In the TCP/IP model, which layer is immediately above the Network Access layer?

• A. Network Access
• B. Internetwork
• C. Transport
• D. Application

Answer: (B)

In TCP/IP, the layers are stacked from local network duties up to application-level services. The bottom layer, Network Access, takes care of how data is framed and transmitted on the local network hardware. Directly above that sits the Internetwork (Internet) layer, which handles addressing and routing of packets across different networks. It’s the layer that makes inter-network delivery possible by using IP addresses and routing logic, independent of any single network’s specifics. Above that are the Transport layer (end-to-end communication, reliability) and the Application layer (protocols like HTTP, SMTP, etc.). So the layer directly above Network Access is the Internet (Internetwork) layer.