Establishing telecommunications connection with abuse protection involves checking user authorization by exchanging at least one security code and checking on at least one side

摘要

The method involves signaling a connection wish to the exchange side (III) by producing a low impedance loop connection on the user side (I). A data exchange is carried out between the exchange and user sides at least at the start of connection establishment to determine the user's authorization, in which at least one security code is exchanged and checked on at least one side. AN Independent claim is also included for the following: a circuit for establishing a telecommunications connection between subscriber and exchange sides.