1. PHYSICAL
   1. PHYSICAL CONNECTION
      1. Electrical, cables, plugs, signals
   2. BIT TRANSFERED
      1. send signals over cables
      2. companies in Vietnam
         1. wired
            1. FPT
            2. VNPT
         2. wireless
            1. Mobifone
            2. Viettel
2. DATALINK
   1. generic stuff
      1. Packets, MAC addresses, error/flow control
      2. simple analogy
         1. driver
      3. choose an approprieate convention to deliver stuff
      4. logical topology
         1. BUS
         2. token ring
   2. FUNCTIONS
      1. TRAFFIC CONTROL
         1. test if connection is ready
         2. methods to prevent data collision
            1. CSMA/CD - detection
            2. used in ethernet
            3. CSMA/CA - avoidance
            4. used in wireless system
            5. TOKEN Passing
      2. DATA CONVERSION for PHYSICAL LAYER
         1. sent thru PHYSICAL LAYER
            1. cable
            2. fiber optics
            3. wireless
            4. cellular (or satellite)
         2. data conversion
            1. from Machine language -> BIT
3. NETWORK
   1. Packets, network addresses, switching, routes
   2. manage connection
      1. from HOST to HOST
   3. Deal with
      1. ADDRESS
         1. Keep track of hops
      2. PACKET SWITCHING
         1. open the shortest path
      3. ROUTING
         1. open the shortest path
   4. Stuff
      1. 1 LAN serviced by 1 router
      2. if router wakes up
         1. broadcast to every routers that awake
         2. initiate exchanging of router tables
   5. firms
      1. Cisco
4. TRANSPORT
   1. ENSURE accurate delivery of data
      1. segmentation and re-assembly
      2. error correction
      3. acknowledgement
   2. deal with
      1. DATA SEGMENTATION
      2. DATA DELIVERY CONTROL
         1. TCP
         2. UDP
5. SESSIONS
   1. CONNECTION MANAGEMENT
      1. application to application
6. PRESENTATION
   1. DATA DISPLAY
      1. encryption/decryption
      2. compression/decompression
      3. data formatting
         1. from Application -> machine language
            1. ASCII
            2. EBCDIC
7. APPLICATION
   1. def
      1. Provides interface between software applications/network
   2. Feature
      1. interpreting applications’ requests and requirements.
   3. protocal
      1. email
         1. smtp
            1. Simple Mail Transfer Protocol
      2. http
         1. http
            1. Hyper Text Transfer Protocol
         2. https
      3. ftp