NEBS (Network Equipment Building System) is the most common set of safety, spatial and environmental design guidelines applied to telecommunications equipment in the United States. NEBS is why telephones work after an earthquake or thunderstorm! NEBS requirements are utilized all over the world for a host of commercial, utility and defense applications. Still, the most frequent application of NEBS is to design and test equipment intended for use in Central Offices. NEBS is officially an industry requirement, but not a legal requirement.
NEBS standards can be categorized into three "levels" as follows.
- Level 1: A low threshold of equipment hazards and network degradation. Addresses safety and personnel requirements of GR-63-CORE and GR-1089-CORE. Operation requirements are not enforced at this level.
- Level 2: Addresses equipment operability within controlled environments such as labs and data centers, areas expected to be free of environmental stress. This vague description has led to this being the least used of the levels of certification.
- Level 3: Signifies that the equipment meet all of the GR-63-CORE and GR-1089-CORE requirements. This level has strict requirements for fire suppression, thermal testing, vibration resistance such as earthquakes, acoustic limits, failure severity, emissions, and testing certification.