Cisco C921-4P User Manual

More spacing may be required depending on the installation environment.
Note
• Enclosed racks must have adequate ventilation. Ensure that the rack is not congested, because each router
generates heat. An enclosed rack should have louvered sides and a fan to provide cooling air. Heat
generated by equipment near the bottom of the rack can be drawn upward into the intake ports of the
equipment above it.
Router Environmental Requirements
Cisco 900 Series ISRs can be installed on a desk or a shelf, under a desk or a shelf, on a wall, and in a rack,
depending on the SKU. The location of your router and the layout of your equipment rack or wiring room are
extremely important considerations for proper operation. Equipment installed too close together, inadequate
ventilation, and inaccessible panels can cause malfunctions and shutdowns, and can make maintenance difficult.
Plan your installation site for accessing both front and rear panels of the router.
When planning your site layout and equipment locations, refer to the General Site Requirements , section. If
you are currently experiencing shutdowns or an unusually high number of errors with your existing equipment,
these precautions and recommendations may help you isolate the cause of failure and prevent future problems.
• Ensure that the room where your router operates has adequate air circulation. Electrical equipment
generates heat. Without adequate air circulation, ambient air temperature may not cool equipment to
acceptable operating temperatures.
• Always follow ESD-prevention procedures described in the Preventing Electrostatic Discharge Damage
to avoid damage to equipment. Damage from static discharge can cause immediate or intermittent
equipment failure.
• When equipment installed in a rack (particularly in an enclosed rack) fails, try operating the equipment
by itself, if possible. Power off other equipment in the rack (and in adjacent racks) to allow the router
under test a maximum of cooling air and clean power.
Power Guidelines and Requirements
Cisco 900 series routers come with the following power options:
• Routers with internal AC power supply
• Routers with external AC power supply
Table 4: SKUs with Internal and External Power Supplies
SKUPower Supply
C921-4P
C931-4P
Internal
Hardware Installation Guide for the Cisco 900 Series Integrated Services Router
12
Prepare for Router Installation
Router Environmental Requirements

Cisco C921-4P Specifications

General

Switch type	Managed
Quality of Service (QoS) support	Yes
USB 2.0 ports quantity	1
Basic switching RJ-45 Ethernet ports type	-
Basic switching RJ-45 Ethernet ports quantity	4
10G support	No
Networking standards	IEEE 802.1D
Product color	Black
Electromagnetic compatibility	47CFR, AS/NZS CISPR22 2, CISPR22, EN55022, ICES003, EN61000-3-2, KCC, EN55024, KN24
Flash memory	2048 MB
Internal memory	1024 MB
MAC address table	- entries
AC input voltage	100 - 240 V
AC input frequency	50 - 60 Hz
Storage temperature (T-T)	-40 - 70 °C
Operating temperature (T-T)	0 - 50 °C
Operating relative humidity (H-H)	5 - 95 %
Security algorithms	802.1x RADIUS
Harmonized System (HS) code	85176990

Weight and Dimensions

Depth	241.3 mm
Width	228.6 mm
Height	43.2 mm
Weight	1200 g