Figure 11: Airflow Through the J2320 Chassis
The cooling system in J2320 and J2350 routers is from side to side. The J2320 router has five cooling fans and the J2350 router has four cooling fans. The fans draw air through vents along the left side of the chassis and exhaust it through vents on the right side of the chassis. The airflow produced by these fans keeps router components within the acceptable temperature range (see Figure 11 and Figure 12). The speed of the fans is adjusted automatically according to the current temperature.
On J2350 routers that comply with Network Equipment Building System (NEBS) criteria, an air filter protects the air intake opening at the front of the chassis and must be replaced periodically. To verify that the system is a NEBS-compliant system, run the show chassis hardware command. A NEBS-compliant system displays the term NEBS in the output. For instructions on how to replace air filters, see Replacing Air Filters on J2350 Routers.
The Routing Engine monitors the temperature of the router components. If the maximum temperature specification, as measured at the CPU junction, is exceeded and the router cannot be adequately cooled, the Routing Engine shuts down the hardware components.
J2320 and J2350 routers shut down when the CPU temperature reaches 80°C (176°F). There is no alarm for temperature. You can view the CPU junction temperature using the show chassis routing-engine command. The CPU temperature runs a few degrees higher than the routing engine temperature displayed on the Monitor>Chassis page of the J-Web interface.
An additional fan is part of each power supply. This fan is not regulated by the operating system.
Figure 11: Airflow Through the J2320 Chassis
Figure 12: Airflow Through the J2350 Chassis
