Method for switching telephone calls between two telephone networks using a central controller

A method for switching calls from a first terminal in a first telephone network to a second terminal in a second telephone network, wherein the first telephone network includes a plurality of private branch exchange systems, and a portion of the plurality of private branch exchange systems have access to the second telephone network, the method comprising the steps of:

• providing one of the plurality of private branch exchange systems with both an LCR module and directory, wherein, for the plurality of private branch exchange systems and depending on a called local area code, the directory identifies a transferring private branch exchange system in which a transfer to the second telephone network will occur;
• setting up a telephone connection from a calling one of the plurality of private branch exchange systems to the private branch exchange system which contains the LCR module;
• transmitting a character sequence of a dialed telephone number, which is associated with the second terminal in the second telephone network, to the LCR module;
• determining the transferring private branch exchange system, using the directory, in which the transfer to the second telephone network will occur;
• and
• setting up a telephone connection from the first terminal in the first telephone network to the second terminal in the second telephone network via the transferring private branch exchange system which has been determined.