An enclosure with a built-in rack for holding and organizing patch panels, switches, hubs, routers, servers, and any other networking equipment within a wiring closet.
Cabinets can be wall-mounted or freestanding, come in various heights, and are usually standardized for 19-inch-wide shelving and paneling. They generally come in 83-inch and 48-inch heights, although many vendors offer custom-designed cabinets. The reason for standardizing the width to 19 inches (18.31 inches to be precise) is that hubs, switches, routers, and other networking devices are produced in this width so that they can be organized in racks and cabinets designed for this purpose. Cabinets come with a variety of accessories for organizing cables, power strips, and so on. Because heat can accumulate in cabinets, they usually include vented walls and have an exhaust fan on top. A cabinet will often have a locking front panel made of clear plastic so that status lights on equipment are easily visible. Shelves can be fixed, mounted, or sliding to enable easy access to the sides and backs of equipment.
When should you choose a cabinet instead of a rack? Choose a cabinet for equipment that is exposed to user traffic, and then you can lock equipment away when the room itself is not locked. Cabinets are also best for expensive networking equipment that you don’t want anyone but authorized administrators to touch. Cabinets with filter fans installed can protect equipment in environments where dust is a problem. Use filler panels to enclose areas of the cabinet that are not occupied by equipment.