TELEPHONE LINE SWITCHING SYSTEM AT PRIVATE TELEPHONE SERVICE STOP FAILURE

PROBLEM TO BE SOLVED: To enable a telephone switching device with a plurality of telephone lines connected thereto to easily maintain and operate connected telephone lines with a configuration for switching the telephone lines to basic telephone sets having a standard function because of a serious failure. SOLUTION: A telephone line switching system includes telephone line switching devices 1-1 and 1-2 for switching a plurality of #1 to #8 lines to the basic telephone sets 2-1 to 2-8 when a switch instruction because of a failure, etc., by a PFT (power failure transfer) is received at an entrance of a LAN exchange system 100 to which the plurality of #1 to #8 lines are connected, just before an MDF 101, and the telephone line switching devices 1-1 and 1-2 detect a conversation current and display a conversation status of each line on a conversation status display panel 3. COPYRIGHT: (C)2005,JPO&NCIPI