Call numbers redirecting method via ISDN exchange

摘要

The method involves storing a transferred call number of a first ISDN subscriber apparatus in a second ISDN subscriber apparatus during a call from the first subscriber apparatus to a second subscriber apparatus. The stored number of the first subscriber apparatus is transmitted automatically to a third subscriber apparatus via an ISDN facility for transmission of additional information during the connection set-up phase via the D-channel after release of the connection between the first apparatus and the second apparatus. Preferably, the stored number in the second apparatus is compared with the numbers for direction to the third subscriber apparatus. The stored number is transmitted to the third apparatus only when the stored numbers are in conformance. The transmission is carried out via ISDN facility sub-addressing.