*續(1) 七層
1 Physical Binary Transmission -- wires connectors voltages
2 MAC(存取不同媒介) ,LLC,Direct Link Control,Access to Media
3. Network Address & Best Path Determination
4. End to End Connections
5. Interhost Communication,between application
用browser 連 server-->這是web application
6 Data Representation: transfer syntax
7 Network Processes to Application
*Peer to Peer Communication
PDU --> Protocol Data Unit
7~5 data
4 segment
3 packets(datagram --> internet的術語)
2 frames
1 bits
*TCP/IP Model-->簡化成4層
7~5 Application --> Generic Client (Browser)<老師覺得最好的>
4 Transport --> Logical Network
3 Internet --> Protocol Network( Ipv4-Ipv6 )
1~2 Network Access --> Physical Network
*encapsulation-->加頭加尾,將資料封裝,才送出(有點像寫地址)
*(下一章)
Network Media(傳輸的媒介)
無線:電磁
有線:雙絞線 同軸電纜 光纖