Nick Ryan University of Kent
Most computer-using social scientists who are based in academic institutions will already be aware of the possibilities for access to remote computers. In many institutions it has long been the normal practice to make use of the more powerful machines at regional computing centres for the more intensive tasks such as statistical analyses and simulations. This seems likely to continue and to be further extended by the increasing need to access the large databases or specialised software that can be maintained most effectively at a single location. Although many will be familiar with this style of computing they may not be aware of some of the more recent developments in remote access and communication. Conversely, those who have at their disposal the facilities of the better appointed institutions may have had little reason to familiarise themselves with any of these developments. This article is intended as a brief introduction for social scientists to some of the facilities currently available in the UK for communication between computer users.
Existing remote access facilities have allowed users to log on to machines at some other institutions and to transfer files between their local machine and the remote site. In principal this has been extended to cover an ever-increasing number of machines located all over the world, greatly increasing the opportunities for collaboration with colleagues in other institutions. Of course it is always necessary to convince the system administrators that you have a genuine reason to use their machine, but this may well be possible for the purposes of collaborative research. In addition to file transfer and remote access to data and software, the range of computer-based communication services that could be exploited by social scientists includes some which are already available to, and widely used by, computer scientists, natural scientists and engineers. Other services could be provided that would be specially designed for social scientists. Together these include information and news services, electronic mail and teleconferencing, and electronic or machine-readable publications.
Each of the services described here makes use of one or other of a number of communication networks, some principal examples of which are summarised below. Access to some of these networks will usually be provided to academic users by either their local or regional computing service who should also be necessary local information and documentation on their use. Often it may be necessary to access a machine on a network to which no local connection is available. In most cases this problem may be overcome by the use of a gateway, a machine which provides the necessary connection between networks.
As the name suggests, electronic mail is a means of sending and receiving messages between computer users. Unlike the simple local messaging systems employed on many machines there is no need for both parties to be logged on to their machines at the same time. A mail system takes care of both the routing of messages to the intended destination and, once received, the storage of messages until they are read by the addressee.
As with conventional mail it is necessary to know the name and address of the intended recipient. The name will usually be the user identification that the recipient uses to login to the destination machine. The format of the address differs between networks and may also depend on the particular mail system that you are using on your local machine. Consequently it is not possible to generalise about how to send mail, the details vary from site to site.
Every site should have someone who acts as `Postmaster'. This usually involves a responsibility for maintaining the mail system and dealing with both local and remote queries. These tasks may be distributed between several people If mail is returned with an error message to the effect that the destination site is unknown, your local postmaster should be able to help in tracing the problem or advise on the correct address. If, however, mail is returned because the user is unknown the addressee should be consulted by more conventional means. It may be possible to send mail to the postmaster at the destination site with an enquiry about how to reach the intended person. Again the local postmaster should be able to advise on the appropriate action.
News services distribute structured `newsgroups' covering a wide variety of topics to all participating sites. Users at any of these sites may select items and topics of interest for reading at any convenient time simply by running the news reading program on their local machine. Other programs may be available to enable articles to be posted to a newsgroup.
All participating sites maintain the appropriate news reading and posting software and often receive large volumes of news on a daily basis. The operation of such a system requires considerable cooperation between participating sites. A large local storage capacity is needed to hold the news for an adequate time to allow users to read it.
Articles are normally submitted to an editor or moderator whose principal tasks are to ensure that the material complies with any legal or local requirements, and that it is posted to the newsgroup at the earliest opportunity. The extent to which editorial control may be exercised beyond this basic level varies greatly between newsgroups and between news networks.
Bulletin boards can provide a similar service to a news system, but without the need to distribute information directly to all subscribing sites. Instead, the bulletin board is established as an open or restricted access account on a single machine and users log on using their local remote access facilities, either a network or dial-up telephone line.
This method is much simpler for the system administrators than a full news service. It is not necessary for all sites with potential users to maintain software or to ensure that they receive the required news. From the consumer's viewpoint the information is not available automatically from a local machine and a conscious effort must be made to log on to the remote machine simply to check whether anything of interest has been posted.
