A colocation center (also spelled co-location, or colo) or "carrier hotel", is a type of

data centre A data center (American English) or data centre (British English)See spelling differences. is a building, a dedicated space within a building, or a group of buildings used to house computer systems and associated components, such as telecommun ...

where equipment, space, and bandwidth are available for rental to retail customers. Colocation facilities provide space, power, cooling, and

physical security Physical security describes security measures that are designed to deny unauthorized access to facilities, equipment and resources and to protect personnel and property from damage or harm (such as espionage, theft, or terrorist attacks). Phy ...

for the

server Server may refer to: Computing *Server (computing), a computer program or a device that provides functionality for other programs or devices, called clients Role * Waiting staff, those who work at a restaurant or a bar attending customers and su ...

, storage, and

networking Network, networking and networked may refer to: Science and technology * Network theory, the study of graphs as a representation of relations between discrete objects * Network science, an academic field that studies complex networks Mathematic ...

equipment of other firms and also connect them to a variety of

telecommunications Telecommunication is the transmission of information by various types of technologies over wire, radio, optical, or other electromagnetic systems. It has its origin in the desire of humans for communication over a distance greater than that ...

and

network service provider Network Service Provider (NSP) is one of the roles defined in the National Information Infrastructure (NII) plan, which governed the transition of the Internet from US federal control to private-sector governance, with an accompanying shift from th ...

s with a minimum of cost and complexity.

Configuration

Many colocation providers sell to a wide range of customers, ranging from large enterprises to small companies. Typically, the customer owns the

information technology Information technology (IT) is the use of computers to create, process, store, retrieve, and exchange all kinds of data . and information. IT forms part of information and communications technology (ICT). An information technology syste ...

(IT) equipment and the facility provides power and cooling. Customers retain control over the design and usage of their equipment, but daily management of the data center and facility are overseen by the multi-tenant colocation provider. * Cabinets – A cabinet is a locking unit that holds a

server rack A 19-inch rack is a standardized frame or enclosure for mounting multiple electronic equipment modules. Each module has a front panel that is wide. The 19 inch dimension includes the edges or "ears" that protrude from each side of the equ ...

. In a multi-tenant data center, servers within cabinets share raised-floor space with other tenants, in addition to sharing power and cooling infrastructure. * Cages – A cage is dedicated server space within a traditional raised-floor data center; it is surrounded by mesh walls and entered through a locking door. Cages share power and cooling infrastructure with other data center tenants. * Suites – A suite is a dedicated, private server space within a traditional raised-floor data center; it is fully enclosed by solid partitions and entered through a locking door. Suites may share power and cooling infrastructure with other data center tenants, or have these resources provided on a dedicated basis. * Modules – data center modules are purpose-engineered modules and components to offer scalable data center capacity. They typically use standardized components, which make them easily added, integrated or retrofitted into existing data centers, and cheaper and easier to build. In a colocation environment, the data center module is a data center within a data center, with its own steel walls and security protocol, and its own cooling and power infrastructure. "A number of colocation companies have praised the modular approach to data centers to better match customer demand with physical build outs, and allow customers to buy a data center as a service, paying only for what they consume."

Building features

Buildings with data centres inside them are often easy to recognize by the amount of cooling equipment located outside or on the roof. Rack001

Colocation facilities have many other special characteristics: *

Fire protection Fire protection is the study and practice of mitigating the unwanted effects of potentially destructive fires. It involves the study of the behaviour, compartmentalisation, suppression and investigation of fire and its related emergencies, as we ...

systems, including

passive Passive may refer to: * Passive voice, a grammatical voice common in many languages, see also Pseudopassive * Passive language, a language from which an interpreter works * Passivity (behavior), the condition of submitting to the influence of o ...

and active elements, as well as implementation of

fire prevention Fire prevention is a function of many fire departments. The goal of fire prevention is to educate the public on the precautions which should be taken to prevent potentially harmful fires and how to survive these fires in the event that they do o ...

programmes in operations.

Smoke detector A smoke detector is a device that senses smoke, typically as an indicator of fire. Smoke detectors are usually housed in plastic enclosures, typically shaped like a disk about in diameter and thick, but shape and size vary. Smoke can be detecte ...

s are usually installed to provide early warning of a developing fire by detecting particles generated by smouldering components prior to the development of flame. This allows investigation, interruption of power, and manual fire suppression using hand held fire extinguishers before the fire grows to a large size. A

fire sprinkler system A fire sprinkler system is an active fire protection method, consisting of a water supply system, providing adequate pressure and flowrate to a water distribution piping system, onto which fire sprinklers are connected. Although historically on ...

is often provided to control a full scale fire if it develops.

Clean agent Gaseous fire suppression, also called clean agent fire suppression, is a term to describe the use of inert gases and chemical agents to extinguish a fire. These agents are governed by the National Fire Protection Association (NFPA) Standard for C ...

fire suppression gaseous systems are sometimes installed to suppress a fire earlier than the fire sprinkler system. Passive fire protection elements include the installation of fire walls around the space, so a fire can be restricted to a portion of the facility for a limited time in the event of the failure of the active fire protection systems, or if they are not installed. *

19-inch rack A 19-inch rack is a standardized frame or enclosure for mounting multiple electronic equipment modules. Each module has a front panel that is wide. The 19 inch dimension includes the edges or "ears" that protrude from each side of the equ ...

s for data equipment and servers,

23-inch rack A 19-inch rack is a standardized frame or enclosure for mounting multiple electronic equipment modules. Each module has a front panel that is wide. The 19 inch dimension includes the edges or "ears" that protrude from each side of the equ ...

s for telecommunications equipment * Cabinets and cages for physical access control over tenants' equipment. Depending on one's needs a cabinet can house individual or multiple racks. * Overhead or underfloor cable rack (tray) and fibreguide, power cables usually on separate rack from data *

Air conditioning Air conditioning, often abbreviated as A/C or AC, is the process of removing heat from an enclosed space to achieve a more comfortable interior environment (sometimes referred to as 'comfort cooling') and in some cases also strictly controlling ...

is used to control the temperature and humidity in the space.

