CONGESTION INFORMATION RELAY METHOD OF BINARY FEEDBACK SWITCH FOR AVAILABLE BIT RATE SERVICE

PURPOSE: A congestion information relay method of a binary feedback switch for an ABR(Available Bit Rate) service is provided to rapidly relay not only congestion information of a current switch but also congestion information transmitted from a front end switch to a lower end switch without a queuing delay. CONSTITUTION: If a data cell is transmitted from a front end switch(S41), a system checks an EFCI(Explicit Forward Congestion Indication) bit of the data cell(S42). If the EFCI bit is '1', the system sets up a relayed EFCI flag as '1'(S43). The system resets the EFCI bit of the data cell in order to prevent the same congestion information from being transmitted twice(S44). If the EFCI bit is '0', the system sets up the relayed EFCI flag as '0'(S45).