Figure 1-12 Internal Air Flow (Side View) - Cisco GSR12/60 - 12012 Router -AnyLAN, SONET/SDH Installation And Configuration Manual

The front and back of the Cisco 12012 must remain unobstructed to ensure adequate air
flow and prevent overheating inside the card cage assembly; we recommend at least
6 inches (15.2 cm) of clearance.
Figure 1-12 Internal Air Flow (Side View)
Top blower module
Air filter
Room air
Bottom blower module
Front
Physical and Functional Overviews
Air exhaust
Upper card cage
Air deflector
Lower card cage
Power supply bay
Air exhaust
Rear
Product Overview 1-35