Network Evolution and the Importance of X.25 and OSI

As traffic on the network increased because of people using new services, this prompted the funding bodies to upgrade the technical infrastructure of the network. The Network Executive rationalised the number of switching centres and upgraded the backbone of JANET and the links to sites (see Figure 2.6). By early 1988, four leased lines between the centres of Rutherford, Daresbury, Manchester, and London operated at 256 Kbps, replacing the old 48 Kbps circuits.110 As well as upgrading the backbone to 2 Mbps, the Network Executive also started to upgrade the lines between institutions and JANET, from 9.6 Kbps to 48 or 64 Kbps.

As JANET continued to develop, so too did the Local Area Networks on campuses throughout the country. During the early 1980s, institutions began to install campus networks. These linked departmental minicomputers and the campus mainframe to JANET via gateways. Using terminals, people could access both local and remote resources using these facilities. Based on X.25 Campus Packet Switching Exchanges (CPSEs), these networks were slow and competing LAN standards soon emerged.111 Cambridge University had developed its Cambridge Ring technology during the 1970s, and in 1982, the JNT, in collaboration with the IT Standards Unit of the DTI, announced this as a new Coloured Book, known as the Orange Book standard.112 By 1985, 43 institutions had installed LANs, 10 of which used 1 Mbps Cambridge Ring technology.113 Another LAN technology, Ethernet, became the Pink Book standard and together with Cambridge Ring, these 10 Mbps LAN technologies started to replace the X.25 local networks. With the availability of campus networks, institutions began to develop new services such as Campus-Wide Information Systems (CWISs).

110

J. Carey, JANET Upgrade Programme, UKERNA, 1988, Available from:

http://www.ja.net/documents/NetworkNews/Issue25/news25.txt, Accessed on: 31 July 2004.

111

The CPSEs interconnected campus LANs to the JANET backbone, transmitting traffic between the campus networks and JANET using switches. Universities could also use the exchanges to develop campus LANs. See L. Clyne, “The LAN/WAN Interface,” Colloquium on the JANET Project (Networking for Universities, Polytechnics and Research Councils), London, 26 November 1985

(London: IEE, 1985), pp. 4/1-4/20.

112

On Cambridge Ring LANs see Appendix G.

113

Report of the Computer Board for the Period 1st April 1983 - 31st March 1985 (London: HMSO, 1985).

9.6 or 48 Kbps leased line 256 Kbps leased line 8 8 1 2 3 4 5 7 6

Figure 2.6. The JANET backbone circa 1988.114

These provided a range of academic-related information to people at institutions, including Bristol, Birmingham, and York, and 22 universities had set up campus systems by 1991.115

114

The figure shows the 8 Network Operations Centres at the regional computer centres and research council sites, interconnected by the upgraded 2 Mbps backbone.

115

C.K. Work, “An Overview of CWIS Developments in the United Kingdom,” in Campus-Wide Information Systems and Networks: Case Studies in Design and Implementation, L. Lloyd ed. (Westport, CT: Meckler, 1992), pp. 282-295. Key 1. Bath 2. RAL 3. London 4. Cambridge 5. Daresbury 6. Manchester 7. Belfast 8. Edinburgh Major node Minor node

As the funding bodies developed JANET and campus LANs, companies and organisations in other countries continued to expand their networks. During the late 1970s and early 1980s, several countries had developed public packet-switched networks. The first network, Telenet, emerged from work on the ARPANET and several others followed. The Post Office in Britain had set up the PSS and the International Packet Switching Service (IPSS), France had developed Transpac, and Canada had launched Datapac.116 All of these networks were compatible with the CCITT recommendation X.25. Several academic networks in Europe followed these commercial ventures. Launched in 1976, the experimental European Informatics Network (EIN) linked research centres in five countries.117 The EIN was a research network that connected the NPL Data Communications Network (DCN), EPSS, and networks within Europe. The Euronet network later succeeded the EIN. Work began on another network in 1984. Called the European Academic Research Network (EARN), this provided a link between European researchers and US institutions. Compatible with the US Because It’s There/Because It’s Time (BITNET) network and based on proprietary technology provided by IBM, EARN began to develop into an X.25 network during the late 1980s.118 EARN was similar to other networks, as its operators intended to adopt OSI protocols when the international community had developed these standards. With this process in mind, European network operators launched the Cooperation for Open Systems Interconnection Networking in Europe (COSINE) project in 1986.119 COSINE encouraged the adoption of OSI protocols for networks, and one of the results of the venture was the International X.25 Infrastructure (IXI) Pilot Service (see Figure 2.7).120

116

The Post Office established the IPSS during 1978. See “UK-US Packet Switched Service,”

Computer Weekly, 13 April 1978, p. 1.

