call transfer (ISDN, GSM) (CT)
Call Transfer (CT) is a switching feature of digital networks.
With this feature, a dial-up connection can be transferred to another terminal or two connections that the subscriber is carrying at the same time can be switched together.
In addition to normal call transfer (CT), there is also explicit call transfer( ECT). In this case, the transfer of a connection can take place in such a way that the switching subscriber disconnects from the call and the other two external subscribers are connected to each other.