Now that we know the layers, let's look at how each of the layers work together during the encapsulation process to create a frame.

During frame formation, the process begins with data. As the data moves down the layers, a header is added one by one until the frame is complete. Each frame has the following components:

• Data and appropriate application layer header (if applicable)
• Segment header
• Packet header
• Frame header

We'll start with the data portion of the frame.