Airflow Guidelines - Cisco ASR 903 Installation Instructions Manual

Installing the Cisco ASR 903 Router as a Satellite Shelf

AirFlow Guidelines

Cool air is circulated through the Cisco ASR 903 Router as a satellite shelf by a fan tray located along the
right side of the router. Airflow is side to side, right to left, as shown in this figure.
Figure 1: Cisco ASR 903 as a Satellite Shelf Chassis Airflow
The fan trays maintain acceptable operating temperatures for the internal components by drawing in cool air
through the vents, and circulating the air through the chassis.
The following guidelines will help you plan your equipment rack configuration:
• To ensure adequate airflow through the equipment rack, we recommend that you maintain a clearance
• If airflow through the equipment rack and the routers that occupy it is blocked or restricted, or if the
• The site should also be as dust-free as possible. Dust tends to clog the router fans, reducing the flow of
• Enclosed racks must have adequate ventilation. Ensure that the rack is not congested, because each
• When mounting a chassis in an open rack, ensure that the rack frame does not block the side intakes and
• When rack-installed equipment fails, especially equipment in an enclosed rack, try operating the equipment
• Avoid locating the Cisco ASR 903 Router as a satellite shelf in a location in which the chassis air intake
of at least 80 mm on each side of the rack at all times.
ambient air being drawn into the rack is too warm, an overtemperature condition can occur within the
rack and the routers that occupy it.
cooling air through the equipment rack and the routers that occupy it, thus increasing the risk of an
overtemperature condition.
router generates heat. An enclosed rack should have louvered sides and a fan to provide cooling air.
Heat that is generated by the equipment near the bottom of the rack can be drawn upward into the intake
ports of the equipment above.
the exhaust fans.
by itself, if possible. Power off all other equipment in the rack (and in adjacent racks) to give the router
maximum cooling air and clean power.
vents may draw in the exhaust air from adjacent equipment. Consider how the airflows through the
Cisco ASR 9000 Series Aggregation Services Router Satellite Systems Installation Guide
AirFlow Guidelines
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