Glossary

Open Systems Architecture

OSI. A model that represents a network as a hierarchical structure of functional layers. Each layer provides a set of functions that can be accessed and used by the layer above. Layers are independent, in that implementation of a layer can be changed without affecting other layers

(D).

open systems management server

OSMS. An optional feature that can be enabled on the director or switch through the Product Manager application. When enabled, host control and management of the director or switch are provided through an Open System Interconnection (OSI) device attached to a director or switch port.

open systems mode

The mode that is used for Hewlett Packard or open fabrics. See also operating mode; S/390 mode.

operating mode

In directors or switches, in managed products, a selection between s/390 and open systems mode. See also open systems mode; S/390 mode.

operating system

OS. Software that controls execution of applications and provides services such as resource allocation, scheduling, I/O control, and data management. Most operating systems are predominantly software, but partial hardware implementations are possible (D, T).

Operating System/390

OS/390™. An integrated, open-enterprise server operating system developed by IBM that incorporates a leading-edge and open communications server, distributed data and file services, parallel Sysplex™ support, object-oriented programming, distributed computing environment, and open application interfaces (D).

optical cable

Single fiber, multiple fibers, or a fiber bundle in a structure built to meet optical, mechanical, and environmental specifications (D, E). See also Jumper cable; trunk cable. Synonymous with fiber-optic cable.

optical drive backup

A data backup system that uses rewriteable optical cartridges (ROCs) as the storage medium.

optical fiber connector

Synonymous with connector.