Large, complex, feature-rich network architecture developed in the 1970s by IBM.

Common name for the suite of protocols developed by the U.S. Department of Defense in the 1970s to support the construction of worldwide internetworks.

Ability of computing equipment manufactured by different vendors to communicate with one another successfully over a network.

Set of rules or procedures that are either widely used or officially specified.

Because they control the physical delivery of messages over the network, the lower layers of the OSI model are sometimes referred to as the media layers.

Because they provide for the accurate delivery of data between computers on the network, the upper layers of the OSI model are sometimes referred to as the host layers.

The physical layer defines the electrical, mechanical, procedural, and functional specifications for activating, maintaining, and deactivating the physical link between end systems

This layer provides reliable transit of data across a physical link. Concerned with physical addressing, network topology, line discipline, error notification, ordered delivery of frames, and flow control.

This layer provides connectivity and path selection between two end systems. The layer at which routing occurs.

This layer is responsible for reliable network communication between end nodes. This layer provides mechanisms for the establishment, maintenance, and termination of virtual circuits, transport fault detection and recover, and information flow control.

This layer establishes, manages, and terminates sessions between applications and manages data exchange between presentation layer entities.

This layer ensures that information sent by the application layer of one system will be readable by the application layer of another.

This layer provides services to application processes (such as electronic mail, file transfer, and terminal emulation) that are outside of the OSI model.

Network layer device that uses one or more metrics to determine the optimal path along which network traffic should be forwarded.