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MX10003 Cooling System

MX10003 Cooling System Description

The cooling system components work together to keep all router components within the acceptable temperature range.

The cooling system consists of the following components:

Fan Modules

The chassis monitors the temperature of the router components. When the router is operating normally, the fans function at lower than full speed. If a fan fails or the ambient temperature rises above a threshold, the speed of the remaining fans is automatically adjusted to keep the temperature within the acceptable range. If the ambient maximum temperature specification is exceeded and the system cannot be adequately cooled, the Routing Engine shuts down the router by disabling output power from each power supply.

The router has four fan modules that install vertically at the rear of the router. Each fan module contains two counter-rotating fans. The fan modules are hot-insertable and hot-removable field-replaceable units (FRUs) (see Figure 1).

Figure 1: Fan ModuleFan Module
Captive screw
Status LED
Fan Module


The router has front-to-back (AIR OUT) cooling system (see Figure 2). Air is pulled through the front the chassis toward the fan module, which exhausts the air out of the router.

Figure 2: Airflow Through the RouterAirflow Through the Router

Air Filter Unit

The air filter unit consists of three parts–the outer filter cover, the air filter, and the inner cage that form the body, and the air filter (see Figure 3). The air filter sits right inside the outer filter cover and the inner cage. The air filter unit is installed into the cable management brackets, and are held tightly by captive screws.

Figure 3: Air Filter UnitAir Filter Unit
Outer filter cover
Inner cage
Air filter

Power Supply Cooling System

The power supplies are self-cooling and are located in the rear of the router (to the left and the right of the rear of the chassis). The exhaust for the power supplies are also located on the rear of the chassis.

MX10003 Fan Module LED

Each fan module contains one bicolor LED. MX10003 Cooling System Description shows the fan module LED.

Table 1 describes the behavior of the fan module LEDs.

Table 1: Fan Module LEDs








Fan module hardware initialization complete and software initialization pending.

On steadily

Software initialization complete and the fan is functioning normally.


On steadily

Faulty and not functioning normally