Public data network


A public data network 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. It was the common name given to the international collection of X.25 providers whose combined network had large global coverage during the 1980s and into the 1990s, which later provided infrastructure for the Internet.

Description

In communications, a PDN is a circuit- or packet-switched network that is available to the public and that can transmit data in digital form. A PDN provider is a company that provides access to a PDN and that provides any of X.25, frame relay, or cell relay services. Access to a PDN generally includes a guaranteed bandwidth, known as the committed information rate. Costs for the access depend on the guaranteed rate. PDN providers differ in how they charge for temporary increases in required bandwidth. Some use the amount of overrun; others use the surge duration.

Networks

Early examples include the following experimental/public networks: RETD/Iberpac in Spain; RCP/Transpac in France; Tymnet and Telenet in the United States; EPSS/Packet Switch Stream, in the United Kingdom; EIN/Euronet in the EEC; DATAPAC in Canada; and AUSTPAC in Australia. The International Packet Switched Service, the first commercial and international packet switching network, was a collaboration between British and American telecom companies.