PURPOSE: To realize a no-loss switching over of cells of a system in the ATM exchange system of duplicate configuration.
CONSTITUTION: An ACT bit representing a switch section of a present system is added to a cell by an incoming line correspondence section 21, Switch sections 23, 24 store once a cell and provides the cell to a proper outgoing line correspondence section. Moreover, the switch sections 23, 24 discriminate an ACT bit of the received cell and stop an output of the cell for a predetermined period when they are switched over to the position of the present system. A system selection section 33 of an outgoing line correspondence section 25 selects a cell outputted to an output line in response to the combination of ACT bits of two cells inputted in parallel from the switch sections 23, 24.
OSHIMA HITOSHI
TAKAGI KOJI
MURATA HATSUO
NIPPON TELEGRAPH & TELEPHONE
NEC CORP