Specifications

Access providers
Primary Entrance Room
(Carrier equipment and demarcation)
Backbone cabling
Equipment Distribution Area
(Cabinets/Racks)
33
724-746-5500 • blackbox.com
Other Standards
Recommended media.
Like the TIA/EIA-568-B standards, the TIA-942 recommends:
• 100-ohm twisted pair cable, Category 6. (At the time of this
writing, Augmented Category 6 is still in draft form.)
• 50- and 62.5-micron multimode fiber optic cable.
Laser-optimized 50-micron is recommended.
• Single-mode fiber optic cable
• 75-ohm coax cable
Each cable type is still governed by all the applicable
requirements in TIA/EIA-568-B.2 and TIA/EIA-568-B.3.
Data center pathways.
The standard lists many recommendations for cable
management, such as each cable type must have separate racks
and pathways. Power cables must be in separate pathways with a
physical barrier. Abandoned cable should be removed. And large
data centers should have access floor systems for running cable.
Hot and Cold Aisles. Cabinets and racks should be arranged in
rows of alternating patterns with the fronts facing each other to
create “hot and cold” aisles. Cold aisles are in front of the cabinets
and racks. Hot aisles are behind the cabinets and racks where
the hot equipment air is exhausted. In addition, there should a
minimum of 1 meter (3.3 ft.) of front space provided for equipment
installation. A front clearance of 1.2 meters (3.9 ft.) is preferred.
A minimum space of 0.6 meters (2 ft.) is required for the rear
clearance with 1 meter (3.3 ft.) preferred. For easy under-floor cable
access, the cabinets and racks should be aligned with the floor tiles.
Redundancy.
Crucial to the operation of any data center are fail-safe systems
that enable continued operation despite catastrophic conditions.
The standard includes four tiers of data center availability. The tiers
are based on research from the Uptime Institute.
Tier 1: Basic
• 99.671% availability
• Annual downtime: 28.8 hours
• Single path for power and cooling
• No redundant components
Tier 2: Redundant Components
• 99.741% availability
• Annual downtime: 22 hours
• Single path for power and cooling
• Redundant components (N + 1)
Tier 3: Concurrently Maintainable
• 99.982% availability
• Annual downtime: 1.6 hours
• Multiple power and cooling paths
• Redundant components (N + 1)
Tier 4: Fault Tolerant
• 99.995% availability
• Annual downtime: 0.4 hours
• Multiple power and cooling paths
• Redundant components 2 (N + 1)
NOTE: N indicates need or level of redundant components for
each tier with N representing only the necessary system need.
Equipment Distribution Area
(Cabinets/Racks)
Main Distribution Area
(Routers, backbone, LAN/SAN switches,
PBX, M13 muxes)
Backbone cabling
Backbone cabling
Horizontal cabling
Horizontal cabling
Horizontal Distribution Area
(LAN/SAN/KVM switches)
Horizontal Distribution Area
(LAN/SAN/KVM switches)
Secondary Entrance Room
(Carrier equipment and
demarcation)
Back
Back
Front
Front
Front
Hot aisle
Cold aisle
Cable trays
Cable trays
Power cable