Chapter 1. Infrastructure, Connectivity, Communications, and Network Security
Networking Basics
The International Standards Organization (ISO) developed the Open Systems Interconnection (OSI) model to enable the delineation of various functions performed by devices in the network and applications. The OSI model is a conceptual model composed of seven layers, each specifying a particular network function. Data being transferred from a software application on one computer system to another must pass through the OSI layers. For example, if a software application in System A has information to transmit to a software application in System B, the application program in System A passes its data to the application layer (Layer 7) of System A. The application ...
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