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Figure 9 – Cabinet aisle in a data center

2.1.1.4 Technology infrastructure design

Technology infrastructure design addresses the telecommunications cabling systems that run
throughout data centers. There are cabling systems for all data centers environments, including
horizontal cabling, voice, modem, and facsimile telecommunications services, premises switching
equipment, computer and telecommunications management connections, keyboard/video/mouse
connections and data communications. Wide area, local area, and storage area networks should link
with other building signaling systems (e.g., fire, security, power, HVAC, EMS).

Figure 10 – Under floor cable runs

2.1.1.5 Electrical power
A bank of batteries in a large data center, used to provide power until diesel generators can start
backup power, consists of one or more uninterruptible power supplies including battery banks,
and/or diesel/gas turbine generators.

To prevent single points of failure, all elements of the electrical systems, including backup systems,
are typically fully duplicated, and critical servers are connected to both the "A‐side" and "B‐side"
power feeds. This arrangement is often made to achieve N+1 redundancy in the systems. Static
transfer switches are sometimes used to ensure instantaneous switchover from one supply to the
other in the event of a power failure.

ITU‐T's Technical Reports and Specifications 229