To avoid the concentration of B-R cells in the ABR service of a bit rate control circuit in an ATM network.
A cell branching part 1 extracting the B-RM cell obtained by folding an F-RM cell transferred through a forward direction line and transmitting it to an inverse direction line 6, a cell generation/insertion part 2 generating the B-RM cell and inserting it into the inverse direction line 6 and a memory 3 storing the content of the B-RM cell for the respective logical lines of VPC and VCC are provided. A comparison arithmetic part 4 which OR-operates the congestion display bit C1 of the contents of the B-RM cell stored in the memory 3 with the arrived B-RM cell, for example, and updates the content of the memory 8 by the operated result and a transmission control part 5 controlling the cell generation/insertion part 2 and transmitting one B-RM cell when that the arriving number of the B-RM cells becomes a prescribed number is detected or that prescribed time is elapsed is detected are provided.
OKUDA MASAHITO
KUSAYANAGI MICHIO
SUDO TOSHIYUKI
