Public data network

A public data network (PDN) is a network established and operated by a telecommunications administration, or a recognized private operating agency, for the specific purpose of providing data transmission services for the public.

The first experimental public packet switching networks, RETD in Spain and RCP in France were deployed in 1972. "Public data network" was the common name given to the collection of X.25 providers, the first of which were Telenet in the United States and DATAPAC in Canada in 1976, and Transpac in France in 1978. The International Packet Switched Service became the first commercial and international packet-switched network in 1978. The networks were interconnected with gateways using X.75. These combined networks had large global coverage during the 1980s and into the 1990s. The networks later provided the infrastructure for the early Internet.