Legacy Glossary

This is a glossary of older terms. While many of the definitions are unchanged, some of the definitions may be out of date and some of the terms may no longer be in use in the Data Center industry. This legacy glossary provides definitions for hundreds of information and communications technology (ICT) and data center terms and acronyms. Arranged alphabetically and searchable, the glossary explains common industry vocabulary.
1 A B C D E F G H I K L M N O P R S T U V W Z
Nameplate Rating

Equipment shall be provided with a power rating marking, the purpose of which is to specify a supply of correct voltage and frequency, and of adequate current-carrying capacity (IEC 60950, Clause 1.7.1)

Natural Convection Overhead (NOH)

An air distribution and cooling strategy in which cooling coils are suspended from the ceiling and air is circulated by natural convection with no fans or ducting


Formerly network equipment-building system. Provides a set of physical, environmental, and electrical requirements for a central office (CO) of a local exchange carrier (LEC). NEBS is a trademark of Telcordia Technologies, Inc.


National Electric Code


National Fire Protection Association


National Institute for Occupational Safety and Health

Non-raised Floor

Facilities without a raised floor utilize overhead ducted supply air to cool equipment. Ducted overhead supply systems are typically limited to a cooling capacity of 100 W/ft2 (Telcordia 2001)