Public Data Networks in the Nordic Countries

Abstract : Public data networks were introduced in many countries app. 1980. Norway, Finland, Sweden and Denmark evolved common networks in the Nordic countries. The project was named NPDN (Nordic Public Data Network). It was a circuit switched network based on the X.21 recommendation from CCITT. NPDN is described and placed as an element in the ongoing development of data transmission via the public telecommunications networks – from analogue modems to fiber and IP.