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CiscoASR 9000 Series Aggregation Services Router Hardware Installation Guide
Chapter1 Preparing for Installation
Site Requirement Guidelines
Site Wiring Guidelines
When planning the location of the router, consider distance limitations for signaling, electromagnetic
interference (EMI), and connector compatibility. If the wiring is run for any significant distance in an
electromagnetic field, interference can occur between the field and the signals on the wires. Poor wiring
can cause:
•Radio interference emanating from the wires.
•Strong EMI, especially when caused by lightning or radio transmitters. EMI can destroy the signal
drivers and receivers in the router, and can even create an electrical hazard by conducting power
surges through lines and into equipment.
Note To predict and remedy strong EMI, you may need to consult with experts in radio frequency
interference (RFI).
Site wiring is unlikely to emit radio interference if you use twisted-pair cable with a good distribution
of grounding conductors. Use a high-quality twisted-pair cable with one ground conductor for each data
signal, when applicable.
Give special consideration to the effect of a lightning strike in your vicinity, especially if the wiring
exceeds the recommended distances, or if it passes between buildings. The electromagnetic pulse (EMP)
caused by lightning or other high-energy phenomena can easily induce enough energy into unshielded
conductors to destroy electronic devices. If you have experienced EMP problems in the past, you may
want to consult experts in electrical surge suppression and shielding.
Most data centers cannot resolve infrequent but potentially catastrophic problems without pulse meters
and other special equipment. In addition, these problems can take a great deal of time to identify and
resolve. We recommend that you take the necessary precautions to avoid these problems by providing a
properly grounded and shielded environment, with special attention to issues of electrical surge
suppression.
Chassis Air Flow Guidelines
Table 1 -1 describes how cool air is circulated through the Cisco ASR 9000 Series Routers.
Table1-1 Chassis Air Flow Guidelines
Router Type Chassis Air Flow
Cisco ASR 9010 Air is circulated by two fan trays located underneath the Route Switch Processor
(RSP) and line cards as shown in Figure1-12.
Cisco ASR 9006 Air is circulated by two fan trays located along the top left side above the RSP
and line cards as shown in Figure1-13.
Cisco ASR 9904 Air is circulated side-to-side by a single fan tray located along the left side of
the chassis as shown in Figure1-14.
If the router is installed in a 2-post 23-inch rack, air flow is circulated
front-to-back. Optionally, you can install air baffles on the chassis to help
isolate the exhaust air from the intake air. For more information, see Installing
Optional Air Baffles on the CiscoASR 9904 Router, page 2-82.