Levels
"NEBS Level 1" means a very low threshold of equipment hazards and network degradation. NEBS Level 1 addresses the personnel and equipment safety requirements of GR-63-CORE and GR-1089-CORE. Operability requirements are not enforced for NEBS Level 1 certification. It is primarily used for getting prototypes into lab trials. RBOCs require all equipment deployed by CLECs to be NEBS Level 1 certified.
"NEBS Level 2" addresses equipment operability in a controlled environment (usually datacenters) that will not be subjected to environmental stress. Because of ambiguity, this level of certification is rarely (if ever) used.
"NEBS Level 3" is a term from Bellcore special report, SR-3580, and means the equipment meets all of the requirements of GR-63-CORE and GR-1089-CORE. NEBS Level 3 has strict specifications for fire suppression, thermal margin testing, vibration resistance (earthquakes), airflow patterns, acoustic limits, failover and partial operational requirements (such as chassis fan failures), failure severity levels, RF emissions and tolerances, and testing/certification requirements.
NOTE:
- Verizon and AT&T do not follow NEBS Level 3 or SR-3580. They use their own NEBS checklist, Verizon Checklist (in MS Word format) and AT&T Checklist, that details what they believe are important to their network's integrity. Both accept the TCG Checklist that can be found at those websites.
Read more about this topic: Network Equipment-Building System
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