The X400 standard for data transmission is due to experience an unprecedented success from next year, and by 1994 an estimated 150,000 computers and 500,000 personal computers will be using X400 to communicate. That is the view of Eliane Jason-Henry of the London-based Ovum Ltd information technology consultancy, who was speaking at the Electronic Messaging and Communications Systems 89 Conference in London last week. First ratified by the Consultative Committee on International Telegraphy and Telephony in 1984 as a standard for networking software between computer systems, and updated four years later, X400 enjoys relative stability, she claimed. At the moment, its most popular use is for interconnecting private electronic mail services such as the IBM Profs and DEC’s All-In-1 office automation systems in companies such as the West German chemical firm Hoechst. Ovum reckons that electronic messaging will grow by a factor of three in the next four years, and use of X400 will increase because the need to connect the various forms of messaging – electronic mail, telex and facsimile, amongst others – is becoming greater. The volume of Electronic Data Interchange will increase by over seven times in the same period, but would still face the problem of the numerous industry-specific and localised protocols that have developed – it was predicted that X400 would gradually replace these protocols as a means of document transmission, and would be used substantially for the Edifact international Electronic Data Interchange software standard from 1992; eventually, it was considered that Electronic Data Interchange would generate more traffic than messaging. Ms Jason-Henry concluded by saying that the future success of X400 depended on the continued acceptance of the standard itself, which was adopted as an Open Systems Interconnection standard last year; the availability of X400 services; and the emergence of X400 software, such as those from Dialcom, Telenet, Retix, Danet and Logica; this area was, however, considered the most problematic because many of these products cannot yet be considered mature. Crucial to the future of X400 was the development of the X500 directory service, a point taken up by the next speaker Roger Molesworth, principal consultant of Logica CES Ltd. X500 was born as a result of the need for a user-friendly addressing system for X400, he said; X500 as a concept is based on a series of attributes such as surname and location, which can then be specified – the idea being that this is a lot easier for the end user to formulate than the data-numeric mix intended mainly for recognition by machines. The X500 directory, he continued, can be seen as a database, with general database principals such as look-up and search applicable to the way it works: the user should key in surname, location and other relevant information about the addressee and let the directory do the rest. It will then align with the X400-based messaging service via the Directory User Agent, which encodes the users requests into the Directory Access Protocol and sends them through to the Directory System Agent; from here, the information can be reached from the Directory Information Base. The protocol mentioned above is central to the effectiveness of the X500 directory: if it can communicate with other Directory Access Protocols, then a series of information stores can be consulted if the original Directory Information Base does not come up with the goods; but this process, known as chaining, was, according to Molesworth, still a long way off.
Store-and-forward
Mainly because the X400 message system provides store and forward message switching while X500 is on-line enquiring, integration between the two was still a problem; Molesworth asked whether it would not be preferable if the X400 messaging system could perform the directory look-up itself by using directly a co-resident X500 directory – in this way, the user need not even be aware of the X500 process. Finishing off, he said that the projected applications of X500 were basi
cally sound – the mapping of names onto addresses, providing a Yellow Pages and business information service and so on – but so far a viable product had not been developed. The first true X500 application, as opposed to a standard database management pack age in fancy dress, he argued, would be Electronic Data Interchange, which could provide the springboard required by both X400 and X500. – Mark John
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