The Book of Wireless, Second Edition

The ISO OSI Model

As the package delivery example demonstrates, the information itself is only part of the process. When information moves across a network, it's essential that all of the parties involved—the originator, the ultimate recipient, and everything in between—agree that they will use the same formatting, timing, and routing rules and specifications. These rules (also called protocols) define the network's internal "plumbing" and the form of the information that moves through it.

As network communication has become more complex, the community of network designers has accepted the International Organization for Standardization's (ISO) Open Systems Interconnection (OSI) model to identify the individual elements of a network link. The OSI ...