[1Day-1CS] The TCP/IP 4-layer model and the application layer

Internet Protocol Suite (

) A set of protocols used by computers to exchange information over the Internet

• Explained using the TCP/IP 4-layer model or the OSI 7-layer model

TCP/IP 4-layer model

• Composed of four abstraction layers based on the scope of networking

  • Application layer

  • Transport layer

  • Internet Layer

  • Link Layer

• The OSI model is characterized by its further subdivision of the Application Layer and Link Layer

Application Layer

• The protocol layer where applications such as FTP, HTTP, SSH, SMTP, and DNS are used

  • FTP: File transfer between devices

  • SSH: Secure Shell Protocol, an encrypted network protocol

  • HTTP: The protocol used to access websites via the World Wide Web

  • SMTP: An Internet standard communication protocol for email transmission

  • DNS: A server that maps domain names to IP addresses

• The layer that actually provides services to users