LINE SELECTION SYSTEM

PROBLEM TO BE SOLVED: To automatically select a more effective network for a call origination request. SOLUTION: When plural Signaling terminating functions 4 are extracted corresponding to a signal virtual channel(SVC) establishment request message from an ATM subscriber, while referring to band management 6, a call processing control function 5 selects the Signaling function 4 having the most residual bands. When plural Signaling terminating functions 4 having the most residual bands are extracted, while referring to selection priority management 8, the Signaling terminating function 4 having the highest priority is most preferentially selected. When SVC establishment request refusal or release request in the middle of SVC establishment is sent corresponding to the SVC establishment request of the Signaling terminating function 4 from an ATM network 9, based on factor information, the call processing control function 5 retrieves a fault detection condition management storage device 7 and when there is a relevant item, the occurrence of any fault on the selected ATM network 9 is judged. Then, the Signaling terminating function 4 having the next highest priority or most residual bands is selected and an SVC establishment request signal is sent out.