g many thou- been fully explored. The challenge to go beyond the current talking sands of words and also capable of understanding the contextual computers can and will be met. issues within speech. The ability to recognise a few words is with us today. The incremental improvement to recognise a few tens of words is in sight. However, the step of being able to interact with the machine as if with a human is not clearly visible (except on Star Trek!). Bibliography In order to enable voice processing to leave behind the stigma of the answering machine and reach its full potential, the ability to hold Frost & Sullivan (1990) The European Market for Voice Processing natural and non-deterministic dialogues is key. Simply programm- Systems, Frost & Sullivan Ltd., London. ing the machine with a tree of responses and menus is not good Tetschner, W. (1991) Voice Processing, Artec House, Norwood, enough. The human-machine dialogue should be natural, allow ISBN 089006 468 7. interruptions and leave people with some doubt as to whether or not Walters, R.E. (1991) Voice Information Systems, NCC, Oxford, it is a machine they are talking to. This may well need advances in ISBN 1 85554 075 4. This page intentionally left blank Electronic data interchange Paul W Bizzell AT&T EasyLink Services Contents Fundamentals of EDI 38/3 38.2 EDI in the messaging marketplace 38/3 38.3 Messaging standards 38/3 38.4 Technical infrastructure 38/5 Internal topologies 38/6 38.6 X.500 directory services 38/6 Security 38/6 Global VAN topologies 38/7 Future trends 38/7 This page intentionally left blank Fundamentals of EDI 38/3 38.1 Fundamentals of EDI such as 'The use of computers to exchange documents using agreed formats and protocols'. Examples of the 'movement' Electronic Data Interchange (EDI) is a subset of the messaging standards relating to messaging are X.400, FTAM and OFTP. marketplace. A working definition of EDI is the computer to com- These standards place the minimum of constraints on the con- puter transmission of documents using agre