Hitachi 9900 manual Glossary, ESA/390, Escon, ESCON Director, Ethernet

Glossary

DRR

Data Recovery and Regeneration.

DSS

Decision Support Systems is a term that refers to computer systems used in the areas of business intelligence, such as data warehousing, data mining, OLAP, and others.

DTA

Data Adapter.

ECC

Error correction code.

ESA/390®

Enterprise Systems Architecture/390®. Often abbreviated S/390®, ESA/390 is an IBM® architecture for mainframe computers and peripherals. Processor systems that follow this architecture include the IBM ES/9000® family. In 2000, IBM changed the server series name to eServer zSeries™.

ESCON®

Enterprise Systems Connection architecture is an IBM mainframe ESA/390 computer peripheral interface or connection between two mainframes for data exchange. The I/O interface utilizes ESA/390 logical protocols over a serial interface that configures attached units to a communication fabric. ESCON is based on networking technology. ESCON provides direct channel-to-channel connections between mainframe systems over fiber-optic links at distances up to 43 kilometers or 25 miles. ESCON also provides a way for communication controllers and other devices to share a single channel to a mainframe.

ESCON Director

An I/O interface switch that allows the interconnection of multiple ESCON interfaces in a distributed-star topology.

Ethernet

A Local Area Network (LAN) protocol developed by Xerox® in cooperation with Digital Equipment and Intel in 1976. Ethernet supports a star or bus topology and supports a data transfer rate of 10 megabits per second or 10Mbit/sec. The Ethernet specification formed the basis of the IEEE 802.3 standard, which specifies the physical and lower software layers. Ethernet uses the CSMA/CD access method for handling simultaneous demands and is one of the most widely implemented LAN standards. Ethernet is also known as 10BaseT. See also Fast Ethernet, Gigabit Ethernet.

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