ANSI-TIA-EIA 942

TIA 942 (full name ANSI / TIA 942 Data Center) is the standard of minimum requirements for operations and security of data centers. Although the standard is primarily for North America, these requirements are respected amongst data centers de-facto worldwide. The standard establishes four levels of data centers (layers, tiers), which vary according to how they ensure protection of servers, connectivity and physical protection against physical threats (intrusion, fire, flood, etc.)

What TIA Standard 942 prescribes?

It is intended for designers and architects of data centers in the development phase and identifies requirements for the entire construction process. describes recommended

• Spatial arrangement
• Arrangement and infrastructure requirements cabling, cable management
• Tiers - reliability and operating conditions of datacenter

What are tier of data centers according to TIA 942 and how do they differ?

• Tier-1 (Basic Site Infrastructure) is a data centre which has single capacity components and a single, non-redundant distribution path serving the computer equipment. It has limited protection against physical events.
• Tier-2 (Redundant Capacity Component Site Infrastructure) is a data center which has redundant capacity components and a single, non-redundant distribution path serving the computer equipment. It has improved protection against physical events. Guaranteed availability is 99.7% (downtime max 22.0 hours per year)
• Tier-3 (Concurrently Maintainable Site Infrastructure) A data center which has redundant capacity components and multiple independent distribution paths serving the computer equipment. Typically, only one distribution path serves the computer equipment at any time. The site is concurrently maintainable which means that each and every capacity component including elements which are part of the distribution path, can be removed/replaced/serviced on a planned basis without disrupting the ICT capabilities to the End-User. It has protection against most physical events. Service availability is 99.98% (max 1,6 downtime per year)
• Tier-4 (Fault Tolerant Site Infrastructure) A data center which has redundant capacity components and multiple independent distribution paths serving the computer equipment which all are active. The data center allows concurrent maintainability and one fault anywhere in the installation without causing downtime. It has protection against almost all physical events. Availability is 99.99% (failure within 15 minutes per year)