Method and equipment for adapting ct2 calls for an isdn subscriber line

摘要

The invention relates to a method and equipment for adapting CT2 calls for a subscriber line (504) having a channel structure corresponding to an ISDN basic access (2B+D). In the method, speech is transmitted in the speech transfer state on the B channels of the subscriber line and data associated with the speech on the D channel of the subscriber line. In order that as many as four simultaneous CT2 calls could be transmitted over the subscriber line having the ISDN basic access, the B channel of the subscriber line is used for data transmission during connection establishment by shaping a predetermined, fixed bit pattern (31) of a SYN channel contained in multiplex 2 used in the CT2 telephone system.