Which layer is NOT part of the TCP/IP model?

The TCP/IP model consists of four layers: Application, Transport, Internet, and Link. The Network Layer, while a term frequently used in network discussions, refers specifically to a layer in the OSI (Open Systems Interconnection) model. It encompasses functions related to routing, switching, and forwarding of data packets, but it is important to note that within the TCP/IP framework, these functions are provided through the Internet Layer.

The Application Layer in the TCP/IP model is responsible for end-user services and protocols used for data exchange, such as HTTP, FTP, and SMTP, thereby facilitating the communication between applications and the underlying network. The Transport Layer is responsible for ensuring reliable transmission of data segments between two devices, which may include protocols like TCP (Transmission Control Protocol) and UDP (User Datagram Protocol). Lastly, the Internet Layer encompasses the routing of data packets across networks, with the Internet Protocol (IP) as its centerpiece.

Understanding the structure and terminology specific to the TCP/IP model is crucial for networking concepts, as it directly influences how communications are carried out over the internet. Recognizing that the Network Layer is not part of this model helps clarify the distinctions between different networking frameworks.