1. The OSI Model An ISO (International standard Organization) that covers all aspects of network communications is the Open System Interconnection (OSI) model. Discovered in 1977 by ISO Advantage Allow multi-vender Allow various H/S to communicate. Allow to discover layer cause problem Help student to understand data transfer between computer

2. OSI 7 layer

3. Application Called Interface application identify protocol used by user or application such as when user used web then protocol is HTTP or used file transfer then protocol called FTP

4. Presentation layer This layer is responsible for Present the data means transform to ASCI (0,1). Compressed and decompressed data Encrypt and encrypt data

5. Session layer Identify path for every application in computer such user open tow web page in the same time that is need every data must be retrieved to specific port Step path Manage path End path Data stream 010101010101010101010

6. Transport layer This layer responsible for Segment:- divide data in small unit Protocol used in transport (TCP or UDP) and then added it to segment SegmentTCP or UDP

7. Network Best way to move data Router :- identify short path IP :- adding source and destination Packet after added IP then data called packet IPSegment1TCP

8. Data link layer Content tow sub layer Logical link control (LLC) Media access control (MAC) Job this layer: LLC :- transform data to frame LLC:- identify type of protocol (is LAN or WAN or Internet )

9. Cont…. MAC :- address the frame by identify MAC address for sender and reception (NIC address ) MAC make H and T ( add begin and end to frame ) Switch : depend on mac addrese HeaderIpSegment1TCPTrailer

10. Physical Capsulation the data and receive data Network card hub HeaderIPSegment 1TCPTrailer 010101010101010101010101010101010101010101010101010