Malicious Call Identification (MCID) is a service feature of digital networks. With the help of this feature, the connection data of incoming calls can be determined. Since the transmitted call number
is checked by the network, it is ensured that the actual call number is always transmitted to the called party. This only affects the part of the call number for which the network is responsible. MCID can be used for criminal offences. The extension digits of a PBX cannot be checked for correctness by the network. The display of the call number is provided between connections in digital networks. In general, a display of the call number of analogue connections is also possible, as this is transmitted in the network.