2-1 Interface Physical Application 7-6 Interface Presentation 6-5 Interface Session 5-4 Interface Transport 4-3 Interface Network 3-2 Interface Datalink 2-1 Interface Physical Network Datalink Physical Network Datalink Physical 3rd 2nd 1st 3rd 2nd 1st 3rd 2nd 1st Peer-to-peer protocol (7 th layer) Peer-to-peer protocol (6 th layer) Peer-to-peer protocol (5 th layer) Peer-to-peer protocol (4 th layer) Physical communication Device ADevice B Intermediate node Intermediate node 7 6 5 4 3 2 1 7 6 5 4 3 2 1

4. Peer-to-peer Processes Interface between Layers

5. Organization of the Layers Layer 1, 2 and 3  physical, data link and network Are network support layer; เป็นการส่งข้อมูลทางกายภาพ จากอุปกรณ์ตัวหนึ่งไปยังหลาย ๆ อุปกรณ์ (electrical Specifications,physical connection, physical addressing,transport timeing) Layer 5, 6 and 7  session, presentation and application The user support layer; interoperability among unrelated software system Layer 4  transport layer เป็นส่วนเชื่อมต่อระหว่าง layer ที่อยู่ บนและล่าง (hardware,software)

6. An exchange using the OSI model L7 data H6 L6 dataH5 L5 dataH4 L4 dataH3 L3 dataH2T2 010101010101101010000010000 7 6 5 4 3 2 1 7 6 5 4 3 2 1 Transmission medium L7 data H6 L6 dataH5 L5 dataH4 L4 dataH3 L3 dataH2T2 010101010101101010000010000

7. Function of the layers Physical layer L2 data 10101000000010 From data link layer Physical layer Transmission medium L2 data 10101000000010 To data link layer Physical layer

8. สิ่งที่จะพิจารณาในขั้นตอนการทำงานของ physical layer Line configuration Data transmission mode Topology Signal Encoding Interface Medium

9. Data Link layer L3 data From Network layer Data Link layer H2T2 Frame 10101000000010 To Physical layer L3 data To Network layer Data Link layer H2T2 Frame 10101000000010 From Physical layer

10. Specific responsibilities of the data link layer include the following;  Node to node delivery  Addressing  Access control  Flow control  Error handling  Synchronization LLC  Logical Link Control MAC  Media Access Control

11. Example Data link layer Data T2 10 87 TrailerSource address Destination address 1028536587

12. Network layer L4 data From transport layer To data link layer H3 Packet L3 data Network layer L4 data To transport layer From data link layer H3 Packet L3 data Network layer

13. Specific responsibilities of the network layer include the following;  Source-to-destination delivery  Logical addressing  Routing  Address transformation  Multiplexing

14. 10 Example Network layer 87 Data T2 10 20 AP R 45 71 9577 Data T2 66 95 AP Data T2 99 33 AP Ring R 33 66 99 20F T N Z Bus G EA P

15. Transport layer L5 data From session layer To network layer H4 L4 data Transport layer H4 L4 data L5 data To session layer From network layer H4 L4 data Transport layer H4 L4 data

16. Specific responsibilities of the transport layer include the following;  End-to-end massage delivery  Service-point (port) addressing  Segmentation and reassemble  Connection control

17. Example Transport layer Data jk A Data2 jk AP Data1 jk AP Data2 jk AP H2T2 Data1 jk AP H2T2 Data jk B Data2 jk AP Data1 jk AP Data2 jk AP H2T2 Data1 jk AP H2T2 Physical link Transport layer Network layer Data link layer

18. Session layer L6 data From presentation layer To transport layer L5 data H5 Session layer syn L6 data To presentation layer From transport layer L5 data H5 Session layer syn

19. Specific responsibilities of the session layer include the following;  Session management  Synchronization  Dialog control  Graceful close

20. Presentation layer L7 data From application layer To session layer L6 data Presen- tation layer Encode,encrypted,and Compresses data H6 L7 data To application layer From session layer L6 data Presen- tation layer Encode,encrypted,and Compresses data H6

21. Specific responsibilities of the presentation layer include the following;  Translation  Encryption  Compression  Security

22. Application layer To presentation layer L7 data Application layer X.500 FTAM X.400 User From presentation layer L7 data Application layer X.500 FTAM X.400 User

23. Specific responsibilities of the application layer include the following;  Network virtual terminal  File access transfer,and management  Mail services  Directory services

24. Summary of Layer Function Application Presentation Session Transport Network Data Link Physical To allow access to network resources To translate,encrypt, and compress data To establish,manage,and terminate session To provide reliable end to end message Delivery and error recovery To move packets from source to Destination; to provide internetworking To organize bit into frames; to provide Node to node delivery To transmit bits over a medium; to Provide mechanical and electrical specification