l tones associated with the analogue transmission of the voice public relations issue. There is a reluctance to accept this technology files. The widespread adoption of these standards is not happening in Europe because of the perception of talking to a machine as being as rapidly as was expected. undesirable. Since caller sessions can be more interactive than in the The X.400 system is split into two main parts; the User Agent case of talking to an answering machine, this barrier is being (UA) and the Message Transfer Agent (MTA). On top of these two overcome. standard parts is the particular manufacturer's user interface. The Links to databases and diversion to live operators can be used to user interface interacts with the UA to set parameters such as enhance the capabilities and usefulness of automated attendant. destination address. Once the necessary parts are complete, the message and UA details are passed to the MTA for delivery to the destination. This can be by a number of data communications 37.1.6.1 Links to PABX/ADC protocols such as X.25, but this detail is hidden and made irrelevant to the user. X.400 is currently used by electronic mail systems. A In many cases the voice processing system is installed behind a number of voice mail suppliers have it as an available option. PABX or ACD. This allows calls to be handled automatically or by The destination address can be selected using a CCITT recom- live operators. Callers can be readily transferred from voice pro- mendation X.500 directory service. This can allow users to select cessing system to live operator or vice versa. However, in many destinations using database search techniques. These standards will situations the maximum benefit can be gained by having the caller Anatomy of a voice processing system 37/5 screened by the voice processing system first; details obtained and speech recognition capabilities of the system. Architecture, soft- then the caller being transferred to a live operator only if necessary. ware and hardware, and modularity