The implementation of Packet Switching into a real network developed in parallel in the US and in the UK. In 1968, two network projects were started: in the US it was started under the auspices of the Advanced Research Networks Agency (ARPA), so that the project was called Arpanet, under the leadership of Larry Roberts - the Director of the relevant office. In the UK it was started at the National Physical Laboratory under its then Laboratory Superintendent Donald Davies and called the NPL Network. The NPL network was comparatively modest in scale, with only a few nodes inside NPL, but with a speed of 768 Kbps. In the US, a much more expensive wide-area network project was mounted. By the end of 1970, it connected around 20 sites, and had two cross-country telephone lines. Its lines were run at 64 Kbps.
The third ingredient for the international extension of the Arpanet was a quite separate development. In 1966, ARPA had established a set of three seismic arrays: in Alaska, Montana and Norway. The last, called the NORSAR array, was at Kjeller, near Oslo. A formal bilateral treaty had established this array and the corresponding collaboration with the US. The arrays were operated for ARPA under the auspices of their Nuclear Monitoring Research Office (NMRO). By 1970, there was a communications link at 9.6 Kbps between Washington and NORSAR. Because of the transatlantic technology of the time, this channel went by Satellite to the UK; in London it was connected onto to a cable to Kjeller.