What is Cage?
A cage is a physically enclosed section of a shared data center floor. Walls of steel mesh or solid panels, usually with a locked door, separate one tenant's racks from the racks of other tenants. The cage is rented as floor space, and the customer fills it with its own cabinets, power distribution and cabling.
A cage sits between two neighbouring options. A single cabinet is one lockable rack in a shared row. A private suite or vault is a full room with solid walls and its own door. A cage gives more physical separation than a shared cabinet, but it is still open above the cage walls in many facilities, and it shares the building's cooling, fire suppression and security with its neighbours.
Providers differ on the details. Cage height, whether the top is open or covered, who holds the keys, the access control method and whether the cage is built to a customer's cabinet layout all vary by facility and by contract. Read the colocation agreement and the site rules before you plan work, because they decide who may enter and what an outside engineer must present at the door.
How it shows up in practice
- Access lists name the people who may enter the cage. An engineer who is not on the list usually cannot start work until the customer or the colocation provider approves them.
- Escorts and badge rules apply on the way to the cage. Allow time for check-in, ID checks and tool inspection in the schedule.
- Cage work often includes rack and stack, cabling between cabinets inside the cage, and cross-connect handoffs at the cage boundary.
- A written scope should name the cage or suite identifier, the cabinet positions, and who supplies power cords, patch cables and labels.
- Photos taken before and after work show the state of the cage and are useful if the provider later asks who changed what.