Uptime Institute: TIA-942 is not a guideline for our data center Tiers

Playing the role of mythbuster, The Uptime Institute says its Tier structure and that of TIA-942 resemble each other on the surface only.

As part of an ongoing effort to expose myths and misconceptions about its Data Center Tier Classification System, The Uptime Institute (TUI) recently took issue with the notion that the TIA-942 Telecommunications Infrastructure Standard for Data Centers is a guideline for tier classifications.

"The similarities between the Uptime Institute Tiers and TIA-942 stop at the surface," the group said in its fourth round of Tier Myths and Misconceptions documents. "Uptime Institute Tiers is functionally disconnected from TIA-942," it continued. "The core objective of Uptime Institute Tiers is to guide a design topology that will deliver high levles of availability, as dictated by the owner's business case. Uptime Institute Tiers evaluates data centers by their capability to allow maintenance and to withstand a fault. Uptime Institute Tiers is not available in checklist form."

Jonathan Jew, one of architects of the TIA-942 standard and a co-editor of its upcoming revision, TIA-942-A, concurs. He explains, "The TIA-942 Tiering scheme was initially developed based on the concept of four tiers originally developed by TUI because we wanted to acknowledge that their scheme was in fact the most widely used for evaluating data center reliability and they had very useful definitions asociated with each tier.

"While TIA has remained with prescriptive definitions for each tier, TUI has decided to move to a functional approach. In the TIA scheme we might recommend a certain design solution, while TUI would be more open to various solutions as long as the result provided the desired level of availability."

He continues, "The TIA's scheme is open to evaluate the relative security and availability levels of a data center. However, just selecting the right pieces still does not guarantee the desired level of availability. It still requires competent engineers to design a system that functions properly."

The TUI's approach is proprietary and is the organization's intellectual property. Jew adds, "Because [TUI's] system is based on function rather than components, their system can't be completely put down in table form."

He says both approaches are useful. While TUI's is the more complex of the two and requires more analysis, TIA's also requires a qualified engineer to put the pieces together for proper functioning, despite the fact that the TIA method is open and standards-based.

This TIA-942 commentary is one of five myths/misconceptions The Uptime Institute is trying to squelch with its most recent 'mythbusting' effort. These five most recent myths are international-based, the organization says. "During recent site visits in Latin Amercia, Europe, Russia, Africa, and Asia, Uptime Institute encountered particular tier myths and misconceptions," TUI said in an email in which it also listed the TIA-942 and four other myths. "These myths have taken attention away from the fundamental concepts of the Tier Classification System. The result has been shortfalls in design topology despite adequate budgeting. These shortfalls put the data center's ongoing uptime at risk. Although encountered more often internationally, the myths ... have also been noted in North America."

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