117

Wells and Verdon, Report of the Network Working Party, p. 7.

118

Gillies and Cailliau, How the Web was Born, pp. 76-77.

119

H.E. Davies, “European Networking and What it Means to the UK,” University Computing, vol. 14, no. 4, 1992, pp. 129-140.

120

See Davies, “European Networking and What it Means to the UK,” pp. 133-134 and D. Law, “European Research Networks,” The Common Market for Information: Proceedings of the Annual Conference of the Institute of Information Scientists, June 1992, M. Blake ed. (London: Taylor Graham, 1992), pp. 44-58.

Figure 2.7. IXI in 1992.121

Launched in 1990, IXI linked 18 countries, with a further nine connections to public packet-switched networks. These networks had coalesced around standardised hardware and software which were compatible with the X.25 protocol. The decisions to use X.25 had therefore established and reinforced X.25’s position as the standard

121

The figure shows the backbone of the IXI network, which linked 13 major nodes in 8 countries. For clarity, the figure only contains three national packet-switched networks.

Link to the US 512 Kbps connection 64 Kbps connection 9.6 Kbps connection 1 2 3 Key 1. HEAnet 2. JANET 3. Transpac Major node Minor node

chosen by many PTTs and organisations across two continents. Many organisations, including the Joint Network Team, assumed that OSI would also become a prominent standard. It therefore actively worked towards this, continuing with the community’s OSI transition strategy. In 1987, the Academic Community’s OSI Transition Group published its final report. This report had taken two and a half years to prepare and had involved representatives from academia and other organisations.122 When the group published its report, the JNT and the Network Executive distributed it to nearly 2,000 people who requested copies, which helped to diffuse the strategy throughout the academic community. Known as the White Book, the report outlined in detail the steps necessary to migrate from the Coloured Book protocols to OSI. The Computer Board approved the proposed transition strategy and therefore allocated £2m to the JNT, which would implement the plan.123 The group again stressed the importance of continuity of service and ensuring that both standards could co-exist during the period of transition. To achieve this aim, the Joint Network Team would need converters to handle the protocol conversions. The report proposed that the funding bodies should choose functionally appropriate OSI standards to replace their Coloured Book equivalents. The group suggested examples, such as migrating from the Blue Book file transfer protocol to the OSI File Transfer Access and Management (FTAM) protocol. The network team prepared a series of operational requirements to transfer the results of the public-funded transition strategy to the private sector. Companies could then develop and support the products necessary for an OSI network. In connection with the community’s transition strategy, the Joint Network Team began two open systems-related projects. The first was the OSI X.400 Message Handling System for e-mail.124 Introduced by the ISO in 1984, X.400 defined how incompatible e-mail systems could communicate with each other. Dismissing the 1984 standard because it lacked functionality, the JNT chose the revised 1988 version of X.400. As the academic community wanted to migrate to OSI, it chose X.400 as the standard for e-mail on JANET. However, X.400 was not compatible with the Grey Book protocol used on the network, so the Joint Network Team needed a converter to handle the necessary translations. During 1987, University College London launched an

122

B. Cooper, OSI Transition, UKERNA, 1988, Available from:

http://www.ja.net/documents/NetworkNews/Issue25/news25.txt, Accessed on: 31 July 2004.

123

R. Gillman, “The Academic Community OSI Transition: A Status Report,” Proceedings of Networkshop 18, University of Newcastle upon Tyne, 27-29 March 1990 (Newcastle upon Tyne: University of Newcastle upon Tyne, 1990), pp. 157-194.

124

experimental gateway.125 This gateway provided conversion facilities between the two standards and enabled JANET users to communicate with people who used European networks such as Ireland’s HEAnet.126 It also allowed interconnection between JANET and commercial networks including BT’s Telecom Gold and Microlink.127 In addition to these X.400-related initiatives, others within academia began to experiment with the standard, including a new X.400 e-mail system developed by the Polytechnic of Central London.128 Examples such as these highlight the academic community’s interest in OSI at this time. Another OSI-related project also illustrates this interest. Known as X.500, this defined a standard for an e-mail directory service.129 Ratified by the ISO in 1988, the academic community decided to adopt this standard, rather than develop an interim version of its own, believing that both would take the same amount of time to complete.130 The JNT intended the pilot project to provide information about people who used JANET. The system would also interconnect with the emerging OSI systems that it was deploying across the network.