| 摘要 |
<p>PURPOSE:To speedily and surely take a countermeasure in case of trouble by detecting whether or not an extra path is set halfway and correcting a by-pass list when the connectivity between crossconnecting devices is confirmed. CONSTITUTION:The cross-connecting device(DCS) is equipped with TRANS9 which sets a by-pass if a fault occurs in a transmission path. A line check frame insertion/extraction part 15 sends and receives a line check frame to and from an adjacent DCS at specific timing to confirm the mutual connectivity. The line check frame is sent and received having a specific multiframe code inserted into the F2 byte of an STSI frame constituent element. When another path is set for a frame addition/drop device between the adjacent DCs, the F2 byte is not transferred between the DCSs any more. A line check part 16 detects that and deletes the corresponding channel from a bypass stand-by channel list registered in the TRANS9.</p> |
