Data Center Tier Requirements

Many IT departments would be happy to keep their systems up and running more than 90% of the time, but data centers have higher standards. Even the lowest-rated data centers have exceptionally high reliability expectations, creating unique challenges for service providers when it comes to network planning, redundant systems and fiber infrastructure.

To demonstrate levels of reliability, the Telecommunications Industry Association has defined ratings, or tiers, for data centers. The lowest rating of Tier 1 could be attributed to something as simple as a server room, and the highest rating of Tier 4 is only used for operations where reliability is of the utmost importance – such as military-grade operations. The higher the tier, the greater the availability, uptime and resiliency, and the more stringent the rules necessary for certification.

Data Center Tier Requirements

Tier 1 Data Center:

  • Single non-redundant distribution path serving the IT equipment
  • Non-redundant capacity components
  • Basic site infrastructure with expected availability of 99.671%

Tier 2 Data Center:

  • Meets or exceeds all Tier 1 requirements
  • Redundant site infrastructure capacity components with expected availability of 99.741%

Tier 3 Data Center:

  • Meets or exceeds all Tier 2 requirements
  • Multiple independent distribution paths serving the IT equipment
  • All IT equipment dual-powered and fully compatible with the topology of a site’s architecture
  • Concurrently maintainable site infrastructure with expected availability of 99.982%

Tier 4 Data Center:

  • Meets or exceeds all Tier 3 requirements
  • All cooling equipment is independently dual-powered, including chillers and heating, ventilating and air-conditioning (HVAC) systems
  • Fault-tolerant site infrastructure with electrical power storage and distribution facilities with expected availability of 99.995%

Data Center Tier Rating Differences

While 0.324%, the difference in annual uptime between Tier 1 and Tier 4 data centers, may seem miniscule, the difference in effort required to maintain a Tier 1 data center compared to Tier 4 facility is sizable, which can be exemplified through the amount of annual downtime allowed. A Tier 1 data center is authorized no more than a 24 hours of downtime throughout the year. A Tier 4 facility can only be offline for less than half an hour during the same time period.

Due to the heavy expectations of a Tier 4 data center, data center owners will often install multiple backup systems to keep data centers up and running in case of emergencies and natural disasters. These power systems run the actual servers, air conditioning and additional networking equipment. If the indoor environment reaches a point where dew accumulates on the electrical systems, major malfunctions can occur.

As for network planning challenges, multiple network paths are required to ensure that if a fiber network goes offline, one or more additional routes can still transmit data for operations. Data center owners must also be mindful of protecting against natural disasters – such as flooding or snowstorms – that may cause fiber lines to break or malfunction.

FiberLocator offers data center location information for over 4,000 unique addresses. What’s more, companies can research the supporting telecom networks at or near a data center to confirm the connectivity available meets their requirements. Talk with one of our network consultants today to learn more about how FiberLocator can help you assess and plan for your data center requirements.

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