ASHRAE The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE ) is an American professional association seeking to advance heating, ventilation, air conditioning and refrigeration (HVAC&R) systems design and constructi ...

recommends a temperature range and humidity range for optimal electronic equipment conditions versus environmental issues. The electrical power used by the electronic equipment is converted to heat, which is rejected to the ambient air in the data centre space. Unless the heat is removed, the ambient temperature will rise, resulting in electronic equipment malfunction. By controlling the space air temperature, the server components at the board level are kept within the manufacturer's specified temperature and humidity range. Air conditioning systems help keep equipment space

humidity Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation, dew, or fog to be present. Humidity dep ...

within acceptable parameters by cooling the return space air below the

dew point The dew point is the temperature to which air must be cooled to become saturated with water vapor, assuming constant air pressure and water content. When cooled below the dew point, moisture capacity is reduced and airborne water vapor will ...

. Too much humidity and water may begin to

condense Condensation is the change of the state of matter from the gas phase into the liquid phase, and is the reverse of vaporization. The word most often refers to the water cycle. It can also be defined as the change in the state of water vapor to ...

on internal components. In case of a dry atmosphere, ancillary humidification systems may add water vapour to the space if the humidity is too low, to avoid

static electricity Static electricity is an imbalance of electric charges within or on the surface of a material or between materials. The charge remains until it is able to move away by means of an electric current or electrical discharge. Static electricity is na ...

discharge problems which may damage components. * Low-impedance electrical

ground Ground may refer to: Geology * Land, the surface of the Earth not covered by water * Soil, a mixture of clay, sand and organic matter present on the surface of the Earth Electricity * Ground (electricity), the reference point in an electrical c ...

* Few, if any, windows Colocation data centres are often audited to prove that they attain certain standards and levels of reliability; the most commonly seen systems are

SSAE 16 Statement on Standards for Attestation Engagements no. 16 (SSAE 16) is an auditing standard for service organizations, produced by the American Institute of Certified Public Accountants (AICPA) Auditing Standards Board, which supersedes Statem ...

SOC 1 Type I and Type II (formerly

SAS 70 SAS or Sas may refer to: Arts, entertainment, and media * ''SAS'' (novel series), a French book series by Gérard de Villiers * ''Shimmer and Shine'', an American animated children's television series * Southern All Stars, a Japanese rock ba ...

Type I and Type II) and the tier system by the Uptime Institute or TIA. For service organizations today, SSAE 16 calls for a description of its "system". This is far more detailed and comprehensive than SAS 70's description of "controls". Other data center compliance standards include

Health Insurance Portability and Accountability Act The Health Insurance Portability and Accountability Act of 1996 (HIPAA or the Kennedy– Kassebaum Act) is a United States Act of Congress enacted by the 104th United States Congress and signed into law by President Bill Clinton on August 21, 1 ...

(HIPAA) audit and PCI DSS Standards.

Power

Colocation facilities generally have generators that start automatically when utility power fails, usually running on

diesel fuel Diesel fuel , also called diesel oil, is any liquid fuel specifically designed for use in a diesel engine, a type of internal combustion engine in which fuel ignition takes place without a spark as a result of compression of the inlet air and ...

. These generators may have varying levels of redundancy, depending on how the facility is built. Generators do not start instantaneously, so colocation facilities usually have battery backup systems. In many facilities, the operator of the facility provides large inverters to provide AC power from the batteries. In other cases, customers may install smaller UPSes in their racks. Some customers choose to use equipment that is powered directly by 48 VDC (nominal) battery banks. This may provide better energy efficiency, and may reduce the number of parts that can fail, though the reduced voltage greatly increases necessary current, and thus the size (and cost) of power delivery wiring. An alternative to batteries is a

motor–generator A motor–generator (an M–G set) is a device for converting electrical power to another form. Motor–generator sets are used to convert frequency, voltage, or phase of power. They may also be used to isolate electrical loads from the elect ...

connected to a

flywheel A flywheel is a mechanical device which uses the conservation of angular momentum to store rotational energy; a form of kinetic energy proportional to the product of its moment of inertia and the square of its rotational speed. In particular, as ...

and diesel engine. Many colocation facilities can provide redundant, A and B power feeds to customer equipment, and high end servers and telecommunications equipment often can have two power supplies installed. Colocation facilities are sometimes connected to multiple sections of the utility power grid for additional reliability.

Internal connections

Colocation facility owners have differing rules regarding cross-connects between their customers, some of whom may be carriers. These rules may allow customers to run such connections at no charge, or allow customers to order such connections for a monthly fee. They may allow customers to order cross-connects to 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 sit in colocation centres and because of the high concentration of servers inside larger colocation centres, most carriers will be interested in bringing direct connections to such buildings. In many cases, there will be a larger

Internet exchange point Internet exchange points (IXes or IXPs) are common grounds of IP networking, allowing participant Internet service providers (ISPs) to exchange data destined for their respective networks. IXPs are generally located at places with preexisting ...

hosted inside a colocation centre, where customers can connect for peering.

References

External links