Colocated Hosting
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Colocation centre
A room in the Telecity colocation center in Aubervilliers near Paris.A colocation center ("colo") or carrier hotel is a type of data center where multiple telecommunications network or service providers, such as telcos or internet service providers, site their connections to one another's networks (points of presence).
Increasingly organizations are recognizing the benefits of colocating their mission-critical equipment within a data center. Colocation is becoming popular because of the time and cost savings a company can realize as result of using shared data center infrastructure. With IT and communications facilities in safe, secure hands, telecommunications, internet, ASP and content providers, as well as enterprises, enjoy less latency and the freedom to focus on their core business.
Additionally, customers reduce their traffic back-haul costs and free up their internal networks for other uses. Moreover, by outsourcing network traffic to a colocation service provider with greater bandwidth capacity, web site access speeds should improve considerably.
Major types colocation customers are:
Web commerce companies, who use the facilities for a safe environment and cost-effective, redundant connections to the Internet
Major enterprises, who use the facility for disaster avoidance
Telecommunication companies, who use the facilities to interexchange traffic with other telecommunications companies and access to potential clients
Most Network Access Point facilities provide colocation.
Trivia
Some colocation centres feature a "meet-me-room" where the different carriers housed in the centre can efficiently exchange data.
Most peering points are sited in colocation centres.
These sites are often used for web hosting.
Most colocation centres have high levels of physical security and multiple redundant power and humidity / air-conditioning systems.
A typical Colocation centre setup would consist of the following hardware and services:
Building:
Usually built near a GlassFibre ring.
Fiber has multiple access points into building to prevent back hoe cuts.
Guarded 24/7 and secured with closed circuit cameras.
"Clean" rooms to ensure optimal running conditions for computer and network hardware.
Empty pipe fire suppression of some sort.
Relay racks, cabinets or cages to mount servers into.
Power:
Connected to two or more different power stations/grids.
Inline power backup using a system of UPS batteries (often with a diesel standby generator).
Possibility to connect two different grids of power distribution to one server.
Most also have Backup Diesel generators standby to support power delivery.
Connections:
Because of the high concentration of servers inside a colocation centre most carriers will be interested in bringing direct connections to such buildings.
In most cases there will be a larger Internet-Exchange hosted inside a colocation centre, on which customers can connect for peering.
Confusingly, one company can operate a colocation center, another can provide the bandwidth, whereas a third company would rent a cage inside the center, renting out racks to hosting providers which would rent the servers themselves to actual clients. Any and all of those companies will claim ownership of the facility and will feature photos and descriptions of it on their web sites. At the actual physical location various ID cards with various logos will be present, including those of the company that built/rents/owns the actual building.
Services offered
Most colocation centres offer different types of services to customers ranging from dedicated suites/rooms or cages to smaller racks or partial racks. Some colocation centres also offer some degree of SLAs (service level agreements) to support a wide range of computer and network related services, for example server reboots, hardware replacements, software updates etc.
There are a few key differences between a dedicated server and colocation servers. Dedicated servers tend to be owned and rented out, while a colocation server is one that you own.
