Network (JANET)
3.3 The Network Reports of 1973 and 1975
Research in Nuclear Science (NIRNS) at Chilton south of Oxford. This housed an ICL Atlas computer, at that time among the most powerful computers avail- able in the world, which was specifically designated to provide access to com- puting resources to anyone in the university or research council sector who could demonstrate a sufficiently good case. It was almost axiomatic that some of those bidding for time on the Atlas would also be holders of research council grants, but that was not a prerequisite. The Atlas computer was later to become a benchmark standard for assessing the power of a computer system.
provision, and to advise on any future actions. The working party’s report met at best with rather muted support, and a certain amount of outright hostility.
One of the main criticisms was that the report did not clearly define the aims of any network development that the Board might undertake. Accordingly I was asked to chair a second working party, whose terms of reference were:
1. to examine the foreseeable requirements of universities for access to remote computing facilities, to assess the traffic involved, and the costs of alterna- tive strategies for meeting these requirements
2. to review current UK progress in computer-to-computer networks, particu- larly those involving the universities and the research councils
3. to consider whether there were any management problems requiring detailed examination.
3.3.1 UK Academic Networks in 1975
The working party’s first act was to survey the existing provision. The results showed that there were star networks operated by Board funded regional computer centres in London, Manchester and Edinburgh and a further mesh network for the South-West universities. Networks connected universities and research council sites to Atlas and to the SRC computers at the Rutherford Appleton laboratory and Daresbury, and to the NERC computers at Swindon and Bidston. In addition to these academic networks, there were networks based on the proprietary protocols associated with various manufacturers, most noticeably IBM and DEC. There were also point to point links operating between pairs of sites. The total annual cost of networking provision was summarized as:
Rental of GPO lines and modems £240K
Support staff £385K
Maintenance charges £300K
Other charges ~£85K
Note that these were annual charges. There was an additional annual expendi- ture, estimated at £350K, on hardware procurement. This was a total annual spend by universities and research councils on networking in the order of £1M, at a time when the Board’s annual grant was just under £10M. The survey also showed that there was frequent overlap between provision by the Board and the research councils, with parallel leased lines running between two sites. Two quite distinct types of network were being developed. There were wide area networks, used to transmit data between sites. In addition, individual universi- ties and research council establishments were introducing local area networks which connected users on a single site to one or more mainframe systems, allowing users to submit jobs and collect results, and to move files of data between systems. In many cases a sites local area network was also connected to the wide area network.
This fact finding was a reasonably straightforward response to the second of the terms of reference. However, it proved much more difficult to address the first of
the terms of reference. It became clear to the working party that it would be dif- ficult to forecast the overall demand for network connections, either in terms of which pairs of sites would wish to be connected, or how much traffic would flow between any pair of sites. The reason lay in the way users responded to the pro- vision of network access. It is self-evident that where there is no network access users would make no use of networks. However, provision made for one, identi- fiable, purpose, would promptly be exploited by users for some other, totally unforeseen, purpose. In part the situation was made more difficult to forecast because of the emergence of intra-site networks, which served to move data across a university campus or research council site. These were usually initially developed to allow workers on that site to connect to their local computing resources, but were then used to provide onwards connections to facilities at other sites. Much of the traffic on the campus network was aligned on the provi- sion of access to interactive computing. When a user submitted work to a large, remote facility, she would usually be prepared to wait some hours for the results to be returned; with interactive computing, the user expected to receive her results within a matter of seconds, or at most a few minutes. From these simple beginnings, there was gradually emerging traffic which passed not between a user at one site, and a facility at another, but between a user at one site and a user at another. Traffic in which the user is present for the duration of the whole of the interaction with the remote system, and person-to-person traffic both put a new type of demand on the network. Equipment does not mind if responses are slow. People do. This puts a premium on having networks which can not only move large volumes of traffic, but can also move small volumes in a short time, measured at most as a few seconds. It seemed to the working party that the only sensible course would be to provide a network which would allow any site to connect to any other, and which could adapt to the differing needs of users, and then let nature take its course. Paradoxically, it was believed that such a com- pletely general purpose provision, which could be upgraded as demand arose, would in the long term be more effective than attempting to arrive at detailed predictions of the flow between each pair of sites, and provide a network configured to meet that need.
On the third term of reference, as to whether there were any management prob- lems requiring detailed examination, the report was fairly guarded. In fact, I was quite clear in my own mind that the main problem areas would not be tech- nical, but would lie precisely in the details of how the community could resolve the issues of who should determine policy as regards funding, setting of objec- tives, and generally controlling a shared resource which would be central to the work of a large fraction of the research and teaching community.
In contrast with the first report this second report was well received. Quite what produced this change in response is difficult to say, since there was little real dif- ference between what the two reports said. The most important recommenda- tions emerging from the second working party were that the Board and the research councils should strengthen their collaboration in the provision of net- working facilities, and together set up a small full-time unit to coordinate net- work developments, and that Board should allocate 3% of its annual hardware expenditure on the provision of network facilities.