LAN Switching first-step

Moving Through the OSI Model

To better understand how network switching works, it is vital to understand how the OSI model works and how data moves through the OSI model. How you move through the OSI model depends on whether you are the sender or the receiver. The sending side wraps, or encapsulates, the data, much as you enclose a letter in an envelope. The receiving side unwraps, or decapsulates, the data, much as the receiver opens an envelope to remove the contents.

Sending, or encapsulating, data requires five steps, as follows:

Step 1.	User data (Layers 5–7—application, presentation, session)
Step 2.	Segments (Layer 4—transport)
Step 3.	Packets (Layer 3—network)
Step 4.	Frames (Layer 2—data link)
Step 5.	Bits (Layer 1—physical)

To demonstrate ...