The cooling system consists of the following components:
The cooling system components work together to keep all services gateway components within the acceptable temperature range (see Figure 1, Figure 2, Figure 3, and Figure 4). The services gateway has two fan trays located in the front of the device that install horizontally above and below the card cage. Each fan tray contains six fans. The fan trays are interchangeable and are hot-insertable and hot-removable.
Figure 1: Airflow Through the Chassis
The host subsystem monitors the temperature of the device components. When the device 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 system by disabling output power from each PEM.
There is a single air intake in the front of the services gateway. Air is pushed up through the card cage and through the upper fan tray where it combines in a common exhaust plenum and is exhausted out the upper rear of the system.
Figure 2: Upper Fan Tray
Figure 3: Air Filter
Figure 4: Air Filter Tray