Chapter 15 / 15.6 / 15.6.5

15.6.5 TCP And UDP Compared

The layered architecture of the Internet becomes particularly apparent at the Transport Layer.

• The Physical Layer transmits bits across the communication medium.
• The Data Link Layer delivers frames across individual network links.
• The Network Layer routes packets between networks.
• The Transport Layer delivers information to the correct application.

Each layer builds upon the services provided by the layer below, allowing complex communication systems to be constructed from relatively simple components.