Network and Transport Layers

The OSI Network Layer is responsible for sending packets across different networks, whereas the OSI Transport Layer handles end-to-end message delivery. These layers correspond to the Internet and Transport Layers in the TCP/IP Reference Model, respectively (see FIGURE 5-1).

The illustration presents the layers in the O S I and T C P or I P reference models. O S I model has seven layers, and T C P or I P has four layers. In the O S I model, the data link layer and physical are separate layers. In T C P, physical and data link are both combined as a single network layer. The internet and transport are the third and fourth layers in both the models. Session and presentation layers are a part of the O S I model. There are no session and presentation layers in the T C P model. The final layer in both the models is the application layer.

FIGURE 5-1 OSI model compared to the TCP/IP model.

NOTE

The term router also refers to a Layer 3 switch. Router is the more commonly used term in networking.

The Network Layer of the OSI model is where the Internet Protocol (IP) operates ...

Get Fundamentals of Communications and Networking, 3rd Edition now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.

Start your free trial