ible SO time sensitive trunk circuits are used phone numbers. For example, one partially specified restriction may less. In another application which provides consultation and advice, be for all numbers in an entire country code, another for a selected and bills callers based on time, the goal could be to encourage city within a country, and another a specific number within a city. continuing the conversations, since the longer the call the more the The restrictions, depending on the PABX, are specified as either the profit. In other applications the goals may be to reduce the number numbers allowed or not allowed to be dialled. If the PABX can of calls or to allow more calls to be made. The reduction of assign a class level to the users, then the restrictions could be applied excessive calls, elimination of under utilised extensions and trunk to all, or selected class levels. Such restrictions are sometimes based circuits, plus improvements in service are other goals useful as cost on date and time. The PABX would use the day of week and time of justification elements. day to map to a specific table to be used from a set of restriction A common approach used in cost justification of an ACD (Auto- tables. The restrictions might also be based on the trunk circuit type matic Call Distributor) to be used for high volume inbound call for which usage or special service charges would be incurred. applications is to assign a cost or profit value to each call, or even Information on the number of attempts to restricted numbers can to each second in time of call duration. The investment in the provide valuable information. Network modifications and removal completely stand alone ACD can be proven just by using the of restrictions may be required if legitimate attempts are being improvement in answering time, compared to other alternatives. For blocked, but are being completed by other methods at a higher cost. example, if the application is moved from a PABX group to the The call restriction tables should be easily change