The International Organization for Standardization (ISO) developed the Open Systems Interconnection (OSI) model to enable delineation of various functions performed by devices in the network as well as the applications. The OSI model consists of seven layers. Figure 1-1 outlines the OSI model and functions of each layer.
FIGURE 1-1 The OSI model
Connection-oriented protocols provide guaranteed delivery of datagrams between devices in a network. Connectionless protocols provide best-effort services during the transmission of datagrams between network devices.
Peer-to-peer connectivity in a network ...