CONNECTION SYSTEM TO PLURAL TRUNK LINES

摘要

PURPOSE:To discriminate whether subscriber lines are paired at the side of an exchange network or not by using the originating subscriber numbers to retrieve a control table containing a memory where terminal numbers are registered and a memory which displays that a corresponding circuit is set for each terminal number. CONSTITUTION:Terminals 1-3 are stored in a switchboard 7 for subscriber lines via subscriber lines 4-6 and then connected to a repeating switchboard 12 via trunk circuits 9-11. A switchboard 7 transmits the originating subscriber identification numbers to the circuits 9-11 when the terminals 1-3 work for transmission. Thus a subscriber number identifier ID8 is started. The originating subscriber number sent from the ID8 is used as a key word to retrieve a control table 13 for plural trunk lines. The table 13 contains a memory 19 where a terminal number to which the communication is permitted is registered in a pair to each subscriber number, memories 23 and 24 which show that a corresponding circuit is set for each terminal number, and a memory 27 which serves as an integrated charging meter for paired trunk lines.