With CTLS, authorized users can seize analog and CAS trunk circuits, digital B channels and also SLMA and TMOM connections (only announcement devices) by entering (dialing) the PEN and, if necessary, the B channels. VMX connections on SLMA and digital trunk circuits belonging to nailed connections cannot be selectively seized. By analyzing the reception of predefined tones the authorized user can recognize the state of the PEN or the terminal to be tested.

Analog trunk circuits, CAS trunk circuits and digital circuits can be trunk and tie lines.

CTLS can be used in OpenScape4000/HiPath 4000 networks. The seizure of trunks or subscriber line circuits by ­entering the PEN is only possible within CorNet-NQ networks.

If in transit connections an outgoing analog, CAS or trunk circuit is seized by entering the PEN, the dialing of the PEN cannot be continued in the next PBX.

Regardless of the following PBX type, the connection can be established by dialing a station number. The signaling method configured for the seized circuit is used.

If in transit connections within a Cornet-NQ network the outgoing circuit is seized by dialing a station number and not by entering the PEN, the dialing of the PEN cannot be resumed in the next PBX.