7.2.10 TCP/IP model

• Functions related to the session layer, presentation, are often handled by protocols at the application layer in the TCP/IP model.

  Additionally the TCP/IP models application layer includes all functions of the OSI models
• TCP/IP application layer - transmitting email?

  Email client creates, formats, and encrypts the email, and a session is established with the email server
• TCP/IP Transport layer - transmitting email?

  Divides email into data packets and reliable transmission is made using TCP
• TCP/IP Transport layer - Receiving email?

  The data packets are reassembled using numbering and errors are checked for using TCO
• TCP/IP Application layer - Receiving email?

  The email client receives the email, decrypts, and formats it, and displays it to the user
• TCP/IP and OSI model have which layers serve an identical purpose across both models?

  Network and internet

  Transport and transport
• TCP/IP Internet layer - Transmitting email?

  Finds the best path (route) for data transfer to the email server using it's IP address
• TCP/IP Internet layer - Receiving email?

  Checks packet targets IP address to check it has been sent to the correct device if not retransmission is forced
• Network access layer, also known as the link layer, combines the functions of the OSI model's physical and data link layers and is the final layer of the TCP/IP model
• TCP/IP Network layer - Transmitting email?

  Data packets are converted into frames, error checked, and then transmitted as bits over the physical medium.
• TCP/IP Network access layer - Receiving email?

  Bits are received, converted back into frames error checked, and then back into packets
• Why is the TCP/IP model considered more practical and widely used than the OSI model?

  It focuses on the protocols that are actually used in the real world

  It has fewer layers, making it simpler