A private data network is a proprietary communications network for the transmission of data between a number of locations which does not use public telecommunication network resources or services.

Private data networks are employed by organisations in order to meet the business requirements of an increasingly global economy. They are used to ensure high-speed, robust reliable communications facilities, without reliance upon a public telecommunications and data transmission infrastructure and without compromising possible security requirements.

Increasingly the design, implementation and management of private data networks is being offered as a service package by traditional telecommunications providers, to the corporate and business sectors.

Private data networks may provide flexible and transparent protocol conversions between local area networks and high speed network linkages, switching systems and dial-in and dial-out capabilities