Fujitsu Corporation

Nippon Telegraph and Telephone Corporation

Yuji Takigawa

Kazuyuki Tajima

Haruo Yamashita

Masaaki Kawai

Hisako Watanabe

Hidetoshi Naito

A cross-connection apparatus for B-ISDN includes plural interface units, multiplexers, virtual path identifier (VPI) conversion tables, demultiplexers, and loop-back units and a switch unit. The interface unit has a reception port for receiving an ATM cell or inserting a monitor cell, and a transmission port for transferring the ATM cell or extracting the monitor cell; The multiplexer is operatively connected to corresponding interface unit for multiplexing the monitor cell; The VPI conversion tables is operatively connected to corresponding multiplexer for converting the VPI to change a transmission route of the monitor cell; The switch unit is operatively connected to the VPI conversion tables for switching the transmission route of the monitor cell based on the VPI; The demultiplexer is operatively connected to the switch unit for demultiplexing the monitor cell and transferring the monitor cell to the transmission port; The loop-back unit is operatively connected to corresponding interface unit for changing the transmission route so as to transfer the monitor cell to the same interface unit which the monitor cell is inserted, and as a result, the apparatus can be monitored by comparing the inserted monitor cell with the extracted monitor cell in the same interface unit.

Growing community of inventors

Kawasaki, Japan

Yuji Takigawa