Colocation

• Colocation centres are facilities that allow for operation and maintenance of an individual or businesses' Internet servers in a common facility. This allows for significant reduction or elimination of overhead and sundry maintenance costs, thereby reducing operational costs. Colocation effectively allows for renting out physical space and maintenance facilities at a colocation provider's premises. Most colocation centres have high levels of physical security, and may be guarded continuously. They may employ closed-circuit television camera. Some colocation facilities require employees to escort customers, especially if there are not individual locked cages/cabinets for each customer. In other facilities, a card access system may allow clients access into the building, and individual cages/cabinets have locks.

• Colocation centres provide a high level of support and maintenance for customers' servers. Colocation facilities usually have heavy duty generators that start soon after utility power fails, usually running on diesel fuel. These generators may have varying levels of redundancy, depending on how the facility is built. Generators however do not start instantaneously, so colocation facilities usually have battery backup systems. Many facilities provide inverters to provide AC power from batteries. Alternatively, the customers may install smaller UPSes in their racks. Some clients prefer to use equipment powered directly by battery banks. This may provide better energy efficiency, and may reduce the number of parts that can fail. One alternative to battery racks is a motor generator connected to diesel engine and flywheel. Colocation facilities are sometimes connected to multiple areas of the utility power grid for more reliability. A colocation facility often provides air conditioning for the computer and telecommunications equipment in the building. The cooling system generally provides some degree of redundancy. In older facilities, the cooling system capacity often limits the amount of equipment that can operate in the building, more so than the available square footage.

• Colocation facility owners have different allowances regarding cross connects between their customers. They may allow customers to run such connections at no charge, or allow customers to order such connections for a significant monthly fee. They may allow customers to order cross connects to certain carriers, but not to other customers. Some colocation centres feature a "meet-me-room" where the different carriers housed in the centre can efficiently exchange data. Most peering points are located in colocation centres. Many carriers will be interested in bringing direct connections to such buildings primarily because of the high concentration of servers inside larger colocation centres. In many cases there will be a larger Internet Exchange hosted inside a colocation centre, where customers can connect for peering. Colocation facilities generally provide multiple locations for fiber optic cables to enter the premises in order to provide redundancy so that communications can continue if one bundle of cables is damaged.