Phase 1: The A-subscriber lifts the handset
nSubscribers’ lines are scanned and off-hook is detected
nSubscriber database checked for sending the dial-tone (depends on service class as for instance are the outgoing calls allowed)nMemory reserved for the number to be dialed in the control systemnA tone receiver for the dual-tone dialing signaling is connected through the time switch in the subscriber stage
nThe dial tone is sent
n
n