Bearer Independent Call Control (BICC) is a signaling protocol based on N-ISUP that is used to support narrowband ISDN service over a broadband backbone network without interfering with interfaces to the existing network and end-to-end services. Specified by the International Telecommunications Union - Telecommunications Standardization Sector (ITU-T) in recommendation Q.1901, BICC was designed to be fully compatible with existing networks and any system capable of carrying voice messages.
BICC supports narrowband ISDN services independently of bearer and signaling message transport technology. ISUP messages carry both call control and bearer control information, identifying the physical bearer circuit by a Circuit Identification Code (CIC).