JANET - History

History

Janet developed out of a number of local and research networks dating back to the 1970s. By 1980, a number of national computer facilities (ULCC London, UMRCC Manchester, Rutherford Appleton Laboratory serving the Science and Engineering Research Council community), each with their own star network had developed. There were also regional networks centred on Bristol, Edinburgh and Newcastle, where groups of institutions had pooled resources to provide better computing facilities than could be afforded individually. These networks were each based on one manufacturer's standards, were mutually incompatible, and overlapping. In the early 1980s a standardisation and interconnect effort started, hosted on an expansion of the SERCnet X.25 research network. The system first went live in April 1983, hosting about 50 sites with line speeds of 9.6 kbit/s. In the mid-80s the backbone was upgraded to a 2 Mbit/s backbone with 64 kbit/s access links, and a further upgrade in the early 1990s sped the backbone to 8 Mbit/s and the access links to 2 Mbit/s, making Janet the fastest X.25 network in the world.

The Janet effort resulted in the standardisation known as the Coloured Book protocols, which provided the first complete X.25 standard. The naming scheme used on Janet (Janet NRS) had similarities to the Internet's Domain Name System, but with domains specified in big-endian format rather than the little-endian style used by DNS. There had been some talk of moving Janet to OSI protocols in the 1990s, but changes in the networking world meant this never happened.