 On January 1, 1983, known as flag day, NCP on the ARPANET was replaced by the more flexible and powerful family of TCP/IP protocols, marking the start of the modern Internet.Early international collaborations on ARPANET were sparse.Connections were made in 1973 to the Norwegian Seismic Array (NORSAR), via a satellite link at the Tanum Earth Station in Sweden, and to Peter Kirstein's research group at University College London which provided a gateway to British academic networks.