Mike Meyers’ CompTIA Network+ Certification Passport, 4th Edition (Exam N10-005), 4th Edition

Organizing the Data: Ethernet Frames

All network technologies break data transmitted between computers into smaller pieces called frames, as you’ll recall from Chapter 1. Functioning at the Data Link layer (layer 2), NICs encapsulate data from the higher levels of the OSI model into frames to enable communication at the Physical layer.

Using frames addresses two networking issues. First, frames prevent any single machine from monopolizing the shared bus cable. Second, they make the process of retransmitting lost data more efficient.

Looking at the first scenario, if a sending computer sends a file as a single huge frame, the frame will monopolize the cable and prevent other machines from using it until the entire file gets to the receiving ...