As with news systems, much of the information available on bulletin boards is provided by its users rather than by a central information provider. Usually articles are submitted either by sending electronic mail or by some form of file transfer mechanism incorporated into the bulletin board software.
Perhaps even more than with news services, the survival and development of a bulletin board depends heavily on the active participation of its subscribers and the quality and relevance of the information that they post. There is always the danger that a bulletin board may decline from a service of wider interest to a discussion group for a small number of individuals with only limited appeal. Despite these potential disadvantages, the relative simplicity with which bulletin boards can be established makes them attractive for the social science and humanities user communities as an initial foray into the world of electronic communication and dissemination of information.
The communication network of immediate and most general interest to British academic users is the Joint Academic Network (JANET) which connects computers in universities, research council establishments and some polytechnics. This network, originally called SERCNET, was developed initially under the auspices of the Science and Engineering Research Council to provide communication and remote access facilities for its grant holders. Subsequently administration and development was taken over by the Computer Board for Universities and Research Councils and the facilities have been extended to all academic users. The services currently available on JANET include remote access, file transfer and, for an increasing number of sites, electronic mail.
Electronic mail between JANET sites is simplified by the use of standardised site names and a centralised Name Registration Scheme (NRS). Thus the same address, in the form user@uk.ac.site may be used irrespective of the source of the message.
JANET uses the British Telecom PSS (Packet Switch Stream) network as its physical communication medium. PSS is a network connecting a large number of commercial sites throughout the UK and also gives access to its international counterpart, IPSS. The use of these latter two networks is charged at a commercial rate with a charge structure similar to that employed for the conventional telephone system. The significant difference for the user between JANET and PSS is that all communication between JANET sites is funded by the Computer Board thus academic users incur no direct costs by its use. Most institutions will pass on all PSS/IPSS charges to their users.
Whereas JANET and many other networks rely on more recently developed packet switching technology, the long-established USENET network employs conventional dial-up telephone lines for most of its inter-machine links. This network provides a simple means for connecting several thousand machines around the world running the UNIX1 operating system. Although once a near exclusive preserve of computing scientists, the increasing popularity of over the last few years has meant that the facilities offered by this network are becoming available to a much wider range of users. USENET provides electronic mail and an extensive news system. The latter carries a wide range of subject groups many of which are of primary interest to computing scientists, but there are also a large number of more general topic area and news groups directed at users of several of the more popular microcomputers. File transfer and remote access are also available using the same dial-up telephone links. Each site is responsible for its own telephone costs thus the cost of running the network is spread amongst participators. Although some institutions manage to absorb these costs, many are forced to pass them on to their users.
Since USENET consists of a large number of links between machines rather than a real network to which all machines have a connection, the technique of mail addressing is differs from that used on JANET. Here it may be necessary to specify a path or route comprising the sites through which the message is to be routed. For example, site1!site2!site3!name would direct the message via site1 and site2 to the destination site3. Although potentially extremely complex, address paths can often be simplified because mail programs often have access to information on the paths to many of the major `backbone' sites.
EARN, the European Academic Research Network, connects many academic and research organisations throughout Europe and has gateways to the North American BITNET and NORTHNET networks that extend the service to the USA, Canada and Japan. The main facilities available are file transfer and, to some sites, electronic mail.
The ARPA network connects a large number of sites in the US and elsewhere. Access is normally restricted to those with funding from, or other connections with, the US Department of Defence Advanced Research Projects Agency, although this in practice covers a much wider range of activities than might be expected. British and European social scientists need not be surprised to discover that messages from American colleagues have travelled by this route. However, outside of the US it is generally more difficult to obtain permission to use this network. In Britain, access to ARPA is usually via a gateway at the University of London computer centre. ARPA provides remote access, file transfer, electronic mail and a structured news system which, like that on USENET, is of primary interest to computing scientists.