call by call (CbC)
Call-by-call (CbC) is a dialing procedure for individual calls in which the long-distance connection is established via a connecting network operator. This is a network operator other than the user's own preset network operator.
If, for example, Deutsche Telekom is the default network operator, you can dial a prefix number to select a less expensive long-distance carrier, which then connects you via its own or leased trunks. To do this, the carrier identification code( CIC) is dialed first during digit dialing. This is the carrier identification code, which begins with the telephone number 010 and consists of two additional digits for the carrier. The local network code and then the subscriber number are then entered.
Variants of the procedure are callback and call-through. Since mid-2004, call-by-call has no longer been restricted to long-distance networks, but has also been approved by the RegTP for the local network.