| 摘要 |
In a memory-programmed dial-up PBX system, with reference to the information stored in a corresponding list in the case of direct inward dialling, depending on the selected destination (normal subscriber station, operator's position, test subscriber, announcement device etc.) and on the switching condition of this destination (e.g. free, busy, not authorised, incoming call protection etc.) and on an origin identifier requested by the respective distant system (e.g. subscriber, payphone, data connection etc.), it is established which final destination in the context of the respective connection is intended to be reached. The switching condition and the type of the destination station and the signalled type of the originating station are used as an address index to access the contents of the stored lists. The control computer unit which performs the switching operations as required reads out the corresponding memory space to find out whether the received dialling information needs to be converted. It is possible, for example, to reject reverse-charge calls at the subscriber station and forward them to the operator's position or to transfer calls from a payphone to the operator's position in the case of busy conditions. If the call emanates from a different subscriber station, a busy tone, for example, can be fed in the same case. <IMAGE>
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