Cabinet size and clearance

• The minimum-sized cabinet that can accommodate the router is 19-in. (482-mm) wide and 23.62-in. (600-mm) deep. A cabinet larger than the minimum requirement provides better airflow and reduces the chance of overheating. If you provide adequate cooling air and airflow clearance, you can stack several routers in a cabinet that has sufficient usable vertical space. Each router requires 2 U.

  A U is the standard rack unit defined in Cabinets, Racks, Panels, and Associated Equipment (document number EIA-310–D) published by the Electronics Industry Association (http://www.eia.org).

• With adequate cooling air and airflow clearance, you can stack multiple MX80 routers in a cabinet with a four-post rack. In all cases, the rack must meet the strength requirements to support the weight.
• The minimum total clearance inside the cabinet is 30.7 in. (780 mm) between the inside of the front door and the inside of the rear door.

Cabinet airflow requirements

When you install the router in a cabinet, you must ensure that ventilation through the cabinet is sufficient to prevent overheating. Consider the following requirements to when planning for chassis cooling:

• Airflow must always be from front to back with respect to the rack. If the device has side to rear airflow, then provisions must be made to ensure that fresh air from the front of the rack is supplied to the inlets, and exhaust exits the rear of the rack. The device must not interfere with the cooling of other systems in the rack. Fillers must be used as appropriate in the rack to ensure there is no recirculation of heated exhaust air back to the front of the rack. Care must also be taken around cables to ensure no leakage of air in situations where recirculation may result.
• Ensure that the cabinet allows the chassis hot exhaust air to exit from the cabinet without recirculating into the router. An open cabinet (without a top or doors) that employs hot air exhaust extraction from the top allows the best airflow through the chassis. If the cabinet contains a top or doors, perforations in these elements assist with removing the hot air exhaust. For an illustration of chassis airflow, see Figure 1.
• Ensure that the cool air supply you provide through the cabinet can adequately dissipate the thermal output of the router.
• Route and dress all cables to minimize the blockage of airflow to and from the chassis.
• Ensure that the spacing of rails and adjacent racks allows for the proper clearance around the router and rack as specified in MX80 Router Clearance Requirements for Airflow and Hardware Maintenance.
• Install the router as close as possible to the front of the cabinet so that the chassis just clears the inside of the front door. This maximizes the clearance in the rear of the cabinet for critical airflow.