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

Using the Seven-Layer Model

The seven-layer model is only a theoretical representation of how networks function. Although knowing it inside-out won’t change your life, it should help you pass the CompTIA Network+ exam. The conceptual use of the model assumes that an event on one computer system (for example, a user pressing ENTER on a login screen) creates some data that sets off a chain of events. The data runs down through the layers on the sending machine and then leaves the system, traveling across the network and then up through the layers on the receiving machine, until the data arrives intact at the Application layer and is processed by the receiving system. Later chapters in this book point out where certain key protocols and hardware ...