REGURATING SYSTEM FOR HEAVY CONGESTION

PURPOSE:To apply impartial restriction to users and to reduce degradation in quality on a data link when heavy congestion takes place in a storage and forward exchange network having only a core procedure of layer 2 by stopping the transmission of a prescribed data link tentatively when the data link encounters congestion in the network. CONSTITUTION:When congestion takes place in an exchange 101, the exchange 101 informs the congestion to a caller exchange 102, 103 or 104. The exchanges 102 to 104 receiving the congestion notice conduct at first control based on a contract throughput. When the congestion is further progressed regardless of the control by the caller exchange based on the contract throughput, the exchanges 102 to 104 detect heavy cougestion. Then the exchanges 102 to 104 count the number of times of received heavy congestion notices by using a counter and regulate or stop the transmission based on the regulated amount corresponding to the count with respect to the total sum of the contract throughput for each deta link. Thus, users are impartially regulated.