It is linked to other European and worldwide NRENs through GEANT, has a private connection to its equivalent CERNET in China and peers extensively with other ISPs at Internet Exchange Points in the UK. Any other networks are reached via transit services from commercial ISPs.
JANET is operated by JANET(UK), formerly known as UKERNA (the United Kingdom Education and Research Networking Association), who are also responsible for the .ac.uk and .gov.uk domains. It is funded by JISC, the Joint Information Systems Committee.
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 Laboratory serving the Science and Engineering Research Council community), each with their own star network had developed. There were also regional networks centred on Bath, 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 the domains specified in the reverse order, e.g. UK.AC.HATFIELD.INFSC1 instead of infsc1.hatfield.ac.uk. There had been some talk of moving JANET to OSI protocols in the 1990s, but changes in the networking world meant this never happened.
In January 1991 the JANET IP Service (JIPS) was set up as a pilot project to host IP traffic on the existing network. Within ten months the IP traffic had exceeded the levels of X.25 traffic, and the IP support became official in November. Today JANET is primarily a high-speed IP network.
In order to address speed concerns, several hardware upgrades have been incorporated into the JANET system. In 1989 SuperJANET was proposed, to re-host JANET on a fibre optic network. Work started in late 1992, and by late 1993 the first 14 sites had migrated to the new 34 Mbit/s ATM system. SuperJANET also moved solely to IP.
In 1995 SuperJANET2 started, adding 155 Mbit/s ATM backbones and a 10 Mbit/s SMDS network encompassing some of the original JANET nodes. JANET's mandate now included running metropolitan area networks centred on these sites.
In March 2001 SuperJANET4 was launched. The key challenges for SuperJANET4 were the need to increase network capacity and to strengthen the design and management of JANET to allow it to meet a similar increase in the size of its userbase.
SuperJANET4 saw the implementation of a 2.5 Gbit/s core backbone from which connections to regional network points of presence were made at speeds ranging between 155 Mbit/s to 2.5 Gbit/s depending upon the size of the regional network. In 2002 the core SuperJANET4 backbone was upgraded to 10 Gbit/s.
SuperJANET4 also saw an increase in the userbase of JANET with the inclusion of the Further Education Community and the use of the SuperJANET4 backbone to interconnect schools' networks. The core point of presence (Backbone) sites in SuperJANET4 were Edinburgh, Glasgow, Warrington, Reading, Bristol, Portsmouth, London and Leeds.
In October 2006 the SuperJANET5 project was launched after £29 million of investment. It provides a 10Gbit/s backbone, with an upgrade path to 40GBit/s over the next few years. The new backbone as a result of the SuperJANET5 project is a hybrid network offering, providing both a high speed IP transit service and private bandwidth channel services provisioned over a dedicated fibre network. It is designed not only to fully accommodate the requirements of the traditional JANET user base - all research institutes, universities and further education - but also to meet the needs of a new userbase in the UK's primary and secondary schools.
Each RNO covers a specific geographical area, as of 2007 the following regional networks are connected to JANET: