periods environment one voice mail system port for 30 users and a 3 minute the use of a voice mail box offers many advantages in business voice storage capacity per user could be a reasonable starting point situations. when sizing the system. Within the UK voice mail competes directly with telephone answering machines and has not been as successful as in North 37.1.6 Automated attendant America. With the advent of GSN cellular telephones and the concept of a This voice processing application is usually used as an overflow personal number for life associated with GSN, the need for large call mechanism in conjunction with switchboard operators. In North delivery oriented voice mail systems will increase and probably America, automated attendants are used with the callers DTMF become an accepted facet of business life within the European phone to reach extensions directly called simulated DDI). The business community. The Pan-European GSN standard will consid- caller is prompted for the required extension or department by the erably facilitate the take up of these services. system. If the person being called is busy or doesn't answer, a voice Voice mail systems can be stand alone or units can be networked mail application is usually made available to the caller SO that an to provide a seamless but geographically separated system. The appropriate message can be left. interface protocols between voice mail systems have been proprie- The use of automated call handling is becoming important for tary until recently. Now there are the AMIS standards for voice mail large corporations striving to reduce costs, make their services systems. One is a digital standard based on the CCITT recommen- available 24 hours a day and improve their image. Here the concept dation X.400, which is a wide ranging messaging standard based on is to handle caller queries as comprehensively as possible and not OSI principles. The other is an analogue standard using DTMF involve an operator if at all possible. Customer care is an important contro