Internet Exchange Point (IXP)
An Internet Exchange Point (IXP) is an entity that is used to enable public peering between two or more Internet Service Providers (ISPs). IXPs are physically located at places where there are preexisting connections to multiple networks, such as large datacenters, where multiple ISPs already operate their physical infrastructure for the networks.
Typically IXPs are independent associations of their constituent participating networks. Many of the largest IXPs in the world have hundreds of participants.
Compared to private peering, the use of IXPs is much more cost effective as the cost of the maintenance and administration of IXP infrastructure is shared among many individual networks.