The American standard ANSI / TIA-942-B Telecommunications Data Center Cabling Standards, published in 2017, contains requirements and recommendations for the telecommunications infrastructure of a data center, including cables and connecting equipment, cable routes, telecommunications facilities.
Appendix F to this standard describes 4 levels of reliability of the data center infrastructure (1st basic, 2nd with redundancy, 3rd continuous service, 4th fault-tolerant) and published tables with records of data center reliability levels: telecommunication system ( Table 11), architecture (Table 12) + added entries on safety, power supply and power distribution system (Table 13), and mechanical data center systems (cold supply, security, fire extinguishing, fuel system) with entries in Table 14.