What is colocation?

Colocation (also referred to as co-location or collocation) is the term used to describe placing telephone switching equipment, antennae or Internet data equipment owned by separate companies at a physical site operated by a third party. Another way of describing this is to say that colocation occurs when multiple telecommunications network or service providers, such as telcos or ISPs, "site" their connections to one another's networks or "points of presence." The physical site of such as data center is referred to as a colocation center or "carrier hotel." Most peering points are sited in colocation centers.

Colocation and Peering

Peering is the practice of exchanging Internet traffic with peers. It involves three elements: the physical interconnection of the networks, the technical liaison between the networks (to allow route-exchange), and the commercial and contractual peering agreements.

Internet service providers (ISPs) set up peering points, the physical locations where exchanges happen, and negotiate peering agreements, legal documents that outline exact details of how traffic will be exchanged. Most peering points are located in colocation centers.

The History of Peering

In the Internet's early days, a single backbone network existed in the form of first the ARPANET and later the NSFNET. All other networks connected with one another via the Internet backbone, and routing information was conveyed between the backbone and the other networks via the Exterior Gateway Protocol (EGP).

The modern Internet no longer has a single backbone in the traditional sense. Rather, it has many backbones, consisting of the individuals backbones of various commercial ISPs and private networks. They are all connected at many different peering points.

Advantages of Colocation

Colocation allows users to retain full management-responsibility for day-to-day hosting, while enjoying access to security-enhanced, reliable data centers and high-bandwidth Internet connectivity. In colocation, customers typically select and manage their own Web servers, including the hardware and software costs and initial hardware investment. The collocation center provides a level of physical security, multiple redundant power and air-conditioning systems, as well as a high-speed Internet connection. In this way, a company that collocates servers can save on costs and enable easier execution of large-scale upgrades.