recy on each line. call handling trunk or tie line, database administration, system 7. Callback on busy and call back on no answer, are all useful statistics and interfacing to other peripheral equipment. everyday features for the general telephone user. Call pick up, which enables a user to pick up a colleague's ringing telephone from his/her own telephone. 34.6.1 Telephone or terminal software Diversion of calls at various stages is helpful for efficient office organisation, as most can be preprogrammed SO as to divert on Telephone or terminal software interprets the commands and func- busy i.e. when the called telephone is busy calls are diverted to tions invoked from the telephone or multifunctional terminal. Apart an alternative telephone. Divert on no answer enables the user from receiving the dialled digits validating them, and passing them to divert calls on no answer to perhaps an alternative telephone Control and administration 34/13 than the divert on busy one. Divert all calls ensures that when calls. Only if the call is not answered will it be routed back to the a telephone is completely unattended e.g. out of office hours, telephone operator. The system may have a voice response attached all incoming calls are diverted to either another telephone, a to the PABX or as an integral feature of the PABX. In any case the voice mail system or a message centre. call will first be placed with the voice response unit to answer, and 10. Multiple party conference is a desirable feature to enable more provide the caller with the initial greeting, before either placing the than two parties to be engaged in a conversation. The ability to call with the operator for onward processing or accepting DTMF dynamically alter the number of parties engaged in the con- signals from the caller to route the call to a particular port on the ference during the call makes the feature much more useful in system. the business environment. The PABX may be a multi-tenant system and the operator may handle the calls for more than one 