Which TCP/IP layer defines how data should be physically sent through the network?

Which TCP/IP layer defines how data should be physically sent through the network?

• A. Network Interface Layer
• B. Application Layer
• C. Transport Layer
• D. Data Link Layer

Answer: (A)

The Network Interface Layer governs how data is actually placed onto the network medium. This bottom layer handles framing for the local link, hardware addressing (MAC), and the electrical or wireless signaling that moves bits across a cable or air interface. Everything above it—Application and Transport layers—deals with data meaning, formatting for apps, and end-to-end delivery, not the physical transmission. In TCP/IP, the equivalent of the OSI Data Link/Physical on the local link is the Network Interface Layer, making it the layer that defines how data should be physically sent through the network.

The Network Interface Layer governs how data is actually placed onto the network medium. This bottom layer handles framing for the local link, hardware addressing (MAC), and the electrical or wireless signaling that moves bits across a cable or air interface. Everything above it—Application and Transport layers—deals with data meaning, formatting for apps, and end-to-end delivery, not the physical transmission. In TCP/IP, the equivalent of the OSI Data Link/Physical on the local link is the Network Interface Layer, making it the layer that defines how data should be physically sent through the network.