Telephone PBX with key dialling and switch dialling extensions - has corresponding dialling signal receiver allocated to extension with switch and key dialling

The type of dialling of a calling extension is determined by interrogation of e.g. an extension store, and a corresponding dialling receiving unit is connected. An MFV dialling receiver is allocated for the whole dialling to the extensions with key dialling for internal and outgoing traffic. An internal circuit as the dialling receiver is allocated to the switch dialling extensions for internal and outgoing traffic, for connections without acknowledgement signal. A local circuit is allocated to extensions with switch dialling for outgoing connections with acknowledgement signals for reception of external dialling code, and a corresponding line circuit for reception of further dialling signals.